The Works Of Messrs. Schneider And Co.

XXXII.-NAVAL MOUNTINGrS FOR QUICK-FIRING GUNS. F11HE construction of naval mountings for quick-firing -L guns is almost as complex a problem as that of breech mechanism ; and the complété solution of tbe question, as illustrated by the most modern types, has been graduai, though always steadily advancing. The con- ditions to be dealt with are very varied, as they differ with the calibres that range from the 37- and 47-milli- metre (1.456 in. and 1.850 in.) guns, to those of medium and large calibres up to the 24-centimetre (9.449 in.). Messrs. Schneider and Canet took a leading part in this work from the beginning, now more than twelve years ago, and they have since then transformer! and improved their first types, until those of 1898 embody the successive improvements which have résultée! from theoretical investi- gations and almost daily expérimenta in the testing ground. The general characteristics, taken as a basis for the first designs of these mountings, and which, although largely modified, grow more marked in tlie successive types, are the following : (a) Automatic recoil and return. (b) Use of progressive-acting brakes and recuperators, which absorb all shocks, so that the varions parts of the gun and mounting, as well as the firing platform, have only to withstand the minimum amount of strains con- sistent with the firing conditions. (c) Réduction in the power required for the varions manœuvres ; and grouping together, within easy reach of the gunner, the laying and training hand-wheels. (cZ) Réduction to a minimum of weight and bulk, resul ting in greater facility for inspection, dismounting, and maintenance. In order to give a means of comparison and an illus- tration of the progress achieved, we have selected some of the earliest types for illustration and description. i. Mounting with Brake Cylinder as Gun Housing (Fig. 730, Plate CXXIV.).—In this type the brake cylinder fonns the housing which surrounds and supports the gun, the latter being fitted with a ring that acts as a piunger or piston; a spring recuperator compressée! by the action of the brake complétés the system. The type illustrated shows a 10-centimetre (3.937 in.) mounting of this type, the principal data of which are as follow : Weight of gun 1980 kg. 4364 1b. ,, mounting ... 1900 kg. 4188 1b. ,, projectile... „ service charge (smokeless powder) 13 kg. 29 1b. 3.5 kg. 7.7 1b. Muzzle velocity in service ... 720 m. 2428 ft. This may be consiclered a gun of medium power. The varions parts and the gunners can be protected by a shield of suitable shape and dimensions, that vary according to whether the gun is for service on board ship or for coast defenee. It should be mentioned that, by means of a special device, the breech can be opened and closed automatically during the running out of the gun. The mounting consists of the three following main parts : the gun carriage, the traversing platform, and the bolster or fixed support. For naval mountings, this is circular, and is bolted to the deck of the ship ; for coast defenee, it is either fixed to the masonry-work or on a wrought-iron base. Its upper surface forms a roller path. The traversing platform rests on the rollers and the bed- plate, and consists of two parallel brackets strongly stayed together. The gun-carriage proper is formed of a cylindri- cal housing, carried by trunnions which rest in the trunnion plates of the traversing platform, the housing forming a cylinder, in which the gun moves to-and-fro during recoil and running out. A ring fitted round the gun, provided with openings, forms the brake piston. The recuperating cylinder is placed below the housing, and is in one piece with it, communication between the two being maintained by a pipe and valve. An air, or a spring, compressor eau be used indifferently. During recoil, the liquid which fills the space between the jacket and the gun passes from i the rear to the front of the brake piston. The diameter of the gun being larger in the front than in the rear of this piston, the liquid displaced is forcée! through the connecting pipe, lifts the valve, and entera the recuperator, j where, acting on a piston, it compresses the air or springs. When the recoil is finished, the liquid is forced back into the jacket through a narrow passage, and runs out the gun. For elevating the gun, a shaft with a hand-wheel is j provided, mounted on a bracket fitted to the left side of the carriage ; this works a pinion through a set of toothed gearing, which engages a toothed sector fixed to the | jacket, and the centre of which corresponds with the axis | of the trunnion. For latéral training, either direct action or transmission gearing can be employed. In the first | case, the gunner acts on a jointed lever on the left side of the mounting, and by working it to the right or to the left, he causes the mounting to turn round on its rollers ; previously, however, lie slightly presses down the lever, in order to disengage a bar which fixes the system in the firing position. In the second case, the lever is replacée! by a hand-wheel, which works a pinion through a set of