Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1898-07-21
sunMARINn .oAnL Es.
how Maintained and how Cut whom
Desired.

How Maintained and How Cut when So
Desired.
A submarine cable. as described in
Electricity, consists OF conductor Of
stranded copper wire, the insulation
usually consisting OF layers Of gutta
peicha, bedding of iute and an exter-
nal shenthing of iron wires covered by
suitably prepared tape. The latter
winding goes to make up the protecting
covering and prevents the stranded
copper conductor from becoming ex-
posed through abrasion. 1t was prin-
oipally through this lack of propsr insu-
latiou ana sheathing that the first
cables that were laid failed. The
thickness of the sheathinR varies with
the depth at which it is proposed to lay
cable. What are known aa deep SCH
cables are lightly sheathed with slender
steel wires. Shore end cables, on the
other hand. which rest upon rocky bot
toms. and are mors or less subject to
the action OF storms and heavy tides,
are heavily armored.
As soon asVit becomes apparent that
signals, can no longer be transmitted
through cable, 1t is necessary 20 ac-
curately locate the break in order to re-
pair it. This III done by measuring
| the electrical resistance of the con-
ductor, usually from each end. Know
| ing what the resistance in ohms per
mile ia of the conductor in that special
| cable, the distance in miles to the break
can readily be computed. Thus when
| Admiral Dewey cut the Manila cnhle il
was Immediately ascertained at Hong
Kong that the cable was parted some AZ
| miea from Manila.
The graphing for and cutting Of a
| submarine cable are by no means Q
simple matter, unless the ship under
taking this work 10 provided with all
the necessary apparatus. A ship OF wal
usually relies upon what is known al
| the cutting grapuel to destroy a cablt
unless it is desired to utilize one
section OF a cut cable for communicating
purposes. In such an event the cable,
after being caught in an ordinary crap
mel, is brought on board the ship, where
it is severed, the end in control OF the
enemy being securely Fastened to !
buoy and dropped overheard. Through
the other end messages may be trans
mitted wherever desired, provided the
vessel ia equipped with suitable trans
hitting aud receiving apparatus.
When il is merely dusired to part I
| ChDib III uuep Wutor u fcubtiuS Rihpue
is lowered and the vessel Bteams SLOWLY
backward and forward at right angler
TO tine line Of cable. As soon as th,
latter is hooked it slips, by means O
pulleys, between two heavy knives O.
teeth, aud the strain in lifting CAUSE
the teeth to close and bite off III,
cable.
The recent cable cutting at the bar
Dor Of Cienfuegos was accomplished il
very different manner. In this cas-
the cable to be cut was IN shallow
water. It had to be. grsppled for b.
small hoats and when caught haulei
up across them. 1t wac absolutsl,
necessary to cut a section many feet il
length out of the cable to prevent tn
ends being spliosd later by the Span
iards and com munication re-estab
liahed. 1his work had to he don
under the most adverse circumstances
the tough steel wires forming tn
armor being hapked off with axes
chisels and saws.
Probably the most important lesso
the present war has taught, So far a
! submarine cables are concerned, is tina
every rnan-of- war should not only b
provided with all the necessary tool
for cable cutting, hut SHOULD clso hav
! on board mirror galvanometer an
other necessary instruments for th
, transmission OF messages. This woul
also 'neusssitate this presence on wa
, vessel of Mt least one or two skilled telt
, graphic operators, just as each wa
! vessel now carries number of expeI
: divers.