The National tribune. [volume] (Washington, D.C.) 1877-1917, 1903-09-03


stallment of the American Commercial
Pacific Gable from San Francisco to
Honolulu, and to the Philippines, thence
to the remOtest confines of the Orient
have very naturally awakened n lively in
terest of late in the system of submarine
telegraphy.
The cable is only one of the many mod
ern scientific inventions which the public IS
wont to readily and daily utilize without
acquiring any general knowledge even rs
to their construction and modus operandl'
yet such information. though somewhat OF
a technical character, is edifylnS, uselui'
and exceedingly interesting.
When one knows that cable messages
can be transmitted from the United States
to England and from America to the far
Orient within the almost incredible time
of five minutes. it not unnaturally arouses
a curiosity to learn how the instrument OF
such wonderfully rapid transmission OF
words is created, worked and maintained.
HOW TIE CABLE Is MADE.
A submarine cable consists of four DIS
tinct parts; namely, the copper WIRE the
insulating covering of the copper, the
hemp or jute serving, and the sheathing.
The essential portion of the cable is the
small thread of copper through which the
electric current passes and by which the
actual signaling is done. This wire or
conductor is usually made up of NUM-
Der of strands of small wires twisted
spirally together to form one large con-
ductOr. The use of number of wires
twisted together makes the completed con-
ductor more pliable and easy to work than
single wire could be, and is less liable to
accident.
The copper wire needs both covered pro-
lection and the means of preventing the
current leaking out: and as Gutta percha
is the best nOn-conductOr of electricity
availa Bile for the purpose. the conductor IS
drawn through 4 die together with heated
gutta percha, which is thus laid on in
uniform covering.
The copper wire, thus protected by gut
tn percha, forms what is known as the
'core" of the cable and really comprises
all that would be needed for transmitting
cablegrams; but it is necessary to provide
still greater safeguard against sub
marine accidents by the additional use OF
hemp or jute. Besides, the cable
must be heavy enough to sink when
cast from the ship; it must be suiti-
GENTLY strong to sustain its weight when
suspended from the ship into the water
when being laid, and to sustain the weight
which comes upon that part OF a cable
which hangs downward toward sub
merged valleyH itI must, moreover, be
strong enough utter lying buried for years,
to be picked up,foK repairs when required.
For these reassns.i therefore, the hemp or
jute is cOvered by process of steel
sheathing wires. ,ifa
This is doneaby4 passing the core with
iute or hemp c6htfhg through the sheath
ing machine. which puts on the wires
sprally. This COMPLETES the cable. unless.
as is sometimes the case. canvas or
strong tape isrspus over the sheathing
wires as a fnal, and. better protection Gov
ering.
THE TESTING OF TIE CABLE.
When the cable is completed. it is coiled
into tanks and, hurled in water. which not
only enables ATTY iDeipient faults in the
insulatOr 70 be detected more easily, but
also forms the hest medium for preserving
the essential qualities of gutta percha.
The cable is also subjected to other severe
tests, both electrical and mechanical. In
fact continuous process Of testing is ap-
piled from its completion until ready for
casting into the ocean.
b. THE CABLE LAYING SHIPS - a-
are, of course. specially constructed for
the work Usually they have three cable
IdHkS. all ov Ieet uttp, tIt ioit thhh Dt
ing 81 feet in diameter. the other 40 feet
in diameter respectively. having total
capacity of 2.0OG miles of cable. A rough
idea of the size of these tanks may be oh
tanned by stating that n moderate sized
house could be contained in one of them
with rooms to spare. The monster vessel
employed by the British Imperial Pacific
Cable Company to lay the cable to the
Fiji Islands above referred to had ca
pacity for carrying 1900 miles of cable!
This ship is 500 feet long with beam Of
sc feet and designed to carry close upon
10000 tons dead weight.
SHIPPING THE CABLE.
When the total amount of cable is near
ing completion. the ship which is to con-
vey it to its destination is mOored off the
works. 1t is imperative that submarine
cable works should be on the banks of a
river or close to docks where cable can
lie for it would be n costly if not an i'm
possible undertaking to transport cable by
land in sections of sufficient length for
subma rine purposes. Temporary engines
fitted up on deck haul the cable out of the
factory on to the ships, where it is coied
down by hand into the water-tight tanks.
The one man receives and carries it with
in reach Of his companions, who are sta
toned around the tank. They take it from
him ana lay 1t carefully ana u1ll1OTIlillS.
one turn against another. The man in the
center is frequently relieved, for the work
is hard, especially in the case of the larger
shore end types, which sometimes weigh as
much as 20 tons per nautical mile. Such
great care is necessary in cOiling. because
sometimes, when being laid, the cable runs
out of the tank at a very rapid rate,
reaching speed of 10 knots or more an
hour.
When all the cable is on board final
tests are taken. then the ship sails for the
station where the first end is to land. The
cable ships may start out with only part
of the cable, and return from time to time
for the remainder, the various connections
being made by Splicing" process. But
the usual way is for ship to take the en-
tire length Of cable: on board and lay it
from start to finish continuously.
SOUNDING OPERATIONS.
Before cable can be laid, careful
soundings over the,prOposed route have to
be taken. ThiS is generally done by a
smaller ship, before the arrival of the one
with the cable 6noboard. 1t is very i'm
portant to know the contour of the ocean
bed on which the cable has to lie. If no
survey has been nude, sufficient slack Il.
e., loose cable) may not be paid out on
nearing a submarine hill, the cable will
therefore hang ip Il. festoon from the top
of it and eventually break with its own
weight Hemp Hires were formerly EN-