340 
NEW GARRISON CARRIAGES. 
order to give them better bearing on the racers and prevent the latter 
being dented on discharge. The racers (steel) to be without flanges, 
4 \ ins. in thickness, and simply bedded in concrete; the front racer 
in one piece, the rear in two. 
2. To modify the hydraulic buffer, on an ingenious plan proposed 
by Mr. Butter (Manager R.C.D.), in order to prevent the shock on 
discharge to the platform and its fittings from the sudden check to 
recoil. The modification consists in replacing the ordinary four holes 
in the piston by a semicircular groove at each side of it—the latter 
fitting over a rib secured along the interior of the buffer cylinder. The 
clearance between the grooves and ribs furnishes the passage for the 
return flow of the oil on discharge, and this clearance is made variable 
—large at first, so that there may be comparatively little opposition to 
recoil, and gradually decreasing after, that the opposition may increase— 
by making the ribs tapering. An adjusting arrangement is also added 
by which the amount of clearance or area of passage can be varied 
with the charge (or probable violence of recoil), consisting of sliding 
pieces placed in the piston head, which by means of a wedge can be 
pushed out to reduce, or drawn in to increase, the area. The wedge is 
moved as required by a graduated screw in the top of the piston, to 
get at which it is necessary to bring the latter under the filling hole of 
the buffer. 
3. To fit the carriage and platform with a “compressor stop,” 
in order to hold the carriage after recoil, and prevent its running up of 
itself. The stop to be formed by two compressor bars under the 
carriage, which on recoil enter and jam between corresponding plates 
on the platform; the latter being set to give the required amount of 
compression, or relieved, by a lever handle at the side of the platform. 
4. To fit the platform with “chain loading” gear (designed in 
R.C.D.), consisting of a pitch chain, formed to bend in one direction 
only, which serves as rammer or sponge stave, the required head 
being keyed to it. The chain lies in an iron trough under the 
centre of the platform, from which it is led to the muzzle by an 
iron standard attached to the breast of the platform; the standard 
being made telescopic in two parts, so that the upper portion may be 
moved clear when the gun is run out. The chain is worked by a 
sprocket wheel, which is driven through suitable wheels and pinions, to 
gain the necessary power, by winch handles at the sides of the platform. 
5. To fit the platform for traversing by external power.* (1) By 
“ steam,” the power being conveyed to the platform by shafting; (2) 
by “ hydraulic power,” conveyed through tubing: in each case the 
power to be applied to the existing traversing and running-back gear 
of the platform, also to work the chain-loading gear and further 
bollards, placed one on each side of the platform, for the loading 
tackle. 
* In a casemate platform, the pivot being imaginary and lying much to the front, it is difficult 
to transmit motion from any fixed point in the casemate to any fixed point in the platform ; the 
distance varying in length and direction with the angle of traverse of the latter. 
