Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-12-06
SUBMARINE MINES
IN WARFARE
By Edwin Tarrisse

A GOOD deal is read these days of the mar
velously constructed submarine mines
that the nations of the earth are ever lnventlng
to employ against one another, should occasion
therefor arise. These terribly ingenious engines
of war are no new thing. They were extern
sively used in our own Civil War, and by the
French in their war with the Prussians in 1871.
These, however, would be as playthings COM
pared to like instruments of destruction pos
sessed by the Powers in 1908.
The simplest form of all is the contact NINE
which explodes the moment it is touched. how
ever lightly. In construction 1t IS simplicity
itself Just iron case containing tour or
five hundred pounds of explosives and a cable
attached to an anchor that keeps 1T in position.
This case has number of projecting points, on
the end of which are firing pins When vessel
strikes of these pins it is driven in, explodes
a percussion cap, and thus bursts the charge
of gunpowder or dynamite
In anchoring these mines, great care is taken
not to place them too near the surface at low
tide Generally, an immersion of at least ten
feet is necessary. and a strong current may
force them down far as to render them use
less, ground mines are often placed on the bot
tom. These contact mines have a trick OF
going adrift, in which Case sad ending awaits
the unluckv vessel that comes upon them
Another form is the observation mine, in
which the firing mechanism and the mine
proper are in separate cases. Should vessel
strike this kind of mine, the firing pin closes
the signal circuit that bell IS rung at the
station on shore There, the observer, standing
at a keyboard, on hearing certain bell ring,
knows that the buoy above the pOndlng
mine has been struck, and Immediately touches
the proper key, thus closing the firing circuit
and causing the mine to explode.
Sometimes submarine mines are placed
checkerwise in several rows and groups OF from
five to seven mines each, so that if vessel gets
safely between two groups on the flrst line 1t
will almost certainly encounter the mines in one
or other of the succeeding lines.
Mining classmates are nothing more, broadly
speaking, than we'll protected magazines on
shore where the wires and instruments. with
the chart of the torpedoes planted, are held.
From this building the field of torpedoes is
operated and as each mine is directly con-
nected by wires leading to the switchboard, any
separate mine or group of mines may be ex-
ploded at will of the operator.
Electrocontact mines are also fired by an
electric cable leading from the shore. When
an enemy is in sight and friendly ships are
passing in and out of the harbor, the mine
may be so arranged that if it is struck it will
not explode This is done by using firing pins
on springs, which cause them to return to the
proper position if accidentally driven in.
Ground mines are fired by very simple
and ingenious system. Two observers are en-
ployed to determine when the enemy is exactly
over mine. Each has separate station pro-
vided with a telescope, which swings on a verti-
cal pivot toward any point of the horizon; and
the instrument is arranged that when it
points toward the mines the break in the cleo
trio current at that station will be closed.