IMPROVEMENTS IN AND RELATING TO APPARATUS FOR RAISING SUNKEN SHIPS AND OTHER SUBMERGED OBJECTS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by George Sutherland Dodman at the
Office of the Commissioners of Patents on the 30th January 1883.
GEORGE SUTHERLAND DODMAN, of 6 Clarendon Terrace, Beaumont Street, Liver-
pool, in the County of Lancaster "IMPROVEMENTS IN AND RELATING TO APPARATUS
FOR RAISING SUNKEN SHIPS AND OTHER SUBMERGED OBJECTS
"
My Invention has for its object the construction of a convenient form of
apparatus to be applied as a means for raising sunken ships and other submerged
objects, and consists of a certain construction of inflatable vessel, or buoy and its
accessory appliances and connections which are used in requisite numbers for
raising the sunken structure, or body being applied in the manner hereafter
set forth.
The vessel, or buoy according to my Invention is of a collapsable form, and has
flat ends parallel to each other, slightly converging sides and an arched top and an
inverted arch bottom. The ends of the vessel are of well seasoned timber and each
end is received into an angle iron frame, which frame is covered with sheet iron.
The wooden end is rabetted to hold the sides and top and bottom of the vessel,
which sides and top and bottom are composed of a continuous collapsable fabric
such as waterproof canvas. The end edges of the canvas come between the
wooden ends and the angle iron frame, the joint being made with india rubber, or
other suitable packing strip on each side of the canvas so as to make a perfect
joint between the wooden end the canvas and the angle iron frame, the wooden
ends being fastened to the angle iron frame by through bolts and so securing the
joint. Both ends of the vessel are of the saine construction and they are held
apart by distance bars, or stays constructed on the elbow, or rule joint principle so
as to allow the vessel to collapse when the two ends are brought together, the
canvas, or waterproof fabric folding up between the ends when the vessel is in a
collapsed state.
Each of the four corners of the two ends are provided with strong metal corner
pieces which are securely bolted to the angle iron frame. Each of these corner
pieces is provided with two projections one of which, namely the top one in the
case of the top corner pieces and the bottom one in the case of the bottom corner
pieces serves as the attachment for the chains hereafter spoken of. The other pro-
jections namely the side projection of each coruer piece are used for fixing the

page_text: elbow jointed stays which keep the ends of the vessel apart when expanded.
These projections also serve to keep the vessel from damage if struck by any
outside object.
The top and bottom of the vessel are provided with chains extending from each
corner. These chains are used to attach the vessel to the submerged object to be
raised and are provided with suitable hooks for that purpose. Chains are also
used in lowering and working the apparatus.
Attached to one end of the apparatus there is a special arrangement of valve
through which the air for inflating the apparatus is forced. This valve consists of
a non return valve fixed on the inside of the end of the vessel and working in a
suitable seat and held up to its seat by a spring. Outside the valve inlet passage
is provided with a grooved flange, which receives the flange of a flexible air pipe
and also receives a shutter valve which, when the air pipe is not in position drops
over the valve inlet and closes same. The flange of the air pipe is provided with
a locking bar, which, when the flange is in the groove, or flange of the inlet
passage, is forced into a recess in such groove by the action of a spring in the air
pipe. This spring is stronger than the spring before mentioned which closes the
inlet valve. The inlet passage is provided with a movable diaphragm, or
equivalent device arranged so that the locking bar of the air pipe bears on one end
of it and the inlet valve bears on the other end of it, so that when in position the
spring of the locking bar being stronger than the spring of the inlet valve the
inlet valve is kept open. Over the spring of the inlet valve there is a lever, one
end of which bears on the spring, or the valve and the other end is provided with
a chain which is led and attached to the other end of the vessel. The function of
this chain and lever is that when the vessel is inflated to its fullest limit, the
chain works the lever and closes the inlet valve, which in the act of closing forces
back the locking bar of the air supply pipe and thus disconnects such pipe from
the vessel. Simultaneously with such disconnecting action, the shutter valve
closes the inlet orifice.
The vessel is provided with a suitable relief, or air escape valve which it is not
necessary to describe as such valves are in common use in connection with helmets
and dresses for divers, and are also being used with inflatable bags for submarine
purposes, their action being to regulate the presssure of air inside the vessel in
accordance with the depth and head of water.
In the application of my Invention to say the raising of a sunken ship, a
number of vessels constructed as herein described are used. These vessels from
their collapsable nature are easily transported to the scene of action. A flexible
air pipe is attached as herein described to the vessel. The vessel is then lowered
by means of its chains and attached by a diver to any convenient part of the
sunken ship, namely by inserting the hooks through the side lights, or attaching
to any convenient part of the ships side, deck, or, hold. The other end of the air
pipe is connected to any suitable air compressing machinery on the salvage vessel
and by this means the submerged vessel is inflated and when inflated the air pipe
is automatically released, is drawn up to the salvage vessel attached to another
collapsable vessel which in its turn is in like manner attached to the sunken ship.
When a sufficient number of these vessels have been attached to the sunken ship
she will come up. The relief valves in the vessels prevent such vessels from
bursting as the head of water is lessened.
The collapsable vessels according to my Invention may be of any convenient
portable size, for example each vessel may have when inflated a displacement of
from six to ten tons.