RML 11-inch 25-ton guns were large rifled muzzle-loading guns used as primary armament on British battleships and for coastal defence. They were effectively the same gun as the RML 12-inch 25-ton gun, bored to 11 inches instead of 12.

Design

Mark I was introduced in 1867. Mark II was introduced in 1871 using the simpler and cheaper "Fraser" gun construction method which had proved successful with the RML 9-inch 12-ton Mk IV gun. In 1874 the process of development made a "New Eighty-one Ton Gun" available in Woolwich.

Naval service

Guns were mounted on:

Ammunition

When the gun was first introduced projectiles had several rows of "studs" which engaged with the gun's rifling to impart spin. Sometime after 1878, "attached gas-checks" were fitted to the bases of the studded shells, reducing wear on the guns and improving their range and accuracy. Subsequently, "automatic gas-checks" were developed which could rotate shells, allowing the deployment of a new range of studless ammunition. Thus, any particular gun potentially operated with a mix of studded and studless ammunition. The gun's primary projectile was 536-543 lb "Palliser" armour-piercing shot, which were fired with a "Battering charge" of 85 lb of "P" (gunpowder) or 70 lb of "R.L.G." (gunpowder) for maximum velocity and hence penetrating power. Shrapnel and Common (exploding) shells weighed 532-536 lb and were fired with a "Full charge" of 60 lb "P" or 50 lb "R.L.G.".

Surviving examples