AN IMPROVED METHOD OF AND APPARATUS FOR RAISING SUNKEN VESSELS
Year: 1882

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A M and
W Clark of 53, Chancery Lane, in the County of Middlesex, Patent Agents,
for an Invention of AN IMPROVED METHOD OF AND APPARATUS FOR RAISING
SUNKEN VESSELS communicated to him from abroad by Paul Oriolle, of
Nantes, France
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 11th November 1882.
ALEXANDER MELVILLE CLARK of the firm of A M & W Clark of 53 Chancery
Lane in the county of Middlesex Patent Agents "AN IMPROVED METHOD OF AND
APPARATUS FOR RAISING SUNKEN VESSELS." [Communicated to him from abroad
by Paul Oriolle, of Nantes, France.]
This Invention relates to a method of and apparatus for raising sunken vessels
by means of air under the atmospheric pressure.
The advantages of this method will be apparent from the following
considerations
In the generality of cases it is only possible to float sunken vessels which are
uncovered at low tide by pumping out the water from the holds, partially
discharging the cargo and employing divers to stop the hole in the hull. When
the vessel is submerged at all times it is possible when it is of small size, to raise
the vessel by means of chains passed beneath the hull and attached to pontoons or
camels, or by means of numerous floats or airbags attached to the vessel or
introduced within the hull. Owing however to the great size of modern vessels
the means hitherto employed are quite insufficient to raise a vessel of large tonnage
which is not uncovered at low tide.
In order to raise a steamer of several thousand tons it is necessary to use a
special description of plant for carrying out and applying the principle of using
air under atmospheric, pressure which together with the means of carrying it into
effect constitutes the subject of this Invention.

page_text: As an example of the application of this principle I will describe the method of
procedure in the case of an iron steamer of 2000 tons covered by 16 feet of water
at low tide, and having a hole in her bottom and settled down upon the hole so
that no part of it is visible to a diver, these being it is believed the most
unfavorable conditions likely to occur.
The object which the Inventor proposes to accomplish is to extract the water
contained in all the compartments of the hull and to replace it with air which will
always be at a pressure lower than that of the atmosphere, and consequently less
than that corresponding to the height of the column of water above the deck.
When this result is obtained the vessel will float and may be towed into dock for
repair. The object in keeping the hull full of dilated air is to have an inward flow
of the water rather than an outward flow of air so that the air will not tend to
escape but on the contrary the inward pressure of the water will more closely apply
the sails, mats, or other stoppings to be placed by the diver over the hole.
The mode of operation is as follows. After having first ascertained the exact
nature of the injury the following plant should be brought to the spot.
1 A tug boat fitted with several powerful steam pumps driven either by the
propeller engines or by independent engines capable of being used either on board
the tug or of being transferred to lighters alongside, these pumps being fitted with
special suction pipes hereafter referred to.
2nd A sheet of sail cloth of sufficient length to envelop the hull and sufficiently
wide to cover more than half the bottom
3rd A sufficient quantity of sail cloths tarpaulins mattresses rolls of felt, tow,
rags, suet nails weights wood &c for stopping all apertures in the deck as well as
the funnel, hatchways, air shafts and the like.
4th A.gun. of special construction and projectiles for the same, for firing under
water, dynamite, batteries, conducting-wires &c for enabling holes to be made..in.
-the-hull-of-any-desirod-dimensious-at-points selected..
With this plant the following operations are to be performed separately or
successively according to the number of divers available
First. A hole is to be made in each hold or compartment of the vessel by means
of dynamite or by the gun provided for the purpose, said hole to be as low as
possible and of a greater area than the suction pipe of the steam pump. Second.
To each of these holes is applied the extremity of a suction pipe terminated by a
large cone or trumpet mouth the edge of which is faced with a ring of india-rubber
projecting about 8 inches beyond for the purpose of making a tight joint between
the hull and the cone when the pumps are set to work. This flaring mouth is held
in place over the hole by iron struts or legs jointed at one end to the cone and
resting with their other ends on the ground so as to press the mouth close against
the hull until the pumps are put in operation whereupon it is caused to adhere
still more closely.
To this cone is attached an air pipe, much smaller than the suction pipe placed
concentric within the cone and extending as far as possible into the interior of the
vessel, through the hole made for the withdrawal of the water, its other end
passing through the side of the cone for the attachment to it of a tube which rises
to above the surface of the water. This air inlet tube may also be fixed directly
to the hull if circumstances prevent it being placed in the position above described,
but this would necessitate a second hole being made in each compartment. This
air tube is to permit the outer air to enter the hold whilst the pumps are working,
and to expand beneath the deck and replace the volume of water withdrawn by
the pumps, for if the hull were little or not at all injured the pumps would extract
little or no water, as they can only throw water conditionally on the inlet of air or
water by the air tube or the injury. Thus the tighter the hull the more air will be
drawn in by this tube, and it will be this volume of air which will enable a true
estimate to be formed of the extent of injury to the hull. If then by setting
pumps to work on all the holds or compartments, of sufficient power to extract a
greater volume of water than that admitted by the injuries, under the modified

page_text: pressures of the expanded air in the holds or compartments, the latter will be filled
with rarefied air down to the level of the hole made for the application of the
suction cone, which is placed as low as possible, and the vessel will float as before
it was sunk, and can be towed away for repair.
It has been supposed above that the deck is nearly watertight but as this is
never the case it must be rendered so as much as possible. This is important and
easily effected by covering all apertures in the deck or decks with sail cloths,
mattresses, felt, rags skins &c which may be easily placed in position by the diver
so as to be pressed close down on the openings by the partial vacuum produced by
the pumps and make a tight closure. With this system it is to be observed the
deck is not subjected to a bursting but to a crushing strain which is the reverse of
all other systems of floating sunken vessels.
It has been assumed above that the injury which caused the sinking of the
vessel, is in the bottom and inaccessible in consequence of the vessel having settled
down upon it. Before the vessel has begun to lift, the ground itself will wholly or
partially stop the aperture, but immediately the wreck rises the aperture will
admit its maximum inflow of water which will be indicated by the air pipo
communicating with the lower hold. It is therefore necessary to encircle the
hull with a long sail held up by its upper bolt rope just beneath the suction cono,
the lower part being stowed upon the ground as close as possible to the bull so
that immediately the latter begins to rise the sail will be carried under by the
current of water flowing towards the aperture so as to stop it wholly or partially
I have described the operation in the case of a vessel covered with sixteen feet
of water at low tido but it may be performed at greater depths and is only limited
by the inability of the diver to work deeper than froin 30 to 50 feet. Tho
operation would be performed in the same way as before except that all the air
pipes of each hold would communicate with a common reservoir or with separate
reservoirs containing air compressed by means of an air pump to a pressure equal.
to that of the column of water above the deck
The invention thus consists in a method of and apparatus for raising sunken.
vessels by pumping out the water contained in the holds through openings made
for the purpose and at same time admitting air at a pressure less than that of the
column of water above the deck whereby a partial vacuum is produced which
renders the leaks more easy of closure from the outside.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Seal Patent Office on the
11th May 1883.
ALEXANDER MELVILLE CLARK of the Firm of A, M, and W, Clark of 53 Chancery
Lane in the County of Middlesex Patent Agents "AN IMPROVED METHOD OF AND
APPARATUS FOR RAISING SUNKEN VESSELS." A communication to me from abroad
by Paul Oriolle of Nantes, France.
This Invention relates to a method of raising sunken vessels by means of air
below the atmospheric pressure. The advantages of this method will be apparent
from the following considerations.
In the generality of cases it is only possible to float sunken vessels which are
-uncovered at low tide by pumping out the water from the holds, partially
discharging the cargo and employing divers to stop the hole in the hull. A vessel
submerged at all times may when of small size, be raised by means of chains
passed beneath the hull and attached to pontoons or camels, or by means of
numerous floats or airbags attached to the vessel or introduced within the hull.
Owing however to the great size of modern vessels, the means hitherto employed
are quite insufficient to raise a vessel of large tonnage which is not uncovered at
low tide.
In order to raise a steamer of several thousand tons, it is necessary to use a
special_description_of_plant for carrying out and applying the principle of using
air at less than the atmospheric pressure, which together with the means of carrying
it into effect constitutes the subject of this Invention. As an example of the
application of this principle, I will describe the method of procedure in the case
of an iron steamer of 2000 tons covered by 16 feet of water at low tide, and
having a hole in her bottom, and settled down upon the halo so that no part of it
is visible to a diver, these being it is believed the most unfavorable conditions
likely to occur.
The object which the Inventor proposes to accomplish is to extract the water
contained in all the compartments of the hull, and to replace it with air which will
always be at a pressure lower than that of the atmosphere, and consequently less
than that corresponding to the height of the column of water above the deck.
When this result is obtained the vessel will float and may be towed into dock for
repair. The object in keeping the hull full of dilated or rarefied air is to have a!!
inward flow of the water rather than an outward flow of air, so that the air will
not tend to escape, but on the contrary, the inward pressure of the water will more
closely apply the sails, mats, or other stoppings to be placed by the diver over
the hole.
The mode of operation is as follows:-After having first ascertained the exact
nature of the injury, the following plant should be brought to the spot. 1st. A tug
boat fitted with several powerful steam pumps driven either by the propeller
engines or by independent engines capable of being used either on board the tug
or of being transferred to lighters alongside, these pumps being fitted with special
suction pipes hereafter referred to. 2d A sheet of sail cloth of sufficient length
to envelop the hull, and sufficiently wide to cover more than half the bottom.
3rd. A sufficient quantity of sailcloths, tarpaulins, mattresses rolls of felt, tow, rags,
suet, nails, weights, wood, &c, for stopping all apertures in the deck, as well as
the funnel, hatchways, air shafts, and the like. 4th. A gun of special construction
and projectiles for the same, for firing under water, dynamite, batteries, conducting
wires, &c, for enabling holes to be made in the hull of any desired dimensions at
points selected.

page_text: With this plant the following operations are to be performed separately or
successively according to the number of divers available :-
First. A hole is to be made in each hold or compartment of the vessel by means
of dynamito or by the gun provided for the purpose, said hole to be as low as
possible and of a greater area than the suction pipe of the steam pump. Second.
To each of these holes is applied the extremity of a suction pipe terminated by a
large cone or trumpet mouth, the edge of which is faced with a ring of indiarubber
projecting about 8 inches beyond for the purpose of making a tight joint between
the hull and tho cone when the pumps are set to work. This flaring mouth is
held in place over the hole by iron struts or legs jointed at one end to the cone
and resting with their other ends on the ground so as to press the mould close
against the hull until the pumps are put in operation whereupon it is caused to
adhere still more closely. To this cone is attached an air pipe much smaller than
the suction pipe placed concentric within the cone and extending as far as possible
into the interior of the vessel through the hole made for the withdrawal of the
water, its other end passing through the side of the cone for the attachment to it of
a tube which rises to above the surface of the water. This air inlet tube may also
be fixed directly to the hull if circumstances prevent it being placed in the position
above described, but this would necessitate a second hole being made in each
compartment. This air tube is to permit the outer air to enter the hold whilst
the pumps are working, and to expand beneath the deck and replace the volume
of water withdrawn by the pumps, for if the hull were little or not at all injured,
the pumps would extract little or no water, as they can only throw water con-
ditionally on the inlet of air or water by the air tubo or the injury. Thus, the
tighter the hull, the more air will be drawn in by this tube, and it will be this
volume of air which will enable a truc estimate to be formed of the extent of
injury to the hull. If then by setting pumps to work on all the holds or com-
partments, of sufficient power to extract a greater volume of water than that
admitted by the injuries, under the modified pressures of the expanded air in the
holds or compartiments, the latter will bo filled with rarefied air down to the
level of the hole made for the application of the suction cone which is placed as
low as possible, and the vessel will float as before it was sunk and can be towed
away for repair.
It has been supposed above that the deck is nearly watertight, but as this is
never the case, it inust be rendered so as much as possible. This is important and
easily effected by covering all apertures in the deck or decks with sail cloths,
mattresses, felt, rags, skins, &c, which may be easily placed in position by the
diver so as to be pressed close down on the openings by the partial vacuum
produced by the pumps and make a tight closure. With this system it is to be
observed the deck is not subjected to a bursting, but to a crushing strain which is
the reverse of all other systems of floating sunken vessels.
It has been assumed above that the injury which caused the sinking of the
vessel is in the bottom and inaccessible in consequence of the vessel having settled
down upon it. Before the vessel has begun to lift, the ground itself will wholly
or partially stop the aperture, but immediately the wreck rises, the aperture will
admit its maximuın inflow of water which will be indicated by the air pipe
communicating with the lower hold. It is therefore necessary to encircle the hull
with a long Bail held up by its upper bolt rope just beneath the suction cone, the
lower part being stowed upon the ground as close as possible to the hull, so that
immediately the latter begins to rise, the sail will be carried under by the current
of water flowing towards the aperture so as to stop it wholly or partially.
I have described the operation in the case of a vessel covered with 16 feet of
water at low tide, but it may be performed at greater depths, and is only limited
by the inability of the diver to work deeper than from 30 to 50 feet. The
operation would be performed in the same way as before, except that all the air
pipes of each hold would communicate with a common reservoir or with separate

page_text: reservoirs containing air compressed by means of an air pump to a pressure equal
to that of the column of water above the deck.
The Invention thus consists in a method of raising sunken vessels by pumping
out the water contained in the holds through openings made for the purpose, and
at same time admitting air at a pressure less than that of the column of water
above the deck whereby a partial vacuum is produced which renders the leaks
more easy of closure from the outside.
the
Having described the nature of the said Invention and the manner of performing
same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is.
The herein described method of raising sunken vessels wherein the water
extracted from the hold of the sunken vessel is replaced by air at a pressure less
than that of the column of water above the deck, substantially in the manner and
by means of the apparatus herein specified.
In Witness whereof I the said Alexander Melville Clark have hereunto set
my hand and seal this tenth day of May, A.D. 1883.