Evening star., 1939-11-26

tIlC 1NOI lAl OSd, L ~ .slliCA DAtta llCutl Oh
ships we're sunk by German mines
and % were damaged. The first
loss of British dreadnought in the
war (the Audacious) was the
result of German mining opera
tions; mine laid by German SUBJ
marine sank the Hampshire with
Lord Kitchener on board. There
was no instance, so far as the writer
knows, of airplanes having been
used by either side to plant mines.
The British and American forces
In the North Sea planted some IT,
600 mines. the great majority of
these during 1918. Over 10000 mines
we're used in the northern mine bar
rage alone, the purpose of which
was to close the whole area of sea
between Scotland and Norway to
the exit of German submarines.
American mine squadron under the
command of Capt. (now Rear
Admiral, retired Reginald R. Bel
KNAPP.
1t is not known how many sub
marines Germany has at present
which are fitted for mine laying.
A submarine designed for this pur-
pose is of very little use for any
other, as the mine cargo and mine
laying devices take up so much OF
the very restricted space within
her hull. The earliest German mine
laying submarine in the World War
carried only II mines, but larger
ones were later put into service
carrying as many as 36. The stand
ard American mine used during the
war contained 300 pounds of INT
and, with it's anchor, had total
weight of about 1,400 pounds.
Mines May Be Smaller.
Obviously, a submarine cannot
carry very large numbers of such
bulky and weighty devices. Air
planes can carry still fewer; it is
therefore to be supposed that If the
Germans are really using airplanes
as mine layers they have greatly
reduced the size and weight OF their
mine and anchor. The cable, which
attaches the mine to the anchor, is
controlled by a device which allows
the mine to float at predeter-
mined distance below the surface OF
the water. A free or drifting mine
is. of course, at the mercy OF wind
and current and is danger to
friend and foe alike. The only
really effective type of mine is that
which can be anchored in a position
where an enemy ship is likely to
hit it.
Mines may be removed by sweep
ing. British practice uses two small
ships for this purpose, towing be-
tween them a wire cable which
catches the mooring cable of the
mine and brings the latter to the
surface. In the American and
French Navies a single ship is used
with sweeps swung out on elthel
side, the outer end being controlled
by an "otter," similar to the we'll
known device used in trawling.
Mine sweeping is very danger
Gus operation, as may be imagined
For the first two months OF the
last war one sweeper was lost for
every two mines swept up. In 1913
as a result of experience, this had
been reduced to one for every 80
mines. However, throughout the
war an average of so per cent OF
the crew was lost every time a
eu,aoncr yuoc mined
Menace Seriously Regarded.
From these facts may be deduceo
some of the difficulties, perils ano
losses which will confront the Brit
;sh Navy when dealing with the
German mine attack. Certainly the
British have all the advantages to
be derived from their experience OF
the last war, including not only
experience in sweeping, but in traf'
fee control-the shifting of traffic
from ports temporarily closed by
mines to others where safety car
be assured. A call for volunteers
with trawler experience to deal with
the new menace is, however, indlca.
tive of the seriousness of the sit.
uation.
The number of small craft re.
quired may be suggested by the
fact that by the end of 1917 a tota
of 400 vessels for mine sweeping
duties were under construction il
the British Isles Constant sweep
ing and patrolling of channels, con.
slant vigilance to detect new min'
fields, with the added difficulty O.
dealing with aerial as we'll as sur
face and sub-surface mine layer
will consume the efforts of vas
numbers of ships, as well as men