| Ordnance RML 11-inch 25-ton gun | |
| Type: | Naval gun Coast defence gun |
| Is Ranged: | YES |
| Is Artillery: | YES |
| Is Uk: | YES |
| Service: | 1867–1903 |
| Used By: | Royal Navy |
| Wars: | Bombardment of Alexandria |
| Manufacturer: | Royal Arsenal |
| Unit Cost: | £1,589 (18751)[1] |
| Variants: | Mk I, Mk II |
| Weight: | 25long ton |
| Part Length: | 145inches (bore + chamber)[2] |
| Cartridge: | 532to Palliser, Common, Shrapnel |
| Caliber: | 11sing=onNaNsing=on |
| Velocity: | 1360ft/s[3] |
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.
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.[4]
In 1874 the process of development made a "New Eighty-one Ton Gun" available in Woolwich.[5]
Guns were mounted on:
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 NaNlb "Palliser" armour-piercing shot, which were fired with a "Battering charge" of 85lb of "P" (gunpowder) or 70lb of "R.L.G." (gunpowder) for maximum velocity and hence penetrating power. Shrapnel and Common (exploding) shells weighed NaNlb and were fired with a "Full charge" of 60lb "P" or 50lb "R.L.G.".[6]