Squid (weapon)

Squid
Squid
	Squid anti-submarine mortar on display at the Devonport Naval Base
Type	Anti-submarine Mortar
Place of origin	United Kingdom
Service history
In service	1943–1977
Used by	Royal Navy
Production history
Designer	Directorate of Miscellaneous Weapons Development
Designed	1942
Specifications
Mass	10 tons
Shell	440 lb (200 kg)
Calibre	12 in (305 mm)
Barrels	Three
Effective firing range	275 yards (250 m)
Filling	Minol
Filling weight	207 lb (94 kg)
Detonation; mechanism	Time fuse

Squid was a British World War II ship-mounted anti-submarine weapon. It consisted of a three-barrelled mortar which launched depth charges. It replaced the Hedgehog system, and was in turn replaced by the Limbo system.

Literally ordered directly from the drawing board in 1942, under the auspices of the Directorate of Miscellaneous Weapons Development, this weapon was rushed into service in May 1943 onboard HMS Ambuscade. The first production unit was installed on HMS Hadleigh Castle, it went on to be installed on 70 frigates and corvettes during the Second World War. The first successful use was by HMS Loch Killin on 31 July 1944, when she sank U333. The system was credited with 17 submarines in 50 attacks. 195 Squid installations had been produced by 1959.

This weapon was a three-barrel 12 inch (305 mm) mortar with the mortars mounted in series but off-bore from each other in order to scatter the projectiles. The barrels were mounted in a frame that could be rotated through 90 degrees for loading. The projectiles weighed 390 lb (177 kg) with a 207 lb (94 kg) minol charge.^[1] Sink rate was 43.5 ft/s (13.3 m/s) and a clockwork time fuse was used to set the depth. Maximum depth was 900 feet (274 m) and all three projectiles had to be set the same.

The weapons were automatically fired from the sonar range recorder at the proper moment. The pattern formed a triangle about 40 yards (37 m) on a side at a distance of 275 yards (250 m) ahead of the ship. Most Squid installations utilised two sets of mortars. All six bombs were fired in salvo so they formed opposing triangular spreads. The salvos were set to explode 25 feet (7.6 m) above and below the target, the resulting pressure wave crushing the hull of the submarine. Postwar trials found Squid was nine times more effective than conventional depth charges.^[2]

Despite its proven effectiveness, some officers, notably Captain Kenneth Adams, RCN, opposed fitting Squid to escorts because it meant sacrificing guns, which would make ships unsuitable for fleet actions.^[3]

In April 1977, the Type 61 frigate Salisbury became the last ship to fire Squid in Royal Navy service.

References

^ Due to shortages of TNT and RDX (cyclonite) in World War II, the British used a 50/50 mixture of ammonium nitrate and TNT (amatol) in naval mines and depth charges. This low grade explosive was later improved by the addition of about 20% aluminium powder, producing minol.
^ Zimmerman, David. Great Naval Battle of Ottawa (Toronto: University of Toronto Press, 1989), p.127.
^ Zimmerman, p.128-9.

Jane's Naval Weapon Systems Issue 33, E R Hooton, ISBN 0-7106-0893-4
Naval Armament, Doug Richardson, 1981, Jane's Publishing, ISBN 0-531-03738-X

External links

Squid Mortar page at HMCS Haida website]

[1] Due to shortages of TNT and RDX (cyclonite) in World War II, the British used a 50/50 mixture of ammonium nitrate and TNT (amatol) in naval mines and depth charges. This low grade explosive was later improved by the addition of about 20% aluminium powder, producing minol.

[2] Zimmerman, David. Great Naval Battle of Ottawa (Toronto: University of Toronto Press, 1989), p.127.

[3] Zimmerman, p.128-9.

[1]

[2]

[3]

v t e 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 5.5-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-pounder 12 cwt Mk V QF 4-inch Mk IV BL 4-inch Mk IX QF 4-inch Mk XVI 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-pounder 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) Mark 8 torpedo (US)

See also

References

External links