Engineering Wonders of the World
Volume I

TORPEDOES. 437 Increasing the Range. quate, and a Last section of all is (6) the tail section. This contains the wheel-gearing for conveying the motion of the engine shafting to the pro- pellers, the gear for providing reverse move- ment in the two screws, and the horizontal and vertical rudders. The fore propeller re- volves in a clockwise, the after one in an anti-clockwise, direction, each counterbalan- cing the other as regards forces tending to revolve the torpedo. The best torpedo in general use to-day has a speed of 35 knots for 1,000 yards, and 30 knots at 1,500 yards. With surface destroyers steaming at 37 or more knots in smooth water, this speed is no longer found to be ade- description of a new develop- ment recently made public will be of interest to readers of this article. It is some years since the world was startled with rumours of extraordinary results having been achieved with the American Bliss-Leavitt apparatus for heating the air of torpedoes. From that time onwards the firm of Messrs. Whitehead and Company have devoted considerable attention to the investigation of this subject, and have now succeeded in producing a heater consider- ably more efficient than any yet tried. This heater consists of a small steel chamber between the air chamber and the engine of the torpedo, in which a certain amount of liquid fuel is burnt in contact with the air passing to the engine. The result is a gain in power of 100 per cent. The whole appa- ratus takes up about 3 inches only of the torpedo’s length, and weighs about 12 lbs. Details of construction are, of course, known to the makers only, but they are such that no difficulty is experienced in handling the torpedo by any man acquainted with this weapon. In order to show clearly the advan- tages obtained by this new invention, the following table gives the speeds at various ranges of the very latest Whitehead torpedo when run cold and with heated air :— With Cold Air. With Heated Air. Speed at 1,000 yards.,.. 43 knots. „ 1,500 30 ....40 „ „ 2,000 „ .... 28 „ ....38 „ „ 3,000 „ .... 23 „ ....32 „ „ 4,000 18 ....28 „ The British Admiralty has never been slow to adopt improvements in the torpedo arma- ment of the fleet. For years Great Britain has led in the matter of submerged tubes for firing torpedoes, and our fleet practises with torpedoes more than any other in the world. An improvement of the kind described above is consequently of greatest value to our navy. Applying the result of the air-heater to ad- vances in the projectile itself, we are now manufacturing a torpedo with a 21-inch diameter, a charge of over 300 lbs. of ex- plosive, and an effective range of 7,000 yards. We may mention briefly in passing a much, smaller torpedo—the 14-inch weapon. This is now becoming obsolete, and its best speed is no more than 30 knots at 600 yards, whilst the explosive charge carried is only 77 lbs. It is still supplied to the smaller submarines of our own and other navies, but in the new, est submersibles and in our own latest battle- ships provision will be made for the 21-inch torpedo only. The American Bliss-Leavitt Company have developed a turbine engine for torpedoes, whereby 130 horse-power is developed from a machine weighing only 20 lbs. The turbine is air driven, and works in conjunction with the super-heater described above. Torpedoes are fired in two positions—from submerged tubes and from deck tubes. These tubes are similar in principle to guns, but. having merely to throw the torpedo clear of the ship’s side, do not need the strength Firing Torpedoes. possessed by guns. The firing of torpedoes is accomplished either by a small charge of pow- der or by compressed air. When fired above water, the torpedo takes to its element almost parallel to the surface, though the method of