RML 12 inch 35 ton gun

• Name — 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 • Unit Cost — £2,154 • Weight — 35 long ton • Part Length — 162.5 in (bore + chamber) • Cartridge — 706 lb (Palliser) 613 lb (Common & Shrapnel) • Caliber — 12 in • Velocity — 1390 ft/s

This gun design originated in 1871 as an 11.6 inch gun firing a 700 lb projectile. Results were unsatisfactory, leading to the gun being bored out to 12 inch and firing a 706 lb shell.

Guns were mounted on: • s of 1873 Note: The two 12-inch guns installed in Thunderer'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. It was one of these "12-inch 38-ton" guns that was accidentally double-loaded and exploded on 2 January 1879.

• Illustration — Studded Palliser, Common and Shrapnel projectiles • Illustration — Studless Palliser, Common and Shrapnel projectiles 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 706 lb "Palliser" armour-piercing shot, which were fired with a "battering charge" of 110 lb of "P" (gunpowder) for maximum velocity and hence penetrating power. Shrapnel and common (exploding) shells weighed 613 lb and were fired with a "full charge" of 85 lb "P" or 67 lb "R.L.G.".