Evening capital. (Annapolis, Md.) 1884-1910, 1892-05-17
HARBoR DEFENsEs.
PLANTING DEADLY EXPLOSIVES TO
PROTECT THE COAST.

Wn8t - vast amount 0t A@400Es cAAA&s
Time and Money L. Needed TO Conn
piete . Thorough system OF Coast De-
fenss-Advantages Of the Torpedo.
There is very widely diffused idea
among people who have not made a
special study Of the subject that torpe-
does, and torpedoes alone, can defend
any harbor against hostile attack.
The destructive effects Of few tor
pedo explosions under the most favor
able circumstances have caused this
branch of warfare to assume an undue
importance, an Importance wholly un-
warranted by the results and created by
generalixations from isolated instances,
entirely without regard to the natural
limitations of the efficiency Of any tor
pedo system, however perfect.
1t is the object of this article TO en-
deavor to show the actual capabilities of
torpedoes, the results attainable by their
use, and the restrictions inevitably at
tending their indefinite expansion into a
complete system of defense.
Great guns must play an important
part in all harbor defense, but for the
proper and adequate defending of navi-
gable chennels bouyant mines. exploded
by contact, ara the mainstays.
With their use, however, q host of per-
picking conditions arise, the twisting
and wearing of the cables and moorings,
the depression due to the currents, the
danger of sympathetic explosions. the
leaking OF the cases, the obstruction of
the channel for friendly navigation--all
these have to be overcome as best they
may be.
Where port has several navigable
channels, and it is practicable to sacri-
fee one or more, their closure by means
of self acting torpedoes is easy.
Where channel, however, cannot be
entirely abandoned, self acting mines
are useless, for in order to be thorough
ly reliable they must be as dangerous to
friend as to an enemy. Furthermore,
their planting. and much more, their re-
moval upon the cessation of hostilities
is to be accomplished cnly at great risk.
The limited applicability OF ground
mines is well known. Torpedo science
furnishes two other types for harbor de-
fense; the buoyant mine aud the dirig-
ible torpedo. although the latter proper
ly forms distinct class.
Great nicely in planting torpedoes
cannot be expected, and this fact, cou-
pied with the inevitable shifting of the
mines from various causes, leads direct
ly to the conclusion that great num-
Der of mines must be relied upon rather
than precision in their manipulation.
Despite the number of mines, a vessel
attempting to pass the lines may still
fail to strike a mine hard enough to
work the circuit closer. To meet this
contingency perfect torpedo system
must provide means for firing the mines
at will IN groups of three or four. II
will always be possible to accurately To-
cate vessel within dangerous space
of this number Of mines, and their stimuli.
taneous explosion will have the desired
effect.
To furnish passage for the electric
current many cables are needed, and to
avoid confusion some regular method of
planting must be adopted. 1t is con.
venient to plant the torpedoes in groups
capable of being fred by Judgment.
these groups constituting the units
which are combined into the larger unit
whose limit is generally the number of
mines that can be operated through a
single seven core cable.
The grand groups thus formed are ar
ranged in lines, the latter radiating in
such manner from the operating case
ments that the separate units can be
easily located by triangulation. The
intervals between the lines are filed with
skirmish lines single mines strung on a
single conductor cable and exploding by
contact only.
Many forms of movable torpedoes for
harbor defense have been tried In differ
ent countries with varying degrees of
success. For accuracy of direction and
range of destructive power the Sims-Ed-
ison fish torpedo is perhaps unexcelled
Extended trials at Willet's point have
satisfactorily demonstrated its ability to
carry 200 pounds of dynamite to a dis
tance of two miles at speed of about
twenty miles per hour. The charge is
exploded upon contact with the vessel
or by the action of the operator on shore.
The dirigibility of the torpedo is per-
feet. It follows its prey as though
endowed with life, swerving to the right
or left as necessary, diving under booms
or other obstructions, cutting through
nets, and never slackening its great
speed until the end of it's cable is
reached. AT present q two mile radius
is deemed sufficient, although this could
be increased il necessary by enlarging
the stishr itself Cosmopolitan.