IMPROVEMENTS IN PONTOONS USED FOR RAISING SUNKEN SHIPS
Year: 1878

page_text: LETTERS PATENT to John Kirkpatrick, Roger Kirkpatrick, John Bradley, and
Levi Kirkpatrick, all of Little Lever, near Bolton, in the County of Lancaster,
for the Invention of "IMPROVEMENTS IN PONTOONS USED FOR RAISING
SUNKEN SHIPS."
PROVISIONAL SPECIFICATION left by the said John Kirkpatrick, Roger
Kirkpatrick, John Bradley, and Levi Kirkpatrick at the Office of the Com-
missioners of Patents on the 8th August 1878.
"
JOHN KIRKPATRICK, ROGER KIRKPATRICK, JOHN BRADLEY, and LEVI KIRK-
PATRICK, all of Little Lever, near Bolton, in the County of Lancaster.
MENTS IN PONTOONS USED FOR RAISING SUNKEN SHIPS."
IMPROVE-
We make each pontoon similar in shape to a cylindrical steam boiler, with convex
ends, but form it with two or more compartments, and provide it with a keel. for
steadying it when being lowered.
To the top of each compartment we attach a pipe of sufficient length to extend
above the surface of the water, and provide each pipe with top and bottom valves,
and to the lower part of each compartment we connect a valve which can be opened
and closed as required by a connecting rod from the top of the pontoon, the valves
being placed in recesses and covered with grids to prevent damage..
When the pontoon has to be lowered to the sunken ship all the valves of the
pipes and the valves at the bottom of the pontoon are opened to allow the internal
air to escape to the atmosphere, and the water to rush into the compartments,
thereby causing the pontoon to sink, and be afterwards chained or lashed to the
sunken ship.
...O
The next operation is to discharge the water from the pontoon, and for this
purpose the tops of the pipes are attached to forcing air pumps, the top valves of
the pipes being closed, and the bottom ones still open, and when the pumps are set
to work the compressed air forces the water out of the pontoon and fills it with air,
and when this is accomplished the pontoon becomes a raising power, according to
its capacity; and as there are as many pontoons as the sunken ship requires, and
each pontoon contains only air, the ship will be raised with certainty and compara-
tive expedition.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Kirkpatrick, Roger Kirkpatrick, John Bradley, and Levi Kirk-
patrick in the Great Seal Patent Office on the 7th February 1879.
JOHN KIRKPATRICK, ROGER KIRKPATRICK, JOHN BRADLEY, and LEVI KIRK-
PATRICK, all of Little Lever, near Bolton, in the County of Lancaster.
MENTS IN PONTOONS USED FOR RAISING SUNKEN SHIPS."
" IMPROVE-
We make each pontoon similar in shape to a cylindrical steam boiler, with convex
ends, but formed with two or more compartments, and provided with a keel for
steadying it whilst being lowered, and a wooden sheath or casing for assisting its
buoyancy.
To the tops of the compartments are fixed flexible pipes of sufficient length to
extend above the surface of the water, each pipe being provided with top and bottom
valves, and at the lower part of each compartment there is a grated aperture for the
inlet and outlet of the water.
On the accompanying Sheet of Drawings Figs. 1 and 2 are side and end views of
a pontoon with two compartments; and Figs. 3 and 4 are end and side views
representing one of the modes in which the pontoons are employed.
In the various Figures the body of the pontoon and the two compartments
are marked a; the keel b; the wooden casing c; the flexible pipes'd; the top and
bottom valves of the pipes e and f; and the grated apertures g.
The pontoon may be made of any desired dimensions, but the one shewn in the
Drawing is supposed to be one hundred yards in length and twelve yards internal
diameter, in which case the pontoon would be made of one inch wrought-iron plates,
and to have as many nine inch flat steel wire ropes marked has may be required,
cach rope being secured around the pontoon by links i, to which are attached chains
with hooks k to fasten to the sunken ship, and the cubic capacity of the pontoon is
about three hundred and five thousand three hundred and sixty-three cubic feet,
equal to about one million eight hundred and ninety-seven thousand seven hundred
and twelve gallons.
When the pontoon has to be submerged to the sunken ship all the valves are
opened to allow the internal air to escape and the water to flow into the compart-
ments, thereby causing the pontoon to sink to permit it to be lashed to the sunken
ship.
The next operation is to discharge the water from the pontoon, and for this
purpose the pipes are attached to a forcing air pump worked by steam, and when
the pump is set to work the compressed air forces the water out of the pontoon
through the grated apertures, the air taking the place of the water, and whilst the
operation is being performed the pontoon becomes a raising power to the extent or
in proportion to the quantity of water forced out and air pumped in. The length
of cylinder of air pump being six feet, and internal diameter two feet, represents
one hundred and seventeen gallons in cylinder, forcing four thousand six hundred
and eighty-five gallons per forty strokes, or forming a raising power equal to twenty-
three tons per minute, or in six hours eight thousand two hundred and eighty
tons.
By using two pontoons a raising power equal to sixteen thousand five hundred
and sixty tons will be obtained in six hours.
Having now described the nature of our said Invention, and in what manner the
same is to be performed, we desire it to be understood that we claim, the arrange-
ment, combination, and construction of the pontoon, having two or more compart-
ments, a keel, a wooden sheath or casing, grated apertures for the inlet and outlet

page_text: of the water, and the flat steel wire ropes, links, and chains, as herein-before
described, and illustrated on the accompanying Sheet of Drawings.
In witness whereof, I, the said John Kirkpatrick, on behalf of myself and
the said Roger Kirkpatrick, John Bradley, and Levi Kirkpatrick, have here-
unto set my hand and seal, this Eighteenth day of January, in the year of
of our Lord One thousand eight hundred and seventy-nine.
Witness,
CHAS. W. COLLINS,
Manchester.
JOHN KIRKPATRICK. (L.S.)