Improved Apparatus and Means for Raising Sunken Vessels.
Year: 1899

page_text: Improved Apparatus and Means for Raising Sunken Vessels.
I, WILLIAM ALFRED MITCHELL, of Pomphlett Mills, Plymouth, Devonshire,
Miller, Corn and Coal Merchant, do hereby declare the nature of this 'invention
to be as follows:-
This invention relates to improved apparatus and means for raising sunken
vessels, and has for its object to provide a simple device which may be easily
applied for said purpose.
According to my invention, I employ a water tight case of any suitable material
and preferably of oblong shape, square in cross section. The inside of said
case is so stayed or constructed that it shall withstand any pressure brought
to bear upon it from without; and, it may be made in two or more parts which
may be easily separated to enable it to be packed in a small space and fitted
again together for use. I prefer to wrap or cover the case with some waterproof
material; but when the case is made of wood, and the latter is sufficiently
substantial, the waterproof material may be dispensed with.
A chain is or chains are, attached to the case aforesaid so as to surround
same and increase its strength, and a valve is fitted at one end of the case, so
that when required, the case can be sunk in the water and the latter pumped
out again.
In applying my invention, any required number of the cases aforesaid are
placed in a perpendicular position on each side of the vessel to be raised; and,
should the latter be stranded upon a rock or sand bank, the vessel's chains are
passed underneath her and brought up on each side to low water mark. The
vessel's anchor and other-if necessary chains are then attached to the chains
or other fastenings around.the floatative cases aforesaid, the weight of the latter
causing the cases to sink a few feet in the water, so that upon the rise of the
tide, they would be buoyed up and raise the vessel with them. The cases afore-
said may also be placed inside the vessel under the beams, in place of the casks
usually employed for floatative purposes.
In the case of a vessel sunk in deep water, iron or steel floatative cases may
be used. These would sink of themselves, and would be connected to one or
more pumps to allow of the water being pumped out of them when in position
ready for the raising of the vessel. Or, (still in the instance of a vessel sunk
in deep water) wooden cases may be employed and be drawn down by means of
a block and tackle on the wreck; in which case there would be no necessity for
the use of pumps. I may also employ a single metal case so constructed that it
would be capable of raising a vessel of any weight.
By placing the improved floatative cases aforesaid in a perpendicular position
about a wreck, as described, they are used to their greatest advantage as regards
strength and effectiveness.
Dated this 3rd day of July 1899.

page_text: Improved Apparatus and means for Kaising sunken y 08B018.
I, WILLIAM ALFRED MITCHELL, of Pomphlett Mills, Plymouth, D Devonsliire,
Miller, Corn and Coal Merchant, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement: ---
This invention relates to improved apparatus and means for raising sunken
vessels and has for object, to provide a simple and efficient device which may be
employed for that purpose.
According to my invention I employ a water-tight case of wood, metal, or
other strong material, preferably of oblong shape and square in cross section.
The insides of said cases are stayed or constructed so as to withstand any
pressure to which they may be subjected from the outside; and, they may be
made in Two or more parts which may be easily separated to enable them to be
packed into a small space or fitted together again for use.
Said cases may be enveloped, wrapped or covered with suitable waterproof
material; but, in' some cases the latter may be dispensed with.
When stecl, iron or other metal is used as the material of which the cases
are made, the joints of the metal plates are fitted with india-rubber or other
packing.
A chain or chains is or are attached to each case so as to surround same and
thereby increase the strength thereof and add to the security of the joints; and,
a valve is fitted at the upper part of the case, for filling it with water, another
valve being fitted at the bottom of the case to allow of the water being pumped
out again.
In applying my invention, any requisite number of the aforesaid cases,-
according to the weight to be lifted, are placed in a perpendicular position on
cach side of the vessel to be raised; and, should the latter be stranded on a
rock or sand bank, the vessel's chains are passed underneath her and carried
up on each side of her to low-water mark. Said chains are then attached to
those first mentioned in connection with the floatative cases; the weight of the
latter causing them to sink a few feet in the water; so that, upon the rise of
the tide, they are buoyed up, and in their ascent raise or lift the vessel with
them. Instead however of the cases being attached to the outside of the vessel,
they might be placed inside, under the beams, instead of the casks usually
employed.
When a vessel is sunk in deep water, iron or steel cases are preferably used,
which sink of themselves, and to which one or more pumps are connected, to
permit of the water being pumped out of the said cases when in position for
raising the vessel: Otherwise, wooden cases may be used: these being drawn
down by means of a block and tackle on the wreck. Under this mode of
procedure, there would be no necessity for the employment of pumps. A single
metal case of suitable size and shape may also be so constructed that it would be
capable of raising a vessel of any weight.
.
In order that the nature of my said invention may the better be understood,
I have appended hereto, the accompanying sheet of drawings, in which Figure 1
is an elevational view of one of the improved water-tight cases aforesaid, and
Figure 2 is a vertical section thereof. Figure 3 is an elevation of a portion
of one of the sides of the case. Figure 4 is a similar view of another side,
connected at right angles to that shewn at Figure 3. Figure 5 is a cross section
of the case, shewing a plan of the bottom. Figure 6 shews a case with the parts

page_text: thereof detached and packed together in a small compass. Figure 7 shews, in
side, view, a ship stranded upon a sand bank or rocks; and, Figure 8 is an end
view thereof with the cascs attached in position to the ship or vessel in the
operation of raising same.
In the several views aforesaid, a, are the water-tight cases, formed, in the
example shewn, of four separate sides joined together at their edges by the
dovetail joints a to form a rectangular cross section; the said joints allowing
of the sides being readily detached, or fitted together again when required.
The cases are closed at each end by the covers b and b, engaging with the sides
by the dovetail joints ; e is a valve in the side of the case, for filling it with
water to allow of sinking the case; and is a valve fitted to the bottom 6', for
emptying the case, by connecting a pump thereto. e, e' are the chains or the
like, surrounding the case and bearing against metal plates or angle irons f, f³,
fitted to the covers aforesaid when the cases are made of wood.
When required to raise a vessel off rocks or a sand bank, upon which it has
been stranded, the cases a are placed in a perpendicular position around each
side of the stranded vessel as shewn Figures 7 and 8; and the anchor and other
chains, y of the vessel, are passed underneath her, and brought up on cach
side to low water mark, where they are attached to the chains e, el surrounding
the cases a, or otherwise secured thereto. Then, upon the rise of the tide, the
cases are buoyed up and in their ascent, raise the vessel with them.
When applying a water proof covering to the cases aforesaid, the covering or
envelope is made in the form of a sack; necessitating only one end being folded
to secure it in position.
When not required for use, the separate parts of the cases may be readily
detached as before described, and be packed together so as to occupy a relatively
small space; thus rendering them very portable and convenient for transport;
at the same time, when required for use, they may be very readily and quickly
fitted together again.
By means of my invention, it is only necessary to ascertain the approximate
weight of the vessel to be raised and to apply the necessary number of cases a,
of a capacity sufficient to allow of accomplishing the work to be done.
In raising vessels sunk in deep water, the cases a are filled with water through
the valve c, thus causing the cases to sink. They are then secured to the sides
of the vessel and the water pumped out of them by means of a pump connected
to the valve d, thus causing the surrounding water to buoy them up and raise
the vessel with them.
By placing the aforesaid cases in a perpendicular position on each side of a
wreck as described, they are used to their greatest advantage as regards strength
and efficacy; but it will be evident, that when found to be more convenient,
they may be fixed horizontally, or, as has been herein before stated, they may
be disposed underneath the beams of the vessel in lieu of the casks usually
employed.
Said cases will also be found very convenient and suitable for keeping at
sea ports in readiness for raising sunken lighters, or other small sunken craft;
and they may also be carried on board ship to be utilised, when required, as
life rafts.
Having now particularly described and ascertained the nature and objects of
my said invention and in what manner the same is to be performed, I declare
that what I claim ia:-
First: The improved apparatus for raising sunken ships or vessels, com-
prising wooden or metal hollow cases preferably of oblong shape and square in
cross section, the sides and ends of said. cases when of wood, being dovetailed
together for the purpose of unfastening and packing them into a small compass
or fitting them together again for use substantially as described.
Second: In apparatus for raising sunken ships or vessels, the combination of

page_text: oblong hollow cases constructed with removable sides, and ends, two or mord
chains or the like, surrounding the cases; inlet and outlet valves fitted to the
latter for the admission of water thereinto or withdrawal therefrom, and tlie
waterproof sack, or covering, enclosing each case, substantially as described
and for the purposes set forth.