MAGNETIC MINES

Waikato Times, Volume 126, Issue 21052, 2 March 1940, Page 7

MAGNETIC MINES

BRITISH NAVY EXAMINATION DROPPED FROM SEAPLANES OF LIMITED EFFECTIVENESS (United Press Assn.—Elec. Tel. Copyright) (Received March 2, a.m.) LONDON, March 1 A highly-placed official revealed that parts of German magnetic mines which the Navy has taken to pieces bear the date 1938. The mines are entirely constructed of non-magnetic aluminium and are fitted with an impact detonator outside, enabling the mine to be used like a bomb and ensuring explosion if it hits the deck of a ship* The impact detonator is not very sensitive and for this reason the mine does not explode when it strikes the water. A parachute attached also arrests its speed. There is another detonator inside where springs hold a pivoted magnet horizontal. When a magnetic body such as a ship passes sufficiently close the magnet’s ends are drawn up, making contact and firing 7001bs of explosive. The magnet mines have mostly been dropped from seaplanes. It is not considered that they are effective beyond fifty fathoms. In contrast to moored mines they lie on the bottom, their effectiveness depending on the degree of sensitivity at which they are set, also the size of the ships, which must pass directly overhead. British Seamen Decorated When the King decorated Lieu-tenant-Commander J. D. D. Ouvray and Petty Officer Baldwin no detailed information was given of the services for which the awards were made. Actually it was for bravery in dealing with the first magnetic mine recovered in England and rendering it harmless at the risk of their lives, in order that it be taken for examination.

Two days after the Germans adopted the method of dropping magnetic mines from the air they dropped two in the Thames Estuary. One was seen to fall by artillery men, who reported to the Admiralty. A naval party organised a long search in bitter wind on exposed mud-flats. Early in the morning they discovered a mine, a black, pear-shaped object, embedded in mud, filled with 7001 b. of high explosive. Later a party of experts from a torpedo school, under LieutenantCommander Ouvray, arrived. Using the utmost care they secured the mine. The task was rendered perilous by the fact that they knew nothing of the mechanism which exploded the mine. Arrangements were made by which one officer went out to the mine, the others staying at a safe distance. Before the officer went he told the others exactly what part of the mine he was going to attempt to get. A Grim Idea

A grim idea was that if he happened to be taking off the detonator without knowing it and the mine exploded the others would know what part not to touch in approaching future mines. It was LieutenantCommander Ouvray who went on this hazardous expedition. He came back with the fitting which he had set off to obtain, and it was concluded that it was the detonator. The whole party, thinking the mine harmless, grouped round it and applied screw-drivers and wrenches with a wilL It was a shock when they found that there was another detonator inside. Safely they negotiated the second danger, eventually finishing the work late in the afternoon, when the mine was taken to the naval .yards for examination. A considerable number of magnetic mines has been recovered intact and others have been charted. One is sitting in the Whitstable oyster beds awaiting recovery at the spring high tide.