The 6-in. guns are mounted on the well-known central pivot principle.
This principle was first introduced by Sir W. G. Armstrong, Whitworth
and Co., and has since been adopted for mounting guns of medium
calibre by all the Governments and armament constructors in the world.
Briefly, to describe this system, it may be said that the gun is
mounted in a cradle in which it recoils, the recoil being absorbed by
an oil buffer attached to it forming a part of the cradle, the piston
of which is attached to the gun. The cradle is mounted by means of
trunnions on a Y piece, which revolves on hard steel balls placed on
a fixed pedestal. This pedestal is bolted to the ship’s structure,
the elevating arrangements are attached to the cradle, thus enabling
the elevating gun number to work the gear even during the firing of
the gun without injury to himself. Telescopic sights are fitted in a
convenient position. Electric circuits are fitted to enable the guns to
be fired by the simple operation of pressing the trigger of a pistol.
Arrangements for percussion firing are also provided. A circular shield
is attached to the revolving Y piece, so as to keep the port opening in
the ship’s side blocked up at any angle of training. This port opening
allows for the guns to be trained through a range of 120 deg., viz. 60
deg. before the beam and 60 deg. abaft.