A New or Improved Semi-collapsible Pontoon for Lifting or Raising Sunken Ships.
Year: 1894

page_text: Date of Application, 8th Aug., 1894
Complete Specification Left, 8th May, 1895--Accepted, 15th June, 1835
PROVISIONAL SPECIFICATION.
A New or Improved Semi-collapsible Pontoon for Lifting or Raising
Sunken Ships.
We, JAMES BAXTER MURRAY of 28 Herriet Street, Pollokshields, Glasgow,
Master Mariner, and JOHN PENDER TURNBULL, of 50 South Kinning Place,
Glasgow, Contractor, do hereby declare the nature of this invention to be as
follows:-
This invention relates to a semi-collapsible pontoon and it has for its object,
by means of one or more of these pontoons, to raise sunken ships of any size or
weight.
The pontoon, consists of a deck structure which may be built of steel or iron
plates strongly braced and stayed, and so arranged as to form a water tight
tank; or of squares or logs of timber. Fitted across this deck structure are one
or more, preferably two, steel or wood lattice or other girders. These girders,
which are fitted with bollards and wire nippers for securing the lifting cables, are
strongly braced and stayed in position. Logs of timber, or smaller girders, as
preferred, are secured across the structure preferably one at each end and one in
the centre.
Secured to the underside of this deck or raft are one, two, four or other suitable
number of air bags. These bags, if the deck is oblong, preferably extend from
end to end of the structure and lie beside each other. They are or may be of a
rectangular cross section. Each bag is provided with an inflating pipe which
leads through the deck structure and has fitted on its end a removable non-return
valve and a goose neck or tube for the connecting pipe leading to the air pump or
pumps. If desired each inflating pipe may be provided, below the valve, with a
stop cock, and, if necessary also a safety valve.
A log or bar is fitted to the structure so as to lie longitudinally at each side of
the outer bags and also below the bags three beams are placed across. Screwed
spindles having handles for turning them at their upper ends are passed through
the ends of the three cross logs on the deck, as aforementioned, down through the
side beams and through the ends of the three bottom logs. These spindles are so
arranged and fitted that by turning them the side and lower cross logs or beams
can be raised or lowered as desired. The side and lower cross beams retain the
bags in their proper positions and prevent the lifting cables chafing against them.
The cross girders on the deck are for keeping the whole rigid and for carrying
the lifting cables.
It is not necessary that the deck or raft should have more buoyancy than is
required to just float itself together with the air bags when they are collapsed.
The deck or raft may be made with a well or space running longitudinally down
the centre, for the purpose of passing lifting cables through, when a number of
these pontoons are used for raising large vessels. The sides of the well would
have longitudinal beams or hars for retaining the bags in position and preventing
the lifting cables chafing them.
The construction and arrangement of the pontoon may be altered to suit different
situations or requirements.
Any desired number of the pontoons can be used at the same time for lifting a
wreck.

page_text: The air bags are, or may be, made of canvas and rubber or of rubber alone, and
may have a tarred canvas or other outer covering.
The advantages of this semi-collapsible pontoon are that it can be easily and
cheaply constructed and that it can be readily taken to pieces or built up at the
place where it is used.
We do not confine ourselves to any special form, size, or shape, of pontoon nor
do we confine ourselves to any special material for its structure.
Air pumps for inflating the bags may be fitted on board the pontoon if so
desired.
Instead of inflating the bags with air they may be inflated with gas.
If desired pressure gauges may be used for indicating the air or gas pressure in
the bags.
Dated this 7th day of August 1904
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.
1
COMPLETE SPECIFICATION.
A New or Improved Semi-collapsible Pontoon for Lifting or Raising
Sunken Ships.
We, JAMES BAXTER MURRAY of 28 Herriet Street, Pollokshields, Glasgow,
Master Mariner, and JOHN PENDER TURNBULL of 50 South Kinning Place,
Glasgow, Contractor, 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:—
This invention relates to a semi-collapsible pontoon and it has for its object, by
means of one or more of these pontoons, to raise sunken ships of any size or
weight.
And in order that our said invention may be properly understood we have
hereunto appended three explanatory sheets of drawings, whereon,
Fig. 1 is a side elevation of the pontoon collapsed.
Fig. 2 is a side elevation of the pontoon extended with the air bags inflated.
Fig. 3 is a deck plan of the pontoon to a reduced scale.
Fig. 4 is an end view of the pontoon collapsed and Fig. 5 an end view of the
pontoon extended.
Fig. 6 is a cross section on the line X-X' Fig. 7 and Fig. 7 a longitudinal
section, on the line X-X Fig. 6, of a pontoon built of iron or steel.
In order to show the pontoon to as large a scale as possible we have drawn
the side views Figs. 1 and 2 out of proper proportion with the end views Figs. 4
and 5. The views Figs. 1 and 2 are shortened to about half their proportionate
length by cutting out pieces on the lines Z, Z1, Z2, Z3. The proportionate length
of the pontoon to its breadth is about 2 to 1 as shown in the reduced plan view
Fig. 3.
It is to he understood that the drawings are merely given by way of example or
illustration as we do not confine ourselves to any special method of constructing
the pontoon.
The semi-collapsible poutoon shown at Figs. 1 to 5 consists of a deck structure A,
built up of transverse logs of timber a, longitudinal logs b, b', deck planks c, and
cross beams d. Fitted across this deck structure are two, preferably steel,
girders e, e, having bollards f, f', and wire nippers 9, g¹, for securing the lifting
cables h, h¹. These girders are strongly braced and stayed in position. Logs of
timber, or smaller girders, as preferred, are secured across the structure
preferably one at each end and one in the centre as shown.

page_text: Three or other desired number of air bags j are secured to the underside of the
deck structure being held in place between the cross logs a and the under. cross
beams k. The bags are preferably made cylindrical with hemispherical ends and
are covered over and enclosed within strong rope netting. They are, preferably,
made to extend the whole length of the pontoon and to lie beside each other in the
curved recesses formed in the underside of the logs a and the upper side of logs k.
Each bag is provided with an inflating pipe which leads through the deck structure
and has fitted on its end a removable non return valve and a goose neck or tube
for the connecting pipe leading to the air pump or pumps on the salvage steamer
or boat. If desired each inflating pipe may be provided, below the valve, with a
stop cock, and, if necessary, also a safety valve.
The logs m, n, are fitted to the structure so as to.lie longitudinally at each side
of the outer bags and these logs in conjunction with the lower cross beams k
retain the bags in their proper positions and prevent the lifting cables chafing
against them.
The cross girders e, e¹, on the deck are for keeping the whole rigid, and for
carrying the lifting cables which pass over the pulleys in the ends, of the
girders.
Carried on the deck in bearings p, p, p², is a longitudinal shaft o having
cranks o¹, o, and drums q, q', g' on it. Wire ropes or cables u are led from the
drums down, at each side of the pontoon, through the logs m, n, and cross beams k
in such manner, as shown, that by turning the cranks o, o, the logs m, n, k, can
be readily raised or lowered. The ropes run over pulleys r in the ends of the cross
beams d.
w, indicates the water line.
Instead of using the wire ropes and drums screwed spindles or other well known
and suitable mechanism may be used for raising and lowering the logs. If screw
spindles are used they may be passed through the logs d, m, n, and secured to the
under beams k in such manner that by turning them, by suitable handles, the logs
can be raised or lowered.
The bags which may be of any required length or diameter, are preferably
inade of two or three ply of cotton cauvas with a sheet of rubber between each
ply. The outer surface is vulcanized and the joints or seams are either sewn or
solutioned together and covered with tape so as to be perfectly air and water
tight at a pressure at least of 30 lbs. to the square inch.
.
The bags are only stayed by the rope netting on the outside and this netting
is arranged and adapted to bear an equal strain,' when 'the bags are inflated, with
the material of which they are composed.
The air inlets for the bags may be 'at the middle or at one or both ends as found
most convenient.
If desired, as shown in the small views Figs. 6 and 7, the deck part of the pontoon
may be made in the form of an oblong cellular tank s composed of light steel
plates. The several divisions or compartments t of the cellular tank communicate
with each other through holes s' and are capable of being filled with water through
a sea cock or cocks and sunk with the bags collapsed outo a wreck and secured
thereto. The tank is provided with a flexible air pipe and suction pipe so that
when the pontoon is secured to the wreck the water can be pumped out and
replaced by air. When the bags indicated by the dotted lines Fig. 6 are also
inflated with air the united displacement of the deck structure and the bags exerts
its influence to raise the wreck. The sea cock in the tank, when it is necessary to
pump out the water therein, can be closed by a diver.
In using the pontoon we generally first secure the deck portion A, with the bags
collapsed, to the wreck, say at low water, and then start the pumps and inflate the
bags with air, until the wreck to be lifted begins to rise.
In some cases it may be necessary to use the air hags separately from the deck
structure, in such cases, the bags are preferably strengthened with an additional
netting of stout manilla rope to prevent chafing. Each bag may also in addition

page_text: to the stop cock and ball valve have a safety valve to prevent bursting under
excessive pressure.
It is not necessary the deck or raft should have more buoyancy than is required
to just float itself together with the air bags when they are collapsed.
The deck or raft may be made with a well or space running longitudinally down
the centre, for the purpose of passing the lifting cables through, when a number
of these pontoons are used for raising large vessels. The sides of the well would
have longitudinal beams such as m, n, for retaining the bags in position and
preventing the lifting cables chafing them.
Any desired number of pontoons can be used at the same time for lifting a
wreck.
The advantages of this semi-collapsible pontoon are that it can be cheaply and
easily constructed and that it can be readily taken to pieces or built up at
the place where it is used. It can also be easily transported from place to
place.
We do not confine ourselves to any special form, size, or shape of pontoon,
nor do we confine ourselves to any special material for its structure.
Air pumps for inflating the bags may be fitted on board the pontoon if so
desired.
Instead of inflating the air bags with air they may be inflated with gas.
If desired pressure gauges may be used for indicating the air or gas pressure in
the bags.
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
consider novel and desire to claim is :-
1. A pontoon for lifting or raising sunken ships having in combination a deck
structure and air bags secured to the structure, said bags being capable of inflation
and deflation, substantially as hereinbefore set forth.
2. The construction, or arrangement and combination of parts, of the special
form of deck structure, substantially as hereinbefore described and shown at
Figs. 1 to 5 of the drawings annexed.
3. The construction, or arrangement and combination of parts, of the semi-
collapsible pontoon with its deck structure and air bags, substantially as hereinbefore.
described with reference to the drawings annexed.
Dated this 7th day of May 1895.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.