51-IN. GUN.
187
5^-In. Gun on Muzzle-Pivoting Mounting (Figs. 610
and 611).
The following are sorne particulars of these guns, which
have been delivered to the Brazilian Government :
roller paths. The slide rests on the bolster through tlie
interposition of a series of truncated conical rollers. Steel
damps hold the slide to the bolster, and prevent it from
rising during firing. The gun-carriage consista of the
Fig. 610. Naval Gun and Mounting; Side View.
Fig. 611. 5.75-in. Naval Gun and Mounting; End View.
Weight of gun 3050 kg. 6710 1b.
,, mounting 2920 kg. 6424 1b.
,, projectile 36.3 kg. 81.8 1b.
,, charge (prismatic br. >wn powder) ... Muzzle velocity ... 13.6 kg. 29.92 1b.
518 m. 1699 ft.
Pressure ... 2000 kg. 12.70 tons per sq. in.
The breech-closing mechanism and firing device of
these guns are very similar to those last described. The
bolster, bolted on the deck, forms a circular sector in
the centre of which is a pivot around which runs the
mounting for training the gun. There are tw.o concentric
ordinary supports placed in guides on the slide ; two recoil
cylinders, communicating with each other, form part of the
gun-cairiage.
A pinion that gears in a curved rack fixed to the
gun serves to elevate it ; a set of gearing working a pinion
which engages a rack fitted round the bolster serves for
training.
The recoil cylinder is hydraulic, on the Schneider-Canet
system, with central counter-rod. The piston is drilled
with radiating holes, which allow the liquid to pass from
one end of the cylinder to the other. These holes are
closed by loaded valves. Vents of small diameter are