VI.

MAGNETIZED CHARGES:

A.

The "CLAM" Mk III:

The Clam is a small time bomb with a magnetic base which enable it to be atta-ched instantly to any flat iron or steel surface, such as engine blocks, railroad tracks, steel plate, etc.

The body is a black plastic box with rounded corners, measuring 5-3/4" x 2-3/4" x 1-1/2". At each end of the box is a magnet compartment, the two magnets being loosely mounted so that they can grip an uneven surface. The center compartment of the box contains about 8 oz. of the H.E. filler (usually TNT/Tetryl , 55/45) and is closed by a flat lid held in place with four screws.

A standard Switch No. 9 "L" Delay Mk I (Lead-break), with a No. 27 detonator attached, serves as the initiator. It slips into a groove in the top part of the body and is held in place by a small clip.

B.

The "LIMPET" Mk III:

The Limpet is a small self-contained delay-action mine with a magnetic base which allos it to be fitted instantly to any iron or steel target, such as a tank or the hull of a ship.

Designed to function either on land or under water, the Limpet carries a charge of 3½ lbs. of H.E. filler (usually TNT/Tetryl 55/45) - sufficient to pierce 60 mm. plate. Exceptionally powerful segmental magnets, flexibly mounted, allow it a firm grip even on uneven surfaces. It will remain in place on the average vessel at speeds up to 16 knots.

The explosive container of the Mk III Limpet is a separate unit which can be de-tached from the magnet ring so that the device can be used without magnets if desired. This container filled weighs about 4¼ lbs. The magnet ring weighs 5¼ lbs., bringing the total weight of the device to 9½ lbs.

A standard Switch No. 9 "L" Delay Mk I (Lead-break), with a No. 8 detonator at-tached, serves as the initiator. It is inserted in a special holder, which gives a watertight joint when inserted in the magazine.

A carrying ring is fitted to the top of the Limpet body.

The earlier Mk II Limpet was fitted with two magazines for a duplicate igniter system to provide against possible failure.

C.

The Rigid Limpet:

The British "Rigid" Limpet is designed for destruction of tanks or other steel structures. The device is painted field gray and consists of a rectangular box of sheet brass, 8-1/4" long, 2-7/12" wide, and 2-7/12" deep.

The box contains a charge of 2.5 lbs. of plastic H.E., moulded to accept a deto-nator at each end.

A pair of brass brackets are riveted to either side of the brass body, and a brass body, and a brass rod is secured between each pair of bracktes. To each rod are fitted three permanent U-shaped magnets, each fastened by metal straps to a rub-ber mounting. These magnets are retained in position by flanges on the rod. The rubber mountings allow limited movement to the magnets so that the Limpet can be readily attached to uneven surface.

An internally threaded brass cap provides a filling hole. A threaded adapter fixed centrally to the brass filling cap and another threaded adapter fitted to the other end of the body provide means for inserting the A.C. Delay Igniter Mk. I, with which the Limpet is fuzed.

(See page 81A for drawing of the Rigid Limpet.)