QF 6 pounder 10 cwt gun

This article is about the naval and coastal defence gun QF 6 pounder 10cwt . For other guns of this size, see 6-pounder gun.

6-pdr / 10cwt QF Mark I
The 6-pounder gun mark I in twin mark I mounting on board HMS Mackay whilst she is at Harwich.
Type	Naval gun and coastal gun
Place of origin	United Kingdom
Service history
Used by	British Commonwealth
Wars	Second World War
Production history
Variants	Naval gun (twin mount) Coastal gun (twin mount)
Specifications
Weight	1,060 lb (481 kg)
Length	9 ft (2.787 m)
Barrel length	47 calibres
Crew	6

Calibre	57 millimetres (2.24 in)
Recoil	12 inches
Elevation	-10/+80
Traverse	360 degrees
Rate of fire	18 rounds per minute
Effective firing range	11,300 yards (10,330 m) @45°

The British QF (quick-firing) 6 pounder 10 cwt gun^{[note 1]} was a 57 mm twin-mount light coast defence and naval gun from the 1930s to 1950s.

Development

Following the emergence of small fast attack craft during World War I, it was decided that the British Royal Navy Dockyards were vulnerable to attack by motor torpedo boats which had the speed to evade the heavy coast defence guns which defended them. In 1925, a design was adopted for a twin barrelled weapon capable of sustained semi-automatic fire. Both barrels of the weapon could be fired singly or they could be combined. The pedestal mounting and the gun crew were enclosed to the front, sides and top in a reinforced-steel barbette.

The first trials took place in 1928 with production beginning at the Woolwich Ordnance Factory in 1933. Formal War Office acceptance occurred on 28 February 1934. A coastal-defence trial using the gun and barbette was conducted at Culver Battery on the Isle of Wight in 1936.^[1] As the shadow of Second World War approached, food equipment and machinery manufacturer, Baker Perkins, was asked to take over production in March 1939; the first guns left its Westwood, Peterborough factory in March 1941.^[2]

The Mark II version of the QF 6 pounder had a monobloc barrel (made from a single forging) instead of a lined barrel in the Mark Is.

Coast Defence

The first twin 6-pounders were installed at Singapore in 1937. The first UK installation was at Eastern Arm Battery in Dover, just before the outbreak of World War II.^[2] Also in 1939, nine pairs of guns were installed in Fort St. Elmo and Fort Ricasoli in the Grand Harbour at Valletta, Malta. These were to play a vital role in the successful defence against an attack by nineteen Italian MAS fast attack boats on 26 July 1941, when five enemy boats were sunk in less than two minutes.^[3] By the end of 1942, 155 of these weapons had been produced for 31 locations worldwide.^[2] The pair installed in 1944 at Fort Rodd Hill at Esquimalt Harbour, British Columbia is thought to be the last in existence.^[4]

Naval Gun

Loading the 6 pounder 10cwt aboard HMS Mackay

The 6-pounder gun mark I in twin coastal artillery mount.

It was fitted to:

One of the problems that persisted throughout the war was lightning surface night attacks by E-boats. These would lie in wait for convoy and then at the appropriate moment sweep across the front, firing torpedoes and making a speedy escape into the darkness. The 4.7-inch and 4-inch guns of destroyers could not fire fast enough to deal with this form of attack, and the 20 mm Oerlikon cannon did not fire a shell heavy enough to cripple the vessel. A remedy was offered in the form of the twin 6 pounder quick-firing coast-defence gun.

For naval use it was mounted in place of No 1 gun (A mount) on four W class destroyers and proved an effective countermeasure. However, since the need for an increased anti-submarine capability was critical, even on the coastal convoys, and the 6pdr competed for space with the new ahead-throwing Hedgehog mortar, only four ships; HMS Walpole, HMS Windsor, HMS Whitshed and HMS Wivern, were fitted with this twin-6-pdr mounting.

Notes & references

Notes

↑ "6 pounder" refers to approximate weight of projectiles, which was a traditional British way of denoting small guns. "10 cwt" referred to the approximate weight of the gun and breech in cwt (hundredweight) rounded up : 10 cwt = 10 x 112 pounds = 1,120 pounds. It was standard British practice to differentiate guns of the same calibre by adding weight in cwt to the description.

Citations

↑ "Fortifications of the Isle of Wight - Culver Battery". BBC. Retrieved 4 September 2013.
↑ 2.0 2.1 2.2 "Westwood Works in World War 2".
↑ The Fortress Study Group - FORTLET Number 2, 2011 - TWENTIETH CENTURY BRITISH COAST DEFENCE GUNS By Terry Gander (p. 2)
↑ Fort Rodd Hill - Belmont Battery

External links

Wikimedia Commons has media related to QF 6 pounder 10 cwt Gun.

Details of the 6pdr Naval and Coastal Gun by Tony DiGiulian
"Playhouses" Rip Invasion Craft With Twin Six-Pounder Gun March 1944 article
Westwood Works in World War 2. The Twin 6-pounder Coastal Defence Gun

British Commonwealth artillery of World War II

Tank & anti-tank guns	QF 2 pounder QF 3 pounder (tank only) QF 6 pounder QF 75 mm (tank only) QF 3 inch Howitzer QF 17 pounder 77 mm HV (tank only) QF 95 mm Howitzer (tank only)

Field guns and howitzers	75 mm Gun M1917 QF 18 pounder 25 pounder Gun-Howitzer 25 pounder Short QF 4.5-inch howitzer

Medium and Heavy guns and howitzers	BL 4.5-inch Medium Field Gun BL 60-pounder gun BL 5.5-inch Medium Gun BL 6 inch Howitzer BL 6-inch Gun Mk XIX 155 mm Long Tom BL 7.2-inch howitzer BL 8 inch Howitzer BL 9.2-inch howitzer 240 mm howitzer M1

Mountain guns	75mm Pack Howitzer M1 3.7 inch Mountain Howitzer

Mortars	SBML 2inch Mortar ML 3-inch Mortar ML 4.2 inch Mortar

Anti-aircraft weapons	Z Battery 20 mm Oerlikon 20 mm Polsten QF 1½-pounder Mk III QF 2-pounder naval gun Bofors 40 mm QF 3 inch QF 3.7 inch QF 4.5 inch Mk II QF 5.25 inch Mk II

Coast defence	QF 6 pounder 10 cwt QF 12 pounder 6 inch Mk VII & Mk XXIV 9.2 inch Mk X

Railway artillery	BL 9.2 inch Mk XIII railway gun BL 12 inch Mk V railway howitzer BL 18 inch railway howitzer

British Commonwealth naval weapons of the Second World War

Monitor guns	BL 15 inch

Capital ship main armament	BL 14 inch BL 15 inch BL 16 inch

Heavy cruiser main armament	BL 7.5 inch Mk VI BL 8 inch Mk VIII

Secondary armament and light cruiser main armament	QF 4 inch Mk V QF 4.5 inch QF 5.25 inch BL 6 inch Mk XII BL 6 inch Mk XXII BL 6 inch Mk XXIII

Minesweeper, Sloop, Corvette, Frigate and Destroyer armament	QF 6 pounder 10 cwt QF 12 pdr 12 cwt Mk V QF 4 inch Mk IV BL 4 inch Mk IX QF 4 inch Mk XIX QF 4.5 inch BL 4.7 inch Mk II QF 4.7 inch Mk IX & XII QF 4.7 inch Mk XI

Submarine guns	QF 12 pdr 12 cwt Mk V QF 3 inch 20 cwt QF 4 inch Mk XII & XXII

Anti-aircraft weapons	Unrotated Projectile Holman Projector 20 mm Oerlikon QF 2 pounder "pom-pom" Mk VIII 40 mm Bofors QF 3 inch 20 cwt QF 4 inch Mk V QF 4 inch Mk XVI QF 4.5 inch QF 4.7 inch Mk VIII

Light weapons	.303 Lewis machine gun .50 Vickers Mk III machine gun QF 3 pounder Vickers

Torpedoes	21 inch Mk VII 21 inch Mk VIII 21 inch Mk X 21 inch Mk XI 24.5 inch Mk I

Anti-submarine weapons	Thornycroft depth charge thrower Hedgehog Squid

Small craft armament	Molins 6 pounder Vickers K machine gun 18 inch torpedo

Foreign-sourced weapons	20 mm Oerlikon 40 mm Bofors 3-inch 23 caliber gun (US) 3-inch 50 caliber gun (US) 4-inch 50 caliber Mark 9 gun (US) 5-inch 51 caliber Mark 8 gun (US) Y gun depth charge projector (US)