SWEEP-PROOF MINES.

Auckland Star, Volume LXVI, Issue 122, 25 May 1935, Page 22

SWEEP-PROOF MINES.

BRITAIN'S LATEST DEVICE.

VEILED IN SECRECY

LONDON, April 17. Sweep-proof mines and controlled mines, which can be set off with absolute precision from a distant point, are the latest devices in the British Navy, which is converting many of its warships into mine layers to supplement the mine layers and submarine mine layers expressly built for the work. Absolute secrecy surrounds the sweepproof mine, but in some way or other the mooring line holding the mine to the sea bed parts when struck by a sweep, but still holds the mine firmly anchored. This means that a nest of sweep-proof mines can be swept time and again by trawlers and be reported non-existent," while all the time they would be lying there ready to blow up the firs', ship that touched one of them. The same secrecy protects the new device that permits explosion of controlled mines from distant points, even in the dark or in fog, as soon as hostile ship nears them. Such mines, which are sweep-proof as well, would be used for protecting ports and estuaries in the event of wars Newest of the mines is the Mark H-2, which weighs about 0001b and carries a heavy charge of TNT. A fairly large number of British warships are being converted into mine layers. The largest unit in the mine laying fleet is the Adventure, carrying 310 mines. Four monitors and several of the newer destroyers, such as the Esk and Express, which have a cruising range of 6000 miles (New York to Plymouth and back without refuelling), have been equipped to lay mines, while four submarines, built or-building, will carry heavy cargoes of mines of the latest type. These craft are the Grampus, Porpoise, Norwhal, and Rorqual.