8-inch Slide.
The carriage is similar to the 7-inch, except that instead of being fitted for tackles it is provided with Scott’s nipping-gear and endless chain.[6] The chain is a slide attachment. The nipping-gear consists of a heavy iron stirrup, movable in a vertical direction by means of an eccentric and lever. The chain passes freely through this stirrup when it is down, but on throwing it up the links of the chain are caught in the teeth of a sprocket-plate fastened to the bed-plate of the carriage, so that the movement of the chain carries the carriage with it. The slide is similar to the 7-inch, except that the Scott chain and gearing is used, which also traverses the slide. There are two chains, one at each side of the slide, which are revolved by pinions at either end. At the rear end the pinions are on a heavy axle, which is revolved by a crank and gearing. For training, this gearing is connected to a short shaft, having a pinion at its forward end, which gears in a metal rack on the deck; this shaft may be revolved or fixed at will by means of a pawl-wheel and screw-break, so that in training the slide can be traversed or fixed as desired. When the slide is a shifting one, the same gearing is used to swing the forward end of it around, by means of another pinion which is shipped just in front of the forward end of the slide. The compressor is the Elswick pattern.
Elswick Compressor.
Carriage and Slide for 9-inch M. L. R.
The broadside 9-inch carriage is the same as the 8-inch; that for ships of the Sultan class differs in several particulars. The carriage is very low, its bottom plate coming well down inside of the slide. It is a double-plate carriage built on a cast-iron frame, the outer plate coming to the top of the slide, whilst the inner one is carried down inside. The rollers are completely hidden in their recesses, the forward ones being permanently in action, whilst the rear ones are on eccentrics. The rear axle between the rollers is bent down so as to give room for the breech of the gun in elevating.
9-inch Elevating-Gear.
The compressor fitted to this carriage is called the bow-compressor. It consists, on each side, of a bow or cramp pivoted at the centre, so that one arm projects inside the carriage through the bracket. A hinged plate is secured to the inner end, while the outer one holds an adjusting-screw which is worked by a hand-wheel, the latter having a pawl to hold it in any desired position. A brass arc near the face of this wheel graduated up to 17° shows the amount of compression. Two projecting pieces are attached to the side of the carriage to support the compressor-plates which hang upon them. These plates are three in number, the two inner ones being tapered, whilst the outer one is square-faced and much heavier. When the carriage is mounted on the slide, these tapering plates lie between the outer side of the slide (the T of which is filled out with wood) and two compressor-bars, which are tapered to correspond with the plates. The adjusting-screw takes against the outer plate, and by turning it the plates and bars are jammed together. The advantage of this compressor is that when once set it is self-acting, going out of action when the carriage is raised on its rear rollers, and coming into action by the weight of gun and carriage when the rollers are down.