Edwin John Payne-Gallwey

“ In electro-mechanical mines two of the wires forming part of the circuit inside the mine may be brought through to the outside and kept apart till the mine is in position, these wires being long enough to allow of the operator retiring clear of the explosion before joining them up and rendering the mine dangerous.
Mechanical mines have the advantage over electrical that they require fewer trained men for their manipulation, are cheaper, and can be placed in position very rapidly. ”

“ Counter-mining.All mines, especially those with electric cables attached, must be protected by gun fire or guard boats, as, if the mine field is un protected, they can be easily destroyed by countermining or creeping. Countermining is carried out by exploding a succession of charges in an enemy's mine field. Mines containing heavy charges would be used for the purpose, several of these mines being dropped in succession from a boat towed by a fast steamer, the whole line being exploded together as soon as the last mine had been dropped. ”

“ A simple form of mechanical mine has a heavy top, which, on being pushed off by a passing ship, either pulls out a pin and re leases a plunger, which is then forced by a powerful spring into a detonator, or a friction tube is fired when the weight falls on a line attached to it. ”

“ Increased cellular subdivision is also being given to ships under construction, and special vessels, called "torpedo catchers," are being built by most nations. A torpedo catcher is a vessel of superior size and strength, but with the same high speed as a torpedo boat, the principal arm of the torpedo catcher being machine guns. ”

“ Each branch wire must therefore have a disconnector in circuit, clear of the explosion. The disconnector consists of a platinum wire fuse contained in a strong iron case, and the same current which fires the detonator in the mine fuses the platinum wire bridge of the disconnector, and the circuit to the broken branch remains insulated.
Mechanical mines.Mechanical mines, of which there are many different patterns, contain the means of ignition within themselves, and are unconnected with any apparatus ashore. They may be ignited by percussion, friction, chemical action, and electricity. ”

“ All torpedo boats under construction, and most of those already completed, are therefore armed with the Whitehead torpedo. A modern torpedo boat is built entirely of steel, the plates often not exceeding 1/16 inch in thickness, as, in order to get the necessary high speed, the minimum of weight consistent with the necessary strength is of the first importance. ”

“ The pole can be rigged out until the torpedo is submerged a short distance ahead of the vessel, and is fired on contact with the enemy's side, either by an operator in the boat completing the electric circuit, or by the circuit being completed by a circuit closer in the torpedo. In rivers, or places with a current, drifting torpedoes can be used. ”

“ This charge is fired on the torpedo striking a ship by a pistol which screws into the nose of the torpedo. On impact the point of the pistol is driven inwards and forces the point of a steel striker into a detonator. By means of powerful air-pumps air is compressed into the air-chamber B to a pressure of 1000 lb on the square inch, and actuates a three-cylinder engine, which drives two propellers revolving in opposite directions in the tail. The mechanism in the balance-chamber C works two exterior rudders on each side of the tail, which keep the torpedo at a uniform depth during its run. ”

“ They can be fired after a given lapse of time by clockwork and other devices, or can be so arranged that the firing arrangement is released on a catch being withdrawn by the action of a propeller wheel, which remains stationary as long as the torpedo drifts with the current, but is revolved by the force of the current when the torpedo is stopped. Towing torpedoes are constructed to diverge from either side of a ship when towed, which is effected by shaping the torpedo like an otter. ”

“ Lay torpedo.The Lay torpedo is a boat of cylindrical form, the fore part being charged with an explosive. The motive power is carbonic acid gas generated in the usual way. As only a very small portion of the boat is visible on the surface, two guide rods, one on each end of the vessel, mark its position at any part of its run. The boat can be started, stopped, and steered by means of an electric cable, containing several insulated wires, which is paid out from the boat as it travels. ”

“ Mines of the first class are used in places where a channel has to be kept clear for screw steamers to pass, the second class in those parts of the channel where there is little traffic, and the third class in channels which it is intended to bar equally against friend or foe. ”