Limpet mine
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A limpet mine is a type of naval mine attached to a target by magnets; they are so named because of their superficial similarity to the limpet, a type of mollusk.
A swimmer or diver may attach the mine, which is usually designed with hollow compartments to give the mine a slight negative buoyancy, making it easier to handle underwater. Normally they are directly attached, but the warhead of the human torpedo was linked to the magnets by wires about 1-foot (30 cm) long.
Usually limpet mines are set off by a time fuse. They may also have an anti-handling device, making the mine explode if removed from the hull by enemy divers or by explosions. Sometimes the limpet mine was fitted with a small propeller which would detonate the mine after the ship had sailed a certain distance, so that it was likely to sink in navigable channels or deep water out of reach of easy salvage and making it harder to determine the cause of the sinking.
A British limpet mine was developed in 1939 by Stuart Macrae, the editor of Armchair Science magazine, and Major C.V. Clarke.[1][2] The "limpets" used by the British during World War II contained only 4 kilograms (8.8 lb) of explosive, but placed 2 metres (6.6 ft) below the water line they caused a 1-metre (3.3 ft) wide hole in an unarmoured ship.[citation needed]
[edit] Examples of use
An example of the use of limpet mines by British special forces was in Operation Frankton which had the objective of disabling and sinking merchant shipping moored at Bordeaux, France in 1942. The operation was the subject of the film The Cockleshell Heroes.
In 1980 a limpet mine was used to sink the Sierra,[3] a pirate whaling vessel which docked in Portugal after a confrontation with Sea Shepherd, both exposing the Portuguese government for lying to international governments about it being a safe haven for illegal whalers and encouraging a worldwide backlash against whaling in general. Later that year, about half the legal Spanish whaling fleet was sunk in a similar fashion.[3] Rewards were also offered for the safe sinking of whaling vessels by various anti-whaling organisations.
Another notorious use was the sinking of the Rainbow Warrior by the French DGSE in Auckland harbour, New Zealand, on July 10, 1985 to prevent them bringing attention to the nuclear testing underway.
[edit] References
- ^ "WW2 People's War (BBC)". Aniseed Balls and the Limpet Mine. http://www.bbc.co.uk/ww2peopleswar/stories/53/a4376153.shtml. Retrieved on 2007-04-24.
- ^ Macrae, Stuart (1971). Winston Churchill's Toyshop. Roundwood Press. ISBN 0900093226.
- ^ a b "The Sea Shepherd". Sea Shepherd. http://www.seashepherd.org/. Retrieved on 2008-01-01.
