Apparatus for Raising Sunken vessels.
Year: 1895

page_text: Date of Application, 15th June, 1895-Accepted, 27th July, 1895
Apparatus for Raising Sunken vessels.
1, ALBERT GEORGE MIDFORD, of No. 263 Broadway, City and County of New
York, State of New York, United States of America Civil Engineer, do hereby
declare the nature of my invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
None of the methods heretofore employed for this purpose have proved wholly
satisfactory or practicable under all circumstances. Thus the inflation with air of
collapsible air tight vessels placed within the vessel's hull can only be practised
where the hold of the vessel is comparatively empty. The drawing down of water
tight caissons or vessels filled with air and attaching them to a sunken hull can
only be accomplished with much difficulty and the pumping of water out of water-
tight caissons by a lifting pump, can only be used at very limited depths.
The object of my improvements is to obviate the difficulties heretofore encountered
and provide a simple means of accomplishing the desired result which shall be
efficient and practicable under all ordinary circumstances.
To this end I attach in any suitable manner to the sunken hull to be raised, a
number of hollow vessels or caissons, filled with water. These are arranged in a
tier or series of tiers along the sides of the vessel, those caissons which are fed
from the same air pipe being upon the same level, and they must be sufficient in
number to buoy up the load to be raised or floated, when emptied of the water
contained in them. Air is then forced into these by means of any suitable air
compressor driving out the contained water and filling the caissons with air until
sufficient buoyancy to float the submerged hull is attained.
The invention will be best understood by reference to the accompanying drawings
in which
Fig. 1 shows a side view and Fig. 2 a section of the submerged hull of a sunken
vessel with caissons attached thereto.
Fig. 3 shows a longitudinal section and Fig. 4 an end view of one of the caissons
with its valves and pipe connections, and Fig. 5 shows the details of a part of
the apparatus.
A A A show the pneumatic caissons which are primarily filled with water and are
arranged in tiers along the sides of the vessel to be raised, all the caissons which are fed
from the same air pipe being on substantially the same level, as otherwise the air
forced into the caissons will, seeking the point of least hydrostatic pressure, fill only
the highest caisson, and they are attached to chains passed under the hull of the vessel.
The caissons are preferably of large size and may be constructed of wood or other
suitable material. With each tier of caissons are connected one or more air supply
pipes a a which lead from a suitable air compressor carried on the wrecking vessel
or tug. One air supply pipe may serve to supply air to all the caissons in each
tier, the caissons being connected by pipes 66 passing from one to another, or the
caissons in each tier may be divided into as many sections as desired with an air
supply pipe to each section.
Within each caisson is an air pipe B to which the air supply pipes a and the
pipes b leading from caisson to caisson are connected.
The pipe B is supplied within the caisson with valves C C C, which open into the
caisson and are controlled by the floats D D D which work within the guides d d
and are adapted to be seated upon and close the water outlet ports E E E, and at
the same time close the valves CCC when the caisson is emptied of water. The

page_text: pipe B is also normally closed by the valve F which is located near the point at
which the air from the compressor enters the pipe, and is closed by hydrostatic
pressure and by the spring G which is located in a box e and bears against a piston
head fitted to the box e.
The outlet ports E E E are located respectively near the centre and ends of the
caisson so that the water will be readily expelled, no matter what position the
caisson may assume, since one or more of the ports will always be located at or
near the lowest point of the caisson.
From the lower end of the box e a pipe g is connected with the pipe B at a point
outside of the valve F and from the upper part of the box e a pipe h leads to the
outside of the caisson. Each caisson is also supplied with a safety valve H in
order to relieve any excess of air pressure within the caisson.
In order to raise a sunken vessel, a suitable number of caissons filled with water
are sunk in proper positions around the hull, and chains passing under the hull are
attached to caissons on either side.
When the caissons are suitably secured in position, the water contained in them
is forced out by air pressure in the following manner.
On operating the air
compressor the air passes down the air supply pipe a to the caisson with which it is
connected.
Through the pipe g the air enters the box e, under the piston head f and forces
up the piston head, driving out the water contained in the box e through the pipe h
and opening the valve F.
The air then enters the pipe B and passes out through the open valves CCC,
into the caisson forcing out the water therein through the water exit ports E E E.
As soon as the water is so far expelled from the caisson that the air pressure can
act upon the floats DDD these are pressed downward closing the water exit
ports E E E, and at the same time closing the valves CC C, and the air ceases to
enter the first caisson and passes on through the connecting pipe to the next in
series from which the water is in turn expelled in the same manner.
In this way a
large number of caissons can be emptied of water and filled with air in a very
short time, and the hull will be floated by means of the buoyancy of the caissons as
soon as the water is expelled from a sufficient number thereof.
In case of a cessation of the air supply from the compressor at any time, as by
reason of stoppage of the compressor or a break in the air supply pipe, the air
pressure is at once withdrawn from below the piston head and the valve F is
quickly closed by the force of the spring G, aided by the hydrostatic pressure and
the air already forced into the caisson is thereby prevented from escaping,
The advantage of my invention will be readily apparent since it affords a
practicable and simple means of raising sunken vessels however loaded, from any
depth of water at which a diver can work.
I do not limit my invention to the precise details of apparatus herein described,
since various modifications that will readily occur to those skilled in the art, may
be used to the same end without departing from the nature of my invention.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is :-
1. An apparatus for raising sunken vessels consisting of tiers of hollow caissons
attached to such vessel and arranged along the sides thereof in one or more tiers,
the caissons in each tier being upon substantially the same level, an air compressor,
pipes leading from such compressor to the caissons, exit ports for permitting the
outflow of water from the caissons and means for closing such ports, substantially
as and for the purposes set forth.
2. In a caisson the combination of a water exit port, a float adapted to close
such port, an air pipe extending through such caisson and a valve in such pipe
opening into the caisson and operated by such float, substantially as and for the
purposes set forth.

page_text: 3. In a caisson for raising sunken vessels, the combination with a main air pipe-
of a valve in such pipe, a spring operating to close such valve and located in a
closed case, a piston-head in such case attached to the valve stem, a pipe from the
main air pipe connecting with such case at a point on one side the piston head, and
a pipe from the outside of the caisson connecting with such case at a point on the
other side of the piston-head substantially as and for the purposes set forth.
4. In a caisson for raising sunken vessels the combination of a series of normally
open water-tight ports located respectively near the center and ends of such caisson,
floats operating to close such ports, an air-pipe pressing through such caisson and
normally open valves in such pipe and means operated by the closing of said ports.
to close such valves substantially as and for the purposes set forth.
5. In a caisson for raising sunken vessels the combination with a main air pipe B.
extending through such caisson of a normally closed valve, F, in such pipe, and
means operated by the pressure of air entering the pipe for opening such valve,
substantially as and for the purposes set forth.
6. In a caisson for raising sunken vessels the combination of a main air pipe
leading to the caisson, a normally closed valve in such pipe, a closed case, a piston
head in such case attached to the stem of such valve, a pipe from a point in the
main air pipe outside of the valve connected with such case on one side of the
piston-head and a pipe from the other side of the piston-head, substantially as and
for the purposes set forth.
Dated this 17th day of June 1895.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicant.