The Black Hills union. [volume] (Rapid City, Pennington County, Dakota [S.D.]) 1889-1904, 1898-11-04

sists of twelve 5O0-pound mines of the
same pattern as those used by the war
department for observation mines.
The cable to which they are attached
and by which they are fired consists
Of a main line LAO feet in length, into
which are fOrked six branches. AS a
rule the counterminines are placed
aboard an ordinary service launch
which is toWed by a fast steamboat,
not infrequently a torpedo boat. AS
this work generally is done in full view
and range Of the enemy, it is designed
to be done automatically as possible,
so that neither nor casual
ties a interfere with it's successful
operation.
Accordingly the steamboat owing
the lanuch proceeds at it's full speed,
being steered on a prearranged bearing.
AS soon as the mine field that is to
be attacked is reached a buoy attached
to the end Of a cable is thrown over
board, while the boats rush on. The
cOuntermines have been hung along the
thwarts Of the launch and are arranged
so that When a certain tension is put
upon their fastenings they are released
automatically and are allowed to drop
into the sea. When the entire line has
gone overheard the towing steamer
hoists a red flag, or, if at night, fires
a rocket.
This is the signal for the firing batter
les at the two ends of the cable to be
joined. A second and similar signal in
dicates the pressing of the firing key
by an officer on the steamer, and the
consequent explosion of the line of
countermines. Almost invariably it is
found that the force of the explosion
has been sufficient to break the connec-
tons of the enemy's line of mines. This
automatic principle Of countermining
shows it's chief usefulness in the fact
that no one need be on board the LAUGH.
"Sweeping' is perhaps the most un-
reliable method known Of clearing a
mine field, but if it is carried out care
fully is frequently effective. When the
federal fleet during the civil wal sailed
n Mobile bay it was found that the
harbor n river were planted so
thickly with improvised mines and tor
pedoes hat the safety of the ships in
the attacking squadron was menaCCd.
An attempt was made to remove them
by ordinary means, but it resulted IN
the destruction of the ship employed
in the work. The method of II
mining was we'll enough known at that
time. but the unreliablitiy of electrical
firing devices in hose days waS such
that all attempts to operate a line Of
countermines failed. In despair Of frrc-
ing the defenses of the harbor the gov
eminent sent to New York for Captain
E. r. Lowe, an experienced diver.
DANGEROUS WORK, THIS.
Captain Lowe tried for some time
to remove the mines n torpedoes bv
means of his divers, but failing to ac-
complish the work he was reduced to
the necessity Of dragging the bottom
of the harbOr with a haWser CT steel
wire. The tCrpedoes were pulled from
their mooriEgs, and although two tug
harbor was cleared so tnat federal ships
were able to attack the forts with
comparative ease. This experience
showed the government that while
divers were often of great use in plac-
ing mines, they were of no value at
all in removing them.
Two or more boats are emp,oyed in
the manipulation of a sweep" Several
kinds Of sweeps are used IN the SER
vice, ranging from the wire cable used
by Captain Lowe to an
which is, PRACTICAL a small counter
nine. The n generally used in the
United States navy is composed Of
about twenty eathoms of two-inch rope
or wire cable, with charges Of gun
cotton at each enc and fitted with arms
to catch the mooring ropes of mines 1t
is suspended by lines from three floats
or bouys attached at the center and
ends. The floats selected for the man,
pulation of q sweep are generally those
drawing the least possible amo unit of
water, so as to reduce the possibility
Of their colliding with a mine to a min
mum. Each boat carries an electrical
firing battery.
When the boats arrive at the passage
which it is intended to sweep clear of
mines eac boat takes an end Of the
cable and. separating, proceeds to drag
it behind them. AS soon as resistance
is felt the boats gradually approach one
another and the position of the obstruc-
ton is determined. This having been
done. the line is pulled so as to bring
the nearest charge Of gun cotton in con-
tact with the mine. and the gun cotton
Is discharged. This process is repeated
until the channel Is considered clear
of mines, when it Is swept once more to
make sure that none has been missed.
Creeping" Is considered the moss Of
fcacious method Of destroying mines.
as it is directed solely against the cable
connecting Tue mine cable with the
shore batteries. Once this is DESTROYED
or cut the mines are considered HARM
| less. Two 'creeps" are used by our
navy. One is q sort of explosive crap
mel consisting Of q charge Of three