IMPROVEMENTS IN SHORING AND SUPPORTING VESSELS ON DOCKS, PONTOONS, OR CRADLES, AND IN FLOATING THEM OVER SHALLOW BARS
Year: 1877

page_text: LETTERS PATENT to Josiah Latimer Clark and John Standfield, both of 6,
4
Westminster Chambers, Victoria Street, in the City of Westminster, for the
Invention of "IMPROVEMENTS IN SHORING AND SUPPORTING VESSELS ON DOCKS,
PONTOONS, OR CRADLES, AND IN FLOATING THEM OVER SHALLOW BARS."
Sealed the 20th March 1877, and dated the 12th January 1877.
PROVISIONAL SPECIFICATION left by the said Josiah Latimer Clark and
John Standfield at the Office of the Commissioners of Patents on the 12th
January 1877.
JOSIAH LATIMER CLARK and JOHN STANDFIELD, both of 6, Westminster Chambers,
Victoria Street, in the City of Westminster. "IMPROVEMENTS IN SHORING AND
SUPPORTING VESSELS ON DOCKS, PONTOONS, OR CRADLES, AND IN FLOATING THEM
OVER SHALLOW BARS."
Our improvements consist in the employment of flexible air bags in conjunction
with ordinary docks or pontoons, or with a rigid frame, which retains the air bags
in a suitable position, so as to form a soft bed, and enable them to raise and support
the bilges and sides of any vessels over nearly the whole area of their surface; also
in their employment for shoring vessels in ordinary docks and on ship lifts and
patent slips.
In order to lift vessels over a shallow bar we construct a floating dock of any
ordinary form, but with a shallow bottom, and upon the floor of this we fix a
series of flexible air bags or matteresses, the edges of which are, by preference,
bolted down to the floor; these mattresses are suited to the form of a vessel, and
are arranged in series along each side of the dock, and are connected by pipes and
valves with a series of air chambers or reservoirs in the sides or bottom of the dock
which contain air under compression supplied to them by engines and pumps in the
manner described in our Patent for "Floating Docks and Pontoons," No. 202,
of 1874. As soon as the vessel is brought into position over the dock and touching
the keel blocks certain valves are opened, which cause some of the mattresses to
become inflated, and to grip or support the vessel on each side, guiding and holding
it firmly in position, the face of the mattresses being protected by timber rubbing
pieces. The remaining valves are then opened, and the whole of the mattresses then
become inflated, filling up the space between the bottom and sides of the dock and

page_text: the vessel, giving as complete a support to the vessel as the water had previously
given; at the same time water is expelled or pumped from the chambers of the
dock, so as to raise the vessel partially out of the water and form the whole into a
raft or dock, drawing very little water, and capable of being floated over a shallow
bar or into shallow water.
When it is required to lower the vessel water is allowed to flow into the chambers
of the dock, the air is allowed to escape from the bags, the dock descends, and the
vessel floats quietly away.
These air mattresses are equally adapted for shoring and supporting vessels in
ordinary stone graving docks, and upon pontoons and patent slips, or upon ship
lifts and ship railways, or upon the depositing dock described in our Patent, No. 514,
of 1875, taking the place of the ordinary bilge blocks and shores. Any of the
mattresses can be readily removed by allowing the air to escape, so as to allow
access to the ship. When used for these purposes they may, if preferred, be inflated
by water instead of by air.
In all cases the mattresses need not be fixed to the frames or dock; they may be
on independant bases, to slide in or out of place; they would then form as it were a
series of independent lifting jacks, each having an elastic surface to conform to the
shape of the body being lifted.
In place of a floating dock of the ordinary form a skeleton framework may be
employed to hold the bags in position, provided with sufficient buoyancy to support
itself and the engines and pumps, or these last may be placed in a separate vessel or
on shore.
SPECIFICATION in pursuance of the conditions of the Lotters Patent filed by
the said Josiah Latimer Clark and John Standfield in the Great Seal Patent
Office on the 11th July 1877.
JOSIAH LATIMER CLARK and JOHN STANDFIELD, both of 6, Westminster Chambers,
Victoria Street, in the City of Westminster. "IMPROVEMENTS IN SHORING AND
SUPPORTING VESSELS ON DOCKS, PONTOONS, OR CRADLES, AND IN FLOATING THEM
OVER SHALLOW BARS."
Our improvements consist generally in the employment of flexible air bags in
conjunction with a rigid structure, such as a floating dock or other suitable frame-
work, for the purpose of gripping, supporting, and raising vessels; the object of the
framework being to support the air bags in their position, and enable them to be
applied firmly beneath the bilges and sides of the vessel, or, by means of the frame-
work, to transmit their united buoyancy to the vessel.
Figures 1, 2, 3, and 4, show this principle as applied to a dock for lifting vessels
over shallow bars. Figure 1 represents in plan a floating dock of ordinary con-
struction, provided with a bow and stern and screw propellers, with a shallow
bottom suitable for floating a loaded vessel over a bar A, A, A; Figures 1, 3, and 4
represent the air cushions ranged beneath the bilges of the vessel, on each side,
along its whole or the greater portion of its length. These air bags are made of
strong flexible india-rubber and canvas cloth of the ordinary character, or of other
similar material, the bottom of each bag being, by preference, of iron, with the
flexible cloth bolted, rivetted, or otherwise suitably fastened to it, and the whole of
the bags are connected by air pipes, as hereafter described. The bags may be of
any convenient form, but, by preference, are made of the form shown in the
Drawings, that is, oblong in plan, as in Figure 1, and wedge shaped in side elevation,
as in Figures 3, 4, and 6. When empty they lie flat upon the dock; when inflated
they protrude upwards and forwards, and take the form of the sides of the vessel,
gripping and supporting her firmly and uniformly over a large surface, as shown in
Figures 3 and 4; they may with advantage be placed close together, as shown in
Figure 1, so as mutually to support each other at the sides; or it may be, in some

page_text: cases, preferred to space them apart, so as to allow room for the insertion of sliding
bilge blocks or other support between them.
Any one or more of the bags can be emptied independently so as to allow access
to the vessel for inspection or working purposes. The bags may, when required, be
strengthened by internal or external iron frames like an ordinary smith's bellows,
the construction of which is so obvious that it is not necessary to describe it, and
they may be strengthened externally by strong webbing, matting, or netting, as
shown in Figure 5. On the upper exposed side we prefer to protect them by an
apron or cover of stout canvas or matting; and where any great tensile strain is
liable to come on them, as in the case of lifting sunken vessels, we make the cover
or curtain of a series of iron links, or a network of chain, wire, or rope, hinged or
jointed to the dock, as shown in Figures 7, 11, and 12.
A certain number of the air bags have a timber waling secured on their face, as
shown at S, S, Figure 5, and these bags, being the first inflated, rise up into a wedge-
shaped form so as to slide the vessel into a central position and when the vessel is
truly centred and touching the keel blocks. The other bags are successively inflated,
so as to take more or less of her weight; at the same time the chambers of the dock
are pumped out, or the water is expelled from them by compressed air, and the dock
and vessel rise out of the water to the required height for floating over the shallow
bar. It is important to observe that as soon as the bags are inflated they entirely
fill the space between the ship and the dock, converting the whole into one mass,
which, from its great breadth, has enormous stability, far beyond that of a floating
dock of the ordinary description.
The compressed air is stored in certain chambers of the dock C, C, C, C, Figures 1
and 2, being pumped into them by air pumps in the manner described in our Patent.
for floating docks, No. 202, of 1874.
A main supply pipe D; Figure 9, is led from these chambers, and branches E are
connected to each air bag, each branch being provided with a stop-eock F for admitting
the air, and also with a separate pipe and stop-cock G for allowing the air to
escape. A valve H, opening inwards, is provided at the bottom of each inlet pipe,
so as to allow the air to enter the bags, but to prevent its escape, except by means
of the pipe and stop-cock G.
In raising vessels on floating docks and pontoons we sometimes prefer to place
the bags in the bottom of open chambers, as shown in Figures 8, 15, and 17, in
which M, M, M, are the chambers of the pontoons, the bags A, A, being shown in
an inflated condition. Or the bags may be fitted beneath the flat bottom of the
dock, in rows arranged longitudinally or transversely, the lifting power being applied
at will directly under the dock or pontoon, as shown at A1, Figures 3 and 4, so as
to increase the lifting power. Or the pontoon or dock may, if required, be composed
entirely or mainly of a skeleton frame carrying the air bags in suitable recesses, the
buoyancy being wholly or partially given by the air bags; in this manner the
lifting power and stability of pontoons, bydraulic lift docks, or floating docks can be
greatly increased.
Figures 5 and 10 shew the system as applied to the shoring of a vessel in ordinary
dry docks. A, A, represent a series of wedge-shaped air bags arranged conveniently
for sliding in beneath the bottom and bilges of the vessel; Čis the reservoir; D, the
supply pipe &c., the same Figures applying as in Figure 9.
Figure 6 represents a single air bag. E is the branch pipe leading to the bag,
which pipe, in this case, is a flexible tube, and H the valve to prevent the air from
returning; G is the escape pipe for allowing the air to escape, as before described;
I, I, I, are iron plates and angle irons forming the base, back, and sides of the air
bag, to which the flexible canvas is attached by bolts, rivets, or other means, the
canvas being gripped between two strips of iron, as shown at J, J. These wedge-
shaped air bags slide in and out and take the place of ordinary bilge blocks, and
it is obvious that any of them can be removed or replaced at pleasure; it is further
obvious that these bags may be inflated by water instead of air, if so preferred, the

page_text: water being supplied from a head of water at any convenient elevation, or from
pumps. By applying sufficient pressure to these bags it is evident that the vessel
may be entirely raised off its keel blocks.
In hauling vessels up slip ways, or along ship railways, or in supporting them on
floating or hydraulic lifting docks, ship lifts, cradles, or stages of any kind, we
support the vessel wholly or partially on air bags in the manner already described,
and it is evident that the support thus given is almost identical with that afforded
by the water itself, so that vessels with a full cargo, or laden with loose grain, &c.,
may be supported and raised out of the water with perfect safety.
In applying the air bags to the lifting of sunken vessels the framework or dock
which carries them is passed down over the vessel, so as to embrace it on each side,
and the air bags are then inflated so as to press in under the sides and bilges, and
grip the vessel on both sides simultaneously, forming, as it were, a pair of nippers, as
shown in Figures 7, 11, 12, and 13; water is at the same time pumped out of the
chambers of the dock or pontoons which support the nippers, so as to cause the vessel
to float, and enable it to be carried into shallower water, or into a tidal river or bay.
Figures 7, 11, and 12, show such a framework, A', A¹, being the air bags inflated
and gripping the sides of the vessel; the arrangement of the pipes and valves is of
the same character as that already described, the compressed air being contained in
an upper tubular reservoir, or pumped in through flexible pipes from an attendant
vessel; to prevent the face of the air bags being torn by the lifting strain which
they have to support they are protected by a curtain or apron of iron chain or rope
netting, to support the tensile strain caused by the lift, as shown in Figures 7, 11,
and 12, and they may be provided with valves and springs opening outwards in a
manner well understood, to prevent their bursting under excess of pressure.
In Figure 12 an arrangement is shown by which the bag, instead of bearing
against the sides of the vessel, is employed to thrust forward an independent
grapnel or curved shoe P, P, of hollow boiler plate hinged or jointed at the top R,
suspended by links which is forced forward by the bag in underneath the vessel, the
face of the shoe being, in some cases, also provided with an air cushion, as shown
at T, T, Figures 11, 12, and 14, so as to expand when inflated and take a secure
grip of the bilges; it is obvious that either water or air may be used for this
purpose.
Any number of these frames or nippers may be applied successively to a vessel,
as shown in Figure 13, until their buoyancy is sufficient to raise the vessel. In
this case each pair of nippers is supported by an independent vertical tube or
pontoon V, V, Figures 11 and 13, which is brought into position over the vessel,
and after the grip has been taken the water is forced out of the pontoons by
compressed air, and also out of the hollow frames W, W, and out of the chambers
in the nippers, so that every part of the apparatus becomes buoyant. A section of
the hollow nippers is shown at Figure 14, in which T shows the air bag on the
front of the nippers for gripping the vessel fully inflated, and A' the bag behind
the hinged nipper, tending to thrust it out under the bottom of the vessel. Similarly
in Figures 7, 11, and 12, A¹ shows the air bag behind the nipper A¹. Figure 11
shows a bag inflated under the bow, and A", Figure 12, shows a bag inflated under
the stern of a vessel without a hinged shoe or nippers, so that the bag can take any
shape required.
The vertical pontoons or tubes V, V, Figures 11 and 13, are constructed of
wrought iron, but the upper portions may consist of inflated cylindrical air bags,
which may be easily handled and removed, and which would not be damaged by
coming into contact with each other, and as the vessel rises these cylindrical bags
may be removed piecemeal. The tops are protected by loose floating annular air
bags inflated, as shown at X, X, in Figures 11 and 13, which surround the tubes
and act as fenders to take off the concussion caused by rough seas.
It is obvious that several of these frames and nippers may be combined together
and provided with vertical tubes, so that the whole may be lowered on to a vessel

page_text: simultaneously, as shown at Y, Figure 13, and such a dock may be usefully provided
with engines, pumps, screw or other propellers, and the other requisite appliances
for raising vessels.
Figures 18 and 19 show such a submarine floating dock provided with numerous
large apertures in the centre, through which the masts and rigging of a sunken
vessel may protrude while being raised, A", A", being the bags, as before.
Figures 15, 16, and 17, show a plan and side and end elevation of another form of
dock or pontoon for raising sunken vessels; A, A, A, show the air bags or bellows
standing in recesses or compartments of the pontoon, each provided with a hole in
its centre, through which a chain or other attachment passes down to the vessel
below or to the nippers or other apparatus which grips the vessel. The bags may
be used in pairs, with a girder across each pair; the object of these bags is to give
an uniform strain to the whole of the descending chains, although their length may
vary.
First. We claim the use of air bags for blocking and supporting vessels on docks,
pontoons, or cradles, as herein-before described.
Second. We claim the use of air bags for supporting and blocking sunken vessels,
so as to grip them securely, for the purpose of raising them, as described.
Third. We claim the use of air bags placed on or under rigid frameworks, as
before described, for the purpose of giving increased buoyancy or stability to floating
docks, pontoons, or cradles.
Fourth. We claim the use of air bags or pontoons and docks, for the purpose of
supporting the chains or other attachments used for lifting vessels and for equalizing
the strain upon them.
In witness whereof, I, the said Josiah Latimer Clark, have hereunto set my
hand and seal, this Tenth day of July, in the year of our Lord One thousand
eight hundred and seventy-seven.
J. LATIMER, CLARK. (L.S.)