| Squid | |
|---|---|
 Squid anti-submarine mortar on display at theDevonport Naval Base | |
| Type | Anti-submarine Mortar |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1943–1977 |
| Used by | Royal Navy,Swedish Navy,Royal Canadian 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 II |
| Filling weight | 207 lb (94 kg) |
Detonation mechanism | Time fuse |
Squid was a BritishWorld War IIship-mountedanti-submarineweapon. It consisted of a three-barrelledmortar which launcheddepth charges. It replaced theHedgehog system, and was in turn replaced by theLimbo system.
Ordered directly from the drawing board in 1942, under the auspices of theDirectorate of Miscellaneous Weapons Development, this weapon was rushed into service in May 1943 on boardHMSAmbuscade. The first production unit was installed onHMSHadleigh Castle; it went on to be installed on 70 frigates and corvettes during theSecond World War. The first successful use was byHMSLoch Killin on 31 July 1944, when she sankU-333. The system was credited with sinking 17 submarines in 50 attacks over the course of the war - a success ratio of 2.9 to 1. In contrast, out of 5,174 Britishdepth charge attacks in WWII there were 85.5 kills,[a] a ratio of 60.5 to 1. TheHedgehog made 268 attacks for 47 kills, a ratio of 5.7 to 1.[1] By 1959, 195 Squid installations had been produced.
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 pounds (177 kg) with a 207-pound (94 kg)minol II charge.[b][2] On some vessels, the Squid installations were at the stern – the bombs were fired over the length of the ship and dropped into the sea slightly ahead of it.[3] Sink rate was 43.5 ft/s (13.3 m/s) and a clockwork timefuze was used to determine the detonation depth. All three projectiles had to be set to the same depth; this could be continuously updated right up to the moment of launch to take into account the movements of the target.[3] The maximum depth was 900 feet (270 m).The weapons were automatically fired from thesonar 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 (251 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. Post-war trials found Squid was nine times more effective than conventional depth charges.[4]
Despite its proven effectiveness, some officers, notablyRoyal Canadian NavyCaptain Kenneth Adams opposed fitting Squid to escorts because it meant sacrificing guns which would make ships unsuitable for fleet actions.[5]
In April 1977, theType 61 frigateSalisbury became the last ship to fire Squid in Royal Navy service. Examples of the mortars are on display at theExplosion! Museum of Naval Firepower in Gosport, Hampshire and another at Devonport Naval Base. The system is fitted toHMS Cavalier (D73), which is part of the historic ships collection in the Historic Dockyard in Chatham, Kent. It can also be seen onHMCS Haida, which is on display inHamilton, Ontario and at the naval museum inMalacca,Malaysia.
TheSwedish Navy continued to use the Squid system until 1982 when theÖstergötland-class destroyers were decommissioned.
