Improvements in Electric Cables.
Year: 1894

page_text: Date of Application, 18th Aug., 1894
Complete Specification Left, 14th May, 1895-Accepted, 17th Aug., 1895
PROVISIONAL SPECIFICATION.
Improvements in Electric Cables.
I, HENRY ALFRED CHARLES SAUNDERS, of Winchester House, Old Broad
Street, in the City of London, Chief Electrician of The Eastern Telegraph
Company Ld., (a communication to me from Captn. Robert Greey R.N. Reserve
and Walter John Murphy Commander and Chief Electrician both of The Eastern
Telegraph Co.'s, Ld., cable ship "Amber") do hereby declare the nature of this
invention to be as follows:-
In submarine cables made in accordance with this invention aluminium and alloys
of aluminium are substituted for iron or steel in the sheathing with the object of
preventing corrosion and decreasing weight. In this way the depth from which a
cable may be successfully lifted and repaired is increased; also the amount of jute
at present necessarily used in the manufacture for lightening the cable and
protecting the outside from corrosion is diminished.
When desired the weight of the alloy employed can be graduated to give weight
to shallow water cables whilst still employing a sheathing having anti-corrosive
properties.
Dated this 17th day of August 1901.
H. A. C. SAUNDERS.
Improvements in Electric Cables.
I, HENRY ALFRED CHARLES SAUNDERS, of Winchester House, Old Broad
Street, in the City of London, Chief Electrician of The Eastern Telegraph
Company Ld. (a communication to me from Captn. Robert Greey, R.N. Reserve
and Walter John Murphy Commander and Chief Electrician both of The Eastern
Telegraph Co.'s Ld., cable ship "Amber") 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 :-
I. The corrosion of the iron or steel sheathings of submarine cables, which has
been found to take place even when they are laid on good mud and clay bottoms
has the effect of allowing the gutta percha core to be exposed in places to the
deteriorating effects of decaying animal and vegetable growths.
II. It was the custom to construct deep sea cables, with sheathings in which
yarns of jute or an equivalent were substituted for alternate iron or steel wires with
the object of decreasing the weight and increasing the length of itself which the
cable would lift, and thus facilitating the laying of the cable with a proper amount
of slack, and the lifting of it for the purpose of repair. In practice it has been
found that the reduction of the number and size of the sheathing wires seriously
diminished the strength and durability of a cable so constructed.
III. Another result of so constructing the cable, is that the spaces between the
sheathing wires, occupied by the jute yarns, prevent the wires bearing against each
other and so inutually strengthening each other by forming practically a complete
[Price 8d.]

page_text: tube with the result that when the cable is suspended at any point, on a grapnel or
leading wheel, the upper wires are pulled upon more than the lower ones, the cable
Hattens out damaging the core and eventually causing the sheathing wires to break
n detail.
IV. If the iron sheathing wires are made of sufficiently farge diameter to prevent
rapid loss of strength through corrosion and to properly surround the core, the
cable becomes very heavy; and this is especially the case now that larger cores are
required to be laid and lifted. The substitution of aluminium and its alloys for
ron makes it possible both to increase the diameter and decrease the weight of the
wires and thus adds to the margin of strength and prolongs the time necessary for
even an equal amount of corrosion to seriously weaken the cable. Thus by making
use of sheathing constructed of aluminium and its alloys in accordance with this
nvention the life of a cable is considerably lengthened.
(a) Because there will be much less corrosion.
(b) Because the cable can be made so much lighter that it will be possible to
lift it even if with time as much corrosion should have set in as would
make it impossible to lift an iron or steel sheathed cable.
(c) Because with increased diameter of the sheathing wires and with a larger
amount of metal to be attacked before a serious weakening by corrosion
can take place the weight of a cable sheathed with aluminium and its
alloys will still be much less than that of an iron or steel sheathed cable.
(d) Also by using aluminium and its alloys the cable may be constructed with
closed sheathings thus greatly adding to its strength and the possibility of
lifting it from great depths, and
(e) Aluminium being less springy and brittle than steel or iron there will be
much less danger of the cable kinking, or of the sheathing wires cracking.
V. Cables sheathed with aluminium and its alloys according to this invention
are constructed on the same general principles as those sheathed with iron or
steel viz.:
tion (as to the latter, generally, a copper stranded conductor insulated by gutta
percha). The dimensions and construction of this part of the cable are not affected
by this invention in any way.
THE TAPINGS.
In cases in which the core is to be protected from teredos or other marine
borers &c. a calico tape will be laid on spirally or otherwise next the core; and
over it laid on spirally an aluminium tape about 004" thick and 6" broad, which
forms the protection against the borers and is substituted for the brass taping at
present used. Over this will be applied a tarred calico tape also laid on spirally
but with an opposite lay to the aluminium tape, to keep the latter securely in place.
These tapings will be omitted in case of deep water cables, or when the temperature
of the sea or the conditions of the bottom otherwise, are such as to make it certain
that no borers exist in the neighbourhood of the cable. In such cases the next
mentioned coating of hemp or jute will be applied directly over the core.

page_text: coating being in opposite direction to the last and that of the last in an opposite
direction or lay to that of the sheathing wires which are afterwards laid on over
the hemp or jute coatings. The total thickness of jute or hemp laid on thus in
layers will be such as to fill up the annular space between the core and the
sheathing wires and may be as thick as desired; but should not be less than
about 05 in. as otherwise the core would stand in danger of being damaged by the
sheathing.
In deep water cables where the bottom is generally covered with globegerina ooze
or is composed of clay which does not attack aluminium, the taping and compound
generally applied to each sheathing wire of iron and steel cables, as a protection
against corrosion may be omitted, and so also the outer jute yarn whipping and the
compound applied around the cable over the sheathing for the same purpose. By
omitting these the co-efficient of friction in water of the cable is greatly decreased
and its repair thereby facilitated especially in bad weather: as the strain when
picking up when the repairing ship is heaving will thus be greatly diminished. The
transport and laying of the cable will also be facilitated by the consequent decrease
of bulk and weight.
But in cases in which the nature of the bottom points to the necessity of safe-
guarding the sheathing against chemical attack each sheathing wire will be
protected by the mechanical application of some such protection, as for instance the
tape and gutta percha compound applied to each sheathing wire of some of the iron
and steel cables at present constructed.
Finally, over the sheathing may be applied if the position in which the cable is
to be laid demands it, one or two coatings or whippings of jute yarns, or of coarse
canvas taping saturated with a compound usually composed of 65 parts of mineral
pitch, 30 parts of silica and 5 parts of tar by weight. These yarns or tapes are
laid on spirally each layer with an opposite lay to the one before it.
Having now particularly described and ascertained the nature of my said inveu-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. In the construction of electric cables for submarine, military, or other purposes

page_text: the employment of aluminium and its alloys in lieu of steel or iron substantially as
herein described.
2. The employment of taping of aluminium and its alloys in lieu of the brass
taping substantially as herein described.
1007
H. A. C. SAUNDERS.