The Crane Co. was eventually able to reach a production of 33 of the 3-inch mortars a day, and up to December 5, 1918, it had built 1,803 completed weapons, together with the necessary tools and spare parts. In the early fall of 1918 an additional contract for 677 of these mortars was placed with the Crane Co. and another for 2,000 mortars of this size with the International Harvester Co., of Chicago. Neither of these two latter contracts ever came to the production stage.
A few days after the original contract for 3-inch mortars was let the Trench Warfare Section took up the matter of producing ammunition for these weapons. Two sorts of shell were to be required--live shell filled with high explosive and practice shell made of malleable iron. The original program adopted in November, 1917, called for the production of 5,342,000 live shell for the 3-inch mortars and 1,500,000 practice shell.
[Illustration: 3-INCH STOKES TRENCH MORTAR.]
[Illustration: 4-INCH STOKES TRENCH MORTAR AND AMMUNITION.]
[Illustration: 6-INCH SUTTON TRENCH MORTAR.]
[Illustration: 11-INCH SUTTON TRENCH MORTAR.]
The plan was adopted of building these shell of lap-welded, 3-inch steel tubing, cut into proper lengths. The contracts for the finished machined and assembled shell were placed with the General Motors Corporation at its Saginaw (Mich.) plant, with H. C. Dodge (Inc.), at South Boston, Mass., and with the Metropolitan Engineering Co., of Brooklyn, N. Y. In order to facilitate production, the Government agreed to furnish the steel tubing. For this purpose it ordered from the National Tube Co., of Pittsburgh, Pa., 1,618,929 pieces of steel tubing, each 11 inches in length, and from the Allegheny Steel Co., at Brakenridge, Pa., 2,332,319 running feet of tubing. These tube contracts were filled by the early spring of 1918.
The railroad congestion of February and March, 1918, held up the delivery of tubing, but the assembly plants utilized the time in tooling up for the future production. All the plants thereafter soon reached a quantity production, the General Motors Corporation in particular tuning up its shop system until it was able to reach a maximum daily production in a 10-hour shift of 35,618 completed shell.