The Works Of Messrs. Schneider And Co.

NAVAL MOUNTINGr WITH HORIZONTAL SLIDES. 215 gearing that engages a circular rack on the bolster. In this type of mounting, tha lateral sights are fixed to the housing and are not affected by the recoil ; the gunner can, therefore, constantly follow the aim during the whole of the service operations, including firing, recoil, and running out. Kigs. 731 to 733, Plate CXXV., illustrate a modification of this type of mounting for a 65-millimétré (2.559-in.) 50-calibre quick-firing gun ; the slide and bolster are, however, of a particular shape, and there is a special system for elevating the gun. The base of the mounting has the form of a truncated cone, bolted on the deck ; the top forms the circular path for the slide, while in the base is the pivot in which the steel pivoting screw rests that supports the slide, which iß guided by a friction ring. The slide is of cast steel, witli two brackets joined at the bottom by a circular plate, and carefully stayed. It is extended downwards by an inverted cone, terminating in a wroue'ht-steel bearing which rests on the rounded head of the pivoting screw ; brass friction rings are fitted on ail the parts that undergo friction. Side openings, usually closed, are cut in the walls of the bolster, to facilitate inspection of the pivot. The gun is trained by the shoulder pressing on the butt rest, which is Hxed rigidly to the slide ; part of the length is screwed and is provided with a box nut, to which is fitted the working hand-wheel ; a hollow cylinder sur- rounds the butt-rod, and slides on it governed by the box- mit ; it is joined to the gun-housing by a bar which ends above the left trunnion ïhe whole of this mechanism, under the action of the hand-wheel, causes the gun-housing to turn round on the trunnions, thus giving the requirecl elevation. The system is completed by a sight bracket fixed to the housing, and by a jointed bar which unités the head of the sight to the axis on which the longitudinal bar acts that unités the hand-wheel to the gun-housing. The gunners and the varions parts of the mechanism can be protected by a shield, the shape and dimensions of which vary according to requirements. 2. Mounting with Horizontal Slides (Fig. 734, Plate CXXIV.).—This type is fitted with fixed horizontal slides ; the tangent scale reeoils with the gun horizontally, and sighting requires the co-operation of two gunners. These arrangements are not cornpletely in accord with the Weight of gun 6300 kg. 13,885 1b. ,, mounting ... 4650 kg. 10,248 1b. ,, projectile ... „ service charge (smokele'-s powder) 40 kg. 88 1b. 10.5 kg. 23 1b. Muzzle velocity in service ... 740 m. 2428 ft. general conditions of the programme already given, and according to which quick-firing Schneider-Canet guns are usually mounted. They have been reproduced in a small number of guns only. In this type of carriage, elevation and training are effected exclusively by elec- tricity, the motor being controlled by one lever. The present description applies to 15-centimetre (5.905-in.) guns, shown in Fig. 734, Plate CXXIV. A suitable shield is made for naval and coast-defence guns. The mounting consista of the three main parts, as usual. The upper face of the traversing platform is made with two horizontal bearing surfaces, on which travel the horizontal slides. These are provided with rollers, to facilitate the displacement of the cradle during the recoil and running out of the gun. The cradle contains the lateral brake cylinders, and also the recuperator placed below, and in the centre line of, the system. The brakes have central counter-rods, and carry the trunnion-plates in which the gun trunnions are placed. The piston-rods are fitted in the front of the travelling platform. The recuperator cylinder is provided with lugs in front, to which are fastened the spring bars. A piston, the rod of which is fixed to the front of the traversing platform, moves in this cylinder during recoil, the cylinder being elosed at the opposite end by a movable bottom, on which are bolted the bars that run in the centre of the set of springs. When the gun is fired, the carriage proper runs on the rollers, which are placée! sliglitly above the top surface of the horizontal slides, and the brake cylinders act in the usual way to absorb part of the recoil energy. The mounting is provided with two sets of gear for elevating and for training the gun, which can be worked by electricity or by band. For elevating by hand, the device comprises a hand-wheel placée! at the rear part of the housing, which works through differential gearing, a pinion that engages a rack fitted to the gun. For training, a hand-wheel is placed in the middle of the left eheek, which works through a set of tootlied wheels, a pinion that gears in the circular rack placed inside the traversing platform. Two small electric motors are provided for driving the elevating and training mechanism ; but, as working by hand and by electricity are not required at the same time-, a lever and clutch are added that throw one or other in or out of gear. The electric motors are driven by a battery of accumulators. The commutators are arrangée! in such a way that the gunner, by acting on the lever in the direction he wishes to give the gun, obtains exactly the position required. The rapidity of the motion is pro- portional to the angle of displacement of the lever from its original position, the gun being fixed immediately it is suitably laid. 3. Mounting with Oscillating Slides (Figs. 735, 740, and 741, Plate CXXVL).—In this type, the slides can be Weight of gun 3130 kg. 6898 1b. ,, mounting ... 3150 kg. 6942 1b. ,, projectile ... 21 kg. 46 1b. ,, service charge (smokeless powder) 6 kg. 11 1b. Muzzle velocity in service 740 m. 2428 ft. inclined according to the degree of elevation requirecl 3 B