| Ordnance RML 12-inch 35-ton gun | |
| Type: | Naval gun |
| Is Ranged: | YES |
| Is Artillery: | YES |
| Is Uk: | YES |
| Service: | 1873–1909 |
| Used By: | Royal Navy |
| Design Date: | 1871 |
| Manufacturer: | Royal Arsenal |
| Number: | 15[1] |
| Unit Cost: | £2,154[2] |
| Weight: | 35long ton |
| Part Length: | 162.5inches (bore + chamber)[3] |
| Cartridge: | 706lb (Palliser) 613lb (Common & Shrapnel) |
| Caliber: | 12adj=onNaNadj=on |
| Velocity: | 1390ft/s[4] |
RML 12-inch 35-ton guns were large rifled muzzle-loading guns used as primary armament on British battleships of the 1870s. They were the longer and more powerful of the two 12-inch British RML guns, the other being the 25-ton gun.
This gun design originated in 1871 as an 11.6adj=onNaNadj=on gun firing a 700adj=onNaNadj=on projectile. Results were unsatisfactory, leading to the gun being bored out to 12inch and firing a 706lb shell.
Guns were mounted on:
Note: The two 12-inch guns installed in 's forward turret were 12.5-inch 38-ton guns bored instead to 12 inches, and designated "12-inch 38-ton", as the necessary 12-inch 35-ton guns were not available. These 2 guns used the same charges and projectiles as the standard 12-inch 35-ton guns installed in Thunderers aft turret which simplified the supply of ammunition.[5] It was one of these "12-inch 38-ton" guns that was accidentally double-loaded and exploded on 2 January 1879.
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 706lb "Palliser" armour-piercing shot, which were fired with a "battering charge" of 110lb of "P" (gunpowder) for maximum velocity and hence penetrating power. Shrapnel and common (exploding) shells weighed 613lb and were fired with a "full charge" of 85lb "P" or 67lb "R.L.G.".[6]