Platform

Is a strong flooring upon which a piece of ordnance, mounted on its carriage, is manœuvred when in battery. Its object is to facilitate the service of heavy guns and mortars, and to insure accuracy of fire. Fixed platforms are used for casemate and barbette batteries in fortifications, and are constructed with the works; siege-platforms for guns and howitzers; and siege-platforms for mortars; the other kinds are the rail-platform, the ricochet-platform, and the platforms for sea-coast mortars. Platforms should po e strength and portability, and the pieces composing them should be constructed of the same dimensions, viz.: 9 feet long, 5 inches wide, and 3 1 ⁄ 2 inches thick. The weight of each piece in a platform is about 50 pounds; and in a siege-platform for guns and howitzers, there are 49 pieces, 1 being used as a hurter on the front part of the platform to prevent the carriage from running too far forward, and 12 for sleepers. The weight of this platform complete is 2601 1 ⁄ 2 pounds. This platform is laid with an elevation to the rear, of 1 1 ⁄ 2 inches to the yard, or 4 1 ⁄ 2 inches in the whole length. This elevation is given to diminish the recoil of the piece and to permit the water to run off. The length of this platform is 15 feet by 9 feet. The platform for a siege-mortar is composed of only 6 sleepers and 21 deck-planks. It is laid level, and the front and rear deck-planks are connected by eye-bolts to every sleeper. This platform is about 9 feet deep by 9 feet wide, and weighs 1220 pounds. The rail-platform for siege-mortars consists of 3 sleepers and 2 rails for the cheeks of the mortar-bed to slide on, instead of the deck-plank, and is very strong, and easily constructed and laid. For method of laying platforms for siege-gun or howitzer, and for mortars, see “Hand-book of Artillery,” by Roberts, pages 143-47.