It was not until July, 1918, that the plans were ready for the 4-inch Newton-Stokes trench mortars. The American Expeditionary Forces estimated that they would require 480 of these weapons. A total of 500 drawn barrel tubes was ordered from the Ohio Seamless Tube Co., of Shelby, Ohio. This concern was able to ship one-fifth of its order within 10 days after receiving it. The barrels were sent to the Rock Island Arsenal for machining. The Crane Co., of Chicago, held the contract for building the bases, tripods, spare parts, and tools, and also for the assembling of the completed mortars. This factory was already equipped with tools for this work, since it had been building similar parts for 3-inch mortars. Consequently, the Crane Co., in August, almost within a month of receiving its contract, was producing completed 4-inch mortars and sending them to the Rock Island Arsenal for proof firing. The Ohio Seamless Tube Co. reached a high daily production of 83 barrel forgings per day; the Rock Island Arsenal, 10 machined barrels per day; and the Crane Co., 19 assembled mortars per day. [Illustration: 240-MILLIMETER TRENCH MORTAR.] [Illustration: 240-MILLIMETER TRENCH MORTAR SHELL.] We planned to build only smoke shell and gas shell for the 4-inch mortars. Large contracts for various parts of these shell were placed and the enterprise was gaining great size when the armistice was declared, but no finished smoke shell and only a few gas shell for 4-inch trench mortars had been produced. The contracts for the smoke shell were let in October, 1918, and work had not started further than the procurement of raw material before the armistice came. A large number of contractors expected to produce the parts for the 4-inch gas shell, and considerable of the raw materials were actually produced; but only one of the machining and assembling contractors, the Paige-Detroit Motor Car Co., actually completed any of these shell, and production at this plant did not start until December 5, 1918. _Production of trench mortars and trench-mortar ammunition._