Two buoys are generally used for the large torpedo, and one for the
small. The buoy-rope is of hemp, about five or six fathoms in length and
two inches circumference, an eye being spliced in the end nearest the
torpedo; to this eye is bent the tow-rope with a single or double sheet
bend, forming the knot by which the torpedo is towed; the other end of
the buoy-rope is passed through the large or small ring in the stern
(according to whether working in deep or shallow water), then through the
tube of the first buoy, an overhand knot made in the rear; then through
the next buoy, and a knot in the rear of that.
[Illustration: DRAWING (X).]
[Illustration: DRAWING 1.]
The brakes are used for the purpose of controlling the tow-ropes; they
can be fixed by screws into the deck at the most convenient place for
command, and, in a properly-constructed vessel, would be worked below the
water-line to prevent exposure of the men. They are so arranged as to
admit of the tow-rope being quickly veered, and at the same time powerful
in bringing the torpedo to the surface when required. Success greatly
depends on the skilful handling of these brakes, for in conjunction with
the cork buoys they give the operator command of the depth at which
the enemy is to be struck. The handles on the leather straps are for
the purpose of lifting the strap off the drum when veering suddenly,
that there may be no friction to interfere. The handles for winding
up would rarely be used in real action, and never should be on when
veering. Unless a very high rate of speed is required, one handspike
will control the tow-rope; the other strap can be thrown off the drum,
and the handspike allowed to lie on the deck ready to be thrown into
gear, if necessary. The surface of the drum in contact with the strap
should be powdered with rosin to increase the friction. The tow-rope
should be so reeled up, that in veering the reel may revolve towards the
men at the handspike (see Plate 2). The spindle will contain several
tow-ropes, that, in the event of one torpedo being cut away, another can
be immediately bent.
The brake for small torpedo requires only one drum and handspike. It can
be fitted to a steam-launch by placing an extra thwart across near one of
the others.
[Illustration: DRAWING 2.]
The drawing shows a small brake fitted for the electric torpedo, having
a hollow central spindle, through which the end of the tow-rope carrying
the insulated wire is rove, after passing out at the axle; a swivel
connection is made with the battery. The brakes, both large and small,
are so made as to ensure durability, they being considered a part of the
ship’s furniture.
Brake for safety-key line is a small reel on the same principle. When
going a slow speed, it may not be necessary, as the safety-key line can
be attended by hand; but when going ten or eleven knots, it will be found
of considerable advantage, both in keeping the light of the safety-key
line from dragging astern, thereby lessening the divergence of the
torpedo, and also in drawing the safety key when a strong stop is used.
The ordinary deep-sea lead line can be used for a safety-key line, or any
hemp-rope from three-quarters to an inch circumference. It should be new
and of good quality; for in the event of its carrying away before the
stop, it would necessitate the recovery of the torpedo.
[Illustration: DRAWING 3.]
[Illustration: (Y)]
The magazine for exploding bolts is fitted with exactly the same size
brass tubing as in the priming case; therefore, if the bolts are kept to
work with the proper pressure when in the magazine, they will do so in
the torpedo. This magazine should be kept apart from the torpedo-room,
and care should be taken that the tube is clear before forcing the loaded
bolt into it. The torpedoes are then no more dangerous than any other
powder case, and, being very strongly made and sealed, are probably less
so.
[Illustration: Plate 2.