Improvements in or appertaining to Submarine Telegraph and like Cables.
Year: 1894

page_text: .Date of Application, 6th July, 1894
Complete Specification Left, 8th Apr., 1895-Accepted, 18th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Submarine Telegraph and
like Cables.
We, HERBERT ARNAUD TAYLOR, Mem. Inst. Civ. Eng. and JOSEPH ARTHUR
LOVEL DEARLOVE, Assoc. Inst. Elec. Eng., both of No. 4 Great Winchester
Street, in the City of London, do hereby declare the nature of this invention to be
as follows:-
:―
Our invention has reference to submarine telegraph and like cables and consists
in so constructing such a cable that an increase of speed in working is obtained.
This result is attained by taking advantage of self induction set up in the cable:and
by the introduction of a "leak" circuit.
The
According to our invention two or more conductors insulated from each other
are included in and form part of the stranded conductor of the cable. The
central wire of the strand, which may be of iron or copper and may itself
consist of a strand, is covered with an insulating material such as silk, cotton,
paraffined or prepared paper, or asbestos paper or other suitable .insulating
substance or compound before it is laid up in the strand. One, two, or more of the
surrounding wires may also be covered with insulating material of the same or
similar nature as the covering used on the central wire and the whole number'may
then be stranded up together in the usual manner. In order that the covered and
bare wires when laid up round the insulated central wire or strand should form a
symmetrical strand the weight of metal in the covered wires may be so reduced
that the diameter of the covered wires is the same as that of the bare oues.
whole strand conductor so made may be coated with "Chatterton's compound or
other similar substance or compound to fill up the interstices after which the whole
may be coated to the required thickness with gutta-percha or other insulating
substance or compound. Or the strand conductor constructed as described may,
after its treatment with the "Chatterton compound or its equivalent and before
receiving its coating of gutta-percha or external insulating envelope, receive a layer
or layers of asbestos compound or paper or paraffined or prepared paper or their
equivalents laid ou either spirally or longitudinally. In order to prevent the
ingress of water for any considerable distauce in the event of the cable being
broken after its submersion, we may saturate a short length of the fibrous insulator
at suitable intervals with a waterproof insulating compound. The building up of
the cable may then be completed in the ordinary way..
"
"
The surrounding wires of the strand may for electrical purposes be used in one
group as a single conductor, or they may be divided into two groups, each group
consisting of two contiguous bare wires and one covered one. The current sent
through them will, by reason of one or more of their number being insulated as
hereinbefore described, be caused to flow in a spiral path around the central wire
or strand of the stranded conductor. When they are divided into two groups and
insulated as described one from the other they may be used in a circuit as "flow"
and "return."
"
We find that when the central wire is of iron the self-induction of the circuit is
increased and in consequence the effect of electrostatic capacity diminished by this
mode of construction

page_text: The central wire or strand may be joined up electrically with the surrounding
wires at both ends of the cable or it may be connected with earth at each or either
end and used as a "leak" circuit.
When the surrounding wires are divided into groups the central wire or strand
may be joined up electrically with either group or it may be used as a "leak" as
before described whether connected to earth at one end or both ends or not.
The central wire or strand, if intended to be used as a leak," may be covered
with an inferior insulator such as cotton or the like or it inay be thoroughly
insulated and the desired leakage provided by the insertion at convenient intervals
along the cable of metallic connections of suitable resistance between the outer
group or groups of wires and the central wire or strand.
Dated this 5th day of I... 1001
3 Improvements in or appertaining to Submarine Telegraph and
=
i
like Cables.
.:!
We, HERBERT ARNAUD TAYLOR, Mem. Inst. Civ. Eng., and JOSEPH. ARTHUR
LOVEL DEARLOVE, Assoc. Inst. Elec. Eng., both of No. 4 Great Winchester
Street, in the City of London, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
"
The conductor of a. submarine telegraph, cable, a
,as at present generally made.
consists of a strand of copper wires,." laid up around a central straight one, all
of them forming one conducting mass of metal.
1
It has been proposed as a means of increasing the working speed of such cables
to use two or more metallic conductors insulated from one another and enclosed in
the one envelope of insulating material, but that .mode of construction is difficult
and costly to carry out in practical manufacture...
Our present object is to so construct a cable that an increase of speed in working.
is obtained, which result is attained by taking advantage of self-induction set up in
such cable, and by the introduction of a "leak" circuit therein..,
Our invention is illustrated in the accompanying drawings
Figure 1 showing on an enlarged scale a piece of the conductor of a cable, and
Figure 2 illustrating diagrammatically an arrangement. for a "leak" circuit.
According to our invention, two or more of the, conductors a, & for example in
Figure 1 which are included in and form part of the stranded conductor of the
cable are insulated from each other. and from the other wires which latter, need not
be separately insulated. The central wire c of the strand, which may be of iron
or copper and may itself consist of a strand, may be covered with an insulating
material such as gutta-percha or a mixture of that material with "Chatterton's
compound, or, it might be silk, cotton, paraffined or prepared paper.or other
suitable insulating substance or compound before it is made up in the completed
conductor...
In order that the covered and bare wires when laid up,round the central wire or
strand should form a symmetrical strand the weight of metal in the covered
surrounding wires may be so reduced that their diameter when covered is the same.
as that of the bare ones.. : -.
The whole strand conductor so constructed may be coated with "Chatterton's'
compound or other similar substance or compound to fill up the interstices, after
which the whole may be coated to the required thickness with gutta-percha or

page_text: 9ther insulating substance or compound. Or the strand conductor constructed as
described may, after its treatment with the "Chatterton's" compound or its
equivalent and before receiving its coating of gutta-percha or external insulating
envelope, receive one or more layers of paraffined or prepared paper or the; like
laid on either spirally or longitudinally, and in order to prevent the ingress of
water for any considerable distance in the event of the cable being broken after
its submersion if an absorbent insulator is employed,' we may saturate a short
length of it at suitable intervals with solutions of gutta-percha, Chatterton's
compound, or india rubber, or insulating varnish, or other suitable waterproof
insulating material or compound:
1.
The building up of the cable may be completed in the ordinary way.
Any two or more wires of the strand may for electrical purposes if not separately!
insulated from each other be used in one group as a single conductor or the central
wire or strand and some of the surrounding ones may be separately insulated:
dividing in the latter case the remaining surrounding wires into two or more groups,.
dach group consisting of (say) two contiguous bare wires and one covered one.
For example as shown in Figure 1, the central wire or strand'e being suitably
insulated, a and b may be separately insulated while de ând fi garerrespectively
the two contiguous bare wires. The current sent through the bare wires will, by
reason of one or more of the other, wires being insulated as described, be caused to
flow in a spiral path around the central wire or strand : When the surrounding
wires are divided into two insulated groups as described they may be used as
"flow" and "return."
We find that when the central wire is of iron the self-induction of the circuit is
increased and in consequence the effect of electrostatic capacity diminished by this.
mode of construction.
The central wire or strand may be joined up electrically with the surrounding
wires at both ends of the cable or it may be connected with earth at each or either
end and used as a "leak" circuit.
When the surrounding wires are divided into groups the central wire or strand
may be joined up electrically with either group or it may be used as a "leak" as
before described whether connected to earth at one end or both ends or not.
The end of the central wire, or a surrounding wire, or a group of them, either
of which wires may be used as the true or " leak " circuit, and whichever is so
used, may be connected at either or both ends to earth through inductive or non-
inductive resistances.
The central wire or strand, if intended to be used as a "leak," may be covered
with an inferior insulator such as cotton or the like or it may be thoroughly
insulated and the desired leakage provided as illustrated diagrammatically in
Figure 2 by the insertion at convenient intervals along the cable of metallic
connections R-R' of suitable resistance between the outer group or groups of
wires represented by X and the central wire or strand represented by Y. The
resistances R-R' may be composed of fine wire of high specific resistance which
may be laid up along the central wire spirally or embedded in the insulating
material round that wire.
The sizes of the central wire and the surrounding wires, and the resistance and
the number of the "leaks" or metallic connections between the true conductor
and return wire or leak circuit are indefinite but depend on the length of core
to be worked in one circuit. The resistance placed between the true conductor and
"leak" circuit may differ in amount, being higher nearer to the sending and
receiving ends of the cable than in the centre of the line. For example
presuming A and B in the diagram to be the sending and receiving ends of the
cable the resistance of R might be 1000 ohms, R₁ 900, R 700, R³ 40', R* 300,
R$ 40',
R 600, R7 700, Rs 900, and R° 1000. Preferably the resistances are so
arranged in amount that :-

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is-
-
1. A submarine telegraph or like cable having the central wire or strand of its
stranded conductor insulated from the surrounding wires of the strand.substantially
as and for the purposes set forth.
2. A submarine telegraph or like cable wherein the individual wires or strands
forming its complete stranded conductor are either individually or in groups
insulated from each other substantially as and for the purposes set forth.
3. The combination, in a submarine telegraph or like cable, of a stranded
conductor having one of its wires or strands. insulated from the others which latter
may themselves be formed in two or more groups, with resistances inserted at
intervals connecting the one wire or strand with the others or connecting such
group or groups to each other substantially as and for the purposes set forth.
4. A submarine telegraph or like cable wherein, for the purpose of obtaining
increased speed in working, means are provided for setting-up self-induction and
for the introduction of a "leak" circuit therein substantially as.set forth..
Dated this 8th day of April 1895.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicants.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicants.