The Works Of Messrs. Schneider And Co.

15-CENTIMETRE QUICK-FIRING MORT AR. 231 original position. This type will be described in a separate section, which deals with disappearing gun carriages. 2. Circular Slide Mountings.—These are made with a traversing platform embodying circular vertical slides, the centre of which coïncides with the axis of the trunnion. By this arrangement, whatever be the angles of elevation, the axis of the hydraulic cylinders follows the direction of the firing line, thus reducing the effort of percussion. A complété description of a mounting of this type has been given in a preceding section, in connection with an ordinary 14-centimetre gun. Fig. 766 shows a 22-centimetre (8.661-in.) howitzer on a mounting with circular traversing platform. Weight of howitzer ... ,, mounting... ,, projectile... Muzzle velocity in service Elevation Training 3,500 kg. 11,600 kg. 116 kg. 300 ni. - 5 deg. + 60 deg. 360 deg. 7,714 1b. 25,566 1b. 255 1b. 984 ft. — 5 deg. + 60 deg. 360 deg. 15-Centimetre Quick-Firing Mortar (Figs. 767 and 768).—The principal parts of this are the following : The mortar, with its breech-closing arrangement ; the housing ; the slide and the bedplate. Plan of 15-Centimetre Howitzer and Mounting. The mortar is furnished with a breech mechanism of the two-action type. To the rear is screwed a recoil jacket, to which is fixed the head of the hydraulic recoil piston. The housing is provided with trunnions, and consists of a cylindrical body in which the mortar slides, and of an hydraulic recoil cylinder with constant résist- ance. The piston is held by the recoil jacket, and a counter-i’od is provided of a slightly larger diameter, which, by penetrating the cylinder during recoil, forces part of the liquid to flow into the recuperator. This is placed outside the right bracket of the slide, and consists of a vertical cylinder in which moves a double diaphragna, combinée! with a set of springs. Communication is established between the recoil cylinder and the recu- perator by a pipe which passes through the centre of the right trunnion of the housing ; a loaded valve placed on the circuit followed by the liquid, is raised during recoil, and falls back on its seat when the recoil is spent. The liquid can only return by flowing through small vents cut in the valve seat ; the mortar then runs out slowly under the relaxing of the recuperator springs. On the left side of the recoil cylinder is the circular rack for elevating the mortar. The slide consists of two brackets, made with stiffening ribs, and strongly stayed togetlier. Its lower part forms a circular plate, round which is the racer that carries the balls for facilitating the rotary movement ; in its centre, the plate is in the shape of a vertical cylinder, which fits on the fixed pivot of the bedplate. The slide is, moreover, provided with the necessary lugs and projections for the fixing of the setting mechanisms. Two clasps, one in front and one in the rear, prevent all raising of the system. The bedplate on which the slide rests is fitted with a circular rack for training the mortar, and with a rine' plate, in the holes of which the foundation bolts are placed. Its central part forms the fixed pivot. The required elevation is obtained by operating the handwheel placed on the left of the slide. This works through two conical pinions, an endless screw and a set of differential gearing, the right-hand pinion which engages the fixed toothed sectoi-, which is on the left side of the housing. The mortar is trained by turning a second handwheel placed slightly to the rear of the preceding one. It works, through an endless screw and a hélicoïdal wheel, a vertical pinion gearing with the circular rack on the bolster. To train the mortar by means of these two hand- wheels, the gunner rests his shoulder on the butt-end, which is so placée! that he can immediately cast his eye on the line of sight. This mounting takes up but little room, and is suitable for large-calibre guns, without any extra provision for stiffening the decks of ships being required. The following are particulars of the 15-centimetre (5.905-in.) quick - firing mortar, on central - pi voting mountinçr : Weight of mortar ... ... ... 480 kg. 1058 1b. ,, mounting... ... ... 2700 kg. 5950 1b. ,, projectile... 40 kg. 88 1b. Muzzle velocity in service ... ... 200 ni. 656 ft. Elevation - 5 deg. - 5 deg. + 60 deg. + 60 deg. Training 360 deg. 360 deg. The above brief data will show that the Schneider- Canet material solves this particular problem, as regards the use of mortars and howitzers on board battle- ships and cruisers.