MINES AND TORPEDOES.

New Zealand Herald, Volume LI, Issue 15767, 16 November 1914, Page 6

MINES AND TORPEDOES.

The naval weapons used by Germany have been the mine and the torpedo. She. has not contested Britain's claim to that superiority in gunfire which gives the ultimate of the seas. Because of its invisibility, the submarine mine is a menace to ships against which it is difficult to guard, and GeVmany has doubtless been led to their indiscriminate sowing by the toll they exacted in the Russo-Japanese war. During the operations at Port Arthur floating mines sent two of the finest battleships of the Japanese Fleet to the bottom, and sank the Petropavlovsk when Admiral Makaroff was leading out the Russian Fleet, Several ships of lesser importance were also sunk by the same agency. Besides it, element of invisibility, the mine has the deadly characteristic that it can be made any size. Charges of five hundred pounds of guncotton can be thus employed, whereas the torpedo generally does not carry more than 2001b. Theoretically, a single mine may sink the largest Dreadnought. Although in principle of operation they are the same, submarine mines may be classified under three divisions—coast defence mines, permanently anchored at a certain' depth, and which can be exploded from the shore; unanchored floating mines; and mines anchored in

selected waters where the depth is I Sot excessive, and which float at a predetermined depth, generally about fifteen feet below the surface. It is the unanchored floating mine which has been so grossly misused by Germany, to the greater hurt of merchant shipping than of the British Navy. The mine itself is a hollow steel sphere filled with explosive, and provided with a detonating charge and a trigger, which, on being struck by a ship, causes the explosion. Sometime!" mines are connected by cable and laid in pairs, so that when a ship engages the cable she draws the two mines against her sides. The only defences against mines are countermining and sweeping. In the former operation an attempt is made to set off the mines by detonating high explosives among them. The more effective method is to remove the mines altogether Jby sweeping, but even this precaution is not necessarily certain. Ceaseless vigilance is demanded of blockading ships to avoid both the mine peril and the deadly torpedo launched by the submarine. The reward of vigilance is not absolute safety. During the present war the torpedo has been used exclusively against cruisers and smaller craft. Every ship known to have been struck is said to have sunk, but it does not follow that one torpedo would destroy a large battleship, subdivided below the waterline into numerous watertight compartments. After many years of experiment, the torpedo of to-day is a potent and marvellously ingenious engine of destruction, capable of covering ranges up to 7000 yards in less than seven minutes. Fired from a submarine at short range it is all the more dangerpus and destructive.