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,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-builtand 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 industryto 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.
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.
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, withoutwaiting 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 out25 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.
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 ofartillery 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 emergencythat 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 byFrance 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 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 wasabandoned 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.
THE 37-MILLIMETER INFANTRY CANNON.
THE 37-MILLIMETER INFANTRY CANNON.
TWO VIEWS OF 75-MILLIMETER FIELD GUN, MODEL 1918 (AMERICAN).
TWO VIEWS OF 75-MILLIMETER FIELD GUN, MODEL 1918 (AMERICAN).
TWO VIEWS OF 75-MILLIMETER FIELD GUN, MODEL 1918 (AMERICAN).
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 acarriage 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.