PLATFORM, Military, is the floor of wood or stone on which heavy guns are placed in order to be more easily worked. In fortresses the platforms are occasionally made of stone in order to withstand long exposure to the weather, but in field-works they are always of timber. For guns the platforms are laid with a slight rise to the rear (about inch in the foot) to enable the gun to be more readily run up after the recoil. The mortar platforms are laid level. The ordinary gun and howitzer platform which, when laid, forms a rectangle 15 ft. long by 10 ft. 6 in. broad, consists of the following pieces : 5 sleepers, each 15 feet long x 5 in. x 5 in.
20 planks ,, 1.01, 9 2 2 ribbands 15 4 4 10 rack-sticks and lashings, or iron bolts.
The weight of the platform is about 14 cwt.
The sleepers are first laid in the direction of the line of fire in cuts or trenches made in the ground, which has been previously levelled, and are firmly pinned down. They are then covered with the planks, which are laid at right angles to the line of fire, and, the ribbands being placed directly over the outside sleepers, are fixed down by the rack lashings, which have been placed, five on each aide, under the sleepers before they were laid.
The platforms may be fixed with screws, or spikes, instead of rack lashings ; but this, besides injuring the wood for further use, should it be necessary to move them, is a noisy operation, likely to attract the enemy's attention if the batteries are close to his works.
There is a description of gun-platform invented by Colonel Alderson, R.E., in which all the pieces, superstructure, and sleepers are of the same size, and are fitted together with dowel pins.
Platforms for mortars, which are laid horizontally, are generally 7 ft. 6 in. by 6 ft. 6 in. In order to resist the effect of the recoil of the mortar, which is fired at an angle of 45°, the sleepers and planks are stronger than in the gun-platform, and seven sleepers are used instead of five. Two sleepers being first laid transversely, then the
five across them, and then the planking.
Madras platforms for guns are composed of a strong framework of wood, consisting of two side.pieces, 12 ft. G in. long and 9 in. x 4 in., on which the wheels of the gun run, and two trail pieces 12 ft. 6 in. long and 4 in. square, for the trail of the gun (this platform being used for guns on travelling carriages). The whole platform is kept together and strengthened by a front and rear transom and three sleepers, to which the side and trail pieces are bolted down. The front transom is fixed close to the parapet, and the platform has a rise to the rear of 8 inches. This platform is very good for siege purposes, and when no great lateral splay is required ; for when it is necessary to change the line of fire the whole platform has to be traversed with handspikes. Siege platforms, as has been stated, are generally made rectangular ; but the stone platforms used in permanent works are made wider at the rear, so as to allow the guns a greater splay. This is not so much required in siege works when the guns have a fixed object, and would further make the platforms more complicated and difficult to lay at night, while the pieces not being uniform would not be interchangeable.
In fortresses, at the salients and in casements, and in coast batteries, the guns are now often mounted on traversing platforms. The gun is then raised on a platform which traverses on runners, the pivot being fixed either in front, centre, or rear.