Torpedoes and Torpedo Warfare / Containing a Complete and Concise Account of the Rise and Progress of Submarine Warfare

by Charles William Sleeman

Two cog wheels, a large and a small one, are fixed on the upper part of the after end of the torpedo, just in front of the screw propellers: the small wheel is fitted with a certain number of teeth, thirty for instance, which gears into an endless screw attached to the propeller in such a manner that one revolution of the propeller moves the wheel one tooth, therefore thirty revolutions would turn the wheel one complete revolution. The big wheel is fitted with much larger teeth than the small one, and by means of a pin on the latter wheel is moved round one tooth for every complete revolution of the small wheel, and clamped in this new position by a spring catch, which is also worked by the pin on the small wheel. In front of these wheels is a stud which works fore and aft in a slot, and attached to a spring which tends to draw it to the after end of the slot. This stud is connected by means of a wire rod to the valve that admits the compressed air to the engines; when the stud is in the fore part of the slot the valve is open, and when in the after part it is closed.

Adjusting Length of Range.—By means of a lever the spring of the stud is compressed, and the stud moved to the fore part of the slot; then the big wheel is moved round until a stud on its face is the required number of teeth above the lever. For every thirty revolutions of the propeller, and consequently one tooth of the big wheel, a certain known distance is traversed, which varies according to the pattern of the torpedo.

Adjusting Apparatus.—When the propeller has made the number of revolutions corresponding to the length of range required, and consequently has moved the big wheel the number of teeth it was set above the lever, the stud on the big wheel presses against the lever and so releases the spring in the slot, causing the slot stud to fly from the fore part to the after part of the slot, by which action the valve admitting the compressed air to the engines is closed, and consequently the engines cease to work.

Attached to the axle of the big wheel is a small brass arm, which is connected by means of a brass rod to the safety wedge, and is so arranged that after the required number of revolutions of the propeller, the safety wedge will be drawn out; or it may be drawn out at the instant of the torpedo leaving the tube, carriage, &c. Also by means of an additional lever at the fore part of the torpedo, which is connected by means of a wire rod to the valve that admits the air to the engines, and by arranging the attachment of the safety wedge to the brass rod from the big wheel, so that on the wedge being withdrawn it is released from that brass rod, on the torpedo having completed its run, the action of closing the valve which admits the air to the engines causes the additional lever to force the wedge into the safety position.

Torpedo to Float at End of Run.—This is due to the difference of buoyancy at the end of a run from what it was at the commencement, owing to the compressed air being used in working the engines.

Torpedo to Sink at End of Run.—This is effected by means of the adjustment chamber (2), in the after end of which there is a spiral spring valve, which can be attached to the brass rod on the outside of the torpedo that works the valve which admits air to the engines, in such a way that on the valve being closed, and therefore the run of the torpedo completed, the spiral spring valve is opened, admitting water to the adjustment chamber (2) of sufficient amount to sink the torpedo.

To Explode the Torpedo at End of Run.—This is effected by connecting the vertical firing whisker to the rod which otherwise would be connected to the safety wedge lever, by which means, on the valve admitting air to the engines being closed, a force is transmitted to the vertical whisker instead of to the safety wedge lever, and consequently the torpedo is exploded.

Adjusting the Depth.—A small wheel, the face of which is marked in feet, is placed on the left side of the fore part of the adjustment chamber (2). To adjust for depth, by means of a key turn the wheel until the number corresponding to the depth of run required is opposite the pointer.

The torpedo is maintained at the desired depth by means of certain mechanical apparatus contained within the adjustment chamber (2), and which constitutes what is termed the secret of the fish torpedo. This chamber is connected by screws to the foremost and after chambers of the torpedo, in such a manner that by means of a number of small holes bored round the circumference, as shown at (2), [Fig. 119], the faces of the chamber are exposed to the pressure of the water, which varies with the depth to which the torpedo descends. Within the adjustment chamber is an endless strong spiral spring, attached to the after face of the chamber, and so arranged that after being set to a certain tension, capable of resisting an equivalent pressure on the outside of the aforesaid face, any increase or decrease in this exterior pressure will cause the spiral spring to work a rod by which the horizontal rudders of the torpedo are regulated, and thus the desired depth for which the spring is set is maintained. The course of the torpedo is represented by a series of curves, above and below the line, representing the depth it is set for, these curves gradually decreasing until at 100 yards' distance from where the torpedo was started the curves are so small that the path of the torpedo is almost identical to that of a straight line.