BL 6-inch Mk VII naval gun

BL 6 inch gun Mk 7
British 6 inch Mk VII gun on Mk. 2 traveling carriage
Type	Naval gun Coast defence gun Heavy field gun
Place of origin	United Kingdom
Service history
In service	1901 - 1950s 1915 - 1918 (field use)
Wars	World War I
Production history
Designer	Vickers
Designed	1899
No. built	898
Specifications
Mass	26 tons
Barrel length	269.5 inch bore (45 cal)
Shell	HE 100 lb
Calibre	6 in (152 mm)
Muzzle velocity	2525 ft/sec
Effective firing range	On Field carriage Mk. II : 13,700 yds Naval : 14,600 yards (light charge); 15,800 yards (heavy charge)

The BL 6 inch Gun Mk 7 was a naval gun dating from 1899, which was mounted on a heavy traveling carriage in 1915 for Army service, and became one of the main British heavy guns in World War I.

Naval gun

The gun was introduced on the Formidable class battleship of 1898 (commissioned September 1901) and went on to equip many capital ships, cruisers, monitors, and smaller ships such as the Insect class gunboat which served throughout World War II.

Mk VIII in Naval service was identical to Mk VII, except that the breech opened to the left instead of to the right, for use as the left gun in twin turrets.

Field gun

The early Mk. 2 carriage mounted the gun in a low position, limiting elevation and hence range. Later carriages carried the gun in a higher position, allowing greater elevation and hence range.

Gun on Mk 3 carriage firing near Beaumetz-lès-Loges, cutting wire for the Australian advance Second Battle of Bullecourt 21 April 1917

It was operated by the Royal Garrison Artillery in World War I, in batteries of 4 guns.

Following its successful employment in the Battle of the Somme its role was defined as counter-battery fire and also they "were most effective for neutralising defenses and for wire cutting with fuze 106 [a new fuze which reliably burst instantly above ground on even slight contact, instead of forming craters]", also for long-range fire against "targets in depth".

It was superseded by the lighter and longer-range BL 6 inch Gun Mk 19 which was introduced from October 1916 but the Mk 7 remained in service to the end of World War I.

Coast defence gun

A notable action was fought by Durham Company RGA of the Territorial Force at Heugh (2 guns) and Lighthouse (1 gun) batteries defending Hartlepool on 16th December 1914. They duelled with the German battlecruisers Seydlitz and Moltke (11 inch guns) and Blücher (8.2 inch), firing 112 rounds and scoring 7 hits while suffering 112 civilians and 7 military killed. The battlecruisers fired a total of 1,150 rounds at the town and the batteries. See Raid on Scarborough, Hartlepool and Whitby.

Ammunition

23 lb Mk III Cartridge	Mk IV Common lyddite shell	Mk VIIA Common lyddite naval shell

See also

• List of artillery#Towed howitzers and field guns
• List of artillery#Naval guns

Surviving examples

• Rotunda, Royal Artillery Museum, London
• A gun on field carriage at The Front Museum, Lappohja, Finland
• 2 coast defence Mk 7 guns at Fort Dunree, Lough Swilly, Ireland
• Fort Siloso at Sentosa Island, Singapore
• A coast defence gun at Newhaven Fort, Sussex, UK

References

• Dale Clarke, British Artillery 1914-1919. Heavy Artillery. Osprey Publishing, Oxford UK, 2005
• General Sir Martin Farndale, History of the Royal Regiment of Artillery. Western Front 1914-18. London: Royal Artillery Institution, 1986
• General Sir Martin Farndale, History of the Royal Regiment of Artillery. The Forgotten Fronts and the Home Base, 1914-18. London: Royal Artillery Institution, 1988.

External links

• British 6"/45 (15.2 cm) BL Mark VII 6"/45 (15.2 cm) BL Mark VIII 6"/45 (15.2 cm) BL Mark XXIV
• Ken Musgrave, Diagram of BL 6inch Mk VII Gun on Mk. 2 Carriage at Landships (scroll to bottom of page)
• Per Finsted, Om den engelske 6-tommers feltkanon 1914-1940 (in Danish)