BL 2.75-inch mountain gun

Ordnance BL 2.75 inch mountain gun
Ordnance BL 2.75 inch mountain gun
	Men of the 4th (Highland) Mountain Brigade with 2.75-inch (70 mm) mountain gun, Kamberli, Salonika front, June 1918.
Type	Mountain artillery
Place of origin	United Kingdom
Service history
In service	1914–1919
Used by	United Kingdom of Great Britain and Ireland; British Raj
Wars	World War I
Production history
No. built	183
Specifications
Mass	586 kg (1,292 lb)
Barrel length	72.5 inch (1.84 m)
Shell	Separate-loading QF
Shell weight	5.67 kg (12.5 lb)
Caliber	2.75-inch (70 mm)
Breech	Breech Loading
Recoil	Hydro-spring, constant,; 38 in (970 mm)
Carriage	Two wheeled, pole trail
Elevation	-15° - 22°
Traverse	4° L & R
Muzzle velocity	1,290 ft/s (393 m/s)
Maximum firing range	5,600 yd (5,100 m) Shrapnel; 5,800 yd (5,300 m) HE

The Ordnance BL 2.75-inch mountain gun was a screw gun designed for and used by the into World War I.

Description[]

The gun was an improved version of the 1901 BL 10-pounder mountain gun.

The new 1911 version improved on the 1901 gun with a new pole trail, recoil buffer, recuperator and gun shield, and increased shell weight from 10 to 12.5 lb (5.7 kg). It was a screw gun design, where the barrel could be separated into two parts via a screw joint. This allowed for the gun to have a heavier barrel, but still be broken into smaller portions for transport by mule teams. This was important for a weapon designed to be used in mountainous and rough terrain, or where adequate vehicle and horse transport was not readily available. The weapon could be carried by six mules or towed.

Service history[]

Firing on the Doiran front, Salonika 1917

The gun was adopted in 1911 and began entering service in 1914.

The weapon served primarily with the Indian Mountain Artillery in the northwest portion of British Indian territory (on what is now the border between Pakistan and Afghanistan) and participated in British-led military action in that theatre.

It also served in Mesopotamia and the Salonika front during World War I.

Due to its specialised nature the gun was produced in only limited numbers, with just 183 manufactured during the war.^[2]

It was superseded at the end of World War I by the QF 3.7-inch mountain howitzer.

Ammunition[]


Cordite cartridge	Mk I Shrapnel shell	No. 80 fuze	T friction tube

Surviving examples[]

2.75-inch mountain gun on display at the Heugh Battery

Front view

A 2.75-inch mountain gun is on display at the Heugh Battery Museum, Hartlepool

Notes and references[]

^ ^a ^b ^c ^d ^e ^f Hogg & Thurston 1972, page 42
^ "Camel artillery ready to fire". New Zealand History. Ministry for Culture and Heritage. 15 July 2013. Retrieved 2 January 2014.

Bibliography[]

Dale Clarke, British Artillery 1914-1919. Field Army Artillery. Osprey Publishing, Oxford UK, 2004 ISBN 1-84176-688-7
Hogg, Ian; 2000; Twentieth Century Artillery; Amber Books, Ltd., ISBN 1-58663-299-X
I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition. London: Ian Allan, 1972

External links[]

Handbook of the 2.75-inch B.L. gun : Mule equipment. London : H.M.S.O. 1920 at State Library of Victoria
Gun drill for 2.75 inch B.L. gun converted MK I and MK I carriage mark I 1921,1923 at State Library of Victoria
2.75 inch Mountain Gun at Landships

[Hogg&Thurston-1] ^ ^a ^b ^c ^d ^e ^f Hogg & Thurston 1972, page 42

[2] "Camel artillery ready to fire". New Zealand History. Ministry for Culture and Heritage. 15 July 2013. Retrieved 2 January 2014.

[1]

[2]

v t British Empire artillery of the First World War
Armoured vehicle guns	QF 3-pounder Vickers QF 6-pounder Hotchkiss QF 6-pounder 6 cwt
Infantry guns	1.59-inch Breech-Loading Vickers Q.F. Gun, Mk II
Field artillery	BL 12-pounder 6 cwt QF 12-pounder 8 cwt QF 12-pounder 18 cwt QF 13-pounder BL 15-pounder BLC 15-pounder QF 15-pounder QF 18-pounder QF 4-inch gun Mk III BL 4-inch gun Mk VII QF 4.5-inch howitzer
Medium & heavy artillery	QF 4.7-inch gun BL 5-inch howitzer BL 5.4-inch howitzer BL 60-pounder gun BLC 6-inch siege gun BL 6-inch gun Mk VII BL 6-inch gun Mk XIX BL 6-inch 26 cwt howitzer BL 6-inch 30 cwt howitzer BL 8-inch howitzer Mk I – V BL 8-inch howitzer Mk VI – VIII
Siege artillery	BL 7.5-inch Mk III naval gun BL 9.2-inch howitzer BL 9.2-inch Mk X naval gun BL 12-inch howitzer BL 12-inch Mk X naval gun BL 15-inch howitzer
Mountain artillery	RML 2.5-inch mountain gun BL 10-pounder mountain gun BL 2.75-inch mountain gun QF 2.95-inch mountain gun QF 3.7-inch mountain howitzer
Mortars	Garland trench mortar 3-inch Stokes mortar Vickers 1.57-inch mortar 2-inch medium mortar Newton 6-inch mortar 9.45-inch Heavy Mortar
Smoke and chemical weapons	4-inch Stokes Mortar Livens Projector Livens Large Gallery Flame Projector
Anti-aircraft guns	QF 1-pounder pom-pom QF 2-pounder "pom-pom" Mk II 75 mm AA gun QF 12-pounder 12 cwt QF 13-pounder 6 cwt QF 13-pounder Mk IV QF 13-pounder 9 cwt QF 3-inch 20 cwt QF 18-pounder QF 4-inch Mk V
Coastal artillery	QF 12-pounder 12 cwt QF 4-inch naval gun Mk I – III BL 6-inch Mk VII naval gun BL 9.2-inch Mk IX – X naval gun RML 9-inch
Railway guns	BL 9.2-inch railway gun BL 12-inch railway gun BL 12-inch railway howitzer BL 14-inch railway gun