IMPROVEMENTS IN APPARATUS FOR RAISING SUNKEN SHIPS
Year: 1880

page_text: LETTERS PATENT to Charles Haslett, of No. 122, Southampton Row, Russell
Square, Manager, Central Investment Coy., and John Gordon Thomson,
Engineer, of 6, Little Quildford Street, Bloomsbury, both in the County of
Middlesex, for an Invention of "IMPROVEMENTS IN APPARATUS FOR RAISING
SUNKEN SHIPS."
PROVISIONAL SPECIFICATION left by the said Charles Haslett & John
Gordon Thomson at the Office of the Commisioners of Patents on the 11th
September 1880.
CHARLES HASLETT, of No. 122, Southampton Row, Russell Square, Manager,
Central Investment Coy., and JOHN GORDON THOMSON, Engineer, of 6, Little
Guildford Street, Bloomsbury, both in the County of Middlesex. "IMPROVEMENTS
IN APPARATUS FOR RAISING SUNKEN SHIPS."
This Invention has for its object improvements in apparatus for raising sunken
ships.
For this purpose we employ pontoons formed of sheet iron, they are cylindrical
except the ends, which are hemispherical.
These pontoons when partly filled with air will float in water; they are
weighted so that they have no tendency to turn over, and there is an aperture at
the lower part by which the interior cavity of the pontoon is always in communi-
cation with the external water. Four or other number of chains are fixed to the
under side of each pontoon; they all pass to an eye or ring, which can be made fast
to a bolt fixed into the side of the ship to be raised. At the upper part of each
pontoon there are two air cocks, and a pipe for the supply of compressed air enters the
pontoon. On the end of the air supply pipe there is a check valve, which closes, to
prevent water entering the pipe. When the air cocks are opened they permit the
air to escape from the pontoon until it sinks. When the water has risen within the
pontoon to the height requisite to sink it, the water covers the outlet passages, and
no further escape takes place, Telescopic pipes are provided at the outlets which
are easily adjustable, so that the pontoons may, when the air cocks are open, still
retain sufficient air nearly to sustain its weight. There are rings at the ends of
Price 6d1

page_text: the pontoons for the passage of guide ropes, by which the pontoons as they sink are
directed to the places where they are required to be used.
In employing the apparatus the guide ropes are first secured to the wreck, and
these ropes having been passed through the eyes at the end of one of the pontoons,
the pontoon is made to sink by opening the air cocks. It descends quietly to the
submerged ship, and is secured by the chains provided for the purpose to a bolt
fastened into the ship.
In conducting the raising operations a ship at the surface is provided, containing
a reservoir of compressed air, and the air pipe or pipes lead from this reservoir in
to the pontoons. As soon as an attachment is made air is admitted to the pontoon
sufficient to give it a tendency to rise; the outlet cocks being first closed and the
pontoon may be further secured to the ship by lashing if considered necessary.
All being ready compressed air is admitted from the reservoir to the air hose, from
which it enters the pontoons, expelling the water by the open holes in the bottoms.
The pontoons thus receive such buoyancy that they risc, bringing the submerged
ship with them. As the pontoons rise and the air expands the surplus escapes by
the open holes, and the apparatus is not in consequence exposed to any strain.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Haslett & John Gordon Thomson in the Great Seal Patent
Office on the 11th March 1881.
CHARLES HASLETT, of No. 122, Southampton Row, Russell Square, Manager,
Central Investiment Coy., and JOHN GORDON THOMSON, Engineer, of 6, Little
Guildford Street, Bloomsbury, both in the County of Middlesex.
"IMPROVEMENTS
IN APPARATUS FOR RAISING SUNKEN SHIPS."
This Invention has for its object improvements in apparatus for raising sunken
ships.
For this purpose we employ pontoons formed of sheet iron, they are cylindrical
except the ends, which are hemispherical.
These pontoons when partly filled with air will float in water; they are
weighted, so that they have no tendency to turn over, and thero is an aperture at
the lower part by which the interior cavity of the pontoon is always in communi-
cation with the external water. Four or other number of chains are fixed to the
under side of each pontoon; they all pass to an eye or ring, which can be made
fast to a bolt fixed into the side of the ship to be raised. At the upper part of
each pontoon there are two air cocks, and a pipe for the supply of compressed air
enters the pontoon. On the end of the air supply pipe there is a check valve,
which closes to prevent water entering the pipe. When the air cocks are opened
they permit the air to escape from the pontoon until it sinks.
When the water
has risen within the pontoon to the height requisite to sink it, the water covers the

page_text: outlet passages, and no further escape takes place. Telescopic pipes are provided
at the outlets which are easily adjustable, so that the pontoon may, when the air
cocks are open, still retain sufficient air nearly to sustain its weight. There are
rings at the ends of the pontoons for the passage of guide ropes, by which
the pontoons as they sink are directed to the places where they are required to
be used.
"
In employing the apparatus the guides ropes are first secured to the wreck, and
these ropes having been passed through the eyes at the end of one of the pontoons,
the pontoon is made to sink by opening the air cocks. It descends quietly to the
submerged ship, and is secured by the chains provided for the purpose to a bolt
fastened into the ship.
In conducting the raising operations a ship at the surface is provided, containing
a reservoir of compressed air, and the air pipe or pipes load from this reservoir into
the pontoons. As soon as an attachment is made, air is admitted to the pontoon
sufficient to give it a tendency to rise, the outlet cocks being first closed, and the
pontoon may be further secured to the ship by lashing if considered necessary. All
being ready, compressed air is admitted from the reservoir to the air hose from
which it enters the pontoons, expelling the water by the open holes in the bottoms.
The pontoons thus receive such buoyancy that they rise, bringing the submerged
ship with them. As the pontoons rise and the air expands the surplus escapes
by the open holes, and the apparatus is not in consequence exposed to any strain.
In order that our said Invention may be most fully understood and readily
carried into effect, we will proceed to describe the Drawings herounto annexed.
snips.
Figure 2 is a diagram illustrating the method of employing these pontoons.
In Figuro 1, a, a, are the iron or steel plates forming the walls of the pontoon ;
b is the aperture at the botton, which always remains open to the water; c, c,
are chains secured to the bottom of the pontoon by which to connect it to the
wreck; d, d, are the cocks for permitting the escape of air from the pontoon.
In each of these cocks the plug is hollow and is always open to the interior of
the pontoon; by side perforations it communicates when the plug is suitably placed
with the outlet pipos d', d'. The shell of the cock is screwed so that a telescopic
end or lengthening piece may be attached to it to regulate the amount of air which
will be retained in the pontoon when the air cocks are open. This should be such
that under these circumstances the pontoon will slowly sink in sea water. If the
cock itself be suitably placed these lengthening pieces are not required. e, c, are
the pipes by which the air enters the pontoon from a reservoir of compressed air
contained in a steam tug or other vessel at the surface; e' is the air hose passing
from the pontoon to the roservoir; f. f, are valves at the end of the pipes c.
These
valves open to allow the air to enter the pontoon, but close when the tendency is
the other way, and prevent water entering the air pipes and air hose; g, g, are
rings at the ends of the pontoon by which it is connected with the guide ropes.
In Figure 2, h, h, represents the wreck or sunken vessel, and i is the tug or
vessel at the surface engaged in the lifting operations.
k, k, are two guide ropes attached to the wreck and brought up to the vessel at
the surface. The pontoon is not lowered until preparations for connecting it with
the sunken vessel have been already made by divers. The way in which the
connections are made will be dependent on circumstances; it may be by holes found
or formed in the side of the vessel, or by chains passed beneath the bottom. When
chains beneath the bottom are required, and the sunken vessel lays in sand, the
operation of passing them is greatly facilitated by the use of a water jet. To the
end of the chain to be passed beneath the bottom an anchor like hook is attached

page_text: and along-side of this there is fixed a nozzle from which the water jet is delivered.
The hook is placed by the diver or otherwise close to the side of the sunken vessel,
and the water being turned on the sand is excavated from beneath it, and the hook
sinks until it can be reached from the other side, As it goes down the diver can
to some extent guide the hook in its course.
When all the pontoons required have been made fast to the sunken vessel, the
compressed air is admitted to all of them, or to so many of them as turn out to be
required in order to raise the vessel; as the vessel rises the surplus air escapes and
the ship is brought quietly to the surface.
By means of the air cocks also the divers can regulate the speed at which the
vessel comes up.
1, in Figure 2, represents a small vessel towing a pontoon to the place where it is
required for use.
Figure 3 is a section of a similar pontoon intended for use as an auxillary. Its
construction is such that it floats on end, which for this special purpose is more
convenient than the horizontal position. The diver can in this case sit upon a
platform on the top of the pontoon and control the rise and fall by stop cocks,
admitting air or allowing it to escape. By means of this pontoon weights can bo
raised and conveyed, and objects of value can be brought to the surface.
--Having-thus. described the nature of our said Invention, and the manner of
performing the same, we would have it understood that we claim our improved
apparatus for raising sunken ships, substantially as herein described, especially we
claim our improved-pontoon-with its arrangements for the supply of compressed air,
a-free-opening-at the bottom and air exits controlled by cocks-at-the-top, such air
exits being so arranged as always to retain in the pontoon.nearly as much air as is
required to float it.
In witness whereof, I, the said John Gordon Thomson, have hereunto set my
hand and seal, this Tenth day of March, in the year of our Lord One
thousand eight hundred and cighty one.