FRONTISPIECE.

"THE END OF THE WAR."

A GRAPHIC RECORD.

One minute before the hour.

All guns firing.

Nov. 11, 1918. 11 A. M.

One minute after the hour.

All guns silent.

This is the last record by sound ranging of artillery activity on the American front near the River Moselle. It is the reproduction of a piece of recording tape as it issued from an American sound-ranging apparatus when the hour of 11 o'clock on the morning of November 11, 1918, brought the general order to cease firing, and the great war came to an end. Six seconds of sound recording are shown. The broken character of the records on the left indicates great artillery activity; the lack of irregularities on the right indicates almost complete cessation of firing, two breaks in the second line probably being due to the exuberance of a doughboy firing his pistol twice close to one of the recording microphones on the front in celebration of the dawn of peace. The two minutes on either side of the exact armistice hour have been cut from the strip to emphasize the contrast. Sound ranging was an important means of locating the positions and calibers of enemy guns. A description of these wonderful devices, which were a secret with America and the Allies, is given in Book III, chapter 4.

[Pg 1]

---

America's Munitions
1917-1918

REPORT
OF
BENEDICT CROWELL

THE ASSISTANT SECRETARY OF WAR
DIRECTOR OF MUNITIONS

WASHINGTON
GOVERNMENT PRINTING OFFICE
1919

[Pg 2]
[Pg 3]

Washington, D. C., December 24, 1918.

Dear Mr. Crowell: American munitions production, which for some time has been in your charge, played an important part in the early decision of the war, yet the very immensity and complexity of the problem has made it difficult for this accomplishment to be adequately understood by the public or in fact by any except those who have had occasion to give the matter special study. As the whole people have been called upon to make sacrifices for the war, all the people should be given an opportunity to know what has been done in their behalf in munitions production, and I therefore ask that you have prepared a historical statement of munitions production, so brief that all may have time to read it, so nontechnical that all may be able readily to understand it, and so authoritative that all may rely upon its accuracy.

Cordially yours,

Newton D. Baker,
Secretary of War.

Hon. Benedict Crowell,
The Assistant Secretary of War.

[Pg 4]

Washington, D. C., May 10, 1919.

Dear Mr. Secretary: Responding to your request, I transmit herewith a brief, nontechnical, authoritative history of munitions production during the recent war. The several chapters have been prepared in the first instance by the officers who have been directly responsible for production, and have been assembled and edited, under my direction, by Hon. Robert J. Bulkley, assisted by Capt. Robert Forrest Wilson and Capt. Benjamin E. Ling. Capt. Wilson has undertaken responsibility for the literary style of the report, and has rewritten the greater part of it, consulting at length with the officers who supplied the original material, and with officers of the statistics branch of the General Staff, in order to insure accuracy.

Maj. Gen. C. C. Williams, Chief of Ordnance; Brig. Gen. W. S. Peirce, Acting Chief of Ordnance; Maj. Gen. C. T. Menoher, Chief of Air Service; Maj. Gen. W. M. Black, Chief of Engineers; Maj. Gen. W. L. Sibert, Chief of Chemical Warfare Service; Maj. Gen. H. L. Rogers, Quartermaster General; Mr. R. J. Thorne, Acting Quartermaster General; Maj. Gen. G. O. Squier, Chief Signal Officer; Brig. Gen. Charles B. Drake, Chief of Motor Transport Corps; and Maj. Gen. W. M. Ireland, the Surgeon General, have cooperated in the preparation of the material transmitted herewith.

Special acknowledgment for the preparation and correction of the several chapters is due to the following officers:

The ordnance problem, Col. James L. Walsh.

Gun production, Col. William P. Barba.

Mobile field artillery, Col. J. B. Rose.

Railway artillery, Col. G. M. Barnes and Maj. E. D. Campbell.

Explosives, propellants, and artillery ammunition, Col. C. T. Harris and Maj. J. Herbert Hunter.

Sights and fire-control apparatus, Col. H. K. Rutherford and Maj. Fred E. Wright.

Motorized artillery, Col. L. B. Moody and Lieut. Col. H. W. Alden.

Tanks, Lieut. Col. H. W. Alden.

Machine guns, Col. Earl McFarland and Lieut. Col. Herbert O'Leary.

Service rifles, Maj. Lewis P. Johnson and Maj. Parker Dodge.

Pistols and revolvers, Lieut. Col. J. C. Beatty and Maj. Parker Dodge.

Small arms ammunition, Lieut. Col. J. C. Beatty, Maj. Lee O. Wright, Maj. A. E. Hunt, and Capt. C. J. Evans.

[Pg 5]

Trench warfare material, Lieut. Col. E. J. W. Ragsdale, Capt. J. R. Caldwell, Capt. R. D. Smith, and Lieut. J. T. Libbey.

Miscellaneous ordnance equipment, Lieut. Col. S. H. MacGregor, Maj. Bashford Dean, Capt. A. L. Fabens, and Capt. James S. Wiley.

The aircraft problem and airplane production, Lieut. Col. George W. Mixter.

The Liberty engine and other airplane engines, Lieut. H. H. Emmons, United States Navy.

Aviation equipment and armament, Lieut. Col. E. J. W. Ragsdale, Maj. E. Bradley, Capt. Robert D. Smith, Capt. H. E. Ives, and Lieut. John M. Hammond.

The airplane radio telephone, Col. C. C. Culver and Lieut. Col. Nugent H. Slaughter.

Balloons, Capt. H. W. Treat.

The Engineers in France, Lieut. Col. J. B. Cress and Capt. C. Beard.

Military railways, Col. J. M. Milliken and Mr. S. M. Felton.

Engineer activities at home, Lieut. Col. J. B. Cress and Lieut. Col. R. W. Crawford.

Sound and flash ranging and searchlights, Lieut. Col. J. B. Cress and Maj. W. D. Young.

Toxic gases, Col. M. T. Bogert, Col. W. A. Walker, Lieut. Col. E. M. Chance, and Lieut. Col. William McPherson.

Defensive gas equipment, Col. Bradley Dewey and Lieut. Col. A. L. Besse.

Subsistence, Lieut. Col. J. H. Adams and Capt. S. B. Johnson.

Clothing and equipage, Lieut. Col. F. A. Ellison and Capt. W. H. Porter.

Miscellaneous quartermaster undertakings: Music, Maj. George H. Richards; fuel, oil, and paints, Mr. J. Elliott Hall; brushes, Capt. T. W. S. Phillips; rolling kitchens, Capt. J. G. Williams and Mr. M. A. Dunning; tools and tool chests, Mr. W. F. Fusting and Mr. M. E. Moye; hardware, Lieut. Col. H. P. Hill and Mr. William A. Graham; factory enterprises, Lieut. Col. H. P. Hill; shoe fitting, Col. F. A. Ellison; meat cutting, Dr. W. O. Trone; packing, Capt. R. H. Moody; horses and mules, Maj. A. Cedarwald.

Motor and horse-drawn vehicles: Motor vehicles, Col. Fred Glover; horse-drawn vehicles, Maj. A. Volgeneau.

Medical and dental supplies, Lieut. Col. J. P. Fletcher and Capt. W. G. Guth.

Salvage, Col. J. S. Chambers and Capt. F. C. Simpson.

Mr. W. L. Pollard, Mr. Aaron Rachofsky, and Lieut. J. J. Cameron have rendered very valuable assistance in assembling data concerning quartermaster activities.

Cantonments and camps, and miscellaneous construction, Maj. W. G. Maupin.

[Pg 6]

Signal Corps material, Brig. Gen. C. McK. Saltzman and Capt. Donald MacGregor.

The accuracy of all statistics and direct statements of fact has been checked and approved by the statistics branch of the General Staff, under the direction of Maj. W. R. Burgess.

Respectfully submitted,

Benedict Crowell,
The Assistant Secretary of War,
Director of Munitions.

Hon. Newton D. Baker,
Secretary of War.

[Pg 7]

PREFACE.

Except in one or two instances, this account of the production of munitions in America for the war against Germany and her allies contains nothing about secret devices invented during the period under discussion. When the necessity for silence with respect to vital matters brought about a voluntary censorship in American publications, the land was filled with rumors of new and revolutionary developments in war matériel, particularly of new weapons of offense. It is fair to the American public to-day to state that such rumors were not without foundation. American inventiveness rose splendidly to the emergency. The expected American offensive in 1919 would have had its "surprises" in numbers, some of which might well have proved to be decisive. Certain of these inventions had been put in large production before the armistice was declared, others had been carried to an advanced experimental stage that insured their success. Since the value of these innovations as part of the Nation's permanent military assets depends largely upon their secret nature, it would be obviously unwise to mention or describe them at this time.

The Director of Munitions wishes to acknowledge the debt of America, so far as the production of munitions is concerned, to the Navy for its cooperation in industrial matters at home and its strong aid in the safe transport of munitions to France, and to all the other Government departments, each one of which contributed in numerous and important ways to the success of the munitions enterprise. The debt also extends heavily to the War Industries Board, its functions of creating facilities for manufacture, opening up new sources of raw materials, allocating materials, decreeing priorities, fixing prices, and acting as purchasing agent for the allies, making it the national industrial clearing house through which the War Department could work without waste effort. Acknowledgment is made to such essential agencies as the United States Railroad Administration, the United States Fuel Administration, the War Trade Board, and the United States Food Administration, and to all official or volunteer activities looking to the conservation and mobilization of our national resources. Without this entire cooperation the history set forth in these pages would not be what it is.

[Pg 8]
[Pg 9]

CONTENTS.

AMERICA'S MUNITIONS, 1917-18

[Pg 12]
[Pg 13]

INTRODUCTION.

As our war against Germany recedes into the past its temporal boundaries become more sharply defined, and it assumes the character of a complete entity—a rounded-out period of time in which the United States collected her men and resources, fought, and shared in the victory.

As such it offers to the critic the easy opportunity to discover that certain things were not done. American airplanes did not arrive at the front in sufficient numbers. American guns in certain essential calibers did not appear at all. American gas shells were not fired at the enemy. American troops fought with French and British machine guns to a large extent. The public is familiar with such statements.

It should be remembered that the war up to its last few weeks—up to its last few days, in fact—was a period of anxious suspense, during which America was straining her energies toward a goal, toward the realization of an ambition which, in the production of munitions, dropped the year 1918 almost out of consideration altogether, which indeed did not bring the full weight of American men and matériel into the struggle even in 1919, but which left it for 1920, if the enemy had not yet succumbed to the growing American power, to witness the maximum strength of the United States in the field.

Necessarily, therefore, the actual period of hostilities, between April 6, 1917, and November 11, 1918, was devoted in this country to laying down the foundations of a munitions industry that should bring about its overwhelming results at the appointed time. What munitions of the more difficult sort were actually produced in this period might almost be termed casual to the main enterprise—pilots of the quantities to come.

The decision to prepare heavily for 1919 and 1920 and thus sacrifice for 1917 and 1918 the munitions that might have been produced at the cost of any less adequate preparation for the more distant future, was based on sound strategical reasoning on the part of the Allies and ourselves.

On going back to the past we find that on April 6, 1917, the United States scarcely realized the gravity of the undertaking. There was a general impression, reaching even into Government, that the Allies[Pg 14] alone were competent to defeat the Central Powers in time, and that America's part would be largely one of moral support, with expanding preparation in the background as insurance against any unforeseen disasters. In line with this attitude we sent the first division of American troops to France in the spring of 1917 to be our earnest to the governments and peoples of the Allies that we were with them in the great struggle. Not until after the departure of the various foreign missions that came to this country during that spring did America fully awake to the seriousness of the situation.

All through the summer of 1917 the emphasis upon American man power in France gradually grew, but no definite schedule upon which the United States could work was reached until autumn or early winter, until the mission headed by Col. Edward M. House visited Europe to give America place on the Supreme War Council and in the Interallied Conference. The purpose of the House mission was to assure the Allies that America was in the war for all she was worth and to determine the most effective method in which she could cooperate.

In the conferences in London and Paris the American representatives looked into the minds of the allied leaders and saw the situation as it was. Two dramatic factors colored all the discussions—the growing need for men and the gravity of the shipping situation. The German submarines were operating so effectively as to make exceedingly dark the outlook for the transport on a sufficient scale either of American troops or of American munitions.

As to man power, the Supreme War Council gave it as the judgment of the military leaders of the Allies that, if the day were to be saved, America must send 1,000,000 troops by the following July. There were in France then (on Dec. 1, 1917) parts of four divisions of American soldiers—129,000 men in all.

The program of American cooperation, as it crystallized in these conferences, may be summarized as follows:

1. To keep the Allies from starvation by shipping food.

2. To assist the Allied armies by keeping up the flow of matériel already in production for them in the United States.

3. To send as many men as could be transported with the shipping facilities then at America's command.

4. To bend energies toward a big American Army in 1919 equipped with American supplies.

In these conferences sat the chief military and political figures of the principal European powers at war with Germany. In the Supreme War Council were such strategists as Gen. Foch for the French and Gen. Robertson for the British, Gen. Bliss representing the United States. The president of the Interallied Conference was M. Clemenceau, the French prime minister. Mr. Winston Churchill, the minister[Pg 15] of munitions, represented Great Britain, while Mr. Lloyd-George, the Prime Minister of England, also participated to some extent in the conferences.

Out of bodies of such character came the international ordnance agreement. It will be apparent to the reader that this agreement must have represented the best opinion of the leaders of the principal Allies, initiated out of their intimate knowledge of the needs of the situation and concurred in by the representatives of the United States. The substance of this agreement was outlined for Washington in a cabled message signed by Gen. Bliss, a document that had such an important bearing upon the production of munitions in this country that its more important passages are set down at this point:

This agreement had a profound effect upon American production of munitions. Most important of all, it gave us time; time to build manufacturing capacity on a grand scale without the hampering necessity for immediate production; time to secure the best in design; time to attain quality in the enormous output to come later as opposed to early quantity of indifferent class.

In the late autumn of 1917, shortly after Russia collapsed and withdrew from the war, it became evident that Germany would[Pg 16] seize the opportunity to move her troops from the eastern front and concentrate her entire army against the French and British in 1918.

This intelligence at once resulted in fresh emphasis upon the man-power phase of American cooperation. As early as December, 1917, the War Department was anticipating the extraordinary need for men in the coming spring by considering plans for the transport of troops up to the supposed limit of the capacity of all available American ships, with what additional tonnage Great Britain and the other Allies could spare us. It is of record that the actual dispatch of troops to France far outstripped these early estimates.

Then came the long-expected German offensive, and the cry went up in Europe for men. England, "her back against the wall," offered additional ships in which to transport six divisions over and above the number of troops already scheduled for embarkation, agreeing further to feed and maintain these men for 10 weeks while they were brigaded with British units for final training. After the six additional divisions had embarked there was still need of men, and the British continued their transports in our service. The high mark of shipment was in July, when 306,000 American soldiers were transported across the Atlantic, more than three times the number contemplated for July in the schedule adopted six months earlier.

ACTUAL TROOP SAILINGS COMPARED WITH PROGRAMS.

[Pg 17]

The effect of this stepping up of the man-power program upon the shipment of supplies was described by Lieut. Col. Repington, the British military critic, writing in the Morning Post (London) on December 9, 1918, in part as follows:

BRITISH AND AMERICAN EXPEDITIONARY FORCES ON WESTERN FRONT.

The really amazing thing which America did was to place in France in 19 months an army of the size and the ability of the American Expeditionary Force. The war taught us that America can organize, train, and transport troops of a superior sort at a rate which leaves far behind any program for the manufacture of munitions.[Pg 18] It upset the previous opinion that adequate military preparedness is largely a question of trained man power.

When the war touched us our strategical equipment included plans ready drawn for the mobilization of men. There were on file at the Army War College in Washington detailed plans for defending our harbors, our coasts, and our borders. There were also certain plans for the training of new troops.

It is worthy of note, however, that this equipment included no plan for the equally important and equally necessary mobilization of industry and production of munitions, which proved to be the most difficult phase of the actual preparation for war. The experience of 1917 and 1918 was a lesson in the time it takes to determine types, create designs, provide facilities, and establish manufacture. These years will forever stand as the monument to the American genius of workshop and factory, which in this period insured the victory by insuring the timely arrival of the overwhelming force of America's resources in the form of America's munitions.

B. C.

Washington, May, 1919.

[Pg 19]

BOOK I.
ORDNANCE.

[Pg 20]
[Pg 21]

CHAPTER I.
THE ORDNANCE PROBLEM.

To arm the manhood called to defend the Nation in 1917 and 1918, to make civilians into soldiers by giving them the tools of the martial profession—such was the task of the Ordnance Department in the late war.

The off-hand thought may identify ordnance as artillery alone. It may surprise many to know that in the American ordnance catalogue of supplies during the recent war there were over 100,000 separate and distinct items. Thousands of the items of ordnance were distinctly noncommercial, meaning that they had to be designed and produced specially for the uses of war.

While the principles of fighting essentially have changed not one whit since the age when projectiles were stones hurled by catapults, nearly every advance in mechanical science has had its reflection in warfare, until to-day the weapons which man has devised to destroy the military power of his enemy make up an intricate and an imposing list. When America accepted the challenge of Germany in 1917, part of the range of ordnance had already been produced in moderate quantities in the United States, part of it had been developed by the more militaristic nations of the world in the last decade or quarter century, and part of it was purely the offspring of two and one-half years of desperate fighting before America entered the great struggle. Yet all of it, both the strange and the familiar, had to be put in production here on a grand scale and in a minimum of time, that the American millions might go adequately equipped to meet the foe. Let us examine the range of this equipment, seeing in the major items something of the character of the problem which confronted the Ordnance Department at the outset of the great enterprise.

Starting with the artillery, there was first in order of size the baby two-man cannon of 37 millimeters (about an inch and a half) in the diameter of its bore—a European development new to our experience, so light that it could be handled by foot troops in the field, used for annihilating the enemy's machine-gun emplacements.

Then the mobile field guns—the famous 75's, the equivalent in size of our former 3-inch gun, the 155-millimeter howitzer, the[Pg 22] French 155 millimeter G. P. F. (Grand Puissance Filloux) gun of glorious record in the war, and its American prototypes, the 4.7-inch, 5-inch, and 6-inch guns—all of these employed to shell crossroads and harass the enemy's middle area.

Beyond these were the 8-inch and 9.2-inch howitzers and the terrific 240-millimeter howitzer, for throwing great weights of destruction high in air to descend with a plunge upon the enemy's strongest defenses.

Then there were the 8-inch, 10-inch, 12-inch, and 14-inch guns on railway mounts, for pounding the depots and dumps in the enemy's back areas. These weapons were so tremendous in weight when mounted as to require from 16 to 24 axles on the car to distribute the load and the recoil of firing within the limits of the strength of standard heavy railway track.

All of these guns had to be produced in great numbers, if the future requirements of the American forces were to be met, produced by the thousands in the cases of the smaller ones and by the hundreds and scores in the cases of the larger.

These weapons would be ineffective without adequate supplies of ammunition. In the case of the mobile held guns this meant a requirement of millions of shell or shrapnel for the incessant bombardments and the concentrated barrages which characterized the great war. The entire weight of projectiles fired in such an historic engagement as Gettysburg would supply the artillery only for a few minutes in such intensive bombardments as sowed the soil of Flanders with steel.

The artillery demanded an immense amount of heavy equipment—limbers, caissons, auto ammunition trucks, and tractors to drag the heavy and middle-heavy artillery. Some of them were fitted with self-propelled caterpillar mounts which could climb a 40° grade or make as high as 12 miles an hour on level ground. These, the adaptations to warfare of peaceful farm and construction machine traction, for the first time rendered the greater guns exceedingly mobile, enabling them to go into action instantly upon arrival and to depart to safety just as soon as their mission was accomplished.

Then, too, this artillery equipment must have adequate facilities for maintenance in the field, and this need brought into existence another enormous phase of the ordnance program. There must be mobile ordnance repair shops for each division, consisting of miniature machine shops completely fitted out with power and its transmission equipment and mounted directly on motor trucks. Then there must be semi-heavy repair shops on 5-ton tractors, these to be for the corps what the truck machine shop was to the division. Each army headquarters called for its semipermanent repair shop for artillery and still larger repair shops for its railway artillery.

[Pg 23]

And in addition to all these were the base repair shops in France, which were erected on a scale to employ a force three times as large as the combined organizations of all the manufacturing arsenals of the United States in time of peace, having a capacity for relining 1,000 cannon and overhauling and repairing 2,000 motor vehicles, 7,000 machine guns, 50,000 rifles, and 2,000 pistols every month. This equipment of artillery and its maintenance organization implies the flow from American industry of enormous quantities of repair parts and spare parts to keep the artillery in good condition.

Coming next to the more personal equipment of the soldier, we find the necessity confronting the Ordnance Department to manufacture shoulder rifles by the million and cartridges for them by the billion. The great war brought the machine gun into its own, requiring in the United States the manufacture of these complicated and expensive weapons by the tens of thousands, including the one-man automatic rifle, itself an arm of a deadly and effective type.

Simultaneously with the mass employment of machine guns in the field came the development of the modern machine gun barrage, the indirect fire, of which required sighting instruments of the most delicate and accurate sort, and tripods with finely calibrated elevating and traversing devices, so that the gunner might place the deadly hail safely over the heads of his own unseen but advancing lines and with maximum damage to the enemy. These thousands of machine guns required water jackets to keep their barrels cool and specially built carts to carry them.

The personal armament of the soldier also called for an automatic pistol or a revolver for use in the infighting, when squads came in actual contact with soldiers of the enemy. These had to be produced by the hundreds of thousands.

The requirements of the field demanded hundreds of thousands of trench knives, murderous blades backed by the momentum of heavily weighted handles, which in turn were protected by guards embodying the principle of the thug's brass "knucks" armed with sharp points.

Then there were the special weapons, largely born of modern trench warfare. These included mortars, ranging from the small 3-inch Stokes, light enough to go over the top and simple enough to be fired from between the steadying knees of a squatting soldier, to the great 240-millimeter trench mortar of fixed position. The mortars proved to be exceedingly effective against concentrations of troops, and so there was devised for them a great variety of bombs and shell, not only of the high explosive fragmentation type, but also containing poison gas or fuming chemicals. Great quantities both of mortars and their ammunition were required.

From the security of the trenches the soldiers first threw out grenades, which burst in the enemy's trenches opposite and created[Pg 24] havoc. From the original device were developed grenades of various sorts—gas grenades for cleaning up dugouts, molten-metal grenades for fusing the firing mechanisms of captured enemy cannon and machine guns, paper grenades to kill by concussion. Then there were the rifle grenades, each to be fitted on the muzzle of a rifle and hurled by the lift of gases following the bullet, which passed neatly through the hole provided for it. The production of grenades was no small part of the American ordnance problem.

In addition to these trench weapons were the Livens projectors, which, fired in multiple by electricity, hurled a veritable cloud of gas containers into a selected area of enemy terrain, usually with great demoralization of his forces.

Bayonets for the rifles, bolos, helmets, periscopes for looking safely over the edges of the trenches, panoramic sights, range finders—these are only a few of the ordnance accessories of general application.

Then those innovations of the great war—the tanks—the 3-ton "whippet," built to escort the infantry waves, the 6-ton tanks, most used of all, and the powerful Anglo-American heavy tanks, each mounting a 37-millimeter cannon and four machine guns.

The war in the air put added demands upon ordnance. It required the stripped machine gun firing cartridges so rapidly that their explosions merged into a single continuous roar, yet each shot so nicely timed that it passed between the flying blades of the propeller. There had to be electric heaters for the gun mechanisms to prevent the oil which lubricated them from becoming congealed in the cold of high altitudes. The airplane guns required armor-piercing bullets for use against armored planes, incendiary bullets to ignite the hydrogen of the enemy's balloon or to fire the gasoline escaping through the wound in the hostile airplane's fuel tank, and tracer bullets to direct the aim of the aerial gunner. Other equipment for the airman included shot counters, to tell him instantly what quantity of ammunition he had on hand, and gun sights, ingeniously contrived to correct his aim automatically for the relative speed and direction of the opposing plane. These were all developments in ordnance brought about by the great war, and in each case they involved problems for the production organization to solve.

Then there were the drop bombs of aerial warfare, of many gradations in weight up to 500 pounds each, these latter experimental ones forecasting the day when bombs weighing 1,600 pounds would be dropped from the sky; then bomb sights to determine the moment when the missile must be dropped in order to hit its target, sights which corrected for the altitude, the wind resistance, and the rate of speed of the airplane; and then mechanisms to suspend the bombs from the plane and to release them at the will of the operator.

The list might be stretched out almost indefinitely—through pyrotechnics, developed by the exigencies in Europe into an elaborate[Pg 25] system; through helmets and armor, revivals from medieval times to protect the modern soldier from injury; through the assortment of heavy textiles, which gave the troops their belts, their bandoleers, their haversacks, and their holsters; through canteens, cutlery for the mess in the fields, shotguns, and so on, until there might be set down thousands of items of the list which we know as modern ordnance.

It will be noted that the most important articles in this range are articles of a noncommercial type. In other words, they are not the sort of things that the industry of the country builds in time of peace, nor learns how to build. Many other war functions came naturally to a country skilled in handling food supplies for teeming populations, in solving housing problems for whole cities, and in managing transportation for a hundred million people; there was at hand the requisite ability to conduct war enterprises of such character smoothly and efficiently. Yet there was in the country at the outbreak of war little knowledge of the technique of ordnance production.

The declaration of war found an American Ordnance Department whose entire commissioned personnel consisted of 97 officers. Only 10 of this number were experienced in the design of artillery weapons. The projected army of 5,000,000 men required 11,000 trained officers to handle every phase of ordnance service. While a portion of this production would have to do with the manufacture of articles of a commercial type, such as automobiles, trucks, meat cans, mess equipment, and the like, yet the ratio of 97 to 11,000 gives an indication of the amount of ordnance knowledge possessed by the War Department at the outbreak of war as compared to what it would need to equip the first 5,000,000 men for battle.

The Government could obtain commissary officers from the food industry; it could turn bank tellers into paymasters, or convert builders into construction quartermasters; find transportation officers in the great railway systems, Signal Corps officers in the telegraph companies, or medical officers in professional life. But there was no broad field to which ordnance could turn to find specialized skill available. The best it could do was to go into the heavy manufacturing industry for expert engineers who could later be trained in the special problems of ordnance.

Prior to 1914 there were but six Government arsenals and two large private ordnance works which knew anything about the production of heavy weapons. After 1914, war industry sprang up in the United States, yet in 1917 there were only a score or so of firms engaged in the manufacture of artillery ammunition, big guns, rifles, machine guns, and other important ordnance supplies for the allies. When the armistice was signed nearly 8,000 manufacturing plants in the United States were working on ordnance contracts. While many of these contracts entailed production not much dissimilar to[Pg 26] commercial output, yet here is another ratio—the 20 or more original factories compared with the ultimate 8,000—which serves as an indication of the expansion of the industrial knowledge of the special processes incident to ordnance manufacture.

When we found ourselves in the war the first step was to extend our ordnance knowledge as quickly as possible. The war in Europe had developed thousands of new items of ordnance, many of them carefully guarded as military secrets, with which our own officers were familiar only in a general way. As soon as we became a belligerent, however, we at once turned to the allies, and they freely and fully gave us of their store of knowledge—plans, specifications, working models, secret devices, and complete manufacturing processes.

With this knowledge at hand we adopted for our own program certain French types of field guns and howitzers and British types of heavy howitzers. The reproduction of the British types caused no unusual difficulties, but the adoption of French plans brought into the situation a factor the difficulties of which are apt not to be appreciated by the uninitiated.

This new element for consideration was the circumstance that the entire French system of manufacture in metals is radically different from our own in its practices and is not readily adapted to American methods.

The English and the American engineers and shops use inches and feet in their measurements, but the French use the metric system. This fact means that there was not a single standard American drill, reamer, tap, die, or other machine-shop tool that would accurately produce the result called for by a French ordnance drawing in the metric system. Moreover, the French standards for metal stocks, sheets, plates, angles, I-beams, rivet holes, and rivet spacing are far different from American standards.

It was discovered that complete French drawings were in numerous cases nonexistent, the French practice relying for small details upon the memory and skill of its artisans. But even when the complete drawings were obtained, then the American ordnance engineer was confronted with the choice of either revolutionizing the machining industry of the United States by changing over its entire equipment to conform to the metric system, or else of doing what was done—namely, translating the French designs into terms of standard American shop practice, a process which in numerous cases required weeks and even months of time on the part of whole staffs of experts working at high tension.

Nor do the French know the American quantity-production methods. The French artisan sees always the finished article, and he is given discretion in the final dimensions of parts and in the fitting and[Pg 27] assembling of them. But the American mechanic sees only the part in which he is a specialist in machining, working with strict tolerances and producing pieces which require little or no fitting in the assembling room. Consequently, in the translating of French plans it was necessary to put into them what they never had before, namely, rigid tolerances and exact measurements.

When an army of 100,000 men expands and becomes an army of 3,000,000, it becomes a job just 30 times bigger to feed the 3,000,000 than it was to feed the 100,000. A soldier of a campaigning army eats no more than a soldier of a quiet military post. The same is true approximately in the case of clothing an army. But the army's consumption of ammunition in time of war is far out of proportion to its numerical expansion to meet the war emergency.

[Pg 28]

For instance, an Army machine gun in time of peace might fire 6,000 rounds in practice during the year. This was the standard quantity of cartridges provided in peace. Yet it is necessary to provide for a single machine gun on the field in such a war as the recent one 288,875 rounds of ammunition during its first year of operation, this figure including the initial stock and the reserve supply as well as the actual number of rounds fired. Thus the machine gun of war increases its appetite, so to speak, for ammunition 4,700 per cent in the first year of fighting.

In the case of larger weapons the increase in ammunition consumption is even more startling. Prior to 1917 the War Department allotted to each 3-inch field gun 125 rounds of ammunition per year[Pg 29] for practice firing. Ammunition for the 75-millimeter guns (the 3-inch equivalent) was being produced to meet an estimated supply of 22,750 rounds for each gun in a single year, or an increased consumption of ammunition in war over peace of 18,100 per cent.

Thus when a peace army of 100,000 becomes a war army of 3,000,000 its ammunition consumption becomes not 30 times greater, but anywhere from 48 to 182 times 30 times greater—an increase far out of proportion to its increase in the consumption of food, clothing, or other standard supplies. Modern invention has made possible and modern practice has put into effect a greatly augmented use of ammunition. Figures 1, 2, and 3 show graphically how ammunition expenditure has increased in modern times.

[Pg 30]

Another circumstance that complicated the ordnance problem was the increasing tendency throughout the great war to use more and more the mechanical or machine methods of fighting as opposed to the older and simpler forms in which the human or animal factor entered to a greater extent.

At the time the United States entered the war the regulations prescribed 50 machine guns as the equipment for an infantry division. When the armistice was signed the standard equipment of a division called for 260 heavy machine guns and 768 light automatic rifles. Of the heavy machine guns with a division, only 168 were supposed to be in active service, the remainder being in reserve or in use for antiaircraft work. However, the comparison in the two standards of equipment shows the tendency toward machine methods in the wholesale killing of modern warfare and indicates the fresh demands made upon the ordnance organization to procure this additional machinery of death. Moreover, when the fighting came to an end the A. E. F. was on the point of adding to its regimental and divisional equipment a further large number of automatic rifles.

The day of the horse was passing in the great war as far as his connection with the mobile artillery was concerned, and the gasoline motor was taking his place, this tendency being accelerated particularly by America, the greatest nation of all in automotivity. Trucks and tractors to pull the guns, motor ammunition trucks displacing the old horse-drawn caissons and limbers, even self-propelling platforms for the larger field guns, with track laying or caterpillar mounts supplying not only mobility for the gun but aiming facilities as well; these were the fresh developments. Some of these improvements were produced and put in the field, the others were under development at the signing of the armistice. The whole tendency toward motorization served to complicate ordnance production in this country, not only in the supply of the weapons and traction devices themselves, but in the production of increased supplies of ammunition, since these improvements also tended to increase the rapidity with which bullets and shell were consumed.

The total cost of the ordnance alone required to equip the first 5,000,000 Americans called to arms was estimated to be between $12,000,000,000 and $13,000,000,000. This was equal to about half of all the money appropriated by Congresses of the United States from the first Continental Congress down to our declaration of war against Germany, out of which appropriations had been paid the cost of every war we ever had, including the Civil War, and the whole enormous expenses of the Government in every official activity of 140 years. To equip with ordnance an army of this size in the[Pg 31] period projected meant the expenditure of money at a rate which would build a Panama Canal complete every 30 days.

Above are sketched some of the difficulties of the situation. In our favor we had the greatest industrial organization in the world, engineering skill to rank with any, a race of people traditionally versatile in applying the forces of machinery to the needs of mankind, inventive genius which could match its accomplishments with those of the rest of the world added together, a capacity for organization that proved to be astonishingly effective in such an effort as the nation made in 1917 and 1918, enormous stores of raw materials, the country being more nearly self-sufficient in this respect than any other nation of the globe, magnificent facilities of inland transportation, a vast body of skilled mechanics, and a selective-service law designed to take for the Army men nonessential to the Nation's industrial efforts for war and to leave in the workshops the men whose skill could not be withdrawn without subtracting somewhat from the national store of industrial ability.

It only remains to sketch in swift outlines something of the accomplishments of the American ordnance effort. In general it may be said that those projects of the ordnance program to which were assigned the shorter time limits were most successful. There never was a time when the production of smokeless powder and high explosives was not sufficient for our own requirements, with large quantities left over for both France and England.

America in 19 months of development built over 2,500,000 shoulder rifles, a quantity greater than that produced either by England or by France in the same period, although both those countries in April, 1917, at the time when we started, had their rifle production already in a high stage of development. (See fig. 4.) However, the Franco-British production of rifles dropped in rate in 1918 because there was no longer need for original rifle equipment for new troops.

In the 19 months of war American factories produced over 2,879,000,000 rounds of rifle and machine-gun ammunition. This was somewhat less than the production in Great Britain during the same period and somewhat less than that of France; but America began the effort from a standing start, and in the latter part of the war was turning out ammunition at a monthly rate twice that of France and somewhat higher than that of Great Britain. (See fig. 4.)

Between April 6, 1917, and November 11, 1918, America produced as many machine guns and automatic rifles as Great Britain did in the same period and 81 per cent of the number produced by France; while at the end of the effort America was building machine guns and machine rifles nearly three times as rapidly as Great Britain and more than twice as fast as France. (Fig. 4.) When it is considered[Pg 32] that a long time must elapse before machine-gun factories can be equipped with the necessary machine tools and fixtures, the effort of America in this respect may be fairly appreciated.

Prior to November 11, 1918, America produced in the 75-millimeter size alone about 4,250,000 high-explosive shell, over 500,000 gas shell, and over 7,250,000 shrapnel. Of the high-explosive shell produced 2,735,000 were shipped to France up to November 15, 1918. In all 8,500,000 rounds of shell of this caliber were floated—nearly two-thirds of it being shrapnel. American troops on the line expended a total of 6,250,000 rounds of 75-millimeter ammunition, largely high-explosive shell of French manufacture drawn from the Franco-American ammunition pool. American high-explosive shell were tested in France by the French ordnance experts and approved for use by the French artillery just before the armistice.

THE MUNITIONS BUILDING, WASHINGTON, D. C.

The Lincoln Memorial and the Potomac River in the background.

A PARK OF AMERICAN-BUILT 155-MILLIMETER HOWITZERS AT ABERDEEN PROVING GROUND.

AMERICAN-BUILT G. P. F. 155-MILLIMETER GUNS STORED AT ABERDEEN PROVING GROUND.

GUNS OF VARIOUS SORTS AND SIZES RETURNED FROM FRANCE BY AMERICAN EXPEDITIONARY FORCES JUST AS THEY WERE UNLOADED FROM TRAIN AT ABERDEEN.

AMERICAN-BUILT ORDNANCE MATERIAL, PARKED ON ABERDEEN PROVING GROUND.

AMERICAN-BUILT ORDNANCE STORES AT ABERDEEN PROVING GROUND.

A PARK OF AMERICAN-BUILT CAISSONS, BACK FROM FRANCE, AT ABERDEEN PROVING GROUND.

CHARGING FLOOR OF AN OPEN-HEARTH FURNACE.

The charging floor of an "open-hearth" furnace building, showing two furnaces on the side into which the raw materials are "charged." Each of these furnaces is 75 feet long and 15 feet wide, and the melted steel lies in a shallow bath inside the three doors, into one of which the man is looking. The pool or "bath," as it is termed, is 33 feet long by 12 feet wide and approximately 2½ feet deep, weighs approximately 60 tons, and is composed of pig iron and well-selected scrap steel from previous operations, which are placed in the furnace through the three doors shown, the furnace being all the time at a temperature so high that the naked eye may not look within the furnace, but must be protected with blue glass or smoked glass, exactly as when looking at the noonday sun. The eye can see nothing in the atmosphere of the bath in which the steel is being melted and refined, due to the exceedingly high temperature, which gives a light as white as that of the sun.

[Pg 33]

In artillery ammunition rounds of all calibers America at the end of the war was turning out unfilled shell faster than the French and nearly as fast as the British; but, due to the shortage in adapters and boosters, a shortage rapidly being overcome at the end of the war, the rate of production of completed rounds was only about one-third that of either Great Britain or France. In total production during her 19 months of belligerency America turned out more than one-quarter as many unfilled rounds as Great Britain did in the same time and about one-quarter as many as came from the French munition plants. In completed rounds alone did America lag far behind the records of the two principal allies during 1917 and 1918. (Fig. 5.)

The production of completed rounds of artillery ammunition was gaining rapidly, beginning with the early summer of 1918, and in the month of October was approaching half the rate of manufacture in[Pg 34] Great Britain or in France. Figure 6 shows graphically the rate at which the artillery ammunition deliveries were expanding.

In artillery proper the war ended too soon for American industry to arrive at a great production basis. The production of heavy ordnance units is necessarily a long and arduous effort even when plants are in existence and mechanical forces are trained in the work. America in large part had to build her ordnance industry from the ground up—buildings, machinery, and all—and to recruit and train the working forces after that. The national experience in artillery production in the great war most like our own was that of Great Britain, who started in from scratch, even as we did. It is interesting, then, to know how Great Britain expanded her artillery industry, and the testimony of the British ministry of munitions may throw a new light on our own efforts in this respect. In discussing artillery in the[Pg 35] war the British ministry of munitions issued a statement from which the following is an excerpt:

Thus it took England three and a half years to equip her army completely with artillery and ammunition on the scale called for at the end of the war. On this basis America, when the armistice came, had two years before her to equal the record of Great Britain in this respect.

As to the production of gun bodies ready for mounting, the attainments of American ordnance were more striking. At the end of the[Pg 36] fighting America had passed the British rate of production and was approaching that of the French. In totals for the whole war period (Apr. 6, 1917, to Nov. 11, 1918) the American production of gun bodies could scarcely be compared with either that of the British or that of the French, this due to the fact that it required many months to build up the forging plants before production could go ahead.

In completed artillery units the American rate of production at the end of the war was rapidly approaching both that of the British and that of the French. In total production of complete units in the 19 months of war, American ordnance turned out about one-quarter as many as came from the British ordnance plants and less than one-fifth as many as the French produced in the same period. Figure 8 represents visually America's comparative performances in the production of gun bodies and complete artillery units.

Stress has sometimes been laid upon the fact that the American Army was required to purchase considerable artillery and other supplies abroad, the latter including airplanes, motor trucks, food and clothing, and numerous other materials. Yet, balanced against this fact is that every time we spent a dollar with the allied governments for ordnance, we sold ordnance, or materials for conversion into munitions to the allied governments to the value of five dollars.[Pg 37] The interallied ordnance agreement provided that certain munitions plants in the United States should continue to furnish supplies to the allies, and that additional plants for the allies should be built up and fostered by us. Thus, while we were purchasing artillery and ammunition from the allies we were shipping to them great quantities of raw materials, half-completed parts, and completely assembled units, and such war-time commodities as powder and explosives, forgings for cannon and other heavy devices, motors, and structural steel. The following table shows the ordnance balance sheet between America and the allied governments:

The credit for the ordnance record can not go merely to those men who wore the uniform and were part of the ordnance organization. Rather it is due to American science, engineering, and industry, all of which combined their best talents to make the ordnance development worthy of America's greatness.

[Pg 38]

CHAPTER II.
GUN PRODUCTION.

The sole use of a gun is to throw a projectile. The earliest projectile was a stone thrown by the hand and arm of man—either in an attack upon an enemy or upon a beast that was being hunted for food. Both of these uses of thrown projectiles persist to this day, and during all time, from prehistoric days until now, every man who had a projectile to throw was steadily seeking for a longer range and a heavier projectile.

The man who could throw the heaviest stone the longest distance was the most powerfully armed. In the Biblical battle between David and Goliath, the arm of David was strengthened and lengthened by a leather sling of very simple construction. Much practice had given the young shepherd muscular strength and direction, and his longer arm and straighter aim gave him power to overcome his more heavily armed adversary.

Later, machines were developed after the fashion of a crossbow mounted upon a small wooden carriage which usually was a hollowed trough open on top and upon which a heavy stone was laid. The thong of the crossbow was drawn by a powerful screw operated by man power, and the crossbow arrangement when released would throw a stone weighing many pounds quite a distance over the walls of a besieged city or from such walls into the camps and ranks of the besiegers. This again was an attempt by mechanical means to develop and lengthen the stroke of the arm and the weight of the projectile.

With the development of explosives, which was much earlier than many people suppose, there came a still greater range and weight of projectile thrown, although the first guns were composed of staves of wood fitted together and hooped up like a long, slender barrel, wound with wet rawhide in many folds, which, when dried, exerted a compressive force upon the staves of the barrel exactly as do the steel hoops of barrels used in ordinary commercial life to-day.

This, the first gun, sufficed for a long while until the age of iron came. And then the same principle of gun construction was followed as is seen in that historical gun, the "Mons Meg," in the castle at Edinburgh. The barrel of that gun is made of square bars of[Pg 39] iron, placed lengthwise, and similar bars of iron were wrapped hot around the staves to confine them in place and to give more resisting power than was possible with the wooden staves and the rawhide hooping.

Thus, all during the age of iron, gun development went steadily forward. Every military power was always striving by the aid of its best engineers, designers, and manufacturers to get a stronger gun, either with or without a heavier projectile, but in every case striving for greater power. As a special development we find in March, 1918, the now famous long-range gun of the Germans, which was at that time trained upon Paris, where it successfully delivered a shell approximately 9 inches in diameter, punctually every 20 minutes for a good part of each day until the gun was worn out. This occurred after a comparatively small number of shots, probably not more than 75 in all. The rapid wearing out was due to the immense demands of the long range upon the material of the gun. The Germans in the shelling of Paris used three of these long-range weapons and 183 shells are known to have fallen in the city.

The Germans evidently calculated with great care and experience upon the factors leading up to this famous long-range type of gun, which had an effective shooting distance of approximately 75 miles, which range, in the opinion of our experts, it is now quite easy for an experienced designer and manufacturer to equal and excel at will. In fact, one would hesitate to place a limit upon the length of range that could be achieved by a gun that it is now possible to design and build. In this connection it is interesting to note that the great French ordnance works at Le Creusot in 1892 produced the first known and well-authenticated long-range gun, which was constructed from the design of a 12-inch gun, but bored down to throw a 6-inch projectile. And instead of the usual 8 miles expected from the flight of a 6-inch shell this early Creusot long-range gun gave a range of approximately 21 miles with a 6-inch projectile, using a 12-inch gun's powder charge.

Closely connected with the development of the gun itself, and a necessary element of the gun's successful use, is the requirement that the weapon itself be easily transported from point to point, where its available range and capacity for throwing the projectile can be made of maximum use. This requires a gun carriage which has within itself various functions, the primary one being to establish the gun in the desired position where it can be made most effective against the enemy. Then, too, the gun carriage must have stability in order to withstand, absorb, and care for the enormous recoil energies let loose by the firing of the gun. It is obvious that the force which propels the projectile forward is equal to the reacting force to the rear, and in order to care for, absorb, and distribute to the earth this reacting force to the rear the carriage must have[Pg 40] within itself some very peculiar and important properties. To this end there is provided what is known as a "brake" which permits the gun, upon the moment of firing, to slide backward bodily within the controlling apparatus mounted upon a fixed carriage.

The sliding of the whole gun to the rear by means of the mechanism of the brake is controlled, as to speed and time, by springs, by compressed air, by compressed oil, etc., either all together or in combinations of two or three of these agencies; so that the whole recoil energy is absorbed and the rearward action of the gun brought to rest in a fraction of a second and in but a very few inches of travel. The strains are distributed from the recoil mechanism to the fixed portion of the carriage that is necessarily anchored to the ground by means of spades, which the recoil force of each shot sets more firmly into the ground, so that the whole apparatus is thus steadily held in place for successive shots.

In mobile artillery, again, rapid firing is a prime essential. The 75-millimeter gun of modern manufacture is capable of being fired at a rate in excess of 20 shots a minute—that is, a shot every 3 seconds.

Rarely however, is a gun served as rapidly as this. The more usual rate of fire is 6 shots a minute or 1 about each 10 seconds, and this rate of fire can be maintained in the 75-millimeter gun with great accuracy over a comparatively long period.

The larger guns are served at proportionately slower rates, until as the calibers progress to the 14-inch rifles, which have been set up upon railway mounts as well as on fixed emplacements for seacoast defense, the rate of fire is reduced to one shot in three minutes for railway mounts, and to one shot a minute for seacoast mounts, although upon occasions a more rapid rate of fire can be reached.

Under rapid fire conditions, the gun becomes very hot, owing to the heat generated by the combustion of the powder within the gun at pressures as high as 35,000 pounds per square inch or more, which are generated at the moment of fire. This heat is communicated through the walls of the gun and taken off by the cooling properties of the air. Nevertheless, the wall of the gun becomes so hot that it would scorch or burn a hand laid upon it. The rapid fire and heating of the gun lessens the effective life of the weapon, due to the fact that the hot powder gases react more rapidly on hot metal than they do upon cold metal; hence a gun will last many rounds longer if fired at a slow rate than if fired at a rapid rate.

It may be helpful to keep in mind throughout that the sole purpose of a gun is to fire a projectile, as was stated at the very beginning of this chapter. All other operations connected with the life of a gun, its manufacture, its transportation to the place where it is to be used, its aiming, its loading and all its functions and operations are bound up in the single purpose of actually firing the shot.

[Pg 41]

Consider now for a moment, the life of, let us say, one of the 14-inch guns.

In the great steel mills it requires hundreds and perhaps thousands of workmen to constitute the force necessary to handle the enormous masses of steel through the various processes which finally result in the finished gun.

From the first operation in the steel mill it requires perhaps as long as 10 months to produce the gun ready for the first test. During the 10 months of manufacture of one of these 14-inch rifles there has been expended for the gun and its carriage approximately $200,000. Of course, while it requires 10 months to make a final delivery of one gun after its first operation is commenced, it should be remembered that yet other guns are following in series and that in a well-equipped ordnance factory two and perhaps three guns per month of this kind can be turned out continuously, if required.

Remembering now that it requires 10 months to produce one such 14-inch rifle and that its whole purpose is to fire a shot, consider now the time required to fire this shot. As the primer is fired and the powder charge ignited the projectile begins to move forward in the bore of the gun at an increasingly rapid rate, so that by the time it emerges from the muzzle and starts on its errand of death and destruction, it has taken from a thirtieth to a fiftieth of a second in time, depending upon certain conditions.

Assuming that a fiftieth of a second has been taken up and that the life of a large high-pressure gun at a normal rate of firing is 150 shots, it is obvious then that in the actual firing of these 150 shots only three seconds of time are consumed. Therefore, the active life of the gun, which it has taken 10 months to build, is but three seconds long in the actual performance of the function of throwing a shot.

However, after the gun has fired its life of 150 shots it is a comparatively simple and inexpensive matter to bore out the worn-out liner and insert a new liner, thus fitting the gun again for service, with an expenditure of time and money much less than would be required in the preparation of a new gun.

As the size of the powder charge decreases, a progressively longer life of the walls of the bore of a gun is attained, so that we have had the experience of a 75-millimeter gun firing 12,000 rounds without serious effect upon the accuracy of fire. Large-caliber guns, such as 12-inch howitzers, with the reduced powder charge required for the lower muzzle velocities employed in howitzer attack, have retained their accuracy of fire after 10,000 rounds.

From the fact that when in action guns are served with ammunition, aimed, fired, and cared for by a crew of men carefully trained to[Pg 42] every motion involved in the successful use of the gun, it is most essential that the design and the material shall be such, both as to calculation in the design and as to manufacture in the material, as will insure the maintenance of the morale of the crew that serves the gun. Each man must be confident to the very last bit of fiber in his make-up that his gun is the best gun in the world, that it will behave properly, that it will protect him and his fellow soldiers who are caring for the welfare of their country, that it will respond accurately and well to every demand made upon it, that it will not yield or burst, that it will not shoot wild, but that it will in every respect give the result required in its operation.

To this end it has for generations been known that the requirements of manufacture of ordnance material, particularly for the body of the gun, are of the very highest order and call for the finest attainable quality in material, workmanship, and design.

It is well known and admitted that the steel employed in the manufacture of guns must be of the highest quality and of the finest grade for its purpose. It requires the most expert knowledge of the manufacture of steel to obtain this grade and quality. Until recently this knowledge in America was confined to the Ordnance officers of the Army and of the Navy and to a comparatively small number of manufacturers—not more than four in all—and only two of these manufacturers had provided the necessary equipment and appliances for the manufacture of complete guns.

Until 1914 the number of guns whose manufacture was provided for in this country as well as in the countries of Europe, excepting Germany, was very small. It might be stated that the sum total of guns purchased by the United States from the two factories mentioned did not exceed an average of 55 guns a year in calibers of from 3-inch to 14-inch, and that the stock of guns which by this low rate of increase of manufacture had been provided for us was pitifully small with which to enter a war of the magnitude of the one through which this country has just passed.

The two factories in question not having been encouraged by large purchases of ordnance material, as were similar industries in Germany, were not capable of volume production when we entered the war. But at the same time the gun bodies produced by these concerns at least equaled in quality those built in any other country on earth; so that while the big-gun-making art was in existence in this country and was maintained as to quality, it was most insufficient as to the quantity of the production available.

When the United States faced the war in April, 1917, arrangements were at once entered into to obtain in the shortest space of time an adequate supply of finished artillery of all calibers required by our troops and to get this supply in time to meet our men as[Pg 43] they should set foot on the shores of France. Many thousands of forgings for guns, and finished guns too, had been ordered by the allies of the few gun makers in this country; and these makers were, at the time we got into the conflict, fully occupied for at least a year ahead with orders from the French and English ordnance departments. All of this production was immediately useful and available for the combined armies of the allies, and so it was allowed to go forward, the forgings preventing a gap in the output of the finished articles from the British and French arsenals which were then using the semifinished guns made in the old factories in existence in this country in April, 1917.

Some idea of the volume of this production in this country will be gained from the following table showing material supplied to the allies between April, 1917, and the date of the signing of the armistice, November 11, 1918.

In supplying all of this material from our regular sources of manufacture in this country to the finishing arsenals of the allies we were but maintaining our position as a part of the general source of supply. The plan of the French and British ordnance engineers at the outbreak of the war in 1914 was to build their factories as quickly and as extensively as could possibly be done. By the time the United States entered the war all of these factories were in operation and clamoring for raw material at a rate which was far in excess of that which could be supplied by the home steel makers in Great Britain and France. Consequently their incursions into the semifinished ordnance material supplies in the United States were necessary. In sending these large quantities of our own materials abroad, when we needed them ourselves, we were distinctly adding to the rate and quantity of the supply of finished ordnance for the use of our own Army in the field as well as being at the same time of inestimable value to the allies. This was because the French and British had agreed to supply our first armies with finished fighting weapons while we were giving them the raw materials which they needed so badly.

The four gunmakers in America meanwhile were being expanded into a total of 19 makers. All of these 19 factories during the month of October, 1918, were practically in full operation. Many of them were producing big guns at a faster rate than that for which the plants had been designed. In the month of October, 1918, with 3 of the 19 factories yet to have their machine-tool equipment completed, there were produced 2,031 sets of gun forgings between the calibers of 3-inch and 9.5-inch, which is at the rate of upward of 24,000 guns a year. This figure, of course, does not indicate anything of the [Pg 44]gun-finishing capacity of the country; yet this expansion may be contrasted to the fact that our supply of finished guns prior to 1917 amounted only to 55 weapons a year.

Our chain of gun factories, that were making this remarkable production, were built as follows:

One at the Watertown Arsenal, Watertown, Mass., near Boston, for the manufacture of rough machined gun forgings of the larger mobile calibers. This factory was entirely built and equipped on Government land with Government money and is splendidly able to produce rough machined gun forgings of the highest quality at the rate of two sets a day for the 155-millimeter G. P. F. rifles, and one set a day of the 240-millimeter howitzers.

At Watervliet Arsenal, Watervliet, N. Y., large extensions were made to the existing plant that had always been the Army's prime reliance for the finishing and the assembly of guns of all calibers, including the very largest. This plant was extended to manufacture complete four of the 240-millimeter howitzers each day, and two a day of the 155-millimeter G. P. F. guns.

At Bridgeport, Conn., there was constructed a complete new factory by the Bullard Engineering Works for the United States to turn out four 155-millimeter G. P. F. guns a day.

At Philadelphia, the Tacony Ordnance Corporation, as agents for the Government, erected complete a new factory officered and manned by experts well-trained and experienced in the difficult art of the manufacture of steel and gun forgings. On October 11, 1917, the grounds for this great undertaking had been merely staked out for the outline of the buildings. Seven months later, on May 15, 1918, the entire group of buildings, comprising a complete steel works from making the steel to the final completion of 155-millimeter gun forgings, was entirely erected at a cost of about $3,000,000. This difficult and rapid building operation was carried through successfully during the extraordinarily severe winter of 1917-18. On June 29, 1918, the first carload of gun forgings was accepted and shipped from this plant, so we have the marvelous enterprise of building a complete steel works from the bare ground forward to the shipment of its first forgings in a total elapsed time of only eight and one-half months.

At another, the works of the Midvale Steel Co. in Philadelphia, large extensions were made to enable some of the larger guns to be produced, to be finished later at the Watervliet Arsenal.

At the Bethlehem Steel Co.'s plant, Bethlehem, Pa., as early as May, 1917, orders were placed and appropriations allotted for expansions to this enterprise to enable a rapid output of a larger number of gun forgings and finished guns.

Large extensions were made at the works of the Standard Steel Works Co., Burnham, Pa., to increase their existing forging and heat treating facilities, so that at this plant two sets of 155-millimeter howitzers and one set of 155-millimeter gun forgings were produced each day.

[Pg 46]

At Pittsburgh, Pa., the plants of the Heppenstall Forge & Knife Co. and the Edgewater Steel Co. were extended so as to provide for the daily production at the first plant of forgings for one 3-inch antiaircraft gun and one 4.7-inch gun, and at the second plant of forgings for one 155-millimeter G. P. F. gun and one 240-millimeter howitzer per day.

At Columbus, Ohio, the Buckeye Steel & Castings Co. in combination with the works of the Symington-Anderson Co. at Rochester, N. Y., had their facilities extended to provide for the manufacture each day of six sets of forgings for the 75-millimeter guns.

At the Symington-Anderson Co. in Rochester, N. Y., there was provided a finishing plant for the 75-millimeter gun with a capacity of 15 finished guns per day.

At Erie, Pa., one of the most remarkable achievements in rapid construction and successful mechanical operation was performed by the erection of a plant that was commenced in July, 1917, and out of which the first production was shipped to the Aberdeen Proving Grounds in February, 1918. The American Brake Shoe & Foundry Co. built and operated this plant as agents for the Ordnance Department, and much credit is due them for their energy and organizing capacity.

It is doubtful if history records any similar enterprise in which guns were turned out in a plant seven months from the date of beginning the erection of the factory. This plant was laid out to manufacture 10 of the 155-millimeter Schneider-type howitzers a day, and before the signing of the armistice it had more than fulfilled every expectation by regularly turning out up to 15 howitzers a day, or 90 a week.

At Detroit, Mich., the Chalkis Manufacturing Co. adapted an existing plant, and additional facilities were erected for the manufacture of three of the 3-inch antiaircraft guns each day.

At Madison, Wis., the Northwestern Ordnance Co. erected for the United States an entire new factory, beautifully equipped for the manufacture of four guns a day of the 4.7-inch model.

At Milwaukee, Wis., the Wisconsin Gun Co. put up for the Government an entirely new works capable of finishing six 75-millimeter guns each day. The plants at both Milwaukee and Madison acquitted themselves very well and gave us guns of the highest quality.

At Chicago, the Illinois Steel Co. expanded existing facilities to produce more of the necessary electric furnace steel, which was forged into guns at several works producing gun forgings, both for the Army and Navy.

At Indiana Harbor, Ind., the works of the Standard Forgings Co., whose sole business had been the volume production of forgings with[Pg 47] steam hammers and hydraulic presses, were expanded to the enormous degree of producing each day 10 sets of gun forgings for the 155-millimeter howitzer and 25 sets a day for the 75-millimeter gun. It should be stated that this was a triumph of organizing ability and that this factory was one of our main reliances for these guns.

At Gary, Ind., the American Bridge Co. created what is perhaps the finest gun-forging plant in the world, comprising four presses from 1,000 tons to 3,000 tons forging capacity and all the other necessary apparatus for the production each day of two sets of 155-millimeter G. P. F. guns and the equivalent of one and one-half sets a day of the 240-millimeter howitzers.

At Baltimore, Md., the plant of the Hess Steel Corporation was enlarged from its peace-time capacity and caused to produce at three times its normal rate the special steels required for gun manufacture.

It will become evident that the collection of machinery, buildings, and equipment necessary to produce these guns in the short space of time required and at the rate of production stipulated, was an enormous task in itself. It required the production of vast quantities of raw materials and the congregating in one place of large numbers of men capable of undertaking the exceedingly intricate mechanical processes of manufacture. The success of this plan and its carrying out is due largely to the loyalty of the manufacturers who unselfishly came forward early in 1917 and agreed at the request of the Ordnance Department to turn over their plants, lock, stock, and barrel, to the requirements of the department; agreed also to undertake the manufacture of products totally unfamiliar to them; agreed likewise to lend all of their organizing ability and great material resources to the success of the plants which the United States found necessary to build in the creation of a new art, in new locations and in an extent theretofore undreamed of.

THE MAKING OF A BIG GUN.

Steel, of course, and steel in some of its finest forms is the basis of gun manufacture. The word "steel" for the purpose of producing guns means much more than is ordinarily carried by the word in its everyday and most commonly accepted use. Only steel of the very highest quality is suitable for gun manufacture, as was indicated previously when attention was directed to the complete reliance which the operating crews must place in their guns and the severity of the uses to which the big guns are put.

Let us take a hasty trip through a big gun plant, watching the processes through which is finally evolved from the raw materials one of our hardy and efficient big guns.

Entering an open-hearth furnace building at one of our big gun plants, we find two large furnaces in which the raw materials are[Pg 48] charged. Each of these furnaces is 75 feet long and 15 feet wide, and in them in a shallow bath or pool lies the molten steel. The pool is about 33 feet long by 12 feet wide and approximately 2½ feet deep. This pool, or "bath" as it is termed, weighs approximately 60 tons and is composed of pig iron and well-selected scrap steel from previous operations.

The furnace is at all times during the operation of melting these raw materials in the bath kept at such a high temperature that the eye may not look within at the molten mass without being protected with blue glass or smoked glass, exactly as when looking at the noonday sun. The eye can see nothing in the atmosphere of the bath in which the steel is being melted and refined because the temperature is so exceedingly high that it gives a light as white as that of the sun.

After 12 or 15 hours of refining treatment in this furnace the metal is tested, analyzed in the chemical laboratory, and, if found to be refined to the proper degree, it is allowed to flow out of the furnace on the opposite side from that through which it entered. Flowing out of the furnace the entire charge of 60 tons finds its way into a huge ladle which is suspended from a traveling crane capable of safely carrying this great weight.

The ladle is then transferred by the crane to a heavy cast-iron mold which is built so as to contain as much of the 60 tons of molten metal as is required for the particular gun forging under manufacture.

The mold, which we have before us now on our imaginary trip through the gun plant, will provide an "ingot" from the molten metal that will be 40 inches in diameter and 100 inches high. On top of this ingot is a brick-lined so-called "sinkhead." This sinkhead is that portion of the molten metal that has been allowed to cool more slowly in the brick lining than the ingot does in the cast-iron mold proper. The ingot with the sinkhead will weigh approximately 60,000 pounds.

This sinkhead is to insure greater solidity to the portion of the ingot which is used for the gun forging. Only that part of the ingot below the sinkhead enters the forging. The sinkhead itself is cut off while hot under the press in a subsequent operation and afterwards remelted.

Next the ingot is placed under a 2,000-ton forging press which handles ingots up to 45 inches in diameter. There it is forged into a square shape after coming from the mold in an octagonal form. Previous to its being put under this press, however, a careful chemical analysis has been made of the ingot to determine that it is satisfactory for gun purposes, and then before being put under the press the whole ingot is heated in the charge chamber and fired either by a gas or oil flame.

VIEW OF LADLE, CONTAINING 60 TONS OF MOLTEN STEEL SUSPENDED FROM A TRAVELING CRANE.

The ladle is receiving metal from the furnace and the crane is conveying the ladle to the mold.

MOLTEN STEEL BEING POURED FROM LADLE INTO MOLD, WHICH IS OF HEAVY CAST-IRON CONSTRUCTION, AT THE TACONY ORDNANCE CORPORATION.

Arrow points from letter A to a completed ingot from a mold. The brick-lined sink head is a part of the mold and is to insure greater solidity to the portion of the ingot which is used for the gun forging; only the part below the sink head entering the forging, the sink head itself being cut off hot under the press in a subsequent operation.

VIEW OF INGOT MOLD.

A 2,000-TON FORGING PRESS AT THE TACONY ORDNANCE CORPORATION PLANT.

This press can forge ingots up to 45 inches in diameter. The ingot under the press is shown in a partly forged state. Note that the original octagonal shape of the ingot as it came from the mold has been forged down to a square shape and later will be forged into a round shape. After coming from the mold, the ingot has been subjected to a careful chemical analysis to determine its fitness for use as a gun barrel.

A 9,000 TON HYDRAULIC FORGING PRESS IN THE PLANT OF THE MIDVALE STEEL CO.

This press is needed for such large caliber guns as the 14-inch and 16-inch guns. The piece of forging under the press is armor plate and not a gun forging.

THREE TUBES OF THE 155-MILLIMETER GUNS SUSPENDED AT FURNACE.

Three tubes of the 155-millimeter guns suspended at furnace ready for heating and quenching to give them the necessary combination of hardness and toughness. The door of the furnace is open. The tubes remain in this furnace for perhaps eight hours at a temperature of 1,500° Fahrenheit or until a bright yellow color, uniform in every part.

A TUBE FOR A 12-INCH GUN JUST OUT OF THE FURNACE, WHERE IT WAS TEMPERED AT WHITE HEAT AND IS NOW READY FOR QUENCHING IN THE PLANT OF THE MIDVALE STEEL CO.

The gun tube is 41 feet long.

TUBE OF A 155-MILLIMETER GUN BEING TURNED, PRIOR TO BORING, AT THE TACONY ORDNANCE CORPORATION PLANT.

TUBE OF A 155-MILLIMETER GUN IN A LATHE BEING BORED.

The ingot out of which this tube was made, came from the mold in an octagonal shape and later was forged into a square shape and finally made round. It now, too, has the hole bored partially into it. Through this hole, ultimately, will pass the projectile.

[Pg 49]

The forging press used for the larger caliber guns, such as 14-inch and 16-inch, is of a 9,000-ton weight capacity.

After the ingot forging has been reduced from squareness to a cylindrical shape under the press, it is allowed to cool, then taken to the machine shop, where it is turned and the hole through which the projectile ultimately will pass is bored into it. This hole is somewhat smaller than the diameter of the projectile, because in the finishing operation, when the gun is assembled finally and put together, the hole must be within one-one-thousandth of an inch of the diameter required, which is all the tolerance that is allowed from the accuracy to which the projectiles are brought. Otherwise the accuracy of the gun in firing would be injured and the reliability of its aim would not be satisfactory.

During all of these operations with the ingot, the steel is largely in the soft condition in which it left the forging press. As is well known, steel is capable of taking many degrees of "temper." Temper is an old term that no longer is quite descriptive of the condition desired or obtained, but it is sufficiently expressive of the condition desired for the purposes here. This condition is one of a certain degree of hardness—greater than that ordinarily carried by the soft steel—combined with the greatest obtainable degree of toughness. This combination of hardness and toughness produced to the proper degree resists the explosive power of the powder and also causes the wear on the gun in firing to be diminished and made as slight as possible.

To effect this combination of hardness and toughness it is necessary to take the bored and turned tubes of the guns and suspend them by means of a specially made apparatus in a furnace where they are heated for a period of perhaps eight hours to a temperature of approximately 1,500° F. or a bright-yellow color, uniform in every part of the piece.

After being subjected to this treatment for the time mentioned, the tube is then conducted by means of a traveling crane apparatus to a tank of warm water in which it is dipped and the heat rapidly taken from it down to a point of practically atmospheric temperature. This "quench" as it is called, produces the required degree of hardness called for by the ordnance officers' design; but the piece has not yet got the required degree of toughness. This toughness is now imparted to the hard piece by heating it once more in another furnace to a temperature of approximately 1,100° F., or a warm rosy red, for a period of perhaps 14 hours. From this temperature, the piece is allowed to cool naturally and slowly to the atmospheric temperature.

The ordnance inspectors at this point determine whether the piece has the required properties in a sufficient degree, by cutting from the[Pg 50] tube a piece 5 inches long and ½ inch in diameter. The ends of this piece are threaded suitably for gripping in a machine. The piece is then pulled until the half-inch stem breaks. The machine registers the amount of force required to break this piece and this gives the ordnance engineer his test as to the degree of hardness and toughness to which the piece has been brought by the heat treatment processes just described.

A satisfactory physical condition having been determined by pulling and breaking the test pieces described, the whole forging is sent to the finishing shop where it is machined to a mirror polish on all its surfaces. The diameters are accurately measured and the forgings assembled into the shape of a finished gun.

In this process there is required a different kind of care and accuracy. Up until this time the care has been to provide a metal of proper consistency and quality. From this point forward the manufacture of a gun requires the machining and fitting of this metal into a shape and form so accurate that the full strength of the gun and the best accuracy of fire may be attained.

To explain how and why hoops are placed upon the gun tubing and how the various hoops are shrunk from the outside diameter of the gun will require a few lines.

Cannon are made of concentric cylinders shrunk one upon another. The object of this method of construction is twofold. The distinctly practical object is the attainment throughout the wall of each cylinder of the soundness and uniformity of metal which is more certainly to be had in thin pieces than in thick ones; the other object is more closely connected with the theory of gun construction.

When a hollow cylinder is subjected to an interior pressure the walls of the cylinder are not uniformly strained throughout their thickness, but the layer at the bore is much more severely strained than that at the outside. This can be readily seen if we consider a cylinder of rubber, for example, with a bore of 1 inch and an exterior diameter of 3 inches, which are about the proportions of many guns. If we put an interior air pressure on the cylinder until we expand the bore to 2 inches, the exterior diameter will not thereby be increased 1 inch. But supposing that it were increased as much as the bore, that is, 1 inch, we would have the diameter, and therefore the circumference, of the bore increased 100 per cent, and the circumference of the exterior increased 33⅓ per cent. That is, the layer at the bore would be strained three times as much as that at the exterior, and the interior layer would commence to tear before that at the exterior would reach anything like its limit of strength. The whole wall of the cylinder therefore would not be contributing its full strength toward resisting the interior pressure, and there would be a waste of material as well as a loss of strength.[Pg 51] Let us now consider, instead of our simple cylinder, a built-up cylinder composed of two concentric ones, the inner one of a bore originally a little greater than 1 inch, and the outer one of exterior diameter a little less than three inches, originally; so that when the outer one is pressed over the inner one (its inner diameter being originally too small for it to go over the inner one without stretching) the bore of the inner one is brought to 1 inch, and the exterior of the outer one to 3 inches. We now have a cylinder of the same dimensions as our simple one, but in a different state; the layers of the inner one being compressed and those of the outer one extended.

If now we commence to put air pressure on the bore, we can put on a certain amount before we wipe out the compression of the inner layer, and bring it to a neutral state, and thereafter can go on putting on more pressure until we stretch the inner layer 100 per cent beyond the neutral state, as before; which would take just as much additional pressure as the total pressure which we employed with our simple cylinder. We have therefore gained all that pressure which is necessary to bring the inner layer of our built-up cylinder from its state of compression to the neutral state. If we have so proportioned the diameter of junction of our inner and outer cylinders and so gauged the amount of stretching required to get the outer one over the inner one that we have not in the process caused any of the layers of the outer one to be overstrained, the gain has been a real one, attained by causing the layers of the outer cylinder to make a better contribution of strength toward resisting the interior pressure. This is the theory of the built-up gun.

The number of cylinders employed generally increases, up to a certain limit, with the size of the gun, practical considerations governing; and the "shrinkage," or amount by which the inner diameter of the outer cylinder is less than the outer diameter of the one which it is to be shrunk over, is a matter of nice calculation. Roughly speaking, it is about one and one half one-thousandths of an inch for each inch of diameter, varying with the position of the cylinder in the gun; and its accurate attainment, throughout the length of the cylinder of a large gun, is a delicate matter of the gun-maker's art and the machinist's skill.

The method of assembly is to have the cold tube set upright and prepared for a circulation of water within the bore of the tube to keep it cool. Then the hoop, whose inside diameter is smaller than the outside diameter of the tube on which it is to be shrunk, is measured and carefully heated to a temperature of approximately 450° F., or just about the temperature of a good oven for baking or roasting. This mild temperature so expands the material in the hoop that the difference of diameter is overcome and the hot hoop is expanded to a larger inside diameter than the outside diameter of the[Pg 52] cold tube on which the hoop is to be placed. Next the hot, expanded hoop is placed in position around the breech end of the tube, and slowly and carefully cooled, so that in contracting from the high temperature to the low ordinary temperature, the hoop shrinks toward its original diameter and thus exerts an inclosing pressure or compressive strain upon the breech end of the tube.

Now when the gun is fired the tube tends to expand under the pressure and this expansion is resisted, first by the compressive force exerted by the shrunken hoop and later by the hoop itself, so that the built-up system is stronger and better able to resist the explosive charge of the burning powder than would be the case if the gun were made in one piece and of the same thickness of metal.

This brief explanation will show why so many pieces are provided for the manufacture of the finished gun and the reason for the large number of machine tools and machining operations necessary in order to carry forward the manufacture of the finished article. Sometimes one or more of the outer cylinders are replaced by layers of wire, wound under tension.

Both our 4.7-inch gun, model 1906, with which our troops have been equipped for a long time and which throws a projectile weighing 45 pounds a distance of about 6 miles, and the French 75-millimeter (2.95-inch) gun, successfully used by the French since 1897, were designed to be drawn by horses, and the guns are best used when drawn by teams of 6 or 8 horses. As the horse has a sustained pulling power of only 650 pounds, it is obvious that the weight to be drawn by the team of 6 horses must not be more than 3,900 pounds. So there is every incentive for making mobile artillery of this kind as light as possible, consistent with the strength required for the work to be done. Thus the pulling power of the horse coupled with his speed has been the limiting factor in the design and weight of mobile field artillery.

As one of our foremost United States ordnance engineers once said, "the limited power of the horse is what has governed the weight of our artillery," and that "if Divine Providence had given the horse the speed of the deer and the power of the elephant, we might have had a far wider and more effective range for our mobile artillery."

A SECTION OF THE MIDVALE STEEL CO. PLANT, SHOWING TYPES OF 6-INCH, 7-INCH, AND 8-INCH, NICKEL-STEEL, BREECH-LOADING RIFLES.

THREE FINISHED 8-INCH RIFLES, 45 CALIBERS, SET UP ON TURRET MOUNTS IN THE PLANT OF THE MIDVALE STEEL CO. WHERE THEY WERE MADE.

In the foreground are three large gun tubes partially completed. This company started the manufacture of the first piece of ordnance material in America in 1880.

[Pg 53]

One of the answers of the United States ordnance engineers to this problem, as developed in the recent war, has been the production of a tractor to replace the horse, and this tractor has the speed of the deer and the power of the elephant. The most powerful tractors are mounted on track-laying devices and are colloquially known as caterpillars. One of these powerful caterpillars, on which is mounted an 8-inch howitzer with a range of 6 miles, which is manned and operated by only two men, and which can go up hill and down hill, over broken brushwood, trees, etc., was recently given a severe test at the Aberdeen Proving Grounds. Here it was sent through a dense wood in which it bumped square into a live locust tree that was 17 inches in diameter at the bottom. This tree, almost the tallest in the wood, was prostrated by the attack of the tractor, which rode over it and then emerged from the wood, took up its position, and fired its shot almost in as short a time as that which it takes to tell of the deed. Truly the power of the elephant and the speed of the deer has been brought to the aid of the ordnance engineer for any future warlike operations.

The number of workmen employed in gun production at once in this country totaled 21,329, and fully that many more are estimated to have been employed in the manufacture of gun carriages and fire-control instruments. Consequently in turning out the complete big guns there were fully 42,000 workmen engaged by the month of October, 1918. Furthermore, these men became so skilled in their work that it may be said that the difficult art of gun making has become firmly established in this country and that the United States may now and at any time in the near future rely on this trained body of artisans for the finest kind of gun-metal manufacture.

[Pg 54]

PRODUCTION OF CANNON FORGINGS.

CANNON MACHINING AND ASSEMBLING.

Chapter III
MOBILE FIELD ARTILLERY.

The chance observer might assume that once the Ordnance Department had succeeded in putting in production the cannon of various sizes described in the preceding chapter the battle of providing artillery was as good as won. But such was not the case. Even after the ponderous tubes had come finished from the elaborate processes of the steel mills, the task of the ordnance officers had only just begun. Each one of these guns had to be rendered mobile in the field and it had to be equipped with a mechanism to take up the retrograde shock of firing (the "kick") and to prevent the weapon from leaping out of aim at each discharge.

Mobility to a gun is given by the carriage on which it rides. The device which absorbs the recoil and restores the gun to position is called the recuperator (in the case of the hydropneumatic French design) or the recoil mechanism. Carriage and recuperator, or recoil mechanism, together are known as the mount.

The forging, boring, reinforcing, machining, and finishing of the gun body is not half the battle of manufacturing a modern military weapon; it is scarcely one-third of it. No ordnance officer of 1917-18 will ever forget the heartbreaking experiences of manufacturing the mounts, a work which went along simultaneously with the production of the cannon themselves. The manufacture of carriages often presented engineering and production problems of the most baffling sort. As to the recuperators, a short analysis of the part they play in the operation of a gun will indicate something of the nature of the project of building them in quantities.

The old schoolbook axiom that action and reaction are equal has a peculiar emphasis when applied to the firing of a modern piece of high-power artillery. The force exerted to throw a heavy projectile 7 miles or more from the muzzle of a gun is equally exerted toward the breach of the weapon in its recoil. Some of these forces handled safely and easily by mechanical means are almost beyond the mind's grasp.

Not long ago a touring car, weighing 2 tons, traveled at the rate of 120 miles an hour along a Florida beach. Conceive of such a car going 337 miles an hour, which is much faster than any man ever traveled; then conceive of a mechanism which would stop this car,[Pg 57] going nearly 6 miles a minute, stop it in 45 inches of space and half a second of time, without the slightest injury to the automobile. That is precisely the equivalent of the feat performed by the recuperator of a 240-millimeter howitzer after a shot.

Conceive of a 150,000-pound locomotive traveling at 53.3 miles an hour. The action of the 240-millimeter recuperator after a shot is equivalent to stopping that locomotive in less than 4 feet in half a second without damage.

The forging for the 155-millimeter howitzer's recuperator is a block of steel weighing nearly 2 tons—in exact figures, 3,875 pounds. This must be bored and machined out until it weighs, with the accessory parts of the complete recuperator placed on the scales with it, only 870 pounds. It is scarcely fair to a modern hydropneumatic recuperator to say that it must be finished with the precision of a watch. It must be finished with a mechanical nicety comparable only to the finish of such a delicate instrument as a navigator's sextant or the mechanism which adjusts the Lick telescope to the movement of the earth. No heavy articles ever before turned out in American workshops required in their finish the degree of microscopic perfection the recuperators called for.

We adopted from the French, the greatest of all artillery builders, four recuperators—one for the 75-millimeter gun, one for the 155-millimeter gun, another for the 155-millimeter howitzer, and the fourth for the 240-millimeter howitzer. These mechanisms had never been built before outside of France. Indeed, one could find pessimists ready to say that none but French mechanics could build them at all and that our attempt to duplicate them could end only in failure. Yet American mechanical genius "licked" every one of these problems, as the men in the greasy overalls say, and did it in little more than a year of time after the plans came to the workshops. There was not one of these beautiful mechanisms, in France the product of patient handiwork on the part of metal craftsmen of deep and inherited skill, that eventually did not become in American workshops a practical proposition of quantity production.

The problem of building French recuperators in the United States, in short, may be regarded as the crux of the whole American ordnance undertaking in the war against Germany, the index of its success. It presented the most formidable challenge of all to American industrial skill. There were men whose opinion had to be considered and who were convinced that it was impracticable to attempt to produce French recuperators here. Although the superiority of these recoil devices in their respective classes were universally conceded, Germany had never been able to make them, while England, with the cooperation of the French ordnance engineers freely offered, did not attempt them. The French built them one by one, as certain custom-built[Pg 58] and highly expensive automobiles are produced. When American factories proposed to produce French recuperators not only but to manufacture them by making parts and assembling them according to the modern practice of quantity production, the ranks of the skeptics increased.

Yet, as we have said, the thing was done. The first of these recuperators ever produced outside of the French industry were produced in America and manufactured by typically American quantity methods.

The first of these recuperators to come into quantity production was that for the 155-millimeter howitzer. Rough forgings began to be turned out in heavy quantities by the Mesta Machine Co. in the spring of 1918, while the Watertown Arsenal, the other contractor, reached quantity production in rough forgings in September, 1918. At their special recuperator plant at Detroit the Dodge Bros. turned out the first finished 155-millimeter howitzer recuperator in July, 1918, and went into quantity production with them in September, producing 495 in the month of November alone, and turning out up to the end of April, 1919, the great number of 1,601 of them.

Next in order of time to be conquered as a factory problem was the 155-millimeter gun recuperator. The rough forgings at the Carnegie Steel Co., the sole contractor, were in quantity production in the spring of 1918. The first of these recuperators finished came from the Dodge plant in October, 1918; and although 30 issued from the plant and were accepted before the end of the year, quantity production may be said to have started on January 1, 1919, when the factory began producing them at the rate of more than four a day. In March the high mark of 361 recuperators was reached, and the total production up to the end of April was 880.

The heavy 240-millimeter howitzer recuperator was third to come into quantity production. The rough forgings were being turned out in quantity in the spring of 1918 by the Carnegie Steel Co., while the Watertown Arsenal, the other contractor, produced a number of these rough forgings in August, 1918. The two contractors for finishing and turning out the complete recuperators were the Otis Elevator Co., at its Chicago plant, and the Watertown Arsenal. The arsenal produced the pilot recuperator in October, 1918. In January the Otis Elevator Co. produced its first four, while quantity production began in February, 1919, both contractors that month sending out 19 recuperators, a number which may be regarded as good quantity when the size of this mechanism is taken into consideration. Both plants together in April turned out the large number of 89 recuperators for the 240.

Last to come through to quantity production was the hardest of the four to build, the one that promised to defy American industry[Pg 59] to build it at all—the 75-millimeter gun recuperator. The two contractors for the rough forgings for this recuperator were the Carbon Steel Co. and the Bucyrus Co. The Carbon Steel Co. was in large series production of them in the spring of 1918, and the Bucyrus Co. reached the quantity basis of manufacture in October, 1918. In that month alone both contractors together turned out 1,305 sets of forgings.

The machining and finishing of the 75 recuperator was in the hands of the Rock Island Arsenal and the Singer Manufacturing Co., which built a costly plant especially for the purpose at Elizabethport, N. J. The first recuperator of this size to appear and be accepted under the severe tests came from the arsenal in October. Thereafter the production ceased for a while. The contractors indeed built recuperators in this period, but the recuperators could not pass the tests. The machining and production of parts seemed to be as perfect as human skill could accomplish, but still the devices would not function perfectly. Adjustments, seemingly of the most microscopical and trivial sort, had to be made—there was trouble with the leather of the valves and with oil for the cylinders. These matters, which could scarcely cause any delay at all in the production of less delicate machinery, indicate the infinite care which had to be employed in the manufacture of the recuperators. At length the producers smoothed out the obstacles and learned all the secrets and necessary processes, and then the 75-millimeter recuperators began to come—2 in January, 1919, and then 13 in February, 20 in March, and 23 in April.

It should be remembered that by quantity production in this particular is meant the production in quantity of recuperators of such perfect quality as to pass the inspection of the Government and to be accepted as part of our national ordnance equipment. In this inspection the Government was assisted by French engineers sent from the great artillery factories in France which had designed the recuperators and which until the successful outcome of the American attempt were their sole producers. Such inspection naturally required that the American recuperators should be the equals of their French prototypes in every respect.

Because the production of French recuperators stands at the summit of American ordnance achievement, here at this point, before there is given any account of the manufacture of field artillery, the theme of this chapter, a performance table is inserted to show the records written by the various concerns engaged in making these devices.

[Pg 60]

The process of manufacture of recuperators requires four steps—forging, rough machining, finish machining, and assembling. In the case of 155-millimeter howitzer recuperators all the machining was done by one firm; in the other cases rough machining was done by various firms, including, in the case of the 155-millimeter gun and 240-millimeter howitzer recuperators, the firms doing the forging. Complete records of rough machining are not available.

[Pg 61]

In discussing here, therefore, the production of field artillery in the war period, we are concerned chiefly with carriages and recuperators, for they offered the major difficulties. Since the production of gun bodies for these various units has been taken up in the preceding chapter, such reference to them as is necessary will be brief. For the sake of additional clearness in the mind of the reader inexpert in these things, the line should be sharply drawn between field artillery and the so-called railway artillery, which was also mobile to a limited degree. The mobile field artillery consisted of all rolling guns or caterpillar guns up to and including the 240-millimeter howitzer in size; and also included the antiaircraft guns of various sizes. All mobile guns of larger caliber than the 240-millimeter howitzer were mounted on railroad cars.

The list of the mobile field artillery weapons in manufacture here during the war period was as follows:

The little 37-millimeter gun, the so-called infantry cannon, one of which two husky men could lift from the ground—a French design;

The 75-millimeter guns—three types of them—the French 75, adopted bodily by the United States; our own 3-inch gun redesigned to the French caliber; and the British 3.3-inch gun, similarly redesigned;

The 4.7-inch gun of American design;

The 5-inch and 6-inch guns, taken from our coast defenses and naval stores and placed on mobile mounts;

The 155-millimeter gun, a French weapon with a barrel diameter of approximately 6 inches;

The 155-millimeter howitzer, also French;

The 8-inch and 9.2-inch howitzers, British designs, being manufactured in the United States when war was declared;

The 240-millimeter howitzer, French and American; and, finally,

The antiaircraft guns.

In modern times, but prior to 1917, the United States had designed types of field-artillery weapons and produced them in quantities shown by the following tabulation:

A comparison of this list with the enumeration above of weapons put in production during the war against Germany indicates that we greatly expanded our artillery in types. That we were able to do this at the outset and go ahead immediately with the production of many weapons strange and unknown to our experience, without[Pg 62] waiting to develop models and types of our own, is due solely to the generosity of the governments of France and Great Britain, with whom we became associated. We manufactured in all eight new weapons, taking the designs of three of them from the British and of five from the French.

It might seem to the uninitiated that the way of the United States to a great output of artillery would be made smooth by the action of the British and French Governments in agreeing to turn over to us without reservation the blue prints and specifications that were the product of years of development in their gun plants. Yet this was only relatively true. In numerous instances we were not able to secure complete drawings until months after we had entered the war, due to the practice of continental manufacturers that intrusts numerous exact measurements to the memories of the mechanics working in their shops. Consequently it required several months to complete drawings, and when we received them our troubles had only begun.

First there came the problem of translating the plans after we received them. All French dimensions are according to the metric system. A millimeter is one one-thousandth part of a meter, and a meter is 39.37 inches. An inch is approximately 0.0254 meter. Thus to translate French plans into American factory practice involves hundreds of mathematical computations, most of them carried out to decimals of four or five places. Moreover, the French shop drawings are put down on an angle of projection different from what is used in this country. This fact involved the recasting of drawings even when the metric system measurements were retained. When it is considered that such a mechanism as the recuperator on the 155-millimeter gun involves the translation of 416 drawings, the fact that the preparation of French plans for our own use never took more than two months is remarkable, particularly so since it was hard to find in the United States draftsmen and engineers familiar with such translation work.

Once our specifications were worked out from the French plans, it then became necessary to find American manufacturers willing to bid on the contracts. The average manufacturer would look at these specifications, realize what a highly specialized and involved sort of work would be required in the production of the gun carriages or recoil mechanisms, and shake his head. In numerous instances no such work had ever before been attempted in the United States.

However, as the result of efforts on the part of the Government an increased capacity for producing mobile field artillery was created as follows:

At Watertown, N. Y., the New York Air Brake Co., as agent for the United States, constructed a completely new factory to turn out[Pg 63] 25 gun carriages a month for the 75-millimeter guns, model 1916—the American 3-inch type modified to the French dimensions.

At Toledo, Ohio, increased facilities were put up at the plant of the Willys-Overland Co. to manufacture a daily output of 17 French 75-millimeter gun carriages, model 1897.

At Elizabethport, N. J., the Singer Manufacturing Co. erected for the Government a complete new factory for finishing daily 17 French 75-millimeter recuperators.

At New Britain, Conn., the plant of the New Britain Machine Co. was adapted and increased facilities were created for the manufacture of two 3-inch antiaircraft gun carriages a day.

At Detroit, Mich., Dodge Bros., as agents for the Government, erected an entirely new factory, costing in the neighborhood of $11,000,000 to give the final machining to the rough-machine forgings for five recuperators daily for the 155-millimeter gun and to machine completely the parts for twelve recuperators daily for the 155-millimeter howitzer. Their huge new plant for this purpose established a record for rapidity of construction in one of the most severe winters of recent history.

At the plant of the Studebaker Corporation at Detroit, facilities were extended for turning out three carriages a day for the 4.7-inch guns.

At Plainfield, N. J., extended facilities were created at the factory of the Walter Scott Co. for manufacturing 20 carriages a month for the 4.7-inch guns.

At Worcester, Mass., at the plant of the Osgood Bradley Car Co. increased facilities were built for the daily manufacture of five carriages for the 155-millimeter howitzers.

At Hamilton, Ohio, at the works of the American Rolling Mill Co., extensions were made to provide for the manufacture each day of three carriages for the 155-millimeter howitzers.

The plant of the Mesta Machine Co., at West Homestead, Pa., near Pittsburgh, was extended to the enormous capacity of turning out the forgings for 40 recuperators a day for the 155-millimeter howitzers.

Extensively increased facilities were made at the shops of the Standard Steel Car Co., at Hammond, Ind., for the daily output of two carriages for the 240-millimeter howitzers.

Increased facilities were created in the plant of the Otis Elevator Co., Chicago, Ill., for the finish machining of the equivalent in parts of two and one-half recuperators a day for the 240-millimeter howitzers.

Large extensions were made to the plant of the Morgan Engineering Co., Alliance, Ohio, for the manufacture monthly of 20 improvised mounts for the 6-inch guns taken from the seacoast fortifications.

[Pg 64]

The facilities of the United States arsenals at Watertown, Mass., and at Rock Island, Ill., for the manufacture of field-gun carriages and recuperators were greatly increased.

This carriage construction for the big guns required the closest kind of fine machine work and fittings where the brake or recuperator construction entered the problem, and the great plants built for this purpose of turning out carriages and recuperators were marvels for the rapidity of their construction, the speed with which they were equipped with new and intricate tools, and the quality of their output.

Every mobile gun mount must be equipped with a shield of armor plate. The size of the artillery project may be read in the fact that our initial requirement for armor for the guns ran to a total of 15,000 tons to be produced as soon as it could be done. Now, we had no real source for getting armor in such large quantities, because the previous demands of our artillery construction had never called for it. The prewar manufacturers of artillery armor were three in number—the Simmons Manufacturing Co., of St. Louis; Thomas Disston & Sons, of Philadelphia; and the Crucible Steel Co. To meet the new demand two armor sources were developed—the Mosler Safe Co. plant of the Standard Ordnance Co. and the Universal Rolling Mill Co. The process of building this armor had been a closely guarded secret in the past, a fact entailing extended experiments in the new plants before satisfactory material could be obtained.

The new artillery program required the manufacture of 120,000 wheels of various types and sizes for the mobile carriages. The Rock Island Arsenal and two commercial concerns prior to the war had been building artillery wheels in limited quantities. One completely new plant had to be erected for the manufacture of wheels, while seven existing factories were specially equipped for this work. We had to develop new sources of supply of oak and hickory and to erect dry kilns especially for the wheel project.

The largest order for rubber tires in the history of the American rubber industry was placed as one relatively small phase of the artillery program, the order amounting to $4,250,000. Rubber tires on the wheels of all the heavier types of artillery carriages, so that the units might be drawn at good speed by motor vehicles, was essentially an American innovation. No tires of this size had ever been manufactured in this country. Consequently it was necessary for the firms who got the orders to build machinery especially designed for the purpose.

With practically all of the manufacturers of the American metal-working industries clamoring for machine tools, and with some branches of the Government commandeering the machine-tool shops in whole sections of the country, it is evident that the necessity for the heavier types of machine tools required by the manufacturers of[Pg 65] artillery material offered a weighty problem at the outset. In fact, the machine-tool supply was never adequate at any time, and the shortage of this machinery hampered and impeded to a great degree the speed of our artillery production.

The Nation was raked with a fine-toothed comb for shop equipment. The Government went to almost any honorable length to procure this indispensable tooling. For instance, when the Dodge plant at Detroit was being equipped to manufacture the 155-millimeter recuperators, the Government agents discovered trainloads of machinery consigned to the Russian government and awaiting shipment. These tools were commandeered on the docks. One huge metal planer had dropped overboard while it was being lightered to the ocean tramp that was to carry it to a Russian port. Government divers fixed grappling hooks to this machine, and it was brought to the surface and shipped at once to the Dodge plant.

The 3-inch gun which we had been building for many years prior to the war was a serviceable and efficient weapon; but still we were unable to put it into production immediately as it was. Our earliest divisions in France, under the international arrangement, were to be equipped by the French with 75-millimeter guns; while we, on this side of the water, reaching out for all designs of guns of proven worth, expected to manufacture the 75's in large numbers in this country. The French 75 in its barrel diameter is a fraction of an inch smaller than our 3-inch gun, the exact equivalent of 75 millimeters being 2.95275 inches. Thus, if we built our own 3-inch gun (and the British 3.3-inch gun, as we intended) and also went ahead with the 75-millimeter project on a great scale, we should be confronted by the necessity of providing three sorts of ammunition of almost the same size, with all the delays and confusion which such a situation would imply. Consequently we decided to redesign the American and British guns to make their bores uniformly 75 millimeters, thus simplifying the ammunition problem and making available to us in case of shortage the supplies of shell of this size in France.

With all of the above considerations in mind, it is evident now, and it was then, that we could not hope to equip our Army with American-built artillery as rapidly as that Army could be collected, trained, and sent to France; and this was particularly true when in the spring of 1917 the Army policy was changed to give each 1,000,000 men almost twice as many field guns as our program had required prior to that date. Consequently, when on June 27, 1917, the Secretary of War directed the Chief of Ordnance to provide the necessary artillery for the 2,000,000 men who were to be mobilized in 1917 and the first half of 1918, the first thought of our officers was to find outside supplies of artillery which we could obtain for an emergency[Pg 66] that would not be relieved until our new facilities had reached great production.

We found this source in France. The French had long been the leading people in Europe in the production of artillery, and even the great demands of the war had not succeeded in utilizing the full capacity of their old and new plants. Two days later, on June 29, 1917, the French high commissioner, by letter, offered us in behalf of France a daily supply of five 75-millimeter guns and carriages, beginning August 1, 1917. The French also offered at this time to furnish us with 155-millimeter howitzers; and on August 19, 1917, the French Government informed Gen. Pershing that each month, beginning with September, he could obtain twelve 155-millimeter Filloux guns and carriages from the French factories.

Before the signing of the armistice 75-millimeter guns to the number of 3,068 had been ordered from the French, and of this number 1,828 had been delivered. Of 155-millimeter howitzers, 1,361 had been ordered from the French and 772 delivered before November 11, 1918. Of 155-millimeter guns, 577 had been ordered from the French and 216 delivered previous to the granting of the armistice.

From British plants we ordered 212 Vickers-type 8-inch howitzers, and 123 had been delivered before the armistice had been signed; while of 9.2-inch howitzers, Vickers model, 40 of an order for 132 had been completed. In addition to this, 302 British 6-inch howitzers were in manufacture in England for delivery to us by April 1, 1919. These figures, with the exception of those relating to the order for British 6-inch howitzers, do not include the arrangements being made by this Government during the last few weeks of hostilities for additional deliveries of foreign artillery.

As to our own manufacture of artillery, when we had conquered all the difficulties—translated the drawings, built the new factories, equipped them with machine tools and dies, gages, and other fixtures needed by the metal workers, and had mobilized the skilled workers themselves—we forged ahead at an impressive rate. When the armistice was signed we were turning out 412 artillery units per month. Compare this with Great Britain's 486 units per month in the fall of 1918 and measure our progress, remembering that England had approximately three years' head start. Compare it with the French monthly production of 659 units per month, and remember that France was the greatest artillery builder in the world. When it came to the gun bodies themselves we obtained a monthly output of 832, as against Great Britain's 802 and France's 1,138. And our artillery capacity was then, in the autumn of 1918, only coming into production.

In the war period—April 6, 1917, to November 11, 1918—we produced 2,008 complete artillery units, as against 11,056 turned out by[Pg 67] France and 8,065 completed by Great Britain in the same period. In those 19 months we turned out 4,275 gun bodies, while in the same months France produced 19,492 and Great Britain 11,852.

THE 37-MILLIMETER INFANTRY FIELD GUNS

The smallest weapon of all the field guns we built was the French 37-millimeter gun, the diameter of its bore being about 1½ inches in our measurements, the figure being 1.45669 inches. This was the so-called infantry field gun, to be dragged along by foot soldiers when they are making an advance. Its chief use in the war was in breaking up the German concrete pill boxes, machine gun nests, and other strong points of enemy resistance. In service it was manned by infantrymen instead of artillerists, a crew of eight men handling each weapon, the squad leader being the gunner. One of the men of the crew was the loader, and he was likewise able to fire the piece. The other six men served as assistants.

The 37-millimeter outfit as it exists to-day consists of the gun, with a split trail, mounted on axle and wheels. By means of a trailer attachment on the ammunition cart it can be drawn by one horse or one mule. The ammunition cart itself is merely a redesigned machine-gun ammunition vehicle. The wheels and axle can easily be removed and left a short distance in the rear of the place where it is desired to set up the gun. The whole outfit weighs only 340 pounds and is about 6 feet long.

The gun rests on its front leg which is dropped to form a tripod with the two legs of the split trail. The gun proper can be removed from the trail and the sponge staff can be inserted in the barrel through the opened breech. Two men can bear this part of the weapon in advancing action. Two other men are able to carry the trail, when its legs are locked together, while the four other members of the squad bring along the boxes of ammunition.

The ammunition cart holds 14 ammunition boxes, each containing 16 rounds. A spare-parts case, strapped to the trail, contains a miscellaneous assortment of such parts as can readily be handled in the field. A tool kit in a canvas roll is also transported on the cart, along with entrenching tools and other accessories.

Equipped with a telescopic sight for direct fire and a quadrant, or collimating sight, for indirect fire, great accuracy is obtained by this small piece of artillery. The length of the barrel of the gun proper is 20 calibers, which means that it is 20 times 37 millimeters in length, or about 29 inches. The length of the recoil when the gun is fired is 8 inches.

Two types of ammunition were provided for this gun at first; but, as the low-explosive type was not so effective as desired, it was[Pg 68] abandoned entirely in favor of the high-explosive type contained in a projectile weighing 1¼ pounds. This projectile is loaded with 240 grains of T. N. T. and detonated by a base percussion fuse. The range of the gun is 3,500 meters, or considerably more than 2 miles. Only three to six shots from this gun were found to be necessary to demolish an enemy machine gun emplacement or other strongly held position.

In the great war the 37-millimeter gun found itself and proved its usefulness. The original model had been designed at the Puteaux Arsenal in France in 1885; but it was not until after 1914 that the weapon was produced in quantities.

In this country we took up the production of 37-millimeter guns in October, 1917. While our shops were tooling up for the effort, 620 of these weapons were purchased from the French and turned over to the American Expeditionary Forces. For the purposes of greater speed in manufacture our executives took the gun apart and divided it into three groups, known as the barrel group, the breech group, and the recoil group. Additional to these, as a manufacturing proposition, were the axle and wheels and the trail.

The barrel group went to the Poole Engineering & Machine Co., of Baltimore, Md., who subcontracted for some of the parts to the Maryland Pressed Steel Co., of Hagerstown, Md. The breech group was manufactured by the Krasberg Manufacturing Co., of Chicago. The C. H. Cowdrey Machine Works, of Fitchburg, Mass., turned out the recoil mechanisms. The axles and wheels were built by the International Harvester Co., of Chicago. The trails were turned out by the Universal Stamping & Manufacturing Co., also of Chicago.

When crated for overseas shipment, the gun, ammunition cart, and all accessories, weighed 1,550 pounds and occupied about 15 cubic feet of space.

The first delivery of completed 37-millimeter guns from our factories was made in June, 1918, and at the cessation of hostilities manufacturers were turning out the guns at the rate of 10 per day. Between June and November 122 American-built 37-millimeter guns were shipped abroad, and more were ready to be sent over when the armistice was signed. The gun had been so successful in use abroad that our original order of 1,200 had been increased to 3,217 before the signing of the armistice, including the 620 purchased from the French.

The various groups of this gun were shipped to the plant of the Maryland Pressed Steel Co., Hagerstown, Md., for assembly and were there tested at a specially built proving ground, 8 miles from the factory.

Three 37's were issued to each infantry regiment, making one for each battalion. The required equipment for a division was, therefore, 12 weapons.

THE 37-MILLIMETER INFANTRY CANNON.

TWO VIEWS OF 75-MILLIMETER FIELD GUN, MODEL 1918 (AMERICAN).

[Pg 69]

THE 75-MILLIMETER GUNS.

Next in order in the upward scale of sizes we come to the 75-millimeter gun, which was by far the most useful and most used piece of artillery in the great war. In fact the American artillery program might be divided in two classes, the 75's in one class, and all other sizes in the other, since it may be said practically that for every gun of another size produced we also turned out a 75. In number the 75's made up almost half of our field artillery. The 75-millimeter gun threw projectiles weighing between 12 and 16 pounds and it had an effective range of over 5½ miles.

We approached the war production of this weapon with three types available for us to produce—our own 3-inch gun; its British cousin the 3.3-inch gun or 18-pounder; and the French 75-millimeter gun, with its bore of 2.95275 inches. The decision to adopt the 75-millimeter size and modify the other two guns to this dimension, giving us interchangeability of ammunition with the French, was an historic episode in the American ordnance development of 1917.

While in 1917 the French with their excess manufacturing capacity began work on our first orders for 1,068 guns of this size to supply our troops during the interim until American factories could come into production, we were preparing our factories for the effort. Roughly speaking the 75 consists of a cannon mounted on a two-wheeled support for transportation purposes. This support also provides a means for aiming by suitable elevating and traverse mechanisms. As previously explained, a recoil mechanism is also provided to absorb the shock of firing, allowing a certain retrograde movement of the cannon and then returning it in position for the next shot—returning it "into battery," as the artillerists say. By its recuperator device the field gun of to-day is chiefly distinguished from its brother of the latter part of the nineteenth century. Without a recuperator the gun would leap out of aim at each shot and would have to be pointed anew; but one with a recuperator needs to be pointed only at the beginning of the action.

When we entered the war we found ourselves with an equipment of 544 field guns of the old 3-inch model of 1902. This gun had a[Pg 70] carriage provided with the old-style single trail. By 1913, however, we had been experimenting with the split trail and it had been strongly recommended by our ordnance experts; and in 1916 we had placed orders for nearly 300 carriages of the split-trail type, which had come to be known as Model 1916. Of these orders 96 carriages were to come from the Bethlehem Steel Co., and the remainder from the Rock Island Arsenal.

Meanwhile for some time the Bethlehem Steel Co. had been engaged in turning out carriages for the British 3.3-inch guns. Here was capacity that might be utilized to the limit; and, accordingly, in May, 1917, we ordered from the Bethlehem Co. 268 of the British carriages. At the same time we ordered from the same company approximately 340 of our own Model 1916 carriages at a cost of $3,319,800. A few weeks later the decision had been made to make all our guns of this sort conform to the French 75-millimeter size, and these British and American carriages contracted for in May were ordered modified to take 75-millimeter guns. The carriages needed little modification and the guns not much. Subsequently, in rapid succession we placed orders with the Bethlehem Steel Co., calling for the construction of an additional 1,130 of the British carriages, all of them to be adapted to 75-millimeter guns.

Next it was the concern of the Ordnance Department to find other facilities for manufacturing carriages for these weapons. The artillery committee of the Council of National Defense located the New York Air Brake Co. as a concern willing to undertake this work; and in June, 1917, this company signed a contract to produce 400 American model 1916 carriages at a cost of $3,250,000.

By December we had the drawings for the French carriages of this size and made a contract with the Willys-Overland Motor Car Co. to produce 2,927 of them. The table at the end of this section shows the production attained at these various plants.

The manufacture of carriages for the 75's produced concrete results, as our factories here were turning them out for us at the rate of 393 per month when the fighting ceased, and our contract plants in France were making 171 per month. In all we received from American factories 1,221 carriages. At the rate of increase we would have been building 800 carriages per month by February, 1919.

It may be said we were thoroughly impressed with the difficulties attached to the transplanting to this country of the manufacture of French 75-millimeter recuperators. It was a question whether this device could possibly be built by any except the French mechanics trained by long years in its production. At first it seemed that we could secure no manufacturer at all who would be willing to assume such a burden. Not until February, 1918, were complete drawings and specifications of the recuperator received from France. At length the Singer Manufacturing Co., builders of sewing machines, consented to take up this new work, and on March 29 the company contracted to produce 2,500 recoil systems for the 75-millimeter gun carriages. In April, 1918, the Rock Island Arsenal was instructed to turn out 1,000 of these recuperators.

TWO VIEWS OF THE FRENCH 75-MILLIMETER GUN.

This type of gun has been used by the French Army since 1897, and was the gun most used by the Allies in the Great War. This gun throws a shell weighing 12.3 pounds a distance of 8,400 meters or shrapnel weighing 16 pounds a distance of 9,000 meters. The weight of the gun and carriage is 2,657 pounds. The service muzzle velocity of the shell is 1,805 feet per second, while for shrapnel it is 1,755 feet per second.

THE 75-MILLIMETER FIELD GUN, MODEL 1917 (BRITISH).

This gun throws a shell weighing 12.3 pounds a distance of 8,300 meters, and 16 pounds of shrapnel a distance of 8,900 meters. The weight of the gun and carriage is 2,887 pounds. Its muzzle velocity for shell is 1,750 feet a second and for shrapnel 1,680 feet a second.

[Pg 71]

The production of gun bodies for the 75-millimeter units was quite satisfactory. The Bethlehem Co., the Wisconsin Gun Co., the Symington-Anderson Co., and the Watervliet Arsenal were the contractors who built the gun bodies. Gun bodies of three types, but all of the same 75-millimeter bore, were ordered—the American type (the modified 3-inch gun), the British type (the modified 3.3-inch gun), and the French type.

Our ordnance preparation would have given us enough 75's for the projected army of 3,360,000 men on the front in the summer of 1919, together with appropriate provision for training in the United States. Of the 75's built in this country, 143 units were shipped to the American Expeditionary Forces before the armistice went into effect. Meanwhile the French had delivered to our troops 1,828 units of this size. The total equipment of 75's for our Army in France from all sources thus amounted to 1,971 guns with their complete accessories.

4.7-INCH GUNS.

In the 4.7-inch field gun, model of 1906, America took to France a weapon all her own. It was a proven gun, too, developed under searching experiments and tests. There were 60 of these in actual service when we got into the war. The 4.7-inch guns, with their greater range and power, promised to be particularly useful for destroying the enemy's 77-millimeter guns.

[Pg 72]

The carriage model of 1906 for the 4.7-inch gun is of the long recoil type, the recoil being 70 inches in length. The recoil is checked by a hydraulic cylinder, and a system of springs thereupon returns the gun to the firing position. The gun's maximum elevation is 15 degrees, at which elevation, with a 60-pound projectile, the gun has a range of 7,260 meters, or 4½ miles. With a 45-pound projectile a range of 8,750 meters, or nearly 5½ miles, can be obtained at 15 degrees elevation. It is possible to increase this range to about 10,000 meters, or well over 6 miles, by depressing the trail into a hole prepared for it, a practice often adopted on the field to obtain greater range. The total weight of the gun carriage with its limber is about 9,800 pounds.

An order for 250 of the 4.7-inch carriages was placed with the Walter Scott Co., at Plainfield, N. J., July 12, 1917, upon the recommendation of committees of the Council of National Defense, who were assisting the Ordnance Department in the selection of industrial firms willing to accept artillery contracts. Of the 250 ordered from this concern, 49 were delivered up to the signing of the armistice.

The Rock Island Arsenal had also been employed previously in turning out 4.7-inch carriages; and the capacity of that plant, although small, was utilized. Under the date of July 23, 1917, the arsenal was instructed to deliver 183 carriages. Late in December, 1917, the Studebaker Corporation was given an order for 500. On September 30, 1918, Rock Island Arsenal was given an additional order for 120 carriages, while the Studebaker order was reduced to 380. Additional plant facilities had to be provided at both the Walter Scott Co. and the Studebaker Corporation.

Up to December 12, 1918, a total of 381 carriages of the 4.7-inch type had been completed and delivered. These carriages included the recoil mechanism. In the month of October, 1918, alone, 113 were produced, and this rate would have been continued had the armistice not been signed.

Cannon for the 4.7-inch units were turned out at the Watervliet Arsenal and the Northwestern Ordnance Co., Madison, Wis. Deliveries from the Watervliet Arsenal began in June, 1918, totaling 120 up to December, while the Northwestern Ordnance Co., starting its deliveries in August, had completed 98 by December.

Up to the 15th of November, 64 complete 4.7-inch units had been floated for our forces overseas.

Forgings for the 4.7-inch gun cannon were made by the Bethlehem Steel Co. and the Heppenstall Forge & Knife Co., of Pittsburgh, Pa.

Owing to the great difference in cross section between muzzle and breech end of the jacket, great difficulty was experienced in the heat treatment of these forgings, particularly on the part of manufacturers who had had no previous experience in the production of gun forgings.

FRONT AND REAR VIEWS OF OUR 4.7-INCH GUN AND CARRIAGE, MODEL 1906, WITH WHICH OUR TROOPS HAVE BEEN EQUIPPED FOR A LONG TIME.

This gun throws a projectile weighing 45 pounds a distance of about 6 miles.

TWO VIEWS OF 155-MILLIMETER GUN, MODEL 1918, G. P. F.

The upper view shows the piece mounted on an auto truck for quick moving about.

[Pg 73]

In order to produce enough forgings to supply the finish-machining shops, an order for 50 jackets was later given to the Edgewater Steel Co., of Pittsburgh, Pa., where the jackets were forged. These were then sent to the Heppenstall Forge & Knife Co. for rough machining and finally returned to the Edgewater Steel Co. for heat treating. An order for 150 jackets was also given to the Tacony Ordnance Corporation.

Shortly before the signing of the armistice, the jacket was redesigned so that the heavy breech end was forged separately in the shape of a breech ring. This design, however, was not produced.

It was desired to develop a 4.7-inch gun carriage having the characteristics of the split-trail 75-millimeter gun carriage, model of 1916, so that greater elevation and wide traverse could be obtained. The Bethlehem Steel Co. was given a small order for 36 carriages of their own design prior to the war, and their pilot carriage had been undergoing tests at the proving ground. The design was, however, not sufficiently advanced to be used in the war.

Sixteen of these units, also 48 which were previously on hand, were floated for overseas up to November 11, 1918.

THE 5-INCH AND 6-INCH GUN MOUNTS.

In the war emergency America sought to put on the front every pound of artillery she could acquire from any source whatsoever. Accordingly, before any of the manufacturing projects were even started, the Ordnance Department conducted a preparedness inventory of the United States to see what guns already in existence we might find that could be improvised for use as mobile artillery in France. The search discovered a number of heavy cannon that could serve the purpose—part of them belonging to the Army, these being the guns at our seacoast fortifications; part belonging to the Navy, in its stores of supplies for battleships; and part of them being[Pg 74] the property of a private dealer, Francis Bannerman & Son, of New York.

The guns for this improvised use were obtained as follows:

From the Coast Artillery, a branch of the Army, we obtained ninety-five 6-inch guns, 50 calibers in length, and twenty-eight 5-inch guns, 44.6 calibers; from the Navy stores came forty-six 6-inch guns, ranging from 30 to 50 calibers in length; from Francis Bannerman & Son, thirty 6-inch guns, 30 calibers long. This was a total of 199 weapons of great destructive power, awaiting only suitable mobile mounts to make them of valiant service on the western front. It was the task of the Ordnance Department to take these guns and as swiftly as possible mount them on field artillery carriages of an improvised type that could be most quickly built.

Minor changes had to be made on many of the guns obtained in this manner in order to adapt them for use on field artillery carriages. The various seacoast guns were retained as they were in length, because it was planned to return them eventually to the fortifications from which they had been taken. The Navy guns, all of the 6-inch size, were shipped to the Watervliet Arsenal to be cut down to a uniform length of 30 calibers.

The need for speed in manufacture demanded that the carriages for these guns should be of the simplest design consistent with the ruggedness required for field operations and the accuracy necessary for effectiveness. When tests of the first carriages produced were made it was found that requirements had been more than met.

Orders were placed on September 24, 1917, with the Morgan Engineering Co., of Alliance, Ohio, for 70 mounts for the 6-inch units. A few days later this number was increased to 74, while on the 28th of September, 1917, the same company was given an order for 18 additional 6-inch gun mounts and 28 mounts for the 5-inch guns. Orders for limbers were placed with the same company on December 1.

It was soon discovered that big transport wagons would be required to carry the long 6-inch seacoast guns separately because of their great weight. On February 15, 1918, the Morgan Engineering Co. was ordered to build these necessary transport wagons.

Difficulties in securing skilled labor, necessary materials, and tools delayed production of these mounts, but the eighteen 6-inch gun mounts ordered September 28, 1917, were completed in March, 1918, while the twenty-eight 5-inch gun mounts ordered on the same date were finished in April. In August, 1918, the seventy-four 6-inch gun mounts were turned out. The production of an additional order for thirty-seven 6-inch gun mounts was just beginning when the armistice was signed.

[Pg 75]

The 6-inch gun carriage, bearing the gun, weighs about 41,000 pounds. A maximum range of over 10 miles can be obtained by this weapon. The complete 5-inch gun unit weighs about 23,500 pounds and has a maximum range of more than 9 miles. In understanding the difficulties that faced the Ordnance Department in building carriages for these guns, it should be recalled that these big weapons were originally built for fixed-emplacement duty and were therefore much heavier than mobile types. This fact complicated the problem of designing the wheeled mounts. They proved to be more difficult to maneuver than the lighter types of guns.

155-MILLIMETER HOWITZERS.

It is a testimonial to the adaptability and skill of American industry that we were able to duplicate successfully in this country the celebrated 155-millimeter howitzer, before 1917 built only in the factory of its original designer, the great firm of Schneider et Cie., in France. This powerful weapon is a fine example of the French gun builders' art, in a country where the art of gun-making has been carried to a perfection unknown anywhere else.

The 155-millimeter howitzer's history dates back to the nineteenth century. In its development the French designers had so strengthened its structure, increased its range, and improved its general serviceability, that in 1914 it was ready to take its place as one of the two most-used and best-known weapons of the allies, the other being the 75-millimeter field gun.

As thus perfected the howitzer weighs less than 4 tons and is extremely mobile for a weapon of its size. It can hurl a 95-pound projectile well over 7 miles and fire several times a minute. The rapidity of fire is made possible by a hydropneumatic recoil system that supports the short barrel of the gun and stores up the energy of the recoil by the compression of air. With the gun pointing upward at an angle of 45 degrees, the recoil mechanism will restore it into battery in less than 13 seconds. The carriage of the gun is extremely light, being built of pressed steel parts that incorporate many ingenious features of design to reduce the weight. The shell and the propelling charge of powder are loaded separately.

[Pg 76]

The American-built 155-millimeter howitzer was practically identical with that built in France. Any of the important parts of the American weapon would interchange with those which had come from the Schneider factory. We equipped the wheels of our field carriage, however, with rubber tires, and gave the gun a straight shield of armor plate instead of a curved shield.

In the spring of 1917 we bought the plans of the howitzer from Schneider et Cie. and began at once the work of translating the specifications into American measurements. This work monopolized the efforts of an expert staff until October 8, 1917.

In order to facilitate the reproduction here, we divided the weapon, as a manufacturing proposition, into three groups—the cannon itself, the carriage, and the recuperator or recoil system—and placed each group in the hands of separate contractors. There was, of course, the usual difficulty in finding manufacturers willing to undertake production of such an intricate device and who also possessed machine shops that had the equipment and talent required for such work, and in procuring for these shops the highly specialized machinery that would be necessary.

The American Brake Shoe & Foundry Co., of Erie, Pa., whose magnificent work in building a special plant has been described in the preceding chapter, took an order in August, 1917, for 3,000 howitzer cannon and by October, 1918, was producing 12 of them every day. The company turned out its first cannon in February, 1918, approximately six months after receiving the contract, having in the interim built and equipped a most elaborate plant. It is doubtful if the annals of industry in any country can produce a feat to match this.

In fact, the production of cannon by the Erie concern so outstripped the manufacture of carriages and other important parts for the howitzer that it was possible by September, 1918, for us to sell 550 howitzer bodies to the French Government. When the armistice was signed on November 11, 1918, the company had completed 1,172 cannon.

In November, 1917, we placed orders for 2,469 carriages for this weapon, splitting the order between the Osgood-Bradley Car Co., of Worcester, Mass., and the Mosler Safe Co., of Hamilton, Ohio. Then followed a long battle to secure the tools and equipment, the skilled mechanical labor, and the necessary quantities of the best grades of steel and bronze, an effort in which the contracting companies were at all times aided by the engineers of the Ordnance Department. All obstacles were overcome and the first carriages were ready for testing in June, 1918. When the armistice was signed 154 carriages had been delivered, and production was moving so rapidly that one month later this number had been run up to 230.

[Pg 77]

The limbers were manufactured by the Maxwell Motor Car Co., which had orders to turn out 2,575 of them. The first deliveries of limbers came in September, 1918, and seven a day were being turned out in October, a total of 273 having been completed by the day of the armistice. A month later the number of completed limbers totaled 587.

It was in the making of the recuperator systems that the greatest problems were presented. No mechanism at all similar to this had ever been made in this country. No plant was in existence here capable of turning out such a highly complicated, precise, and delicate device.

Finally, after much Governmental search and long negotiation, the Dodge Bros., of Detroit, motor car builders, agreed to accept the responsibility. In this effort they built and equipped the splendid factory, costing $10,000,000, described elsewhere.

This howitzer recuperator is turned out from a solid forging, weighing 3,875 pounds, but the completed recuperator weighs only 870 pounds. Each cylinder must be bored, ground, and lapped to a degree of fineness and accuracy that requires the most painstaking care.

Difficulties of almost every sort were experienced with the forgings and other elements of the recuperators. The steel was analyzed and its metallurgical formulas were changed. The work of machining proceeded favorably until the very last operation—that of polishing the interior of the long bores to a mirrorlike glaze and still retaining the extreme accuracy necessary to prevent the leakage of oil past the pistons. Such precision had been theretofore unknown in American heavy manufacture. Until the many processes could be perfected, the deliveries were held back.

Even with the delivery of the first recuperator, difficulties did not vanish. This mechanism has no adjustments which can be made on the field, but depends for its wonderful operation upon the extreme nicety of the relation of its parts. It required the alteration of certain small parts before the first trial models could be made to function.

However, all obstacles and difficulties were finally overcome, and in the plant that had been erected during the bitter cold of one of our severest winters, and with practically entirely new machinery and workmen, production got under way, and the first recuperator was delivered early in July, 1918, nine months after the contract was signed. Production in quantity began to follow shortly after that month, and by November an average of 16 recuperators a day was being turned out. Of the 3,120 recuperators contracted for, 898 had been finished when the armistice was signed, and this quantity was increased to 1,238 one month later.

[Pg 78]

The steel required for the recuperators in these 155-millimeter howitzers, and also for those of the 155-millimeter guns, was of special composition; yet all the forge capacity in this country was being utilized in other war manufacture. New facilities for the manufacture of these forgings had to be developed by increasing the capacity of the Mesta Machine Co. of Pittsburgh, until it could meet our requirements. The Government itself contracted for these forgings and supplied them to Dodge Bros.

Each howitzer required some 200 items of miscellaneous equipment, such as air and liquid pumps and other tools. These were purchased from many sources, and many of these contractors had just as much difficulty with the small parts as the larger firms had with the more important sections of the howitzers.

Many of the problems involved in turning out the complete unit could not be known or understood until they were met with in actual manufacture. Mechanical experts representing Schneider et Cie. were on hand at all times to help solve difficulties as they arose.

The Government turned to France for an auxiliary supply of carriages for the American-built howitzers, placing orders for 1,361 with French concerns. Of this number 772 had been completed when the armistice was signed, and the French expected soon to turn out the carriages at the rate of 140 per month. It might also be noted here that we placed an order in England for 302 British 6-inch howitzers, a piece very like the French howitzer. The British contract was to be completed April 1, 1919.

The various parts of the 155-millimeter howitzer were assembled into complete units and tested at the Aberdeen Proving Grounds. After being assembled and tested, the whole unit was taken apart and packed into crates especially designed for overseas shipment. One crate held two howitzer carriages with recuperators in less space than would have been occupied by one carriage on its wheels.

It will be noted that the first gun body of the 155-millimeter howitzers made in this country was delivered in February and the first recuperator in July. Before the recuperators were ready, the other parts of the howitzer had been proof-tried by using a recuperator of French manufacture.

During the months of August and September, 1918, the first regiment equipped with 155-millimeter howitzers was made ready at Aberdeen. The big weapons were packed and on the dock for shipment overseas when the armistice was signed. These first ones were to be followed by a steady stream of howitzers. All arrangements had been made to assemble units and crate them for overseas at the Erie Proving Ground at Port Clinton, Ohio.

[Pg 79]

None of the 155-millimeter howitzers built here reached the American Expeditionary Forces, but French deliveries of the weapon up to the signing of the armistice totaled 747.

THE 155-MILLIMETER G. P. F. GUNS.

The reproduction in the United States of the French 155-millimeter G. P. F. (the French designation) gun presents much the same story as that of the howitzer of equal size—a story of difficulties in translating plans, writing into them the precision of finishing measurements that the French factory usually leaves to the skill of the mechanic himself, difficulties in finding manufacturers willing to undertake the work, and then of providing them with suitable raw materials and machinery, and, above all, of locating the necessary skilled mechanics.

This strange, big monster of a weapon is of rugged design. The entire unit weighs 19,860 pounds. The gun has the extremely high muzzle velocity of 2,400 feet per second, a rate of propulsion that throws the 95-pound projectile 17,700 yards, or a little more than 10 miles.

The wheels of the carriage have a double tread of solid rubber tire. By an ingenious arrangement a caterpillar tread can be applied to the wheels in a few minutes whenever soft ground is encountered.

The center of gravity of the unit is low. The wheels are of small dimensions and the cradle is trunnioned behind in such a fashion as to reduce the height of the cannon. The carriage has a split trail, which allows for a large clearance for recoil at a high elevation and a large angle of traverse. The carriage when traveling is supported on semielliptical springs, as is also the carriage limber.

Two large steel castings make up the carriage of this unit. The bottom part of the carriage is supported by the axle, which carries the two sections of the split trail upon the hinge pins. The top part of the carriage is supported by and revolves upon the bottom carriage and carries in trunnioned bearings the recuperator. The prin[Pg 80]cipal difficulty in carriage manufacture was to obtain in this country the extremely large steel castings of light-section, high-grade steel.

The carriages, 1,388 in number, were ordered in November, 1917, from the Minneapolis Steel & Machinery Co. The first delivery of carriages was made in August, 1918, and in the last week of October they were being turned out at the rate of seven a day. Up to the armistice date 370 had been produced, of which 16 had been sent overseas.

We also placed orders in France for 577 of these carriages, of which 216 had been completed upon the signing of the armistice. The American monthly rate of production of carriages in October was 162.

The 155-millimeter gun itself is far from being simple to manufacture. It is of considerable length and is built of a number of jackets and hoops to give the required resistance to the heavy pressures exerted in firing, this being a high-velocity gun. Except for a slight change in the manner of locking the hoops to the jacket, our gun is identical with that of the French.

Orders for 2,160 cannon were given to the Watervliet Arsenal and the Bullard Engineering Works, at Bridgeport, Conn., in November, 1917. The Bullard Engineering Works had to construct new buildings and to purchase and install special equipment, and the Watervliet Arsenal had to extend its shops and also purchase and install much additional machinery—a job that took time at both places.

The first deliveries of cannon came from Watervliet Arsenal in July, 1918. During October 50 cannon were delivered, and it seemed certain that by early in 1919 the projected eight cannon per day would be the rate attained. We shipped 16 of the cannon overseas. By November 11 we had received 71 cannon, a number increased to 109 by December 12.

Limbers in the same quantity as carriages were ordered from the Minneapolis Steel & Machinery Co., which produced a limber to accompany each one of its delivered carriages. This limber has an extremely heavy axle, similar to the automobile front axle. Its size and weight caused difficulty in obtaining it as a drop forging.

To Dodge Bros. was assigned the task of producing the recuperators for this gun in their special plant. The 155-millimeter gun recuperators, however, were made secondary to the production of the recuperators for the 155-millimeter howitzers, which were the easier of the two sorts to build.

Forgings were available and work started on recuperators in April, 1918. No rapid completion of these intricate mechanisms was possible, however, as the first forgings encountered many delays in their machinings. In the cycle of operations, with everything speeded up to the limit, more than three months must elapse from the day the recuperator forging is received to the day when the completed mechanism can be turned over to the inspector as an assembled article.

155-MILLIMETER HOWITZER, MODEL 1918 (SCHNEIDER).

This weapon throws shell or shrapnel weighing 95 pounds. Muzzle velocity for shell is 1,420 feet per second. The weight of the howitzer and carriage is 7,600 pounds.

8-INCH HOWITZER, MODEL 1917.

[Pg 81]

It was in October, 1918, that the first 155-millimeter gun recuperator was delivered. The factory expected to reach a maximum capacity of 10 a day. The company built 12 more by December 1. After the armistice was signed the company's order was reduced to 880, which had all been completed by May 1, 1919.

In order to have recuperators available for use for the units shipped from the United States minus these mechanisms, 110 rough-machined recuperator forgings were shipped to France, where the work of machining and completing was done.

The translation of the French plans for this weapon furnished one of the most difficult pieces of work undertaken by the Ordnance Department. Without counting in the gun pieces, the carriage and limber is made up of 479 pieces, while the recoil mechanism itself has 372 pieces. A total of 150 mechanical tracings had to be made by our draftsmen for the carriage and test tools; 50 for the carriage limbers; 142 for the recoil mechanism; 74 for the tools and accessories; or a total of 416. It was extremely difficult to secure draftsmen who could do this work, and the translation, accomplished in a few weeks, is regarded as a remarkable achievement.

The cannon for this gun were tested at the Erie Proving Grounds and there packed for overseas shipment. We had many cannon and carriages awaiting shipment when the armistice was signed, the plan being to send them to France, where they would be equipped with recuperators.

8-INCH HOWITZERS

In the early days of the war the British designed an 8-inch field howitzer that proved itself on battle fields in France. Great Britain loaded her own plants with orders for this weapon and then turned to the United States for additional facilities. The Midvale Steel & Ordnance Co. at Nicetown, Pa., was manufacturing this unit for the British at the time we entered the war.

On April 14, 1917, exactly eight days after we had formally announced our purpose of warring with Germany, an order for 80 of these 8-inch howitzers was placed with the Midvale Steel Co. It was understood that production on our order was to be begun upon[Pg 82] the completion of the British contract on which the Midvale Co. was then engaged. The order included the complete units, with carriages, limbers, tools, and accessories, all to be built in accordance with British specifications.

Contracts for the trails were sublet by the Midvale Co. to the Cambria Steel Co; for the wheels, to the American Road & Machinery Co.; for the limbers and firing platforms, to the J. G. Brill Co.; and for the open sights, to the British-American Manufacturing Co. Panoramic sights for these guns were furnished by the Frankford Arsenal.

So satisfactory did the production proceed that on December 13, 1917, the first of the 8-inch howitzers was proof-tried with good results. Early in January, 1918, the complete units began to come through at the rate of three a week, increasing to four a week in April and to six a week in May.

A subsequent contract with Midvale brought the total number of howitzers ordered from that plant up to 195. These weapons, all of the model known as the Mark VI, were all produced and accepted before the signing of the armistice, 96 of them being shipped overseas, with their full complement of accessories. Each completed unit cost in the neighborhood of $55,000. These weapons throw a 200-pound projectile 11,750 yards.

The progress of the war moved so swiftly, however, that there soon was need for artillery units of this same size but with longer range. Accordingly, a new design, known as the Mark VIII½, was brought out, having a range of over 13,000 yards. On October 2, 1918, we placed with the Midvale Co. an order for 100 of these 8-inch howitzers, specifying carriages of the new, heavier type.

When we entered the war the Bethlehem Steel Co., at Bethlehem, Pa., was producing for the British Government a howitzer with a bore of 9.2 inches. The Bethlehem Co. expected to complete these British contracts in July, 1917. The 9.2-inch howitzer was approximately the same size as the 240-millimeter howitzer which we were getting ready to put into production. However, in our desire to utilize every bit of the production facilities of the country, we ordered 100 of the 9.2-inch howitzer units from the Bethlehem Steel Co. and placed additional orders for 132 of these units in England. The British concerns delivered 40 howitzers before the armistice was signed.

THE 9.2-INCH HOWITZER, MODEL 1917.

This gun shoots shell weighing 290 pounds 8,690 meters. The weight of the howitzer and carriage is 29,100 pounds.

TWO VIEWS OF THE 240-MILLIMETER HOWITZER, MODEL 1918.

[Pg 83]

THE 240-MILLIMETER HOWITZERS.

The scheme of production of the French 240-millimeter howitzers was entirely aimed at the year 1919; since even if American heavy manufacturing establishments had not been loaded with war orders, it would have been well-nigh impossible to turn out this mighty engine of destruction in quantities in any shorter period of time.

Although approximately the same size as the British 9.2-inch howitzer (the exact diameter of the bore of the 240 being 9.45 inches) and only a little larger than the 8-inch howitzer, the French gun was far more powerful than either. The 8-inch and the 9.2-inch howitzers had ranges in the neighborhood of 6 miles, while their shell weighed from 200 to 290 pounds. The 240, on the other hand, hurled a shell weighing 356 pounds and carrying a bursting charge of between 45 and 50 pounds of high explosive. Its range was almost 10 miles.

We produced the 8-inch and the 9.2-inch howitzers to fill the gap during the two years which must elapse before we could get into quantity production of the 240. The French and British governments in the fall of 1917 asserted their ability to equip our first 30 combat divisions in 1918 with heavy howitzers, so that if our production came along in the spring of 1919 it could meet the requirements of the war situation.

Consequently we planned to equip our first army of 30 divisions with 8-inch and 9.2-inch howitzers in equal numbers of each. Our second army of 30 divisions should be wholly equipped with 240-millimeter howitzers; and our expected production of these, being beyond our own contemplated needs, would serve to replace such 8-inch and 9.2-inch howitzers as had been lost in the meantime.

As we adapted it from the French Schneider model, the 240-millimeter howitzer consisted of four main parts—the howitzer barrel, the top carriage, the cradle with recoil and mechanism, and the firing platform. Each of these four parts had its own transportation wagon and limber drawn by a 10-ton tractor. The weapon was set up with the aid of an erecting frame and a small hand crane.

Each of the main sections is composed of numerous smaller assembled parts made up of various grades of iron and steel and raw materials, all requiring the greatest precision in their manufacture and all having to pass rigid and exacting tests for strength and dimensions.

The production of even one of these enormous weapons would have been a hard job for any American industrial plant, but to manufacture over 1,200 of them, and that within the comparatively limited time allowed and under the abnormal industrial and transportation conditions then prevailing, was a task of tremendous difficulty and complexity.

[Pg 84]

On September 1, 1917, an order was placed with the Watertown Arsenal for 250 carriages for the American 240's, to be turned out complete with the recoil mechanism, transportation vehicles, tools, and accessories. To show the size of the job, an allotment of $17,450,000 was set aside to cover the estimated expenses at the arsenal.

Well equipped as the Watertown Arsenal was said to be at the time for the production of heavy gun carriages, it was found necessary, in order to handle this job, to construct a new erecting shop that had a capacity practically as large as all the other buildings of the plant put together. The number of employees at the arsenal was increased from 1,200 to more than 3,000.

The greatest difficulty experienced was in obtaining the large number of heavy machine tools required, and experts were sent out to scour the country in an effort to locate these tools wherever they might be available. Raw materials could not be procured in sufficient quantities, while numerous transportation delays impeded the work.

Finally, in October, 1918, the pilot carriage was completed and sufficient progress had been made on the entire contract to assure production of the required number of units in the early part of 1919.

A second carriage contract (Nov. 16, 1917) went to the Standard Steel Car Co., of Hammond, Ind. This called for the delivery of 964 carriages complete with transportation vehicles, limbers, tools, etc., but not with recuperators. These the Otis Elevator Co., of New York, undertook to deliver.

The Standard Steel Car Co. is one of the most important builders of railway cars, freight and passenger, in the country, and it possessed a large and well-equipped plant. Nevertheless, the company was compelled to construct several additional buildings and practically to double the capacity of its huge erecting shop in order to prepare adequately for the tremendous task undertaken.

As a means to save time, subcontracts were immediately placed with more than 100 firms throughout the East and Middle West for the production and machining of as many as possible of the component parts needed by the Standard Steel Car Co. Wherever practicable, the subcontractors working on similar contracts for the Watertown Arsenal were retained by the Indiana company, so that better prices might be obtained, parts standardized, and the whole production greatly facilitated.

Once the work was well under way the ramifications of this one contract, with its subcontracts for parts, materials, tools, building construction, etc., extended throughout practically the entire industrial facilities of the eastern and central sections of the country.

[Pg 85]

As in the case of the contract given the Watertown Arsenal, there were many difficulties in obtaining tools and raw materials. In a large majority of cases allocations, partly of iron and steel products, had to be obtained through the War Industries Board. When allocations had been granted, priority orders had to be secured, as the producers of these materials were already overworked with Government orders of varying importance.

With the pilot carriage complete in the early part of October, production on all the main parts had progressed by November to such an extent that a large output of finished carriages was assured for December and thereafter, had not the signing of the armistice intervened and ended the necessity for further expedition of the work.

Orders for howitzer bodies were placed as follows:

The Watervliet Arsenal on November 20, 1917, was instructed to do the machining of forgings so as to turn out 250 gun bodies for the 240-millimeter howitzers, and three months later this order was doubled. On November 7, 1918, an additional 660 were ordered from Watervliet, making a grand total of 1,160 howitzer cannon of this caliber ordered machined and completed at the Watervliet Arsenal. The arsenal contracted to reach an output of 100 cannon a month and deliver the last of the 1,160 not later than September 30, 1919.

It was found necessary to erect an entirely new shop for the machining of these howitzers. This shop was completed in May, 1918. During the war period $13,164,706 was spent or allotted to the Watervliet Arsenal for increasing its facilities. Forgings were furnished to the arsenal by the Government, but the forging situation was never a delaying factor in the production of 240-millimeter howitzers.

In all, 158 sets, of 1,467 ordered, were delivered up to December 12, 1918. The pilot howitzer was delivered by the Watervliet Arsenal to the proving ground on August 24, 1918.

In the summer of 1918 the Watertown Arsenal contracted to build 252 additional recuperators for these howitzers. Work was started at once in the shops, and, though additional facilities had to be prepared and much new equipment added, the production of the first recuperator was begun without delay. It was found that the planing equipment at the arsenal was not sufficient to handle the work, and therefore a great deal of the rough planing was done by subcontractors.

The Watertown Arsenal was to furnish its own forgings, but it was quickly found that an additional source of supplies was required.[Pg 86] The Carnegie Steel Co. had been given an order on December 27, 1917, for 1,300 recuperator forgings, and some of these were sent to the Watertown Arsenal.

The first recuperator was completed October 28, 1918, and 16 had been finished up to December 31, 1918, when 280 forgings were in the process of machining.

To handle its order for 1,039 recuperators, the Otis Elevator Co., of New York, found it necessary to rebuild a plant which it owned in Chicago. Forgings were furnished by the Government.

On May 1, 1918, the Otis Elevator Co. started its rough machining. Hard spots were found in the metal, causing great trouble at first, but this difficulty was overcome by changes in the heat treatment. The Carnegie Steel Co. was then instructed to rough-machine the forgings before sending them to the Otis Elevator Co. An order was also given to the Midvale Steel Co. to rough-machine 24 forgings. Early in November, 1918, the Otis Elevator Co. finished its first recuperator.

One 240-millimeter howitzer unit was completed at the time of the signing of the armistice, out of a total of 1,214 contracted for; but had war conditions continued, the expectation was for a monthly capacity of 80 units by 1919. Actual deliveries are given below:

FIGHTING THE AIRPLANE WITH ARTILLERY.

The American development of antiaircraft artillery had, previously to 1917, been confined almost exclusively to the task of designing and constructing stationary units of defense for our coast fortifications. It was naturally expected that it would be at those points that we would first, if ever, have to meet an attack from the air. Very little attention had been paid mobile artillery of this sort.

Before April, 1916, the Ordnance Department had designed a high-powered 3-inch antiaircraft mount for the fixed emplacement at coast fortifications. The gun on this mount fired a 15-pound projectile with a muzzle velocity of 2,600 feet a second. It is still to-day the most powerful antiaircraft weapon of its caliber. Between May, 1916, and June 18, 1917, orders for 160 of these mounts were placed with the Watertown Arsenal and the Bethlehem Steel Co. Up to April 10, 1919, a total of 116 of these had been completed and sent for emplacement at the points selected.

TWO VIEWS OF ANTIAIRCRAFT GUNS ON TRUCK MOUNTS.

TWO OTHER VIEWS OF ANTIAIRCRAFT GUNS.

[Pg 87]

By the end of 1916, however, it was foreseen that it would be necessary to provide antiaircraft artillery of a mobile type as part of the equipment for any field forces that might be sent abroad. Since that contingency seemed entirely possible at that time, and as it appeared to be impossible to provide a suitable design that would have a sufficient period of time in which to get proper consideration and test, it was decided to improvise a simple structural steel design that would permit quick construction and on which a 75-millimeter field gun, that was already in production, could be mounted.

This design was completed May 1, 1917, and an order for 50 placed with the Builders Iron Foundry. Deliveries on these were made during the fall of 1917, and the carriages were at once shipped to France for equipment with French field guns and recuperators that had been already procured for the purpose.

In its mobility the improvised antiaircraft gun mount was far from perfect. It was necessary to disassemble it partly and mount it on trailers. The need for a mount that could be moved easily and speedily had been realized before our entrance in the war, and a design embodying these qualities was completed as early as December, 1916.

This truck was designed to be equipped with the American 75-millimeter field gun, model of 1916. Before the drawings were completed an order for the pilot mounts of this type was placed with the Rock Island Arsenal. The war came on, and it was decided not to wait for a test of the mounts before starting general manufacture. Accordingly the New Britain Machine Co., in July, 1917, was given an order for 51 carriages. No further orders were placed for carriages of this sort, as it was not thought best to go too heavily into production of an untried mount.

It may be noted here that our first 26 antiaircraft guns were mounted on White 1½-ton trucks.

It was also realized that the field guns with which these mounts were to be equipped did not have the power and range that the war experience was showing to be necessary. The only reasons that the field guns of the 75-millimeter caliber were used in this way was because they were the guns most quickly available and because the French were already using them for this purpose.

To meet the need of more powerful antiaircraft weapons, a need becoming more pressing each day, a 3-inch high-powered antiaircraft gun was designed and mounted on a four-wheel trailer of the automobile type. This mount permitted elevations of the gun from 10[Pg 88] degrees to 85 degrees and also allowed for "all around" firing. An order for 612 of these carriages was given to the New Britain Machine Co. in July, 1917, shortly after the contract for the 51 truck mounts had been placed with that concern.

Because of the urgency of the situation it was necessary to construct these carriages without the preliminary tests on a pilot carriage. This, of course, is a very undesirable practice, but under the existing conditions no other procedure would have been practicable. The French antiaircraft auto truck mount, which had the French 75-millimeter field gun with its recuperator placed upon a special antiaircraft mount, was not adopted at the time, because, in July, 1917, the whole question of the possibility of constructing French recuperators in this country was still entirely unsettled. It was imperative then that we develop our own designs.

All of the 51 truck mounts for the antiaircraft guns were delivered during the fall and early winter of 1918, and 22 of them were in France before December, 1918.

Delivery of the first carriage for the 3-inch high-powered gun mounted on the trailer carriage was made in August, 1917. It had been rushed ahead of general production in order to be given some sort of a test. No further deliveries were made, but manufacture reached a point where production in quantity could begin.

A representative of the Ordnance Department was sent to France and England in December, 1917, to gather all the information possible on antiaircraft artillery. As a result of his investigations it was determined that it would be best to procure the greater part of our fire-control equipment in France, since the instruments developed there were in some cases of a highly complicated nature and their manufacture entirely controlled by private parties. Orders were placed for enough of these instruments for the equipment of the first 125 batteries.

Meanwhile, fire-control instruments of various types were in the process of development in this country; but, as they were largely based upon theoretical construction derived from study of the French practices, it was deemed best not to manufacture any of these instruments in quantity, as better instruments of French design were available. Drawings of the French instruments were brought back by the Ordnance officer on his visit to France and were available in this country in the spring of 1918, when manufacture of some of them began in the United States.

At the signing of the armistice our forces in France were equipped almost wholly with antiaircraft artillery loaned to us and supplied by the French. This, of course, does not include the 101 improvised and truck mounts completed during 1917. Production here, how[Pg 89]ever, had reached such a point that shipment of material would have begun in quantity in January, 1919.

The estimated requirements of antiaircraft artillery for 2,000,000 men in 48 divisions is only 120 guns. Other material, of course, would have been required previously for defense of depots, railheads, etc., dependent in a great measure upon the activities of German bombers. It is estimated that about 200 guns would have sufficed for this purpose.

To summarize, 50 of the so-called improvised 75-millimeter antiaircraft guns and mounts had been ordered and completed up to the time of the signing of the armistice; 51 of the 75-millimeter antiaircraft mounts, model of 1917, had been ordered and 46 completed; while 612 of the 3-inch antiaircraft trailer carriage mounts, model of 1917, had been ordered, of which 1 had been actually delivered at the signing of the armistice, the balance to come at the rate of 26 per month starting in December.

By "complete units" is meant gun body complete, carriage, and recoil mechanism or recuperator. Units are given as complete when their component parts were complete, although the actual assembly of these parts at a common point, testing, and final delivery usually required from two weeks' to two months' additional time.

The 5-inch, 6-inch, 10-inch, and 12-inch seacoast guns and the 12-inch seacoast mortars were taken from the fortifications and modified for use with mobile carriages, all above 6 inches for railway mounts.

The 75-millimeter gun, model 1897, was the approved model for active service in France. Model 1916 and model 1917 were used for training purposes both in the United States and in France.

[Pg 90]

1½-TON ANTIAIRCRAFT MACHINE GUN TRAILER.

TWO VIEWS OF THE 7-INCH NAVY RIFLE MOUNTED ON A PEDESTAL ON A RAILWAY CAR.

This rifle has a range of about 10 miles and throws a projectile weighing 165 pounds. Note the means of loading and the depression angle.

[Pg 91]

CHAPTER IV.
RAILWAY ARTILLERY.

As soon as war was declared against Germany the Ordnance Department, in its search for an immediate equipment of strong artillery, surveyed the ordnance supplies of the country and discovered some 464 heavy guns which might be spared from the seacoast defenses, obtained from the Navy, or commandeered at private ordnance plants where they were being manufactured for foreign Governments. There were six guns of this last-named class—powerful 12-inch weapons which had been produced for the Chilean Government. It was seen that if all, or if a large part, of these guns could be made available for service in France, America would quickly provide for herself a heavy artillery equipment of respectable proportions.

The guns thus available for mounting on railway cars ranged in size from the 7-inch guns of the Navy to the single enormous 16-inch howitzer which had been built experimentally by the Ordnance Department prior to 1917. The list of these guns according to number, size, length, and source whence obtained was as follows:

In addition to these there was the 16-inch howitzer, 20 calibers in length, which had been built by the Ordnance Department before 1917.

The expression 14-inch gun, 50 calibers, means that the gun has a barrel diameter of 14 inches and that the gun body is fifty times the caliber of 14 inches, or 700 inches (58 feet 4 inches) long.

The Ordnance Department conceived that the only way to make these guns available for use abroad would be to mount them on railway cars. These guns were not vital in the defense of our coast under the conditions of the war with Germany, but it was[Pg 92] evident that they would make a valuable type of long-range artillery when placed on satisfactory railway mounts.

Mounting heavy artillery on railway cars, however, was not an idea born of the recent war. The idea was probably originally American. The Union forces at the siege of Richmond in 1863 mounted a 13-inch cast-iron mortar on a reinforced flat car, this being the first authenticated record of the use of heavy railway artillery.

In 1913 the commanding officer of the defenses of the Potomac, which comprise Forts Washington and Hunt, was called upon to report on the condition of these defenses. In reply, he advised that no further expenditure be made on any one of the fixed defenses, but recommended that a "strategic railroad" be built along the backbone of the peninsula from Point Lookout to Washington, with spurs leading to predetermined positions both on Chesapeake Bay and the Potomac River, so placed as to command approaches to Washington and Baltimore.

Further, he recommended that 4 major-caliber guns, 16 medium-caliber guns, and 24 mine-defense guns be mounted on railroad platforms, with ammunition, range finding, and repair cars making up complete units, so that this armament could be quickly transported at any time to the place where most needed. He suggested that this scheme be made applicable to any portion of the coast line of the United States. His argument was based upon the fact that guns in fixed positions, of whatever caliber, violate the cardinal military principle of mobility.

The nations engaged in the war now ending developed to a high stage the use of heavy artillery mounted on railway cars, bringing about a combination of the necessary rigidity with great mobility, considering the weight of this material.

Railway artillery came to be as varied in its design as field artillery. Each type of railway mount had certain tactical uses and it was not considered desirable to use the different types interchangeably. The three types of cannon used on railway mounts were mortars, howitzers, and guns. It was not practicable to use the same type of railway mounts for the different kinds of cannon. Moreover, these mounts differed radically from the mounts for such weapons at the seacoast defenses.

The three general types of railway mounts adopted were those which gave the gun all-around fire (360-degree traverse), those which provided limited traverse for the gun, and those which allowed no lateral movement for the gun on the carriage but were used on curved track, or epis, to give the weapons traverse aim.

The smaller weapons, such as the 7-inch and the 8-inch guns and the 12-inch mortars, were placed on mounts affording 360-degree[Pg 93] traverse. The limited traverse mounts were used for the moderately long-range guns and howitzers. The fixed type of mount was used for long-range guns only, and included the sliding railway mounts, such as the American 12-inch and 14-inch sliding mounts and the French Schneider à glissement mounts.

The work of providing railway artillery—that is, taking the big, fixed-position guns already in existence within the United States and similar guns being produced and designing and manufacturing suitable mounts for them on railway cars—grew into such an important undertaking that it enlisted the exclusive attention of a large section within the Ordnance Department. This organization eventually found itself engaged in 10 major construction projects, which, in time, had the war continued, would have delivered more than 300 of these monster weapons to the field in France and, to a lesser extent, to the railway coast defenses of the United States.

As it was, so much of the construction—the machining of parts, and so on—was complete at the date of the armistice, that it was decided to go ahead with all of the projects except three, these involving the mounting of 16 guns of 14-inch size, 50 calibers long, the production of 25 long-range 8-inch guns, 50 calibers, and their mounting on railway cars, and the mounting of 18 coast-defense, 10-inch guns, 34 calibers long, on the French Batignolles type of railway mount.

Inasmuch as it will be necessary in this chapter to refer frequently to the barbette, Schneider, and Batignolles types of gun mounts for railway artillery, it should be made clear to the reader what these types are.

The barbette carriage revolves about a central pintle, or axis, and turns the gun around with it. When it was decided to put coast-defense guns on railway cars, the guns were taken from their emplacements, barbette carriages manufactured for them, and the whole mounted upon special cars. The barbette mount revolves on a support of rollers traveling upon a circular base ring. In the railway mount the base ring is attached to the dropped central portion of the railway car. The barbette railway mount is provided with struts and plates by which the car is braced against the ground.

The Schneider railway mount is named after the French ordnance concern Schneider et Cie, who designed it. In this mount the gun and its carriage are fastened rigidly parallel to the long axis of the railway car. Thus the gun itself, independently of any movement of the car, can be pointed only up and down in a vertical plane, having no traverse or swing from left to right, and vice versa. In order to give the weapon traverse for its aim, special railway curved tracks, called epis, are prepared at the position where it is to be fired. The car is then run along the curve until its traverse aim is[Pg 94] correct, and the vertical aim is achieved by the movement of the gun itself. In the Schneider mount there is no recoil mechanism, but the recoil is absorbed by the retrograde movement of the car itself along the rails after the gun is fired. This movement, of course, puts the gun out of aim, and the entire unit must then be pushed by hand power back to the proper point.

In the Batignolles type, gun and cradle are mounted on a so-called top carriage that permits of small changes in horizontal pointing right and left. Thus with the railway artillery of the Batignolles type also, track curves, or epis, are necessary for the accurate aiming. The Batignolles mount partially cushions the recoil by the movement of the gun itself in the cradle. But, in addition, a special track is provided at the firing point and the entire gun car is run on this track and bolted to it with spades driven into the ground to resist what recoil is not taken up in the cradle. The unit is thus stationary in action, and the gun can be more readily returned to aim than can a gun on a Schneider mount.

THE 7-INCH RIFLES.

The conditions under which the war with Germany was fought virtually precluded any chance of a naval attack on our shores which would engage our fixed coast defenses. The British grand fleet, with the assistance of fleets of the other allies and America, had the German battle fleet securely bottled. On the other hand there was the prowling submarine able at all times to go to sea and even to cross the ocean, and some of the latest of these submarines were armed with long-range medium-caliber guns. It was not beyond possibility that some sort of an attack would be made on our shores by submarines of this character, yet it was safe to believe that these craft would keep well out of range of the guns at our stationary coast defenses.

To protect our coast from such attack the Ordnance Department conceived the plan of mounting heavy guns on railway cars. They might then be moved quickly to places on the seacoast needing defense. For this purpose the Navy turned 12 of its 7-inch rifles over to the Ordnance Department for mounting. Meanwhile our ordnance officers had designed certain standard railway artillery cars, known as models 1918, 1918 Mark I, and 1918 Mark II, for 7-inch and 8-inch guns and 12-inch mortars, respectively. These cars all had the same general features.

The model 1918 car was selected for the converted 7-inch Navy rifle. The rifle was mounted on a pedestal set on the gun car in such a manner as to give all-around fire, or 360-degree traverse. The pedestal mount permitted the gun to be depressed at an angle[Pg 95] suitable for firing from high places along the coast down upon the low-lying submarines.

Contracts for the various parts for these cars and the pedestal gun mounts were let to concerns engaged in heavy steel manufacture, but the assembling was done by the American Car & Foundry Co., of Berwick, Pa. Twelve of the 7-inch rifles were so mounted. As this equipment was intended exclusively for use in this country, the gun cars were equipped with the American type of car couplings.

THE 8-INCH GUNS.

For the 8-inch guns taken from seacoast fortifications the Ordnance Department designed a barbette mount giving complete, 360-degree, traverse, thus providing for fire in any direction. There were 96 such guns available for railway mounts. Orders for 47 gun cars with carriages for mounting the weapons were placed with three concerns—the Morgan Engineering Co., of Alliance, Ohio, the Harrisburg Manufacturing & Boiler Co., of Harrisburg, Pa., and the American Car & Foundry Co., of Berwick. Two of the three contractors found it necessary to provide additional facilities and machine-tool equipment at their plants in order to handle this job.

The first railway mount for the 8-inch gun was completed and sent to the Aberdeen Proving Ground for test in May, 1918. In early June the test had shown that the weapon was efficient and entirely satisfactory. Before the end of the year 1918 a total of 24 complete units, with ammunition cars for standard-gauge track, shell cars for narrow-gauge track, transportation cars, tools, spare parts, and all the other necessary appurtenances of a unit of this character, had been completed. Three complete 8-inch units were shipped overseas before the armistice was signed.

When the armistice came the Harrisburg company had delivered 9 of these mounts and the Morgan Engineering Co. an equal number, making 18 in all. The former concern had reached an output of 5 mounts per month and the latter 10 per month.

An interesting feature of this mount is that it can be used either on standard-gauge or on narrow-gauge railroad track. The narrow gauge adopted was that in standard use in the fighting zones in France, the distance between the rails being 60 centimeters, or the approximate equivalent of 24 inches. Each gun car was provided with interchangeable trucks to fit either gauge. The artillery train necessary for the maneuvering of the weapon was also similarly equipped to travel on either sort of track.

As a rule the longer the barrel of a cannon, the greater its range. The 8-inch seacoast guns thus mounted were 35 calibers in length, that is, thirty-five times 8 inches, or 23 feet 4 inches. The requirements of our forces in the field in France called for guns of this same size[Pg 96] but of longer range. Consequently an 8-inch gun of 50 calibers—that is, 10 feet longer than the seacoast 8-inch gun—was designed, and 25 of them were ordered. This project came as a later development in the war, the guns being intended for use abroad in 1920. The railway mounts for the weapons had not been placed in production when the armistice came. Because of the incomplete status of this project in the autumn of 1918, the whole undertaking was abandoned.

10-INCH AND 12-INCH GUNS.

There were at the seacoast defenses and in the stores of the Army a large number of 10-inch guns of 34 calibers. Of these 129 were available for mounting on railway cars. It was proposed to mount these weapons on two types of French railway mounts—the Schneider and the Batignolles.

The project to mount 36 of these weapons on Schneider mounts was taken up as a joint operation of the United States and French Governments, the heavy forging and rough machining to be done in this country and the finishing and assembling in the French shops. The American contractors were three. The Harrisburg Manufacturing & Boiler Co. undertook to furnish the major portion of the fabricated materials for the carriages and cars. The Pullman Car Co. contracted to produce the necessary trucks for the gun cars, while the American Car & Foundry Co. engaged to build the ammunition cars.

Eight sets of fabricated parts to be assembled in France had been produced before the armistice was signed. Gen. Pershing had requested the delivery in France of the 36 sets of parts by March 2, 1919. After the armistice was signed there was a natural letdown in speed in nearly all ordnance factories, but even without the spur of military necessity the contracting concerns were able by April 7, 1919, to deliver 22 of the 36 sets ordered. Had the war continued through the winter there is little question but that all 36 sets of parts would have been in France on the date specified.

The 10-inch seacoast gun, Batignolles mount project, was placed exclusively in the hands of the Marion Steam Shovel Co., of Marion, Ohio. It had been proposed also to mount 12-inch seacoast guns on this same type of equipment, and this work, too, went to the Marion concern. There were to be produced 18 of the 10-inch units and 12 of the larger ones.

8-INCH RAILWAY ARTILLERY, BARBETTE TYPE.

This view shows gun in act of hurling projectile parallel to track.

8-INCH SEACOAST RIFLE, WITH RECOIL MECHANISM, SET UP ON A SPECIALLY DESIGNED RAILWAY MOUNT.

This gun, thus mounted on a railway car, is capable of an all-around fire and can deliver a shot in any direction from its location on the car.

12-INCH RIFLE IN ACT OF FIRING.

The force of the recoil sends the entire car back on track about 5 feet.

12-INCH RIFLE ELEVATED TO ITS MAXIMUM POSITION.

It is capable of hurling a 700-pound shell 25 miles. This is a modified Schneider type of carriage.

TWO VIEWS OF 12-INCH RIFLE ON SLIDING TYPE RAILWAY MOUNT.

[Pg 97]

The Marion Steam Shovel Co. had had a large experience in producing heavy construction and road-building equipment. The concern encountered numerous difficulties at the start in translating the French drawings and in substituting the American standard materials for those specified by the French. These difficulties, combined with struggles to obtain raw materials and the equipment for the increased facilities which had to be provided at the factory, so delayed production that no mount for either the 10-inch or 12-inch guns had been delivered at the time of the armistice. The first mount of these classes—one with a 12-inch gun—reached the Aberdeen proving ground about April 1, 1919. The 10-inch project, calling for 18 mounts, was canceled soon after November 11, 1918. The work on the dozen mounts for 12-inch guns, however, had progressed so far that the Ordnance Department ordered the completion of the entire equipment.

As has been stated, the Government found in this country six 12-inch guns being made for the Republic of Chile. Their length of 50 calibers gave them a specially long range. It was decided to place the Chilean guns on a sliding mount. In a mount of this type the retrograde movement of the car along the track as and after the gun is fired takes up and absorbs the energy of fire.

The first sliding railway mount used on the allied side in the great war was of French design. But our manufacturers had so much trouble with French designs that when the project came up of mounting the Chilean guns in this fashion it was decided that it would be quicker to design our own mount. Consequently the French design was taken in hand by our ordnance engineers and redesigned to conform to American practice, with the inclusion in the design of all original ideas developed by the Ordnance Department in its creative work during the war period up to that time. The manufacturers who looked at the French design of the sliding railway mount estimated that it would take from 12 to 18 months before the unit could be duplicated in this country and first deliveries made. They looked at the American design and estimated that they could build it in 3 months.

It was decided to build three mounts of this character and thus have a reserve of one gun for each mount to serve as replacement when the original guns were worn out. Contracts were placed in the early summer of 1918, and all three mounts were delivered before the armistice was signed, the first mount being completed within 85 days after the order was placed. For these mounts the American Bridge Co. furnished the main girders or side pieces, the Baldwin Locomotive Co. built the railway trucks, and the Morgan Engineering Co. manufactured the many other parts and assembled the complete units. The speed in manufacture was made possible by the fact that the plant engineers of the three companies helped the ordnance officers in designing the details. With such intimate cooperation, the concerns were able to begin the manufacture of component parts while the drawings were being made.

All three weapons with their entire equipment, including supplies, spare parts, ammunition cars, and the whole trains that make up[Pg 98] such units, were ready for shipment to France in November, 1918. Each mount as it stands to-day is 105 feet long and weighs 600,000 pounds. The load of the gun and the peak load put on the carriage when the gun is fired are so great that it requires four trucks of 8 wheels each, 32 car wheels in all, to distribute the load safely over ordinary standard-gauge track.

THE 12-INCH MORTARS.

In years past the Ordnance Department had procured a large number of 12-inch mortars for use at seacoast defenses. These great weapons are 10 calibers in length, or 10 feet in linear measurement, the diameter of the barrel being just an even foot. Of the number stationed at the coastal forts and in reserve it was decided that 150 could be safely withdrawn and prepared for use against Germany. When Gen. Pershing was informed of the proposal, he asked that 40 of these weapons mounted on railway cars should be delivered to the American Expeditionary Forces for use in the planned campaign of 1919. In order that there might be an adequate supply of them, the Ordnance Department let contracts for the mounting of 91 of these mortars on railway equipment, a project which would give the United States a formidable armament and still provide a reserve of 59 mortars to replace the service mortars on the carriages after repeated firing had worn them out.

This job proved to be one of the largest in the whole artillery program. The entire contract was let to the Morgan Engineering Co., of Alliance, Ohio. In order to handle the contract, a special ordnance plant, costing $1,700,000 for the building alone, had to be constructed at the company's works at Alliance. The work was so highly specialized that machine tools designed for the particular purpose had to be produced. The Government itself bought these tools at a cost of $1,800,000. Although work on this plant was not started until December 10, 1917, and although thereafter followed weeks and weeks of the severest winter weather known in recent years, with all the delays in the deliveries of materials which such weather conditions bring about, the plant was entirely complete on June 1, 1918, not only, but the work of producing the mounts had started in it long before that, some machines getting to work as early as April.

The gun car used for mounting the mortar carriage was of the same design as that for the 7-inch and 8-inch guns, except that each truck had six wheels. The carriage built upon this car was of the barbette type, and it allowed the gun to be pointed upward to an angle as high as 65° and provided complete traverse, so that the mortar could be fired in any direction from the car. A hydropneumatic system for absorbing the recoil of the mortar after firing was adopted. This recuperator in itself was a difficult problem for the manufacturer to solve, being the first hydropneumatic recuperator of the size ever built in this country.

12-INCH SEACOAST GUN ON A CREUSOT RAILWAY MOUNT.

This huge weapon in this position is ready to fire half a ton of shot a distance of 25 miles. It requires only two men to operate the powerful elevating apparatus necessary to bring the gun into quick-firing position.

TWO VIEWS OF 12-INCH MORTAR ON RAILWAY MOUNT.

Lower view shows the mortar in its extreme position of recoil.

[Pg 99]

In spite of the weight and elaborate character of this unit it was put into production in an astonishingly short space of time. The pilot mount came through on August 22, 1918, less than nine months after the spade was first struck in the ground to begin the erection of the ordnance plant. By the end of August the pilot mortar had successfully passed its firing tests at Aberdeen, functioning properly at angles of elevation from 22 degrees to 65 degrees and in any direction from the mount. While this unit was put through hurriedly for these tests, the preparation for the rest of the deliveries was made on a grand scale, looking toward quantity production later on. When the armistice was signed, every casting, forging, and structural part for every one of the 91 railway mounts was on hand and completed at the works of the Morgan Engineering Co., and thereafter the process was merely one of assembling, although in a unit of such size the assembling job alone was one of great magnitude. Even at the reduced rate of production incident to the relaxation of tension after the armistice was signed, the company delivered 45 complete units to the Government up to April 7, 1919, or five more than Gen. Pershing said he would require during the whole campaign of 1919. Careful estimates show that if the war had continued the company would have delivered the mounts at the rate of 15 per month beginning on December 15, 1918, a rate which would have completed the entire project for 91 mounts by the middle of June, 1919.

As in the case of the 8-inch railway guns, the 12-inch mortars were provided with interchangeable wheel trucks allowing the unit to travel and work either on standard-gauge track or on the 60-centimeter, narrow-gauge track of the war zone in France.

14-INCH GUNS.

The War Department did not have any 14-inch guns which could be spared from the seacoast defenses for use abroad. The Ordnance Department, therefore, inaugurated the project for the construction of 60 guns of 14-inch caliber. For the construction of such guns complete new plants were required, as all available facilities were already taken over for other projects considered more important. This contract was to have been turned out by the Neville Island ordnance plant. The Navy Department in May, 1918, expressed willingness to turn over to the Army certain 14-inch guns, 50 calibers, then under construction and of which it was estimated that 30 would be completed by March, 1919.

It was decided to place some of these 14-inch guns on American sliding railway mounts, and 16 such mounts were ordered from the Baldwin Locomotive Works, deliveries to begin February 1, 1919. The 16 units were to be delivered prior to April, 1919, but due to the[Pg 100] signing of the armistice work was suspended on the contracts, since the mounts were designed for use in France. The contract was canceled in March, 1919.

The Navy itself placed five of these guns on railway mounts of another design to be operated in France by naval forces on shore. Eleven such mounts were built by the Baldwin Locomotive Works under the supervision of the Navy Ordnance Bureau, and six of them were afterwards turned over to the Army.

THE 16-INCH HOWITZER.

Without discussing here the 12-inch howitzers, 20 feet long, which the Ordnance Department ordered produced and mounted on railway trucks, a development for use abroad in 1920, we come, finally, to the largest weapon of all in the railway artillery program, the 16-inch howitzer, the barrel of this mighty weapon being 26 feet 6 inches long. The American 16-inch howitzer had been forged out and finished prior to the date of America's entrance into the war. It was proposed to place this weapon on a railway mount and make it available for use on the western front.

The Ordnance Department completed the design for the mount on February 10, 1918. In order to turn out the unit in the shortest possible time, the project was placed with three manufacturers, each of whom was to produce different parts. The American Bridge Co. received the order to build the structural parts, the Baldwin Locomotive Works contracted for the trucks, while the Morgan Engineering Co. undertook to assemble the unit and also to build the top carriage and other mechanical parts. The contractors did a speedy job in producing the mount for this howitzer.

In nearly all railway artillery of this size it is necessary to provide bracing when the gun is set up in position for firing. The 16-inch howitzer mount was unique in that the weapon could be fired from the trucks without any track preparation whatsoever. An exhaustive test at the Aberdeen proving grounds demonstrated that this piece of artillery ranked with the highest types of ordnance in use by any country in the world.

In the meantime orders had been placed for 61 additional howitzers. The American Expeditionary Forces asked that 12 of these enormous weapons be sent overseas as soon as they could be produced, a job which would have extended over a period of months, if not years. Since none of the additional howitzers had been produced when the armistice was signed, the project of building mounts for them never got under way. The pilot howitzer and mount were not shipped abroad.

TWO VIEWS OF 14-INCH RAILWAY ARTILLERY.

This type was evolved entirely by the Ordnance Department. It is an excellent weapon for coast defense and hurls a 1,200-pound projectile more than 18 miles.

16-INCH HOWITZER ON RAILWAY MOUNT.

A 1,600-pound projectile being loaded into the 16-inch howitzer from which it will be sent on a journey of approximately 13 miles.

16-INCH HOWITZER ON RAILWAY MOUNT.

This view shows howitzer in the act of firing.

[Pg 101]

In the design of railway equipment for high-angle weapons such as howitzers, two loads must be considered by the builders in order to provide a gun car of sufficient strength to hold its freight. One of these loads, the lighter one, consists merely of the ordinary weight of the gun and its carriage upon the car wheels. The other load, the so-called firing load, consists of the weight of the unit plus the additional weight of the down-thrust of the howitzer when it recoils. In the case of the 16-inch howitzer the firing load is 748,231 pounds. The weight of 748,231 pounds must be distributed along the tracks by the numerous sets of wheels at the instant the gun is fired.

The mount for the howitzer is so constructed that this load is partly taken up by the slide of the gun car along the track. In addition, the howitzer is equipped with a hydraulic recoil cylinder. Thus the unit has a double recoil system. The car trucks in the tests comfortably transmitted, through a series of equalizer springs, this enormous load upon an ordinary rock-ballast track, without any distortion to the track or roadbed or impairment to the working parts of the unit. After each discharge the whole huge mount moves backward along the track for a distance of 20 or 30 feet.

Each railway artillery project called for the manufacture of a great equipment of ammunition cars, fire-control cars, spare-parts cars, supply cars, and the like, a complete unit being a heavy train in itself. Such armament-train cars, together with numerous other accessories and necessary equipment, were designed by the Ordnance Department and produced for each mount. In all, 530 ammunition cars were produced up to April, 1919. Most of them were shipped abroad, but 118 were retained for use in this country. Since the overseas cars were to be used with French railway equipment, it was necessary to fit them out with French standard screw couplers, air brakes, and other appliances for connecting up with French railway cars.

The matter of traction power for these gun and armament trains near the front set a problem for the Ordnance Department to solve. It was out of the question to use steam engines near the enemy's lines, since the steam and smoke would betray the location of artillery trains at great distances. The Ordnance Department adopted a gas-electric locomotive of 400 horsepower to be used to pull railway artillery trains at the front, and was on the point of letting a contract to the General Electric Co. for the manufacture of 50 of them when the armistice was signed.

NEVILLE ISLAND.

It seems fitting at this point to say something about the Neville Island ordnance plant, on an island in the Ohio River near Pittsburgh, which would have produced weapons of the character of those used with railway mounts and would have turned them out in large numbers had the armistice not come to put an end to this enormous project. The plant was being erected for the Government by the United States Steel Corporation without profit to itself. The[Pg 102] estimated cost of this plant when finished was $150,000,000. Designed to supply the needs of the Army for artillery of the heaviest types, the Neville Island plant was being constructed on such a scale that it would surpass in size and capacity any of the famous gun works of Europe, including the Krupps.

It was being equipped to handle huge ordnance undertakings, such as the monthly completion of 15 great 14-inch guns and the production of 40,000 projectiles monthly for 14-inch and 16-inch guns. The plans of the Government contemplated the production of 14-inch guns to the number of 165 in all and their shipment to France in time to be in the field before May 1, 1920. An initial order for 90 of these weapons had been placed at the arsenal while it was being erected.

Besides 14-inch guns the plant was being equipped to turn out 16-inch and even 18-inch weapons. The immense size of the machinery necessary for such production can be understood when it is noted that an 18-inch gun weighs 510,000 pounds and a 14-inch gun 180,000 pounds. It requires from 12 to 18 months to produce guns of this size, yet Neville Island was being developed on a scale to build hundreds of them simultaneously. The entire plant was to cover 573 acres and was to employ 20,000 workmen when in full operation.

At the signing of the armistice work was suspended at Neville Island, and four months later the whole project was abandoned.

CHAPTER V.
EXPLOSIVES, PROPELLANTS, AND ARTILLERY AMMUNITION.

The Interallied Ordnance Agreement of the late fall of 1917, supplying to the United States as it did French and British artillery and other heavy ordnance supplies until the developing American ordnance industry could come into production, nevertheless called upon the United States to produce heavily the explosives and propellants that are of such major importance to a modern army. These commodities were needed by the armies of France and Great Britain more than any other sort of ordnance which America could supply.

The result was an enormous production of propellants and explosives in the United States during the period of American belligerency, no other prime phase of the ordnance program being carried to such a stage of development. The reader will clearly see the distinction between propellants and explosives. The propellant is the smokeless powder that sends the shell or bullet from the gun; the explosive is the bursting charge within the shell.

To realize the expansion of the American explosives industry during the war period, consider such figures as these: America in 19 months turned out 632,504,000 pounds of propellants—the powder loaded into small-arms cartridges or packed into the big guns behind the projectiles to send them against the enemy. In those same 19 months France produced 342,155,000 pounds of propellants and Great Britain 291,706,000 pounds. The American production was practically equal to that of England and France together.

In those 19 months we produced 375,656,000 pounds of high explosives for loading into shell. In the same 19 months England produced 765,110,000 pounds of high explosives and France 702,964,000 pounds. America was below both France and England in total output, but in monthly rate of output America had reached 47,888,000 pounds as against France's 22,802,000 pounds and England's 30,957,000 pounds. Our rate of manufacturing propellants at the end of the fighting was up to 42,775,000 pounds as against France's 17,311,000 and England's 12,055,000.

Figure 9 shows graphically the achievements of America in manufacturing propellants and explosives.

[Pg 104]

In the production of artillery ammunition a comparison with France and Great Britain shows that our monthly rate in turning out unfilled rounds of ammunition at the end of the war was 7,044,000 rounds, as against 7,748,000 rounds for Great Britain and 6,661,000 rounds for France. In producing complete rounds of artillery ammunition, our monthly rate at the signing of the armistice was 2,429,000 rounds while that of Great Britain was 7,347,000 rounds and that of France 7,638,000 rounds.

In the 19 months of our participation in the war our production of unfilled rounds in ammunition was 38,623,000 rounds, while that of France was 156,170,000 rounds and that of Great Britain 138,357,000 rounds. In that time we had produced 17,260,000 complete rounds, while France had produced 149,827,000 rounds, and Great Britain 121,739,000 complete rounds.

The entrance of the United States into the war found the existing American explosives manufacturers operating to the very limit of their capacity in production for the allied governments and for general commercial purposes.

[Pg 105]

Since the outbreak of the war in 1914 the explosives business in this country had increased enormously and the trained men familiar with manufacturing operations and conditions in this highly specialized and extremely dangerous industry had fallen short of meeting demands.

When we entered the war, therefore, it became necessary at once to distribute this limited force of experts as equitably as possible and to put chemists, engineers and other specialists in the various plants under the supervision of this trained personnel so as to produce in as quick a time as possible a vastly enlarged force of competent operators and supervisors for the production of explosives.

Summed up, the problem that faced the Ordnance Department was, while maintaining the current great production of explosives, to expand enormously the facilities for further production, to provide personnel for operating these expanded facilities, to build up entirely new manufacturing plants for making both propellants and high explosives, and in addition to all of this, to bring into existence huge loading plants.

In all, 53 new plants for making explosives and propellants and for loading these were undertaken at a cost of approximately $360,000,000. When the armistice was signed a very large part of this construction work had been completed and was in an efficient state of operation.

How creditably this reflects upon America can be understood when it is made plain that in addition to the development of production there was also to be worked out the very intricate question of design, not only of the plants themselves but also of their products, which required an exceptional degree of technical skill and thorough control.

Prior to our entry into the war the Ordnance Department had depended upon ammonium picrate, known in the Army vernacular as explosive "D," as a bursting charge for our high-explosive shell.

During the progress of the European conflict the British had developed an explosive they called amatol, which is a mixture of trinitrotoluol—T. N. T.—and ammonium nitrate. As this had proved to be entirely satisfactory in actual service on European battle fields, and as ammonium nitrate could be produced here in large quantities, we adopted it.

The Ordnance Department eventually put into effect a standard policy for the use of high explosives. Every effort was being made to conserve the supply of T. N. T., and consequently this explosive was specified for the shell of smaller calibers only. The standard filling scheme was as follows: T. N. T. for shell between and including the calibers of 75-millimeter and 4.7-inch; amatol for shell of calibers between 4.7-inch and 9.2-inch, including the latter; ammonium picrate, or explosive D, for shell of 10-inch caliber and higher. While[Pg 106] these were the standards the scheme was not always followed rigidly. As a matter of fact amatol was loaded into shell of all sizes and so was T. N. T., although explosive D was never used in shell smaller than those for the 10-inch guns. These departures from standard practice were due to the necessity for keeping certain plants in production and to other special causes and exceptional circumstances.

Production of large quantities of T. N. T. and ammonium nitrate was the first big problem to be solved by the high-explosives section of the Ordnance Department. All the work of the explosives section can be subdivided under four group heads—raw materials, propellants, high explosives, and loading.

RAW MATERIALS.

The first steps taken in the endeavor to meet the need for raw materials were to increase greatly the available means for obtaining toluol, phenol, caustic soda, sodium nitrate, sulphuric and nitric acids, ammonia liquor or aqua ammonia, and to attempt to provide a substitute for cellulose in case a shortage of cotton should render its use necessary.

How to increase the supply of toluol, the basic raw material from which T. N. T. is made, was the greatest and most pressing of all the problems in regard to the existing raw materials. Before the war the sole source of this ingredient was from by-product coke ovens. The monthly capacity of these ovens in 1914 was, approximately, 700,000 pounds. By April, 1917, when we stepped into the conflict, this capacity had been increased to 6,000,000 pounds a month.

By the time the armistice was signed our efforts for greater production had been carried on so successfully that the supply had been increased to 12,000,000 pounds a month, and the average cost of this was only 21 cents a pound. This tremendous increase of production not only took care of all demands for commercial purposes and permitted the shipment of about 11,000,000 pounds to the allied Governments, but was more than ample to take care of our own entire explosives program, leaving a stock on hand December 1, 1918, of 17,000,000 pounds.

A few details of how this tremendous increase in production was brought about through the energies of the officials charged with this task and the most efficient and whole-hearted cooperation of patriotic business concerns are interesting.

Three general sources existed from which toluol was obtained: first, from the by-product recovery coke ovens; second, by the stripping or absorbing of toluol from carbureted water and coal gas; and third, by the cracking or breaking down of oils.

[Pg 107]

In augmenting the supply of toluol through the first process, construction of additional by-product coke ovens by the following big steel companies was arranged:

The total cost of these additional ovens was about $30,000,000, which was met by private capital after contracts for the purchase of the product had been made, insuring a secure return on the investment. Production was to begin in 1919.

In addition to this there was arranged construction for 320 additional ovens at the following places:

From these sources the monthly production of toluol in 1920 would have been increased by 600,000 pounds a month.

While all these arrangements for vastly increasing the supply of this chemical in 1919 and 1920 were being made, technical experts of the Ordnance Department stimulated production by visiting existing by-product coke ovens and advising as to changes and alterations in the plants, both in regard to equipment and methods of operation.

Investigations were made early in the summer of 1917 on the possibility of recovering toluol by stripping illuminating gas, and a report was made on this subject in October, 1917. Construction of the necessary plants to carry out this plan was begun late in November, and the first plants were in operation in April, 1918. This was considered a remarkable record, in view of the fact that the operating personnel for the purpose had to be established and trained in this entirely new line of activity.

In this connection it is extremely interesting to note that the American people in 13 of the largest cities of the country played an unconscious part in contributing to the successful termination of[Pg 108] the war by using artificial gas of considerably less heating power, as a result of the removal of the toluol for explosive purposes. For example, in New York City, due to the extraction of toluol, the artificial gas there was reduced in heating value approximately 6 per cent and the candlepower lowered from 22 to 16 because of this stripping process.

Contracts for taking the toluol from artificial gas were made with companies in the following cities: New York and Brooklyn, N. Y.; Boston, Mass.; New Haven, Conn.; Albany, N. Y.; Utica, N. Y.; Elizabeth, N. J.; Washington, D. C.; Detroit, Mich.; St. Louis, Mo.; New Orleans, La.; Denver, Colo.; and Seattle, Wash.

The total cost of the installations made for this purpose in these cities in connection with the gas plants was about $7,500,000.

For the production of toluol by cracking crude oils or petroleum distillates, three processes of the many submitted were officially approved and contracts awarded for operation.

The first and most important of these was that of the General Petroleum Co. of Los Angeles, Calif. Under their scheme a yield of 6 per cent toluol was obtained from a petroleum distillate, of which there was a large quantity available, by treatment under temperature and pressure. To facilitate production of toluol by this means, two large plants, one at Los Angeles and the other at San Francisco, were erected at a cost of approximately $5,000,000. These plants have a monthly capacity of 3,000,000 pounds of toluol and their construction destroyed all possibility of a shortage in this vital raw material.

Another process was that known as the Rittman process, evolved by a scientist of the Bureau of Mines. This scheme, which called for producing toluol from solvent naphtha or light oils by cracking under high pressure and temperature, was finally demonstrated to be capable of operation under war conditions, and production had just started at a plant on Neville Island, Pittsburgh, Pa., at the time of the signing of the armistice.

A third process was that known as the Hall process, by which toluol was also obtained by cracking solvent naphtha under high pressure and temperature by another, different, mechanical system. This scheme was in operation on a small scale during 1918 at the Standard Oil Plant, Bayonne, N. J.

Phenol, one of the essentials in the manufacture of picric acid, was another raw material, the production of which was greatly augmented. At the time of our entry into the war the monthly production amounted to 670,000 pounds, while in October, 1918, it had been increased to 13,000,000 pounds. In December, 1917, the price of phenol as fixed by the War Industries Board was 46 cents a pound, while Government contracts in force a year later had reduced this figure to 31 cents a pound.

[Pg 109]

The price of sulphuric acid jumped from $14 a ton to $60 a ton early in the war, while nitric acid advanced from 5¼ cents a pound to 10 cents. The shortage of sulphuric acid was met by the erection of both chamber and contact plants in all high-explosives factories built for or under direction of the Ordnance Department.

Both pyrites and sulphur were used at the beginning of the war, but the submarine warfare stopped the importation of the pyrites from Spain, and therefore sulphur deposits in Texas and Louisiana were depended upon. A destructive storm in the early part of 1918 temporarily curtailed the production from Louisiana deposits, but repairs were made in time to prevent its effect being felt by the acid manufacturers.

The submarine also had the effect of lessening the importations from Chile of sodium nitrate, which prior to the war were depended upon entirely in the production of nitric acid. It became necessary, therefore, to develop other methods of production. After investigations a plant for the fixation of nitrogen under what is known as a modified Haber process was erected at Sheffield, Ala., while a plant for the same purpose using the cyanamide process was erected at Muscle Shoals, Ala.

Both of these were equipped for the oxidation of ammonia to nitric acid, each using a different process. When the armistice was signed these plants were just coming into production. The existence of these two nitrate plants insures the independence of this country in its supply of commercial nitrogen, either for peace or for war.

There were also in course of erection, though not in operation on November 11, 1918, great plants for the extraction of nitrogen from the air, at Toledo and Cincinnati, Ohio, but construction on these two plants, each of which was to cost $25,000,000, was stopped when the armistice was signed.

PROPELLANTS.

In army usage the term "propellant" includes both smokeless powder and black powder.

At the outbreak of the European war, the producing capacity in this country for smokeless powder was approximately 1,500,000 pounds a month. By the time the United States got into the war this capacity had been increased from 25 to 30 times, and under the explosives program laid down by us it was indicated that even this capacity would have to be greatly increased.

The increase in the production of smokeless powder was helped by the construction of two of the largest smokeless-powder plants in the world—one known as the Old Hickory Plant, located almost on the site of Andrew Jackson's old home at Nashville, Tenn., and the other at Nitro, near Charleston, W. Va.

[Pg 110]

The Old Hickory Plant was the larger and more complete of the two. It is probably the biggest plant of its kind in the world and is entirely self-contained; in other words, the plant actually takes the crude, raw cotton and, producing both the acid and solvents used, puts it through every process until the final product is attained.

Nine powder lines were planned for this enterprise, each with a capacity of 100,000 pounds per day, although developments from the early operations indicated that the ultimate production of the plant would reach 1,000,000 pounds a day.

The estimated cost of this huge undertaking was in the neighborhood of $90,000,000. Negotiations were begun in October of 1917 and led to a contract with the du Pont Engineering Co., under which this concern was to construct the plant and operate it for a six months' period after its completion.

Operation of the first powder line in the plant was to start September 15, 1918, or seven and one-half months after the signing of the contract. Ground was broken March 8, 1918, and work was pushed so efficiently and successfully that on July 1, 1918, the first powder line was put in operation, 75 days ahead of the schedule called for in the contract.

Some idea of the magnitude of this enterprise can be realized in the statements that the plant covers an area of 5,000 acres and that in addition to the powder plant proper there was built a city, housing twenty odd thousand people, complete with schools, churches, and all other elements that go to make up a town. There was also built in connection with the plant a number of subprocess plants for the manufacture of purified cotton, sulphuric acid, nitric acid, diphenylamine, and other chemicals used in powder manufacture. Each of these was an undertaking of no little size in itself.

Operation of the plant during the four and one-half months preceding the signing of the armistice showed a production in excess of contract requirements. On November 11, 1918, the plant was over 90 per cent complete and about 50 per cent in operation. At that time 6,000,000 pounds of powder over and above contract expectations had been produced, the total capacity having reached 423,000 pounds a day.

The second powder plant, located at Nitro, is somewhat smaller than the Old Hickory Plant. It has a capacity of 625,000 pounds of smokeless powder a day. It was built under the direction of D. C. Jackling, director of United States Government explosive plants, by the Thompson-Starrett Co., of New York. The contract was dated January 18, 1918, and ground was broken February 1. A contract for the operation of the plant was signed with the Hercules Powder Co., and at the time of the armistice the output was running approximately 109,000 pounds a day, with the expectation of early and speedy increase. As in the case of the Old Hickory Plant, a large village and many subprocess plants were constructed in connection with this enterprise.

NITRO, WEST VIRGINIA.

[Pg 111]

When the war began smokeless powder was dried by the circulation of warm dried air for a long period of time over the damp powder as it came from the solvent recovery house. This process required from six weeks for small-caliber powder to nine months for large-caliber powder. This time-consuming method being obviously impracticable in war, the Ordnance Department authorized the so-called water-drying process. This consists in the immersion of the powder as it comes from the solvent recovery house in warm water for varying periods up to 72 hours, the water then being expelled by filtration or centrifugal force and the surplus external moisture dried off by hot air. By this method the time of drying was reduced to 4 days for the small-caliber powder and to 22 days for powder for the larger caliber guns.

Just prior to the signing of the armistice an entirely new drying process had been experimentally tried out. This was known as the Nash or alcohol-drying process. The preliminary tests indicated that this method was a great improvement both in safety and in the reduction of cost. The indications were that drying could be reduced from days to hours by this new method. The Nash process also insured apparently a more uniform and tougher grade of powder, both of which characteristics were greatly to be desired.

In spite of the rise in price of labor and of almost everything else, the cost of powder was being reduced. At the beginning of the war cost figures were 80 cents a pound for small-arms and 53 cents a pound for cannon powder. When the armistice was signed these costs had been reduced to 62 cents for small-arms powder and 41¼ cents for cannon powder.

At the time of the signing of the armistice there was on hand approximately 200,000,000 pounds of smokeless powder.

It early became evident that the supply of cellulose, even though all available sources of supply were utilized to the utmost, would nevertheless be insufficient to meet our vast production program. For years it had been rumored that the Germans in the manufacture of their smokeless powder had been using, with great success, cellulose produced from wood pulp. Following out this idea, experimental work was undertaken in an effort to develop cellulose that could be produced from wood pulp in suitable physical form for nitration and which would meet the chemical requirements.

In the southern and southwestern portions of the United States there are large tracts of land from which timber has been removed and there[Pg 112] are also vast acreages of swamp lands. Processes developed by the Ordnance Department had in view the idea of taking as much of these lands as possible for farming and reforesting and utilizing the tree stumps thereon. These stumps contained quantities of turpentine and resin that could be recovered and the resultant pulp after proper treatment could be prepared in suitable form as cellulose for nitration purposes.

The question of black powder, while an important one, did not present many difficulties excepting one, the necessary supply of potassium nitrate. This was because Germany was the principal source of the potash. It was thought that sodium nitrate might possibly have to be used as a substitute. Experimental work along these lines indicated that by using certain precautions, this substitution, if necessary, could be made, although it was never adopted.

Black powder of all grades for military purposes was being produced at the rate of 840,000 pounds a month, at a cost of 25 cents a pound, at the time the armistice was signed. At that time there was on hand 6,850,000 pounds of black powder.

If the war had continued the United States could have produced during the year 1919 more than 1,000,000,000 pounds of smokeless powder. Two-thirds of this would have been available for our overseas forces and the balance would have gone to the allied governments. This rate of production would have amounted to about seven times the quantity of explosives normally manufactured in peace times.

LOADING THE PROPELLANTS.

In addition to solving the problem of producing a sufficient quantity of propellant powder there was also the problem, just as important, of assembling this powder into fixed ammunition, or loading it into bags. The Frankford Arsenal and commercial cartridge factories, after expansion, were enabled to take care of the expanded small-arms program. But it became necessary for the Government to erect and operate several great bag-loading plants. These were located at Woodbury, N.J., Tullytown, Pa., and Seven Pines, Va.

The ordinary cartridge fired from the rifle is familiar to most people. The projectile is fitted into the metal case in which the explosive force is contained. Projectiles for big guns are made along similar lines, until the 4.7-inch gun is reached. Up to and including guns of this caliber the projectile is fired with what is known as fixed ammunition—that is to say, the shell itself is fixed into a metal container which holds the powder.

Guns above the caliber of 4.7 inches, however, are fired with unfixed ammunition—that is, the powder is loaded in silk bags,[Pg 113] the projectile placed in the gun, and a number of bags, depending upon the size of the charge necessary, put into the breach of the gun behind the projectile. The powder is then ignited and the big shell ejected by the gases generated.

From the mills the powder is shipped to the bag-loading plants in bulk. The silken bags are manufactured in huge quantities by industrial plants and forwarded to the bag-loading plants, where are also daily received large quantities of metal and fiber containers, into which are loaded bags packed for overseas shipment not to be unpacked again until they have reached the battle field.

Filling the bags is a precise and delicate operation. Chances can not be taken or averages struck. Errors may mean the possible loss of battles. A battery commander who has figured his range and who is about to drop a number of high-explosive shell on an enemy battery must know exactly how much powder he has behind his charge. If more powder is in the bag than he calculates on, he will overshoot his mark; if less, the shell instead of dropping upon an enemy battery may explode in midst of his own advancing troops.

The three bag-loading plants the Government constructed at Woodbury, Tullytown, and Seven Pines were built to load bags that were to be used in firing guns from 155-millimeter caliber up to a caliber of 10 inches. The estimated average capacity of each plant was 20,000 bags a day, but as a matter of fact a maximum capacity of 40,000 bags a day at each plant had been reached before the signing of the armistice. Two shifts a day were used at these plants most of the time. In each shift there were approximately 3,500 operatives, most of them women.

At each of these plants, which are located in comparatively isolated points, because of the dangerous work, special housing facilities had to be constructed. For example, at Tullytown there were 70 bungalows, 13 residences for officers and executive heads, and six 98-room dormitories, while at Woodbury 19 great dormitories were built to house workers.

The number of buildings at Tullytown is 215. They range from guardhouses to electrical generating stations for power and light. Besides this construction there are between 22 and 30 miles of railroad track laid at each of these points. The extremely dangerous nature of the work makes it necessary to store not more than 400,000 pounds of explosives in a single building, and where powder is stored the buildings are at least 350 feet apart.

Up to the time of the signing of the armistice there were loaded into small-arms ammunition 19,741,500 pounds of powder; there were[Pg 114] assembled into fixed ammunition approximately 33,000,000 pounds of smokeless powder; and there were assembled into bags, properly packed for shipment, approximately 32,300,000 pounds of smokeless powder.

HIGH EXPLOSIVES.

When Europe was plunged into the great war in August, 1914, the American production of trinitrotoluol for commercial purposes amounted to approximately 600,000 pounds a month of varying grades of purity. This quantity was almost entirely consumed in the making of explosives for blasting purposes. When we entered the war this production had been increased to 1,000,000 pounds a month, exclusive of that which was being used here commercially. Under pressure of our own war-time needs the production of this highly important explosive chemical had been run up to 16,000,000 pounds a month at the termination of hostilities in November, 1918.

During the early stages of the war the average price of T. N. T. for military purposes was $1 a pound. Largely, however, because of the tremendous quantity production and enormous economies effected by reason of this, and despite the scarcity of raw materials, and notwithstanding the greatly increased labor cost, this price had been reduced at the time of the signing of the armistice to 26½ cents a pound. There were in the course of erection at the time of the armistice, two great Government T. N. T. plants—one at Racine, Wis., that was to have a capacity of 4,000,000 pounds a month, and one at Giant, Cal., with a capacity of 2,000,000 pounds a month.

During the war three grades of T. N. T. were produced. Grade I was used for booster charges—that is, those charges which initiated the explosive wave in the main shell charge. Grade II was used as a shell filler; while Grade III was utilized with ammonium nitrate in producing amatol.

In view of the fact that high explosives were produced in such enormous quantities and that it was necessary to carry on these tremendous manufacturing operations with an inexperienced force, the toll of life taken in the production was remarkably small. Only two explosions of any magnitude occurred in plants where explosives were manufactured and both of these took place in T. N. T. producing plants. One of these happened at Oakdale, Pa., in the plant of the Aetna Explosives Co. in May, 1918. This cost the lives of 100 persons. The other took place on July 2, 1918, at Split Rock, N.Y., in the plant of Semet-Solvay Co., where 60 people lost their lives. At the time of the explosions neither of these plants was operating on War Department contracts.

[Pg 115]

Before the great war about 58,000,000 pounds of ammonium nitrate used in the manufacture of commercial explosives were being produced annually in this country, at an average cost of about 12 cents a pound. By January, 1917, the commercial explosives manufacturers had extended their facilities so that they had increased their production by 1,700,000 pounds monthly. This expansion, however, was insufficient to meet our demands, and a Government ammonium nitrate plant was erected at Perryville, Md. This plant was operated under the supervision of the Atlas Powder Co., who also cooperated in its erection.

It did this manufacturing under the Brunner-Mond process that was developed in England under the patents of Capt. Freeth. Under this process ammonium nitrate is produced by the double decomposition of ammonium sulphate and sodium nitrate.

In December, 1917, the Atlas people detailed several technical men to go to England and study the Brunner-Mond process as carried on there. In 1918 these men returned to the United States and prepared designs as a result of the information they had gained abroad.

Ground was broken for the plant at Perryville March 8, 1918, and it was in production by July 15. This plant is a large one, of excellent construction, and absolutely fireproof, as is necessary because of the nature of the work conducted in it. Because of the type of the building the rapidity of its construction may well be classed as phenomenal. Even while the plant was being put up, experimental work of a highly technical nature was being carried on.

At the time of the signing of the armistice production of ammonium nitrate at the Perryville plant had reached 452,000 pounds a day, and this was greatly in excess of that being obtained at the English plant of a similar size that had been in operation for months before ground had been broken for our American plant.

Each of the Government-owned nitrogen fixation plants at Muscle Shoals, Ala., and Sheffield, Ala., was also equipped to produce ammonium nitrate by neutralization. Our total capacity from all sources at the time of the signing of the armistice was 20,000,000 pounds monthly. Ammonium nitrate is the one material in the field of explosives that shows an increase in price over that of normal times. The average cost of this substance used for military purposes was 17½ cents a pound. There were on hand 60,500,000 pounds of ammonium nitrate on November 11, 1918.

Picric acid as such is not used by this country directly for military purposes. But it is one of the raw materials used in producing ammonium picrate, or explosive D, and in the manufacture of the poisonous gas known as chlorpicrin.

[Pg 116]

Picric acid is, however, the main explosive used by the French, who had placed enormous contracts for this material with explosives manufacturers prior to the entry of the United States in the war. Because of our purchase of early large supplies of ammunition and guns from the French Government, to be largely paid for by picric acid, large contracts were entered into by our Government for this explosive, which was produced here in accordance with French specifications and subject to joint inspection by our officers and the French.

In November, 1917, we were turning out 600,000 pounds of picric acid monthly, and a year later this had been increased to a monthly production of 11,300,000 pounds; the average cost was 56 cents a pound.

To insure production quickly for the needs of the times, three Government picric-acid plants were authorized. One of these was located at Picron, near Little Rock, Ark., to be operated by the Davis Chemical Corporation; another was located at New Brunswick, Ga., to be operated by the Butterworth-Judson Corporation; and the third was located at Grand Rapids, Mich., for operation by the Semet-Solvay Co. All of these contracts were made on a cost-plus basis. Each of these plants was to have a capacity of 14,500,000 pounds of picric acid a month. The plant at Picron in Arkansas was the only one that had started production before the signing of the armistice.

Ammonium picrate, otherwise known as explosive D in our Army annals, is produced by the ammoniation of picric acid, and because it is more insensitive than picric acid and is less liable to form sensitive salts with metals it is used as the explosive charge for all armor-piercing projectiles.

Our average monthly production of ammonium picrate in May, 1917, was 53,000 pounds, and this had been increased without the erection of any Government plants to a monthly capacity in November, 1918, of 950,000 pounds. There was on hand at the time of the signing of the armistice 6,500,000 pounds of this explosive, the average cost of which was 64 cents a pound.

Tetryl, on account of its high cost and the lack of manufacturing facilities for its production, was not used except as a loading charge for boosters. It is more sensitive than T. N. T. and has a higher rate of detonation.

Only two companies, the du Pont Powder Co. and the Bethlehem Loading Co., manufactured tetryl. Expansion of these two plants increased the monthly capacity of 8,700 pounds in December, 1917, to 160,000 pounds in November, 1918, while its cost was reduced from $1.30 a pound to 90 cents a pound.

[Pg 117]

This increased capacity, however, was not in excess of our explosives requirements, and there was authorized by the Government the erection of a plant at Senter, Mich., that was to be operated by the Atlas Co., and which was to have a monthly capacity of 250,000 pounds. This plant had not reached production when the armistice was signed.

The Aetna Powder Co. at the time we entered the war was manufacturing for the Russian Government tetranitroaniline that was to be used in the loading of boosters and fuses. This company's plant at Nobleston, Pa., was destroyed by an explosion. Ordnance officers learned that this material was equal to tetryl as a military explosive. Consequently a contract was entered into with Dr. Bernhardt Jacques Flurschein, the holder of the patent rights, to have manufactured T. N. A. for our own uses. A Government plant was authorized for erection on the ground of the Calco Chemical Co., Bound Brook, N.J., to be operated by that concern. Production at this plant was to be on a cost-plus basis, the estimated cost of the material being 70 cents a pound. When the armistice was signed, about 8,000 pounds of T. N. A. had been produced, but none had been utilized.

Mercury fulminate, a very sensitive and powerful explosive, was used only in caps, primers, detonators, etc., as a means of initiating detonation, on account of its own high rate of detonation. The three plants operating in this country to produce this explosive for commercial purposes, the du Pont Co., Pompton Lake, N.J., the Atlas Powder Co., Tamaqua, Pa., and the Aetna Powder Co., Kingston, N.Y., expanded their facilities sufficiently to meet our program. Their average monthly production in 1918 was 50,000 pounds at a cost of $3.21 per pound, and there was on hand in November, 1918, 330,900 pounds of this explosive.

In the early stages of the war to meet the apparent shortage of T. N. T. and ammonium nitrate then existing because of our enormous explosives program, it was necessary to develop an explosive for trench warfare purposes that could be used for filling hand and rifle grenades, trench-mortar shell, and drop bombs. To meet this need, the Trojan Powder Co., of Allentown, Pa., submitted a nitrostarch explosive. After exhaustive investigations and complete tests, this explosive was authorized for use in loading the hand and rifle grenades and the 3-inch trench-mortar shell.

Development of a nitrostarch explosive for commercial purposes had been under consideration and investigation by two other large experienced manufacturers for a number of years, but the difficulties incident to the production and purification of nitrostarch were such that their efforts had met with little success.

[Pg 118]

The Trojan Powder Co., operating under secret process, solved this problem, and all nitrostarch explosives used were produced by this company, although another nitrostarch explosive known as "grenite," which was produced by the du Pont Co., was tested and authorized for use.

Our country was the only Government that used nitrostarch explosives during the war, and the development of this explosive made the loading problem easier and made possible the use of materials that were available and whose cost was low. The average cost of this explosive was 21.8 cents a pound. In July, 1918, the average monthly production of nitrostarch was 840,000 pounds and this had been increased by November, 1918, to 1,720,000 pounds a month.

There were loaded with nitrostarch explosive 7,244,569 defensive hand grenades; 1,526,000 offensive hand grenades; 9,921,533 rifle grenades and 813,073 three-inch trench-mortar shell. At the time of the signing of the armistice there was on hand of this explosive 1,650,500 pounds.

The du Pont Co. developed an explosive called lyconite, and this was authorized for use in the loading of drop bombs.

Anilite, a liquid explosive used by the French, was thoroughly investigated and improvements were made in it to render its use safer, but development had not progressed far enough to warrant authorization for its use prior to the signing of the armistice.

Chlorate and perchlorate explosives were also investigated and several types developed that were considered entirely satisfactory for use, but these never got into production before the end of the war.

AMMUNITION AND SHELL LOADING.

When we entered the war the quantity of field artillery ammunition on hand was considerably less than a single month's supply, basing our rate of expenditure on the estimated rate for November, 1918. There were no facilities of any degree of magnitude available to take care of our projected program for filling the high-explosive shell necessary for use by our overseas forces.

Consequently it became necessary at once to plan and to develop the resources of the country for the production of metallic parts, such as the shell proper, the fuse, boosters and adapters, as well as to design and build entirely new plants and to train completely new forces for the loading of the shell with the high explosives.

HIGH EXPLOSIVE NOSE FUSE SHELL

75M/M TYPE

Detonator (explosive)

Bourrelet

Explosive charge (T. N. T.) or (Amatol)

Smokeless powder

Primer (brass)

Adapter (steel)

Percussion fuse

Booster case, or Jacket, or Gaine. (cold drawn or pressed steel-machined)

Copper band or rotating band

Cartridge case (drawn brass)

GIRLS LOADING POINT-DETONATING FUSES FOR HIGH-EXPLOSIVE SHELL IN BODY-MACHINING DEPARTMENT OF A LOADING PLANT.

[Pg 119]

The explosion of an H. E. shell is really a series of explosions. The process of the burst is about as follows: The firing pin strikes the percussion primer, which explodes the detonator. The detonator is filled with some easily detonated substance, such as fulminate of mercury. The concussion of this explosion sets off the charge held within the long tube which extends down the middle of the shell and which is known as the booster. The booster charge is a substance easily exploded, such as tetryl or trinitroaniline (T. N. A.). The explosion of the booster jars off the main charge of the shell, T. N. T. or amatol. This system of detonator, booster, and main charge gives control of the explosives within the shell, safety in handling the shell, and complete explosion when the shell bursts. Without the action of the booster charge on the main charge of the shell, the latter would be only partially burned when the shell exploded, and part of the main charge would thus waste itself in the open air.

The shell used by our Army before the war had been largely of the base-fuse type. Interchangeability of ammunition with the French required that we adopt shell of the nose-fuse type. The boosters and adapters that went with this type were unfamiliar to our industry.

The adapter is the metallic device that holds the booster and fuse and fastens them in the shell. The adapter, therefore, is a broad ring, screw-threaded both outside and inside. The inside diameter is uniform, so as to allow the same size of booster and fuse to be screwed into shell of different sizes. The outside diameters of the adapters vary with the sizes of the shell they are made to fit, the rings thus being thicker or thinner as the case may require. Fuses of several sorts are employed by the modern artillerist; and with shell equipped with adapters, any fuse may be inserted in the field right at the gun.

Unexpectedly the manufacture of boosters and adapters proved to be much more difficult than it appeared to be at the start, and the shortage of these devices was a limiting factor in the American production of shell.

On May 1, 1917, drawings and specifications were sent to the principal manufacturers of ammunition and ammunition components inviting bids on 3-inch ammunition. These bids were opened on May 15, 1917, and after full discussion with the Council of National Defense orders were placed for 9,000,000 rounds of 3-inch shell and shrapnel ammunition. The bids for shell and shrapnel ammunition for all the other calibers of guns and howitzers we had on hand then were about to be asked, when the French mission to this country arrived; and the sending out of proposals was deferred, while discussion ensued as to changing our 3-inch and 6-inch artillery to 75-millimeter and 155-millimeter calibers, so as to make our ammunition interchangeable with that of the French. This decision was made June 5, 1917.

There then took place much discussion and consideration of the French ammunition. The French had several distinct types of shell,[Pg 120] ranging from the very thin walled high capacity kind to the thicker walled types. The French specifications were radically different from our own or those of the British. The steel shell in the French practice was subjected to a drastic heat treatment, which did not seem necessary to us for the thicker walled types of shell.

The French fusing system also was entirely different from that used by our service. French fuses were carried separately, and the adapter and the booster casing were screwed permanently into the shell.

Our decision to adopt French types of ammunition made it necessary to rearrange all our plans, and to obtain drawings of the shell, boosters, adapters, and fuses from France. This caused much negotiating, and a considerable amount of time was consumed in getting the necessary specifications and drawings here.

As a result of recommendations from French officials against production in this country during 1917 of the so-called "obus allongé" and the semisteel type of shell, no attempt was made to produce these for the 155-millimeter guns and howitzers during the first year of the war, but as a result of new recommendations and investigations of our officers in France in the spring of 1918 both of these types of shell were put into quantity production here. When the armistice was signed they were being turned out in such quantities that it appeared that there was sure to be an ample supply on hand in the early spring of 1919.

Radical differences of manufacture existed between the French and British in the matter of specifications and methods of production. Large quantities of British ammunition had been made in this country, and we had adopted the British 8-inch howitzer, so that it appeared we should use British practice in the manufacture of shell. Manufacturers claimed that great delay would result in the production of shell here if the heat treatment and hydraulic tests were insisted upon as the French specifications called for, and investigation proved this to be essentially true, as no facilities for heat treating and hydraulic testing existed.

The upshot of the entire matter was that it was decided to use French dimensions and shell for the 75-millimeter and 155-millimeter calibers so as to obtain uniformity of ballistics, but to permit American metallurgical practice to obtain in the manufacture. Shells made under these specifications were tested by the French commission in France. The verdict on these shell can be summarized in this quotation from their report:

Our designs for shrapnel and time fuses had been proven to be entirely satisfactory, and they were continued as they were. In fact[Pg 121] it was generally agreed that ours was the best time fuse used on the allied side during the war. That our decision in the matter of continuing production of shrapnel and time fuses was warranted, is borne out by the fact that we obtained early deliveries in sufficient quantities to meet requirements.

In the use of the adapters and boosters, which introduced an entirely new component to our service in shell making, we had had no experience, and subsequently met with great difficulties due to this lack of experience. Delays were encountered because in this part of shell manufacture it was generally necessary to await information from France whenever difficulties were encountered, or to conduct experiments before we could proceed.

When we began receiving our bids for 3-inch gun ammunition there were comparatively few factories in the United States that were able to turn out complete rounds of ammunition. There were many factories, however, capable of turning out one or more of the shell components. It was necessary to place orders for complete rounds of ammunition with those factories that could furnish them, and have the remaining components manufactured separately, and to provide assembling plants. To get as many factories as possible on a production basis in anticipation of the future large orders for ammunition that must necessarily follow with extension of operations by our field forces, orders for our initial quantities of ammunition were distributed as widely as possible.

To prevent confusion and loss of time because of the scramble for steel forgings and other raw materials it was decided that the Government would purchase all raw materials as well as furnish components for ammunition.

How successful we were in getting into quantity production on ammunition after the numerous and large obstacles in the early months of the war can be indicated best by the fact that of the 11,616,156 high-explosive shell for 75-millimeter guns machined up to November 1, no less than 2,893,367 passed inspection in October; while of the 7,345,366 adapters and boosters for 75-millimeter guns that had been machined up to the 1st of November, 2,758,397 passed inspection in October.

The figures for the 4.7-inch and 155-millimeter guns and howitzers follow:

[Pg 122]

Ammonium picrate or explosive D upon which this country had depended almost entirely up to the time of our entry into the war was forced into the shell under hydraulic pressure. The adoption of the point-fused shell and an explosive for shell filling new to this country, namely, amatol, made necessary the provision of new methods for shell loading and the expansion of plant facilities for these new methods capable of loading the vast and tremendous numbers of shell required in modern warfare. As a result of reports, following investigations by our officers of methods used abroad, various new shell-loading plants were built in the United States.

The names, location, and output of the shell-loading plants in our country are as follows:

It was found necessary in the early stages of the war to fill all shell with T. N. T., regardless of cost, until there could be built the required and properly equipped plants for the mixing and loading of amatol.

Two methods for loading T. N. T. were adopted. The one most largely used, however, was the casting method by which the chemical was brought to a molten condition in a steam jacketed kettle and poured into the shell. To do this two operations were usual. First, the shell was filled approximately two-thirds full with the molten material, and then as soon as a crust was formed this was broken through and the second filling took place. This process was necessary to prevent the formation of cavities in the filling charge. Such cavities cause breakdowns, resulting almost invariably in incomplete or entire failure of detonation.

The ammonium nitrate first produced in this country during the war was of such a character that proper densities could not be obtained when mixed with T. N. T. to form amatol. This difficulty was overcome after much investigation, and proper methods were outlined for the ammonium nitrate manufacturers, with the result that Grade III ammonium nitrate was produced as a sharp, hard crystal at a setting point of not less than 290° F. This was found to be perfectly satisfactory.

EIGHT-INCH SHELL BEING LOADED WITH AMATOL.

View of extruding machine bulkhead in background.

MARK V FUSE ASSEMBLY.

This picture shows two complete units for this assembly work. The operation begins in the foreground with cap assembly and progresses toward background, the fulminate detonator being inserted midway down table. The protecting bulkhead for cap supply is shown in the foreground.

[Pg 123]

The so-called 50-50 amatol, composed of 50 parts ammonium nitrate and 50 parts T. N. T., is loaded into shell by a casting method similar to that used in loading T. N. T. alone.

The so-called 80-20 amatol, composed of 80 parts ammonium nitrate and 20 parts T. N. T., was originally loaded cold, by hand, and then followed up with mechanical pressing. As a substitute for this method, which is accompanied by a certain element of danger, the use of hot 80-20 amatol, was resorted to in England. This was tamped by hand to the proper density, it being more compressible than cold amatol.

As this is an exceedingly tedious method of operation it was entirely done away with in England, except for large shell, by the use of what is known as the horizontal extruding machine. With this machine the British were able to load 80-20 amatol with great success into the 75-millimeter shell and higher calibers up to 8 inches.

This machine took a mixture of T. N. T. and ammonium nitrate in a jacketed hopper, so that the temperature might be maintained, and the hopper fed it down through a funnel upon a screw that was placed against the shell by counterweights to give the proper density. One of these machines was imported here from England, but, as it was unsatisfactory from a construction standpoint, new and satisfactory machines were built on the same principles of construction in our own amatol loading plants.

Experimental work with these machines was carried on at the Government testing station Picatinny Arsenal, Dover, N. J., and the du Pont Experimental Station, Gibbstown, N. J., as well as experimental plant operations at the Morgan plant of the T. A. Gillespie Co., Parlin, N. J., and the Penniman plant of the du Pont Co., Penniman, Va. All difficulties of the operations were overcome so satisfactorily that the greater portion of the loaded shell was produced by this method.

The metal parts as received at the shell-filling plant are inspected and cleaned to remove all traces of foreign matter such as grit or grease before being sent to the loading room. After being loaded the shell are again inspected. At intervals a split shell is loaded and then taken apart and examined, so that any loading defects may be found quickly and conditions remedied, before any large quantities of shell are produced.

The cavity left in the amatol by the tube of the extruding machine is filled with molten T. N. T., and a cavity is produced in this T. N. T.[Pg 124] into which the booster fits. This is necessary in order to provide for complete detonation. The booster cavity is produced either by the use of a former, which upon removal leaves a cavity of the proper size, or by plunging the booster into the shell filling before this is cooled, or by drilling out a cavity for the booster after the filling has been thoroughly cooled.

A large number of rounds of ammunition of all calibers had also to be loaded with a flashless compound that was inserted in the propelling charges, so that the discharge of the guns would not betray their positions to the enemy at night, while a smoke compound was inserted in a large quantity of shell so that each missile of this character might be located after firing to determine the accuracy of the shot.

Coordination of manufacture of metallic parts so as to cause the proper quantities of shell, fuse, and boosters to be produced without leaving any incomplete rounds that would have to be held awaiting other components caused the greatest difficulty.

The magnitude of the task of providing the necessary shell components in the tremendous quantities required can be better appreciated by a realization of the fact that the various parts of each component must be made to fit each other properly and perfectly. Gauging had to be resorted to frequently in the process of manufacture to make certain that there was perfect interchangeability of parts of each component to prevent any waste of time in selecting parts to fit each other.

The complete components, too, must themselves be made with equal care and scrupulous attention to make certain that they fit properly. Thus, the booster had to be made in such a fashion and with such precision and accuracy that it would fit perfectly into the shell as well as into the booster cavity in the shell filling into which it is screwed and also at the same time accommodate the fuse which screws into the booster.

This extreme accuracy made necessary a large number of gauges, which had to be designed at the same time as, and in coordination with, the design of the component. For example, in a complete round of artillery ammunition, 80 dimensions must be gauged. To standardize the gauges used for these 80 dimensions, 180 master gauges are required, while the actual number of different gauges used during the various stages of manufacture of a complete round is over 500.

Government inspectors required over 200 gauges in their work of inspecting and gauging the finished components for the shell, so in all about 800 gauges were used in the process of manufacturing a complete round of artillery ammunition, to insure interchangeability of parts, proper fit for the projectile in the gun, and perfect functioning of the various parts.

LOADING SMOKELESS POWDER.

Notice safety door at the girl's elbow. A flash in this room will not communicate to an adjoining room. The room is heated by overhead hot-air heating system.

FULMINATE COMPOSITION CHARGING, STEEL SHIELD, WITH WINDOW OF HEAVY GLASS TO THE RIGHT.

Girl operating the same device on the left. The view shows the bulkhead between the operations.

SHELL PAINTING.

This view shows the exhaust hood open and turntable lowered. Operator raises turntable by foot lever and closes hood before spraying.

GENERAL VIEW OF SHELL-PAINTING ROOM.

Shell is received on the elevated platform and trucked to the edge on hand trucks, where the trolley hook just enters the eyebolt as shell is removed from truck, thus making it unnecessary to lift the shell during any operation in this room.

[Pg 125]

All fixed ammunition was assembled at the shell-filling plants, making it necessary to install at these points storage capacity and equipment to handle the propellant powder as well as to fill the high-explosive shell. Boosters and fuses were loaded at separate plants and shipped to the shell-filling assembly places to be packed for shipment with the shell for transportation overseas.

The cost of a loaded 75-millimeter shell with the fuse and propellant charge ready to be fired is about $11. Such a shell contains a little over 1½ pounds of high explosive, which costs $1. The loading and assembling of the complete round costs $4.

A loaded 155-millimeter shell complete with fuse costs about $30, exclusive of the propellant charge of powder, which is loaded separately. A shell of this caliber holds about 14¼ pounds of high explosive, which costs $10, while the loading and assembling costs $4.

The 75-millimeter and 155-millimeter shell were used in the greatest quantities on the European battle fields, and at the time of the signing of the armistice our American loading plants were concentrating on filling ammunition for guns of these two calibers.

The nature of the work carried on at these shell-loading plants, of course, made the danger of a disaster ever present. Prior to our entry into the war an explosion at the Canadian Car & Foundry Co.'s plant, Kingsland, N. J., resulted in the entire destruction of the plant with large loss of life.

In October, 1918, the Morgan plant of the T. A. Gillespie Co., South Amboy, N. J., was wiped out by an explosion in which about 100 employees lost their lives. Plans for rebuilding this plant, had progressed far when the armistice was signed. In the fall of 1917, 40 people were killed in an explosion at the Eddystone Loading Plant, Eddystone, Pa.

For the successful carrying out of our program for the production of vast quantities of explosives and propellants, as well as shell loading, the women of America must be given credit, on account of the highly important part they took in this phase of helping to win the war. Fully 50 per cent of the number of employees in our explosive plants were women, who braved the dangers connected with this line of work, to which they had been, of course, entirely unaccustomed, but whose perils were not unknown to them.

In connection with the production of shell themselves, the American Ordnance Department adopted certain changes of design which were not only radically different from what we had known before the war but were interesting for the way in which they were brought about and for the results they accomplished.

[Pg 126]

The modern shell as we knew it before the war was simply a metal cylinder cut off squarely at the base and roundly blunted at the nose. The shell is zoned with a so-called rotating ring, a circular band of copper which by engaging the rifling channels of the gun gives to the shell the whirl that keeps it from tumbling over and over and thus holds it accurately on its course in flight.

In the proof-firing of the 6-inch seacoast guns it was discovered that their fire was none too accurate; and the American ordnance engineers began studying the shell to see if the fault lay there. One of these experts was Maj. F. R. Moulton, who before accepting a commission in the Army had been professor of astronomy at the University of Chicago. Maj. Moulton began a study of the 6-inch shell; and soon it was discovered that the mathematics which could chart the orbits of comets could also deal with the flight of projectiles, calculate the influences of air resistance and gravitation, and eventually work out new, scientific contours for offsetting these influences as much as possible.

Maj. Moulton first dealt with the inaccuracy of our 6-inch shell. He discovered the cause in the rotating band. Although but a slight portion of this band was upraised above the surface of the shell's circumference, yet the enormous force exerted upon the projectile to start it from the gun actually caused the cold copper to "flow" backward. The result was that when the shell emerged from the muzzle of the gun it bore around its sides an entirely unsuspected and undesirable flange. This flange not only shortened the range of the shell by offering resistance to the air, but it was seldom uniform all the way around, a condition giving rise to the idiosyncracies of our 6-inch shell as they were fired at the target.

The remedy for this was a redesigned rotating band, making it somewhat thicker in front. The "flow" of the copper could thus be accommodated without causing any detrimental distortion to the projectile. When this improvement was made the 6-inch shell became as accurate as any.

But Maj. Moulton was to make an even greater contribution to the 6-inch shell. This shell, like those of our other types, was square ended at the base. Maj. Moulton in his new design tapered in the sides somewhat, making the shell "boat ended." He elongated the nose, bringing it out to a much sharper point. The result was the first American "streamline" design for a shell. Shell of this new model were built experimentally and tested. The 6-inch gun could fire its old shell 17,000 yards, while the streamline shell went 4,000 or 5,000 yards farther—2 or 3 miles added to the range of an already powerful weapon by the application of brains and mathematics.

[Pg 127]

The French were experimenting with streamline shell. We adopted the French streamline 75-millimeter shell and put it into production, calling it our Mark IV shell. Our regular 75-millimeter shell, known as the Mark I 1900 shell, had a maximum range of 9,000 yards. The[Pg 128] Mark IV shell proved to have a maximum range of 12,130 yards, giving an increase in range of well over a mile. America up to April 3, 1919, turned out about 524,000 of these streamline shell.

The French also built shell of semisteel, steel to which iron was added. It was claimed that these shell, by bursting into fine fragments upon exploding, were more effective against troops than all-steel shell, because the fragments of the latter were larger. We adopted this shell also and produced it experimentally. In contour it was a compromise between the old cylindrical shell and the extreme streamline type and was easier to make than the latter.

[Pg 129]

The following table lists the name of each manufacturer of the various types and sizes of shell for big guns and states the quantity turned out by each:

CHAPTER VI.
SIGHTS AND FIRE-CONTROL APPARATUS.

At the threshold of the war with Germany we were confronted with the problem of providing on a large scale those instruments of precision with which modern artillerists point their weapons. As mysterious to the average man as the sextant and other instruments which help the navigator to bring his ship unerringly to port over leagues of pathless water, or as those devices with which the surveyor strikes a level through a range of mountains, are the instruments which enable the gunner to drop a heavy projectile exactly on his target without seeing it at all.

The old days of sighting a cannon point-blank at the visible enemy over the open sights on the barrel of the weapon passed with the Civil War. As the power of guns increased and their ranges lengthened, the artillerists began firing at objects actually below the horizon or hidden by intervening obstacles. These conditions necessarily brought in the method of mathematical aim which is known as indirect fire.

In the great war indirect firing was so perfected that within a few seconds after an aviator or an observer in a captive balloon had definitely located an enemy battery, that battery was deluged with an avalanche of high-explosive shell and destroyed, even though the attacking gunners were located several miles away and hills and forests intervened to obscure the target from view. With the aid of correlated maps in the possession of the battery gunners and the aerial observer, a mere whisper of the wireless sufficed to turn a torrent of shell precisely upon the enemy position which had just been discovered. So accurate had indirect artillery fire become that a steel wall of missiles could be laid down a few yards ahead of a body of troops advancing on a broad front, and this wall could be kept moving steadily ahead of the soldiers at a walking pace with few accidents due to inaccurate control of the guns firing the barrage.

The chief difference between the old and the new methods of artillery practice is the degree of precision attained. At the time of the Civil War the artillery was fired relatively blindly, reliance being placed upon the weight of the fire regardless of its accuracy and its effectiveness; but modern artillery has recognized the importance of the well-placed shot and demands instruments that must be marvels[Pg 136] of accuracy, since a slight error in the aiming at modern ranges means a miss and the total loss of the shot. Such uncanny accuracy is made possible by the use of those instruments of precision known as fire-control apparatus. The gunner who is not equipped with proper fire-control instruments can not aim correctly and is placed at a serious disadvantage in the presence of the enemy. These instruments must not only be as exact as a chronometer, but they must be sufficiently rugged to withstand the concussion of close artillery fire.

Equipment classified under "Sights and fire-control apparatus" comprises all devices to direct the fire of offensive weapons and to observe the effect of this fire in order to place it on the target. Included in this list are instruments of a surveying nature which serve to locate the relative position of the target on the field of battle and to determine its range. For this purpose the artillery officer uses aiming circles, azimuth instruments, battery commander telescopes, prismatic compasses, plotting boards, and other instruments. Telescopes and field glasses equipped with measuring scales in them are also employed in making observations.

Instruments of a second group are attached directly to the gun to train it both horizontally and vertically in the directions given by the battery commander. These devices include sights of different types, elevation quadrants, clinometers, and other instruments. The intricate panoramic sight which is used especially in firing at an unseen target is one of the most important instruments of this group.

Still another set of instruments comprises devices such as range deflection boards, deviation boards, and wind indicators which, together with range tables and other tables, assist the battery commander to ascertain the path of the projectile under any condition of range, altitude, air pressure, temperature, and other physical influences. When it is understood that the projectile fired by such a weapon as the German long-range gun which bombarded Paris at a distance of 70 miles mounts so high into the air that it passes into the highly rarified layers of the air envelope surrounding the earth and thus into entirely different conditions of air pressure, it can be realized how abstruse these range calculations are and how many factors must be taken into account. The fire-control equipment enables the artilleryman to make these computations quickly.

In addition to the above items many auxiliary devices are needed by the Artillery, notable among these being the self-luminous aiming posts and other arrangements which enable the gunners to maintain accuracy of fire at night. This whole elaborate set of instruments is supplied to the field and railway artillery—the big guns—and in part to trench-mortar batteries and even to machine guns, which in the latter months of the war were used in indirect firing.

[Pg 137]

Still another group of pointing instruments is used by antiaircraft guns against hostile aircraft to ascertain their altitude, their speed, and their future location in order that projectiles fired by the antiaircraft guns may hit these high and rapidly moving targets. Sights are also used on the airplanes themselves to aid the pilot and the observer in the dropping of bombs and in gunfire against enemy planes or targets. One of these sights corrects automatically for the speed and direction of the airplane.

Fuse setters, which enable the gunner to time the fuse in the shell so that the projectile moving with enormous speed explodes at precisely the desired point, were required in large numbers.

The responsibility for the design, procurement, production, inspection, and supply of the above equipment to the American Expeditionary Forces was lodged in the Ordnance Department. The effectiveness of the artillery on the field of battle depended directly on the fire-control equipment furnished by this bureau.

The optical industry in this country before the war was in the hands of a few firms. Several of these were under German influence, and one firm was directly affiliated with the Carl Zeiss Works, of Jena, Germany; the workmen were largely Germans or of German origin; the kinds and design of apparatus produced were for the most part essentially European in character; optical glass was procured entirely from abroad and chiefly from Germany.

It was easier and cheaper for manufacturers to order glass from abroad than to develop its manufacture in this country. Educational and research institutions obtained a large part of their equipment from Germany and offered no special inducement for American manufacturers to provide such apparatus. Duty-free importation favored and encouraged this dependence on Germany for scientific apparatus.

With our entrance in the war the European sources of supply for optical glass and optical instruments were cut off abruptly and we were brought face to face with the problem of furnishing these items to the Army and Navy for use in the field. Prior to 1917 only three private manufacturers in the United States had built fire-control apparatus in any quantity for the Government. The Bausch & Lomb Optical Co., Rochester, N. Y., had made range finders and field glasses for the Artillery and Infantry, and gun sights, range finders, and spy glasses and field glasses for the Navy; the Keuffel & Esser Co., Hoboken, N. J., had produced some fire-control equipment for the Navy; the Warner & Swasey Co., Cleveland, Ohio, with J. A. Brashear, Pittsburgh, Pa., had furnished depression-position finders, azimuth instruments, and telescopic musket sights to the Army. The only other source of supply in this country had been the Frankford Arsenal.

[Pg 138]

Prior to 1917 the largest order for fire-control equipment which our Army had ever placed in a single year amounted to $1,202,000. The total orders for such instruments placed by the Ordnance Department alone during the 19 months of war exceeded $50,000,000, while the total orders for fire-control apparatus placed by the Army and Navy exceeded $100,000,000.

To meet the situation, existing facilities had to be increased, new facilities developed, and other, allied, industries converted to the production of fire-control material.

Quantity production had to be secured through the assembling of standardized parts of instruments which heretofore had either never been built in this country or only in a small, experimental way. A large part of the work had of necessity to be done by machines operated by relatively unskilled labor. The manufacturing tolerances had to be nicely adjusted between the different parts of each instrument, so that wherever less precise work would answer the purpose the production methods were arranged accordingly. Only by a careful coordination of design, factory operations, and field performance could quantity production of the desired quality be obtained in a short time. Speed of production meant everything if our troops in the field were to be equipped with the necessary fire-control apparatus and thus enabled to meet the enemy on even approximately equal terms.

To accomplish this object a competent personnel within the Army had to be organized and developed; the Army requirements had to be carefully scrutinized and coordinated with reference to relative urgency; manufacturers had to be encouraged to undertake new tasks and to be impressed with the necessity for whole-hearted cooperation and with the importance of their part in the war; raw materials had to be secured and their transportation assured. These and other factors were faced and overcome.

Although American fire-control instruments did not reach the front in as large numbers as were wanted, great quantities were under way, and we had attained in the manufacturing program a basic stage of progress which would have cared for all of our needs in the spring and summer of 1919. Incidentally there has been developed in this country a manufacturing capacity for precision optical and instrument work, which, if desired, will render us independent of foreign markets. At the present time there exists in this country a trained personnel and adequate organization for the production of precision optical instruments greatly in excess of the needs of the country. One of the problems which we now have to consider is the conversion of this development brought about by war-time conditions into channels of peace-time activity.

[Pg 139]

At the present time American manufacturers are in a position to make instruments of precision equal to the best European product, and the industry will continue, provided there is an adequate market for its product. Such a market will exist if the universities and commercial laboratories of the country will obtain scientific apparatus from American manufacturers rather than import it from abroad as has heretofore been the custom.

In April, 1917, the most serious problem in the situation was the manufacture of optical glass. Prior to 1914 practically all of the optical glass used in the United States had been imported from abroad; manufacturers followed the line of least resistance and preferred to procure certain commodities, such as optical glass, chemical dyes, and other materials difficult to produce, direct from Europe rather than to undertake their manufacture here. The war stopped this source of supply abruptly, and in 1915 experiments on the making of optical glass were under way at five different plants—the Bausch & Lomb Optical Co. at Rochester N. Y.; the Bureau of Standards at Pittsburgh, Pa.; the Keuffel & Esser Co. at Hoboken, N. J.; the Pittsburgh Plate Glass Co. at Charleroi, Pa.; the Spencer Lens Co. at Hamburg, Buffalo, N. Y.

By April, 1917, the situation had become acute; some optical glass of fair quality had been produced, but nowhere had its manufacture been placed on an assured basis. The glass-making processes were not adequately known. Without optical glass fire-control instruments could not be produced; optical glass is a thing of high precision and in its manufacture accurate control is required throughout the factory processes. In this emergency the Government appealed to the Geophysical Laboratory of the Carnegie Institution of Washington for assistance.

This laboratory had been engaged for many years in the study of solutions, such as that of optical glass, at high temperatures and had a corps of scientists trained along the lines essential to the successful production of optical glass. It was the only organization in the country with a personnel adequate and competent to undertake a manufacturing problem of this character and magnitude. Accordingly, in April, 1917, a group of its scientists was placed at the Bausch & Lomb Optical Co. and given virtual charge of the plant; its men were assigned to the different factory operations and made responsible for them. By November, 1917, the manufacturing processes at this plant had been mastered and large quantities of optical glass of good quality were being produced. In December, 1917, the work was extended, men from the Geophysical Laboratory taking practical charge of the plants of the Spencer Lens Co. and of the Pittsburgh Plate Glass Co.

[Pg 140]

The cost to the Geophysical Laboratory of contributing to the Government the solution of the optical glass problem amounted to about $200,000, but the results attained surely more than justified these expenditures. These results could not have been attained, however, without the hearty cooperation of the manufacturers and of the Army and Navy, which assisted in the procurement and transportation of the raw materials. An ordnance officer was in charge of the Rochester party from the Geophysical Laboratory and was responsible for much of the pioneer development work accomplished there. It was at this plant, that of the Bausch & Lomb Optical Co. at Rochester, that the methods of manufacture were first developed and placed on a production basis. The Bureau of Standards aided in the development of a chemically and thermally resistant crucible in which to melt optical glass; also in the testing of optical glass, and especially in the testing of optical instruments. The Geological Survey aided in locating sources of raw materials, such as sand of adequate chemical purity.

By February, 1918, the supply of optical glass was assured; but the manufacture of optical instruments was so seriously behind schedule that a military optical glass and instrument section was formed in the War Industries Board and took charge of the entire optical instrument industry of the country. Through the efforts of its chief, Mr. George E. Chatillon, of New York, the entire industry was coordinated. By September, 1918, the production of fire-control instruments in sufficient quantities to meet the requirements of both the Army and Navy during 1919 was believed to be assured.

To the accomplishment of this result the Ordnance Department contributed most effectively. The information and long experience of Frankford Arsenal in instrument manufacture and in the work of precision optics were placed at the service of contractors; trained officers of the Ordnance Department were stationed at the different factories; in many factories these officers rendered valuable aid in devising and developing proper and adequate factory operations, in establishing production on a satisfactory basis, in securing the proper inflow of raw materials, in devising testing fixtures, in establishing proper manufacturing tolerances, and in testing the performance of the assembled instruments. Schools for operatives in precision optics were established at Frankford Arsenal, Philadelphia, Pa., at Rochester, N. Y., and at Mount Wilson Observatory, Pasadena, Cal. To many contractors financial aid had to be extended. The fire-control program required, in short, all the available talent and resources of the country to carry it to a successful finish.

The general procedure adopted by the Ordnance Department was to assign the more difficult instruments to manufacturers who had had experience along similar lines. To others, who had produced[Pg 141] articles allied only in a distant way to fire-control instruments, less intricate types of instruments were awarded. In certain instances the optical elements were produced by one firm, the mechanical parts by another, the final assembly of the instrument being then accomplished by the latter.

Because our Army had adopted a number of French guns for reproduction here, it became necessary to build sights for these weapons according to the French designs. This gave us much trouble, not only because of the delay in securing samples and drawings from France, but because of the difficulties in producing articles from these French drawings by American methods and with American workmen.

The most intricate of these French sights was the Schneider quadrant sight. It was used with the French 155-millimeter gun, the 155-millimeter howitzer, and the 240-millimeter howitzer. The structure of this sight was highly complicated, and extreme accuracy was required at every stage of production. These sights were put into production by the Emerson Engineering Co. of Philadelphia, the Raymond Engineering Co. of New York, and by Slocum, Avram & Slocum of New York.

The design of this sight was received from France early in 1918, yet it was the 1st of November—10 days before the armistice was signed—when the first Schneider sight was delivered to the Army; but at all times the progress made was as rapid as could be expected. A total of 7,000 Schneider quadrant sights was ordered, which meant a year's work for 1,000 men. Of this order 3,500 sights were to be manufactured by the Schneider Co. in France and the rest by the three firms in this country. On November 11 the American factories had delivered 74 sights and since that time over 560 have been completed.

The amount of labor involved in the case of Schneider quadrant sights is shown by the fact that while the raw material for it cost about $25, the finished sight is worth about $600. In order to expedite production the Government extended financial assistance to some of the factories to aid in the procurement and installation of additional equipment. On November 11 the number of these sights completed was short of requirements for installation on completed carriages by about 400, but the rate of progress which had been attained in production would have overtaken the output of gun carriages by January 1, 1919.

Another difficult task was the construction of telescopic sights for the French 37-millimeter guns, the "Infantry cannon" which we adopted for reproduction in this country. Here again we encountered the same difficulty of adapting French plans to our methods. The original contract was placed with a firm which had had no ex[Pg 142]perience with optical instruments of precision, but no other company was available for the work. When by May, 1918, this concern had produced only a few sights the contract was taken from it and placed with a subcontractor, the Central Scientific Co., of Chicago, who had been building mechanical parts for the sights. In this plant the complete force had to be educated in the art before any production could begin. When the armistice was signed the gun factories had produced 884 of the 37-millimeter guns, but only 142 telescopic sights had been completed. The rate of production of these sights by the Central Scientific Co. was such, however, that the shortage would have ceased to exist shortly after January 1, 1919.

The French design for the telescopic sight for the 37-millimeter gun used on the tanks was also adopted by the Army. Here again difficulty was experienced in manufacture, but excellent progress was made especially by one firm (Burke & James of Chicago, Ill.), and the output in adequate quantities was assured for 1919. The French collimator sight for the 75-millimeter gun presented difficulties to the manufacturer, especially in the optical parts. These were, however, overcome by the Globe Optical Co., who furnished the optics to the Electric Auto-Lite Corporation and to the Standard Thermometer Co. of Boston, with the result that at the time of the signing of the armistice the production of these sights was progressing well.

Periscopes from 20 inches to nearly 20 feet in length were produced in quantity. These periscopes enabled the men in the front-line trenches to look over the top with comparative safety. The long periscopes were used in deep-shelter trenches and bomb proofs. The production of the short-base periscopes and also of the battery commanders' periscopes by the Wollensak Optical Co., Rochester, N. Y., and of the 3-meter and 6-meter periscope by the Andrew J. Lloyd Co. of Boston, Mass., was progressing at such a rate that the needs of the Army for 1919 would be met on time.

At the outbreak of the war the policy followed by the Ordnance Department was to place orders for standard fire-control apparatus, such as range finders of different base lengths, battery commander telescopes, aiming circles, panoramic sights, musket sights, and prismatic compasses with firms of established reputation and experience. The result was that when requests from the Army in France came for instruments of new design, new sources of manufacture had to be sought out and these organizations educated in the methods of precision optics. Such a procedure necessarily caused delay, but it was the only course of action left. Wherever possible part of the total contract was awarded to an experienced manufacturer, so that some production was assured.

PANORAMIC SIGHT.

BATTERY COMMANDER'S TELESCOPE.

BATTERY COMMANDER'S PERISCOPE.

AIMING CIRCLE.

BRACKET FUSE SETTER, MODEL OF 1916.

RANGE FINDER.

FRENCH QUADRANT SIGHT WITH AMERICAN PANORAMIC SIGHT.

SIGHT FOR 75-MILLIMETER FIELD GUN.

[Pg 143]

The records show that the experienced manufacturers overcame the difficulties encountered and had obtained in general a rate of output which was satisfactory at the time of the signing of the armistice. Thus the Bausch & Lomb Optical Co. had delivered large numbers of range finders of base lengths of 80 centimeters, 1 meter and 15 feet, and battery commanders' telescopes; Keuffel & Esser had made many prismatic compasses and a few range finders; the Spencer Lens Co. had produced aiming circles in quantity; the Warner & Swasey Co., with J. A. Brashear of Pittsburgh, had furnished large numbers of the valuable panoramic sights with which much of the artillery fire is directed. Much credit is due the above organizations for the efficient manner in which they placed the manufacture of these items on a high-speed production basis. Frankford Arsenal proved to be a most reliable source of supply for battery commander telescopes, panoramic sights, azimuth instruments for 3-inch telescopes, plotting boards, and other ordnance fire-control instruments.

The manufacture of many other types of instruments was undertaken in this country. Among these the French sitogoniometer, a device which assists the battery commander in obtaining data for the direction of fire, was successfully produced by the Martin-Copeland Co. of Providence, R. I.; quadrant sights for the 37-millimeter gun by the Scientific Materials Co. of Pittsburgh; lensatic compasses and Brunton compasses were furnished by Wm. Ainsworth & Sons of Denver, Colo.; prismatic compasses by the Sperry Gyroscope Co. of Brooklyn, N. Y.; telescopes for sights on antiaircraft carriages by the Kollmorgen Optical Corporation of Brooklyn; altimeters, gunners' quadrants, elevation quadrants, and aiming stakes by the J. H. Deagan Co. of Chicago, Ill.; panoramic telescopes and fuse setters by the Recording & Computing Machines Co. of Dayton, Ohio; battery commander telescopes by Arthur Brock of Philadelphia; tripods for fire-control instruments by the National Cash Register Co. of Dayton, Ohio. Optics for different sights were furnished by the American Optical Co. of Southbridge, Mass., and by the Mount Wilson Observatory of Pasadena, Calif. These and other organizations entered into the task and devoted their energy to the production of equipment desired by the Government.

At no time during the fighting did our artillery units have a sufficient supply of fire-control instruments. This was due to the fact that we were not able to secure in Europe the amount of this equipment required to take care of our needs while our own industry was being developed.

With almost a total lack of optical glass in this country, with an equal lack of factories and workmen familiar with military optical instrument-making, we were suddenly called upon to produce about[Pg 144] 200 different types of instruments in large quantities. These included many new designs of fire-control apparatus made necessary by new artillery developments both among the allies and in our own factories, by the adoption of trench warfare in place of open warfare, by the development of weapons for use against aircraft, by the extension of indirect fire-control methods to weapons which formerly had been fired by direct sighting, and by the use of railway and seacoast artillery.

While we did not solve all the difficulties in this development, we had met and conquered the worst of them, and we were making such great strides in production when the war ended that all the requirements of the Army would have been met early in 1919. It has been a source of inspiration to witness the high sense of patriotic duty and cooperation shown by the manufacturers which made possible the remarkable expansion of the optical glass and instrument industry in the United States during the period of the war.

The following table shows the principal items of sights and fire-control apparatus, the firms that did the work, the quantity of the various kinds of instruments ordered, and the deliveries made up to November 11, 1918, and to February 20, 1919: