Limbo, or Anti Submarine Mortar Mark 10 (A/S Mk.10), was the final development of the forward-throwing anti-submarine weapon Squid, designed during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

and was developed by the

Admiralty Underwater Weapons Establishment The Admiralty Underwater Weapons Establishment was an Admiralty research department dedicated to underwater detection systems and weapons. It was formed at the Isle of Portland in 1959 and later became part of the Admiralty Research Agency (ARE) ...

in the 1950s. Limbo was installed on the quarterdeck of

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against ...

escort ships from 1955 to the mid-1980s, Australian–built destroyer and s. Limbo was widely employed by the

Royal Canadian Navy The Royal Canadian Navy (RCN; french: Marine royale canadienne, ''MRC'') is the naval force of Canada. The RCN is one of three environmental commands within the Canadian Armed Forces. As of 2021, the RCN operates 12 frigates, four attack submar ...

, being incorporated into all destroyer designs from the late 1950s to the early 1970s, including the , , , and classes and the Type 12 President Class frigates built for the South African Navy in the 1960s.

Operation

Limbo was loaded and fired automatically with the crew under-cover and was stabilised in pitch and roll. The firing distance of the mortars was controlled by opening gas vents; rounds could be fired from . The weapon was linked to the

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on o ...

system of the ship, firing on command when the target was in range. The rounds were projected so that they fell in a triangular pattern around the target in any direction around the ship.YouTube showing loading and firing
/ref> The weapon was used in the 1982 Falklands War and remained in service in the Royal Navy and Commonwealth navies until the 1990s. A surviving system is preserved at Explosion! Museum of Naval Firepower in Gosport, Hampshire.

Sonar control of the A/S Mortar Mk 10

The firing of the Mortar Mk 10 was controlled by the Type 170 (and later the 502) attack sonar from the Sonar Control Room (SCR), which was generally located next to the operations room in the warship. The 170 sonar had three operators who maintained sonar contact with the target and aimed the weapon in bearing, range and depth. Firing was done by means of a pistol grip and trigger mounted to the deckhead.

General characteristics

* Total system weight: 35 tons including 51 projectiles (17 salvos).

Display items

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Play Station- Canberra, Australian Capital Territory

References

{{Reflist 305 mm artillery Anti-submarine mortars Explosive weapons Naval weapons of the Cold War Naval weapons of the United Kingdom Military equipment introduced in the 1950s