RML 16-inch 80-ton gun
|Ordnance RML 16-inch 80-ton gun|
|Place of origin||United Kingdom|
|Used by||Royal Navy|
|Wars||Bombardment of Alexandria (1882)|
|Designer||Royal Gun Factory|
|Barrel length||288 inches (7.3 m) (bore)|
|Shell||1,684 pounds (763.8 kg) Palliser, common, Shrapnel|
|Calibre||16-inch (406.4 mm)|
|Muzzle velocity||1,590 feet per second (480 m/s)|
|Maximum firing range||8,000 yards (7,300 m)|
RML 16-inch 80-ton guns were large rifled muzzle-loading guns intended to give the largest British battleships parity with the large guns being mounted by Italian and French ships in the Mediterranean Sea in the 1870s.
Design and history
The gun was constructed of a toughened mild steel inner "A" tube surrounded by multiple wrought-iron coils, breech-piece and jacket. Rifling was of the "polygroove plain section" type, with 33 grooves increasing from 0 to 1 turn in 50 calibres (i.e. 1 turn in 800 inches) at the muzzle.
After a long design and experimentation period beginning in 1873, HMS Inflexible with four guns became the only ship to mount them, in 1880. By that time such muzzle-loading guns were already obsolescent and were being superseded by a new generation of rifled breechloading guns.
Two more guns were mounted for coastal defence in the Admiralty Pier Turret at Dover.
This was a second-generation RML gun, equipped with polygroove rifling and firing only studless ammunition and using automatic gas-checks for rotation.
The only two remaining example are in the ruins of the Admiralty Pier Turret, Dover, Kent, UK.
Notes and references
- Brassey 1882, Page 95
- Text Book of Gunnery 1887, Table XVI
- 1590 feet/second firing a 1684-pound projectile, with a charge of 450 pounds Prismatic brown powder (gunpowder). Text Book of Gunnery 1887, Table XVI. The original charge was 450 pounds of prismatic black powder giving a muzzle velocity of 1604 feet/second, but this damaged the barrels and was replaced by brown powder from April 1885. N.J.M. Campbell, "British Super-Heavy Guns".
- Text Book of Gunnery 1902, Table XII. This was the maximum practical range at the low elevations used for firing armour-piercing projectiles on a flat trajectory intended to pierce the armoured sides of ships. Longer ranges would have been attained at higher elevations, but the armour-piercing properties would have been diminished at the lower terminal velocity and oblique angle of impact.
- Text Book of Gunnery, 1887. London: Printed for His Majesty's Stationery Office, by Harrison and Sons, St. Martin's Lane
- Text Book of Gunnery, 1902. London: Printed for His Majesty's Stationery Office, by Harrison and Sons, St. Martin's Lane
- Sir Thomas Brassey, The British Navy, Volume II. London: Longmans, Green and Co. 1882
- N.J.M. Campbell, British Super-Heavy Guns
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