Coat hanger

[Tony Smith]

There is a fully restored, operational one that I understand is the only one in the Southern Hemisphere at Tairoa Head, Dunedin NZ. So clever design, a joy to see working.
The gun carriage is on a Hydro-Pneumatic ram. It is loaded and raised into position by a hand pump, then laid for aim. On firing, the recoil of the gun pushes it back into the lowered position, compressing the air in the ram. When reloaded, the air pressure in the ram raises the gun and puts it back on aim. The gun crew remain out of sight (and harm) in the gun pit. The really clever part of this coast defence gun is that by the time the target hears the shot, or feels it's effect, the gun has already lowered and it's position is hard to determine. It can be exposed and fired and rehidden in a matter of seconds since it comes back on aim when raised.