[11]Carriage alone.
[11]Carriage alone.
[12]Carriages with recuperators.
[12]Carriages with recuperators.
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 VIEWS OF ANTIAIRCRAFT GUNS ON TRUCK MOUNTS.
TWO VIEWS OF ANTIAIRCRAFT GUNS ON TRUCK MOUNTS.
TWO OTHER VIEWS OF ANTIAIRCRAFT GUNS.
TWO OTHER VIEWS OF ANTIAIRCRAFT GUNS.
TWO OTHER VIEWS OF ANTIAIRCRAFT GUNS.
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 10degrees 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, however, 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.
[13]Project complete.
[13]Project complete.
[14]No deliveries made by Bethlehem Steel Co. on U.S. Army orders until after signing of the armistice because of priority given to British orders placed before the American declaration of war.
[14]No deliveries made by Bethlehem Steel Co. on U.S. Army orders until after signing of the armistice because of priority given to British orders placed before the American declaration of war.
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.
[15]Does not include 51 improvised mounts for which guns were furnished by French.
[15]Does not include 51 improvised mounts for which guns were furnished by French.
[16]Includes sixteen 155-mm. guns and carriages shipped without recuperators.
[16]Includes sixteen 155-mm. guns and carriages shipped without recuperators.
[17]Built for the Marine Corps.
[17]Built for the Marine Corps.
[18]Includes sixteen 8-inch howitzers built for the Marine Corps.
[18]Includes sixteen 8-inch howitzers built for the Marine Corps.
1½-TON ANTIAIRCRAFT MACHINE GUN TRAILER.
1½-TON ANTIAIRCRAFT MACHINE GUN TRAILER.
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.
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.
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.