RML 6.3-inch howitzer

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RML 6.3-inch howitzer
RML 6.3 inch howitzer on siege carriage Mark I diagram
RML 6.3 inch howitzer on siege carriage Mark I, diagram from Handbook, War Office, 1886
Place of originUnited Kingdom
Service history
Used byBritish Empire
Production history
Mass2,016 lb (914 kg) barrel[2]
Barrel length3 feet 9 inches (1.1 m) bore (7.14 calibres)[2]

Shell70 lb (32 kg)[2]
Calibre6.3 inches (160 mm)
Muzzle velocity751 ft/s (229 m/s)[3]
Effective firing range4,000 yards (3,700 m)[1]

The RML 6.3-inch howitzer was a British rifled muzzle-loading "siege" or "position" howitzer/mortar proposed in 1874 and finally introduced in 1878 as a lighter version of the successful 8-inch howitzer that could be carried by the existing 40-pounder gun carriage.[4]

By 1880 the RML 6.3-inch was superseded by a longer 6.6-inch howitzer with higher muzzle velocity.[5]


Barrel construction

The barrel consisted of an inner "A" tube of toughened mild steel, surrounded by wrought-iron "B" tube and jacket.

Rifling was of the "polygroove" type, with 20 grooves and a twist increasing from 1 turn in 100 calibres (i.e. 630 inches) to 1 in 35 (i.e. 220 inches).[4]

The howitzers could be mounted on either a travelling siege carriage, which enabled them to be semi-mobile, or on a steel bed, which were then positioned in fixed defences or fortifications.

Operational use[edit]

Ten 6.3-inch Howitzers were landed in Egypt in 1882 to form part of a Royal Artillery Siege Train during the Anglo-Egyptian War, however they were not used in action.[6] Many were mounted in Forts and batteries around the United Kingdom as part of the fixed defences scheme. Most were dismounted and scrapped after 1902.

A number of RML 6.3-inch howitzers were used by the British forces during the Second Boer War, normally mounted on 40 pr RML carriages.[1]


Mk I studless common shell, 1886

The 6.3-inch Howitzer used a number of different types of projectiles, depending on the selected target. This included common shell for use against buildings, earthworks or vehicles, or shrapnel shell for use against 'soft' targets, such as infantry or cavalry on open ground. Case shot could be used against soft targets at close range - typically less than 400 yards.

The howitzer used black powder propellant, in silk bags which were ignited by friction tube.

The gun was the first British rifled muzzle-loader to dispense entirely with studs on shells to impart spin : its shells from the beginning had gas checks attached to their base which expanded and engaged with rifling on firing to impart spin to the shell.[4]

Surviving examples[edit]

One of the two guns used during the Siege of Ladysmith

Two of these guns, called Castor and Pollux, used during the Siege of Ladysmith, stand in front of the Ladysmith town hall. They have been declared Heritage Objects by the South African Heritage Resource Agency.[7][8][9] Both the guns and their ammunition were outdated by the time of the siege and they tended to make a lot of smoke when fired.[10]

See also[edit]


  1. ^ a b c Hall, Darrell (1971). "Guns in South Africa 1899-1902 Part V and VI". The South African Military History Society. Retrieved 22 October 2008.
  2. ^ a b c Text Book of Gunnery 1902, Table XII Page 338.
  3. ^ 751 ft/second firing 70 lb projectile, using 4 lb RLG2 (gunpowder) propellant. Text Book of Gunnery, 1902, Table XII page 338.
  4. ^ a b c Treatise on Construction of Ordnance in the British Service, 1879, pages 79; 171; 259-260
  5. ^ "The Gun - Rifled Ordnance: Howitzers". Royal New Zealand Artillery Association. Archived from the original on 28 February 2009. Retrieved 14 July 2009.
  6. ^ Goodrich, Caspar F (Lt Cdr), Report of the British Naval and Military Operations In Egypt 1882, Navy Department, Washington, 1885, p.231
  7. ^ "9/2/415/0028 - Castor and Pollux 6 3 in. RML Howitzer Ladysmith". South African Heritage Resource Agency. Archived from the original on 25 January 2016. Retrieved 28 August 2012.
  8. ^ "Managing Heritage Objects that form part of the National Estate" (PDF). South African Heritage Resource Agency. 15 July 2005. Retrieved 22 October 2008.[permanent dead link]
  9. ^ "Government Gazette Vol. 477" (PDF). Government of South Africa. 30 March 2005. p. 5. Retrieved 22 October 2008.[dead link]
  10. ^ Nevinson, H. W. Ladysmith - The Diary of a Siege. METHUEN & CO. p. 125. Retrieved 22 October 2008.


External links[edit]