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.
[edit] History
Following an approach by Major Millis Jefferis, 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 the Second World War 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]
A smaller version "Clam" was developed from the British limpet for use on land.
[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.
Limpet mines were also used by the Norwegian Independent Company 1 in 1944 to sink the SS Monte Rosa. On January 16, 1945, 10 limpet mines were placed along the port side of the SS Donau approximately 50 centimetres (20 in) beneath the waterline. These bombs were to detonate once the Donau cleared Oslofjord and reached open sea, however, the departure time was delayed and the explosion occurred before the Donau reached Drøbak.
In 1980 a limpet mine was used to sink the Sierra, a whaling vessel which docked in Portugal after a confrontation with the Sea Shepherd.[3] Later that year, about half the legal Spanish whaling fleet was sunk in a similar fashion.[4]
Another notorious use was the sinking of Greenpeace's Rainbow Warrior by French DGSE agents in Auckland harbour, New Zealand, on July 10, 1985,[5] called "a major criminal act" by New Zealand Prime Minister David Lange.[6]
[edit] References
- ^ "WW2 People's War (BBC)". Aniseed Balls and the Limpet Mine. http://www.bbc.co.uk/ww2peopleswar/stories/53/a4376153.shtml. Retrieved 2007-04-24.
- ^ Macrae, Stuart (1971). Winston Churchill's Toyshop. Roundwood Press. ISBN 0900093226.
- ^ "Paul Watson: Sea Shepherd eco-warrior fighting to stop whaling and seal hunts". Telegraph.co.uk. 2009-04-17. http://www.telegraph.co.uk/earth/5166346/Paul-Watson-Sea-Shepherd-eco-warrior-fighting-to-stop-whaling-and-seal-hunts.html. Retrieved 2009-07-15.
- ^ "The Sea Shepherd". The Sierra Campaign. http://www.seashepherd.org/who-we-are/the-sea-shepherd.html.
- ^ Bremner, Charles (July 11, 2005). "Mitterrand ordered bombing of Rainbow Warrior, spy chief says". Times Online (Times Newspapers). http://www.timesonline.co.uk/tol/news/world/article542620.ece. Retrieved 15 December 2009.
- ^ "Rainbow Warrior sinks after explosion". On This Day (British Broadcasting Corporation). 10 July 1985. http://news.bbc.co.uk/onthisday/hi/dates/stories/july/10/newsid_2499000/2499283.stm. Retrieved 2009-11-11.
