At present the Elswick Company is engaged in supplying the Italian Government with breech-loading 100-ton guns. The breech-block is of the French type, and arrangements are made for moving the block as well as loading by hydraulic or steam power. The 100-ton gun has no carriage proper, its trunnions resting in heavy blocks on the fixed slide, being connected in rear with hydraulic recoil pistons which are themselves connected in such a manner as to equalize the strain of recoil. The movements of running out and in and loading are all performed by hydraulic power. The vent of the 100-ton gun is axial both in the breech and muzzle loader.
Armstrong Projectiles ([see page 209]).
Armstrong Fuze ([see page 211]).
Armstrong Breech Mechanism and Rotating Belt.
The points of peculiarity of the Armstrong breech mechanism are: 1st. The face of the breech-block is made slightly convex so that the gas-check springs back when the pressure comes on it, throwing the edge outwards, and making a wedged joint. This comes free again the moment that the block is started. 2d. The rear of the shaft holding the gas-check in place is held by a spiral spring, so that in turning the block to lock it the gas-check is not revolved in its seat.
CARRIAGES.
Naval gun carriages and slides, as a rule, are built of plate-iron, although many of the wooden ones are still retained in service for the lighter calibres. The lighter carriages are worked by tackles, and the heavy ones by gearing. Breechings are no longer used with slide carriages, the recoil being checked by friction compressors or hydraulic recoil cylinders and buffers.
Wooden carriages are furnished for all smooth-bores and breech-loading rifles, and for 64-pdr. muzzle-loaders. Iron carriages may be furnished for these guns, but wooden ones are never furnished for others.
The wooden standing carriage is the old-fashioned four-truck one. The wooden rear-chock carriage is similar to what is known elsewhere as the Marsilly. Breechings are rove through holes in these carriages, and are not attached to the guns. The wooden slide-carriages and their slides are of the ordinary old-fashioned type. The compressor for these carriages consists on each bracket of the carriage of two iron plates with hinged pieces on their lower ends. They are suspended on iron bolts passing through the bracket so that their lower ends hang down and overlap the side of the slide. Through the upper ends of the plates and the bracket an iron screw and lever passes, whose motion separates or approaches the pieces, allowing them to release or grip the slide. Some slide-carriages are provided with hydraulic recoil cylinders.