IMPROVED APPARATUS FOR RAISING SUNKEN WOODEN SHIPS OR VESSELS FROM CONSIDERABLE DEPTIIS
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the Office
of the Commissioners of Patents on the 19th December 1876. A com-
munication from abroad by Charles Gimello, of Nice, (Alpes Maritimes),
France.
WILLIAM EDWARD GEDGE, of No. 11, Wellington Street, Strand, in the County
of Middlesex, Patent Agent. "IMPROVED APPARATUS FOR RAISING SUNKEN
WOODEN SHIPS OR VESSELS FROM CONSIDERABLE DEPTIIS." A Communication from
abroad by Charles Gimello, of Nice (Alpes Maritimes), France.
It is well known that the depth at which divers can work without danger is
from 40 to 45 yards. At such depth a submerged ship of sufficient value to justify
the necessary expenses or outlay might in certain cases be raised, but beyond this
limit the divers are stopped; they can no longer stop the openings and leaks,
which later allow the pumps to act. It is therefore necessary to seek other means.
Ships carrying very valuable cargo are wrecked on coasts or in bays, and
numberless trials have been made to save or raise them from the sea. Among
others may be instanced the efforts mado since 1869 by a company to raise ships
having valuable cargoes. The idea of the promoters of this enterprise was simple
and reasonable; large sheet-iron cylinders were sunk at the sides of the ship, which
were attached to the vessel by chains where possible; the water was afterwards
withdrawn from the cylinders by compressed air; the ascending force floated both
ship and cylinders, but the chains could never be so placed as to give any successful
result.
This Invention, which I will now proceed to describe, relates to a new system,
producing a mode of attachment sufficiently rigid and powerful to raise the ship at
the same time as the cylinders. Suppose a cylinder of sheet iron, containing a
machine capable of being worked by compressed air, this air engine being of three
or four horse power, and its motive power communicated by toothed gearing to a
certain number of endless screws with gimlet ends. The apparatus boing sunk at
the sides of the ship and the engine set at work the gimlets or borers turn, pierce the
side planks of the ship, and fit therein. The volume or quantity of air compressed,

page_text: and its pressure must be calculated, so that the engine may compel the gimlets to
pass through the side planks in the desired direction. When this is effected the
compressed air is exhausted in the machine, and the gimlets are stopped; air is then
compressed in an ordinary apparatus on the deck of a vessel, and this air driving
the water out of the cylinders croates an ascending force tending to raise the
cylinders; but these being attached to the ship by the adhesion produced by the
screws when the water expelled from the cylinders give an ascending power equal
to the actual weight of the ship, this and the cylinders will float. An apparatus of
this description is to be placed on each side of the ship in suchwise that it may
have no tendency to heel over during the operation.
Such is the general feature of this system, which will be now described in detail,
taking note of the arrangements we have made that the force produced may not
exceed the limit of resistance which the sides or planking of the ship or the
apparatus may be able to bear. Suppose a vessel having at the bottom of the sen
an effective weight of 500 tons, two cylinders producing an ascending power of 250
tons each would be required; if we allow the cylinders a radius of about 2 yards
that will give a section of about 18 yards. This section will not be entirely
required for the production of ascentional force, as there are openings in its lower
part, through which pass the screws, and by which also compressed air will escape
when the pressure becomes greater than the corresponding column or body of
water. The weight of the apparatus must also be taken into account, and there-
fore a length of about 21 yards should be decided on. The engine fed by air
compressed to 15 or 16 atmospheres will put in motion the driving shaft, which
will transmit its power by means of a simple toothed gearing to a shaft carrying
as many wheels as there are endless screws, and it is the wheels on this shaft which
give motion the endless screws. In the Drawing there aro 14 endless screws by
which 14 points of adhesion by each cylinder are obtained, but their number may
bo incroased. The gearing is so arranged that the movement of the screws is very
slow, and consequently the power which puts them in motion is very great.
These details will be readily understood by reference to the accompanying Sheet
of Drawing; they may however be varied according to circumstances. Suppose the
side planks to be pierced, and that air is compressed in the cylinders; these latter
will have a tendency to rise, but will be retained by the screws, which in their turn
will transmit to the side planks the power which is driving them up. This power
will be multiplied by the length of the screws, which will be not less than three
yards; this will give too great a bending movement, which the ship's side would be
incapable of supporting; therefore the endless screws are so arranged that they do
not act as lever arms, and that they transmit only the necessary effort.
The endless screw is composed of three parts:-
1°. The gimlet or drill which should set or embed itself in the ship, and is from
16 to 20 inches long, and from 3 to 4 inches in diameter; it carries a ring moving
with little friction, and united by a chain to the lower part of the cylinder.
20. The screw properly so called.
3°. A small piece of wood of from 4 to 6 inches in length, which unites them ;
it is sufficiently firmly set in these two pieces as to resist the torsion or twisting
movement during the operation, but arranged so as to detach itself when the
cylinders experience an ascending power determined beforehand; the cylinder will
then rise held to the ginlets or drills embedded in the ship by the before-inentioned
chain.
By this arrangement the strain which the ship's planks or side will have to
support is about equal to that necessary for the raising of the ship.
The cylinder is constructed so as to be able to resist the different strains it will
have to encounter; it is strengthened from yard to yard by hoops or bands of iron,
which increase its rigidity. The compressed air engine, the endless screws and their
supports rest on a framing firmly secured to the cylinder. Ballast inumoveably
fixed secures the sinking of the cylinder vertically to the plane of tho screws. The

page_text: dimensions of the screws, the gimlets or drills, and chains are so calculated as to
support the greatest strains to which they are to be submitted. Theso divers
calculations are not entered into, as they would uselessly prolong this description.
In conclusion the cylinder is carried on a framing of wood, which ensures a great
number of bearing surfaces for the apparatus when sunk to the bottom of the sea.