During the Second World War Britain’s Special Operations Executive (SOE) developed a whole series of sabotage devices for use behind enemy lines. Using unique archival footage this series of short videos examines some of the weapons developed for use by SOE agents in occupied Europe. In this episode we look at one of the numerous version of the magnetic Limpet Mine developed by SOE and other clandestine organisations.

In this very rare footage we see a Free French Air Force officer, possibly training as a member of the SOE, place a limpet mine on a substantial piece of metal plate.

The mine seen in the footage is clearly much smaller than the Limpets used against ships. The Limpet mine was developed by Military Intelligence (Research) in late 1939-40. Stuart Macrae and Cecil Vandepeer Clarke developed a mine with enough magnetic strength to attach an explosive charge to the hull of a ship. The initial design seen here was quite large but the design was refined as the war went on with various types and marks. Here’s a Type II limpet, a MkIII and here is a Type 6 MkII.

The idea was that divers or saboteurs in small boats could quietly attach the mines to enemy shipping while at anchor. However, the usefulness of magnetic charges was clear and it appears that smaller versions, like that we see in the footage here, were developed for use against armoured vehicles and other substantial armoured targets.

It’s unclear from the film what the explosive charge was, how big it was or how it was laid out inside the mine but from the damaged plate displayed at the end of the footage it may have been a ring of plastic explosive held in place by the four magnets. This would blow the characteristic round hold in the plates.

Interestingly, the limpet mine seen in the film is very similar to a Japanese design, the Type 99 anti-tank mine, however, it has a different fuse design and the four magnets are blocky rather than rounded. Whether the Japanese magnetic mine influenced this design developed by SOE is unknown.

I’ve been unable to find out these mine’s designation, it may not have been given one but it does appear to be fairly well developed. In this photograph we can see that a metal plate carrier has been developed to allow a soldier to carry 4 mines on his back. Perhaps these mines were developed for a specific mission. The magnetic Clam charge, which we have covered in an earlier video, would have done a similar job for smaller task

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Bibliography:

World War II Allied Sabotage Devices and Booby Traps, G.L. Rottman (2006)

SOE’s Descriptive Catalogue of Special Devices and Supplies, (1944)

SOE’s Secret Weapons Centre: Station 12, D. Turner (2007)

SOE: The Scientific Secrets, F. Boyce & D. Everett (2009)

British Land Mines and Firing Devices, U.S.N.B.D. (1945)

The footage is part of the Imperial War Museum’s collection © IWM MGH 4324 and is used under the Non-commercial Use agreement.