RML 16-inch 80-ton gun

Ordnance RML 16-inch 80-ton gun
Ordnance RML 16-inch 80-ton gun
	Port/forward turret on HMS Inflexible
Type	Naval gun
Place of origin	United Kingdom
Service history
In service	1880–1902
Used by	Royal Navy
Wars	Bombardment of Alexandria (1882)
Production history
Designer	Royal Gun Factory
Designed	1874
Manufacturer	Royal Arsenal
Unit cost	£10,000
No. built	8
Variants	Mk I
Specifications
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

In 1868 trials, the Krupp breechloader 24 cm K L/20 unexpectedly proved itself superior to the British 9-inch muzzle loader. This potentially posed a huge problem for the Royal Navy. The British manufacturers could not produce the huge ingots of quality steel that were required to manufacture comparable guns and relying on imported guns was unacceptable from a strategic perspective. However that might be, the German Navy was very small. Therefore, the British could counter the Krupp guns by simply increasing the size of their less effective muzzle loaders.

In parallel to the contest between muzzleloaders and breechloaders, there was a race between armor and guns. On the Krupp side, this race processed gradually up till the 30.5 cm caliber. It then escalated with Krupp producing the 35.5 cm MRK L/22.5 of 56t and the United Kingdom making the 16-inch 80-ton gun.

After a long design and experimentation period beginning in 1873, HMS Inflexible with its four guns, became the only ship to mount the 16-inch 80-ton gun, 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 By that time such muzzle-loading guns were already obsolescent and were being superseded by a new generation of rifled breechloading guns.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.

Characteristics

The gun was constructed of a toughened mild steel inner "A" tube surrounded by multiple wrought-iron coils, breech-piece and a 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 in (2,000 cm)) at the muzzle.^[3]

The 16 inch 80 ton was a second-generation RML gun, equipped with polygroove rifling and firing only studless ammunition and using automatic gas-checks for rotation.

The maximum range of the gun was 8,000 yards (7,300 m). 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.^[4]

The original charge was 450 pounds of prismatic black powder giving a muzzle velocity of 1604 feet/second. However, as this damaged the barrel, it was replaced by brown powder from April 1885. N.J.M. Campbell, "British Super-Heavy Guns". The final velocity was 1590 feet/second firing a 1684-pound projectile, with a charge of 450 pounds Prismatic brown powder (gunpowder).^[2]

Surviving examples

The two guns in the Admiralty Pier Turret as they are today

The only two remaining example are in the ruins of the Admiralty Pier Turret, Dover, Kent, UK.

Notes and references

^ Brassey 1882.
^ ^a ^b ^c Mackinlay 1887, p. Table XVI.
^ ^a ^b Mackinlay 1887.
^ ^a ^b Text Book 1902, p. Table XII.

Bibliography

Brassey, Thomas (1882), The British Navy, vol. II, Longmans, Green and Co., London
Campbell, N.J.M. (2002), British Super-Heavy Guns, archived from the original on 2011-03-02
Mackinlay, George (1887), Text Book of Gunnery. 1887, His Majesty's Stationery Office, by Harrison and Sons, St. Martin's Lane
Text Book of Gunnery. 1902, His Majesty's Stationery Office, by Harrison and Sons, St. Martin's Lane, 1902, archived from the original on 2012-07-12

External links

Flickr photos of the guns in the Dover turret : [1] [2] [3] [4]
Photograph of Palliser projectile at Royal Marines Museum, Portsmouth, from Flickr

[FOOTNOTEBrassey1882-1] Brassey 1882.

[FOOTNOTEMackinlay1887Table_XVI-2] Mackinlay 1887, p. Table XVI.

[FOOTNOTEMackinlay1887-3] Mackinlay 1887.

[FOOTNOTEText_Book1902Table_XII-4] Text Book 1902, p. Table XII.

[1]

[2]

[3]

[4]

v t e British Empire naval weapons of the Victorian era
Smoothbore muzzle-loading cannons	18-pounder 24-pounder 32-pounder 55 cwt 32-pounder gun 68-pounder Somerset cannon
Smoothbore muzzle-loading shell guns	8-inch 10-inch 86 cwt
Mortars	10-inch Blomefield 13-inch Blomefield
Howitzers	12-pounder Millar 24-pounder Millar
Rifled breechloaders (Armstrong)	RBL 9 pounder RBL 20-pounder RBL 40-pounder RBL 7-inch 110-pounder
Rifled muzzle-loaders (Lancaster)	68-pounder Lancaster gun
Rifled muzzle-loaders (converted)	RML 64-pounder 71 cwt
Rifled muzzle-loaders (Woolwich)	RML 9-pounder 8 cwt RML 64-pounder 64 cwt RML 7-inch RML 8-inch RML 9-inch RML 10-inch RML 11-inch RML 12-inch 25-ton RML 12-inch 35-ton RML 12.5-inch RML 16-inch
Breech-loaders (new pattern)	BL 4-inch BL 5-inch BL 6-inch 80-pounder BL 6-inch Mk II – VI BL 8-inch BL 9.2-inch Mk I – VII BL 9.2-inch Mk VIII BL 10-inch BL 12-inch Mk I – VII BL 12-inch Mk VIII BL 13.5-inch BL 16.25-inch
Quick-firing guns	QF 3-pounder Hotchkiss QF 6-pounder Hotchkiss QF 6-pounder Nordenfelt QF 12-pounder 12 cwt Mk I QF 4-inch QF 4.7-inch QF 6-inch
Light weapons	Gatling gun Gardner gun Nordenfelt gun 1-inch Nordenfelt gun
Torpedoes	Whitehead torpedo