IMPROVEMENTS IN APPARATUS EMPLOYED IN DELIVERING SUBMARINE TELEGRAPH CABLES FROM SHIPS
Year: 1857

page_text: LETTERS PATENT to George Wirgman Hemming, of 10, Belsize Road,
St. John's Wood, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN APPARATUS EMPLOYED IN DELIVERING SUBMARINE
TELEGRAPH CABLES FROM SHIPS."
Sealed the 27th November 1857, and dated the 25th August 1857.
PROVISIONAL SPECIFICATION left by the said George Wirgman
Hemming at the Office of the Commissioners of Patents, with his
Petition, on the 25th August 1857.
I, GEORGE WIRGMAN HEMMING, of 10, Belsize Road, St. John's Wood, in
the County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN APPARATUS EMPLOYED IN DELIVERING SUBMARINE TELEGRAPH
CABLES FROM SHIPS," to be as follows:-
I
pass the cable over, under, round, or through one or more moveable
supports, wheels, drums, sheaves, rings, tubes, or other equivalent con-
trivances, so arranged that the length of cable consumed in passing over,
under, round, or through such moveable supports, wheels, sheaves, drums,
rings, tubes, or other equivalent contrivances, either alone or in conjunction
with any one or more fixed supports, wheels, drums, sheaves, rings, tubes, or
other equivalent contrivances may be caused to vary according to the strain
upon the cable on the motion of the ship, or otherwise, as may be desired, by
which means the rate of delivery of the cable from the ship may be made to

page_text: accomodate itself to the irregular motion of the ship, and to counteract the
alternating increase and decrease of the strain occasioned by the pitching or
other irregular motion of the ship, especially in bad weather.
The motion of any moveable support or supports, &c., may be regulated
either by machinery worked by hand, or by machinery so adjusted as to be
worked by the motion of the ship, or simply by the action of the varying
strain of the cable itself upon the moveable supports, &c., supported or
retained by means of counteracting springs or counterpoises, or by a com-
bination of these three methods; the principle of the action which I claim as
my Invention being in every case to accumulate a portion of slack in or
about the machinery or apparatus of delivery at the time when the motion of
the ship tends to relieve the strain upon the cable, and to give it off again
when by the pitching or other motion of the ship the strain upon the cable
would otherwise increase. By these means the irregularity of the strain on
the cable is avoided, and the risk of injury greatly reduced.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Wirgman Hemming in the Great Seal Patent Office
on the 25th February 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WIRGMAN HEMMING, of 10, Belsize Road, St. John's Wood, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of August, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Wirgman Hemming, Her special licence, that I, the said George
Wirgman Hemming, my executors, administrators, and assigns, or such others
as I, the said George Wirgman Hemming, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN APPARATUS EMPLOYED IN DELIVERING SUBMARINE
TELEGRAPH CABLES FROM SHIPS," upon the condition (amongst others) that I,
the said George Wirgman Hemming, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and scals,

page_text: should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Wirgman Hemming, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Sheet of Drawings hereunto
annexed, and to the letters and figures marked thereon (that is to say):-
My Invention consists of improvements in the apparatus employed in
delivering submarine telegraph cables from ships, whereby I keep the strain
upon the cable approximately constant, and the rate of delivering from the
coil approximately uniform within sufficiently narrow limits.
In order to render the nature of my Invention more clear, I will first state
the defects against which it is intended to provide, and refer to certain known
methods by which it has been attempted or proposed to remedy those defects.
In the ordinary apparatus a retarding force is applied to the cable by
means of brakes, over which the cable passes in its course from the coil to the
sea. The average strain on the cable and its average rate of leaving the ship
are regulated by the retarding force applied at the brakes and by the speed
of the ship, but the rate at which the cable ought to pass overboard in order
to keep the strain constant (which may be called the demand for cable) is
liable to fluctuations from the pitching or other irregular motion of the vessel
and other disturbing causes, and the strain on the cable is subject to corre-
sponding variations, which, in bad weather, become very violent.
A partial
remedy is sometimes supplied by easing the brakes by hand when the strain
becomes dangerously great, thereby allowing the cable to run more rapidly
off the coil to supply the increased demand, and so relieve the strain. Another
remedy which has been proposed is to employ self-acting machinery to ease
the brakes whenever the strain approaches the highest which it is con-
sidered safe to permit. These remedies are defective, inasmuch as that they
are not continuous in their action, and involve irregularities in the rate of
delivery.
The object of my apparatus is to make the supply of cable vary continuously
with the demand, in such manner as to prevent the strain varying beyond
certain limits above and below its average amount for the time being, and at
the same time to obviate the necessity of easing the brakes, and the con-
sequent irregularity in the rate of delivery from the coil, and thus to lessen the
risk of fracture and the waste caused by slack.

page_text: To effect these purposes I pass the cable in its course between the brakes
and the sea round or about one or more travelling sheaves or other moveable
supports, so arranged that the length of cable consumed in passing round or
about such sheaves or supports, in conjunction with other sheaves or supports
fixed in position, may be caused to vary according to the strain upon the
cable. My travelling sheaves or other moveable supports are held back by
means of counteracting springs or counterpoises, so as to yield to any increase
in the strain of the cable and to recoil when the strain is diminished; the
principle of the action being to increase the accumulation of cable in or
about the apparatus whenever the motion of the ship or other disturbing
cause tends to lessen the strain on the cable, and to give off cable from such
accumulation when the motion of the ship or other disturbing cause tends to
increase the strain. Thus the rate of delivery of cable from the ship is made
to accomodate itself to the irregular motion of the ship or other disturbing
cause, and to compensate for variations of strain.
My apparatus which I have thus generally described may be arranged in
various forms and with different kinds of springs or counterpoises. I will
now particularly describe the form of apparatus which I consider the best
adapted for the purpose, explaining it with reference to the Drawings here-
unto annexed. I may premise that when I speak of horizontal and vertical
planes and lines, I mean planes and lines relating to the ship considering the
deck as a horizontal plane. I suppose the apparatus from the coil to the
brakes inclusive to be in any known form, and I make the cable pass
through my apparatus after leaving the brakes.
In Fig. 1, C₁ is the cable coming from the brakes; A₁, A, A, A, are
similar and equal equidistant sheaves, revolving in the same vertical plane on
axles working horizontally at a common elevation in bearings fixed on the
horizontal part of the frame M. In the same vertical plane with these fixed
sheaves A1, A2, A3, A4, are sheaves B₁, B2, B3, the bearings of whose axles are
free to slide vertically in grooves or slots in fixed frames D₁, D2, D,, placed
midway in the intervals between each pair of the fixed sheaves. These
travelling sheaves B₁, В, B₁, are similar and equal to one another. The
distances of the centres and of the diameters of the fixed and travelling
sheaves are so arranged as to allow the latter room to pass freely between
the former, and the grooves in the frame are, as a measure of precaution,
made high enough to allow each of the travelling sheaves to rise until its
lowest point is on a level with the highest point of each fixed sheave;
however, in the ordinary action of the apparatus when properly adjusted, the
actual play of the travelling sheaves should not extend beyond the interval

page_text: from the lowest position allowed by the frame up to the level of the fixed
sheaves, and this is the interval which I refer to when I speak herein-after of
the play of the travelling sheaves. I pass the cable C₁, C, C, C, after it leaves
the brakes, alternately over the fixed and under the travelling sheaves in
succession, and ultimately from the last fixed sheave A, of my apparatus over
guiding appliances, which may be in any known form, into the sea. The
bearings d, d, of the travelling sheaves B₁, B2, B3, are all held down the
action of air springs in the same manner; and it will suffice to describe this
part of the apparatus with reference to one of them, B,, as follows:-Fig. 2
is a transverse view of the frame D₁, with its travelling sheave B,; d, d, d, d,
are the bearings of the axle of B., sliding in the frame D. To each of the
bearings d, d, on the inner side of the frame D₂, is attached a vertical bar b,
and these two vertical bars b, b, are connected just below the sheave B₂ by
a horizontal cross bar a, the ends of which may be made to slide in the
grooves or slots which carry the bearings. From the middle of the cross
bar a, a chain E descends vertically, and is coiled round and fixed to the wheel
F, the axle H of which is mounted in fixed bearings. A chain G is fixed to
and coiled round the barrel L on the same axle H, in such direction that
a downward force applied to this chain G will exert a downward strain on the
bearings of the axle of B. The lower extremity of the chain G, which
descends vertically from the barrel L, is attached to the piston rod of a piston
working air-tight in a vertical cylinder K, the upper end of the cylinder being
open to the atmosphere, and the lower end closed, but communicating by
means of a pipe P with an air-tight reservoir R. The receiver is in com-
munication with an air pump, by which it may be exhausted to any extent
required; also with a supply pipe, by which air may be restored to it, and
with a guage to indicate the pressure of the air within it at all times. The
air pump, supply pipe, and guage are not represented in the Figure, being
matters all well understood; they may be of any known suitable construction.
When the apparatus is used, the receivers of the air spring cylinders appertain-
ing to the several sheaves B₁, B., B,, are exhausted to such an extent that when
the strain on the cable is at the average amount, which results from the speed
given to the ship and the retarding power applied at the brakes, the several
sheaves B,, B, B3, may be in equilibrium about half-way between their lowest
possible position and an elevation on a level with the fixed sheaves.
The apparatus being thus adjusted, when the pitching of the ship or other
disturbing cause increases the strain upon the cable, the travelling sheaves
B₁, B, B, immediately rise and ease the strain by giving off cable; on the
other hand, when the strain diminishes, the springs draw down the travelling

page_text: sheaves below their mean position, and increase the accumulation of cable in
readiness to provide for the next increase of strain and demand for cable.
India-rubber stops may be used at the bottom of the frames D₁, D2, D3, or at
the bottom of the cylinders, to prevent the possibility of the travelling sheaves
being stopped with a jerk in the event of their being drawn to their lowest
position:
I have described the apparatus with only one air spring and reservoir to
each travelling sheave, but as a precaution against the consequences of any
leakage or other accident to the machinery, two or more air springs may be
applied to the axle of each sheave, with distinct and separate receivers, capable
of being connected or disconnected at will: The wheel and axle interposed
between each air spring and the bearings of the corresponding sheave may
be replaced by any other known mode of multiplying velocity, or it may be
omitted altogether, and the air springs made to act directly on the bearings.
When a considerable amount of traverse or play is to be given to the
travelling sheaves, the wheel and axle or other multiplying mechanism is
advantageous by reducing the stroke of the piston required. The sheaves
may be replaced by drums or by semicircular or other curved frames, net
revolving themselves, but fitted round their circumference with a series of
small sheaves, drums, or rollers to diminish the friction, but I prefer the use
of simple sheaves. Moreover, the arrangement of the travelling sheaves or
other moveable supports may be altered in a variety of ways; they may be
made to work in a horizontal instead of a vertical plane, they may converge
to. a centre instead of working parallel to each other, or a number of sheaves
may be placed side by side in one sliding or otherwise moveable block, and
the cable made to pass round these sheaves and corresponding fixed sheaves,
as in a common purchase tackle, or other modifications of the arrangement
above described may be made without departing from the principle of my
Invention; but of all these arrangements I prefer that which I have described,
and shown in the Drawings hereunto annexed. The air springs may also be
replaced by metallic, india-rubber, steam, or other springs, or by any arrange-
ment of counterpoising weights; but I prefer the air springs which I have
described, as combining in the greatest degree the convenience of adjustability,
sensitiveness, and power. In the above description the number of travelling
sheaves is supposed to be three, but the apparatus may be constructed with
one, two, three, or any other number of travelling sheaves, according to
circumstances.
The dimensions of the different parts of the apparatus, the number of the
sheaves, and other parts will depend upon the circumstances of each case, and

page_text: must be adapted to the cable to be laid, the vessel to be used, and the voyage
to be performed; the main considerations by which these matters should be
regulated are as follows:-
1. The total area of the piston or pistons appertaining to each sheave must
be sufficient to insure the requisite power being obtainable to keep the appa-
ratus in action with the highest amount of strain which is to be reached at
any time during the voyage.
2. The total amount of cable which can be given off by the traverse or play
of all the travelling sheaves together should be amply sufficient to compensate
for the greatest possible irregularity in the ship's motion. For example,
supposing twenty feet of cable to be sufficient for the purpose, and the sheaves
so placed that the successive lengths of cable C, shown in the Figures, may
be parallel, one travelling sheave with a play of ten feet, or two or more
travelling sheaves with proportionally less play, would suffice. If, again, a
supply of sixty feet is necessary, having regard to the size and character of
the ship and the nature of the service, one travelling sheave with a play
of thirty feet, or three travelling sheaves with a play of ten feet each, may be
used; or the number and play of the sheaves may be adjusted in any other
way which may be most suitable to the vessel employed and the service to be
performed.
3. The apparatus will be, cæteris paribus, more sensitive the more nearly
the successive lengths of cable C approach to parallelism.
4. The air springs will be, cæteris paribus, more or less sensitive in pro-
portion to the size of the receivers. By giving these a sufficient capacity
the increase of the strain upon the cable which will suffice to raise each
travelling sheave through a given number of feet may be reduced to such
amount as desired. The size of the receivers should therefore be such that
the fluctuations of strain may be confined within sufficiently narrow limits
above or below the average which it may be considered desirable to maintain
at any time during the voyage; moreover, the sensitiveness of the apparatus
will be increased by diminishing the inertia of the moveable parts, which
should therefore be made as light as is consistent with the strength and size
required.
When the average strain at which it is intended to work is changed, the
air springs will require to be readjusted, by altering the degree of exhaustion
of the receivers. As my apparatus is capable of giving the requisite relief
without easing the brakes, there need be no appreciable irregularity in the
rate of delivery from the coil; this obviates much waste in slack, and allows
the speed of the ship to be greater than would otherwise be safe.

page_text: Having described the nature of my Invention, and the manner of performing
the same, I wish it to be understood that I do not limit myself to the precise
form of the apparatus which I have above particularly described, inasmuch as
the apparatus admits of much variation in detail without departing from the
principle of my Invention; and I declare that I claim as my Invention to be
secured under the herein-before in part recited Letters Patent,-
First, the use and arrangement of travelling sheaves, springs, and other
parts as a compensating apparatus, for the purpose and in the manner herein-
before particularly described.
Secondly, the employment in any other form of travelling sheaves or other
equivalent moveable supports for the cable to pass round in combination with
springs or counterpoises acting directly or indirectly upon such sheaves or
supports, as a means of compensating irregularities in the strain upon the
cable by gathering up and giving off accumulations of cable as the strain
diminishes and increases respectively.
In witness whereof, I, the said George Wirgman Hemming, have here-
unto set my hand and seal, this Twenty-fifth day of February, in the
year of our Lord One thousand eight hundred and fifty-eight.
Witness,
W. CLARK, Patent Agent,
53, Chancery Lane, London.
G. W. HEMMING (L.S.)