CERTAIN IMPROVEMENTS IN THE MEANS OR APPARATUS TO BE EMPLOYED FOR THE PURPOSE OF RAISING SUNKEN VESSELS OR OTHER SUBMERGED BODIES, AND ALSO IN THE APPLICATION OF A SELF-ACTING BALANCE AND REGULATOR TO THE PONTOONS USED THEREIN
Year: 1862

page_text: LETTERS PATENT to Thomas Henry Hopwood, of Hulme, in the City of
Manchester, in the County of Lancaster, Engineer, for the Invention of
"CERTAIN IMPROVEMENTS IN THE MEANS OR APPARATUS TO BE EMPLOYED FOR
THE PURPOSE OF RAISING SUNKEN VESSELS OR OTHER SUBMERGED BODIES, AND
ALSO IN THE APPLICATION OF A SELF-ACTING BALANCE AND REGULATOR TO THE
PONTOONS USED THEREIN."
Scaled the 24th October 1862, and dated the 7th May 1862.
PROVISIONAL SPECIFICATION left by the said Thomas Henry Hopwood
at the Office of the Commissioners of Patents, with his Petition, on the
7th May 1862.
I, THOMAS HENRY HOPWOOD, of Hulme, in the City of Manchester, in the
County of Lancaster, Engineer, do hereby declare the nature of the said
Invention for "CERTAIN IMPROVEMENTS IN THE MEANS OR APPARATUS TO BE
EMPLOYED FOR THE PURPOSE OF RAISING SONKEN VESSELS OR OTHER SUBMERGED
BODIES, AND ALSO IN THE APPLICATION OF A SELF-ACTING BALANCE AND REGULATOR
TO THE PONTOONS USED THEREIN," to be as follows:-
My Invention relates to a novel arrangement and application of pontoons
or air cylinders for raising sunken or stranded vessels or other subinerged
bodies, or for raising vessels in dock for repair; and, further, to the use and

page_text: addition of a balance and regulator to such pontoons to retain them in any
position required whilst submerged.
lowered.
My improvement consists, first, in dividing the cylinder, which I call the
pontoon, used for raising sunken vessels, into three, four, or more compart-
ments or chambers in a vertical, diagonal, spherical, or other form for the
following objects:-I place at any portion of the pontoon (although I prefer
them at each extreme end), one, two, or more compartments of such a
capacity that when the other compartments or chambers within the pontoons
are filled with water they will have buoyancy sufficient to allow the pontoons,
whatever may be their actual weight, to sink horizontally, gradually, and
with no inconvenient strain on the tackle by which they are suspended and
These compartments may be made air and water-tight, and of suffi-
cient strength to resist external pressure, or a tube and a valve may be fixed
in connection with the air pump, so as to regulate the pressure of air to the
pressure of water externally. The other portion of pontoon I divide into any
number of compartments, according to the size and nature of construction of
the pontoon; but in order to prevent any uncontrollable buoyancy at either
end of the pontoon, I prefer the compartments to be made of a diagonal form,
so as to confine the water to a more limited space, and thus be more under
control. These compartments may be in whole or in part, that is to say, they
may each and every one of them be made up to the top and bottom to the
exclusion of any other compartment; or they may be connected by a portion
being left open at top or bottom resembling a wall; or they may be made to
communicate (as I prefer them to be) consecutively with each compartment
with a valve or valves at the top for the escape of the air when sinking, and
valves also at the lowest defined point, the advantage in this arrangement
being that one compartment would be nearly emptied of water before the air
would enter into the next compartment. The air can be made to enter by
having additional tubes into each compartment separately or simultaneously;
but I prefer in most cases to commence pumping into the centre compart-
ment, which prevents the sudden rise of the pontoons at either end by the
greater lever power naturally existing in greater ratio as diverging from the
centre. By the above-mentioned arrangement I am enabled to raise a vessel
lying in a sloping direction, the air being prevented from escaping by the
interposition of the compartments.
My improvements consist, secondly, in the use and application of the duplex
self-acting pontoon balance and regulator for the purpose of preventing the
pontoon rising in a vertical or irregular position without any material waste

page_text: of lifting power.
I fix or adapt to any of the compartments inside or outside
be pontoon two or more weighted pendulums or other similar contrivance;
which on the pontoon rising out of the level immediately opens a valve tap
or other outlet, and causes a flow of air, either to escape altogether or force it
way into the heaviest end; at the same time another pendulum shuts off the
outlet of water at the lightest end of pontoon, thus bringing it by the com-
bined action to its original level. The motion of this weight and rod or
pendulum is limited in one direction by means of a stop or pin, which prevents
it from swinging from the centre except in one direction, as needed. This
self-actor can be set or locked at pleasure. Another form of regulator is to
place a hollow ball or any floating body in a cistern of water, which must be
covered at the top, and will so act with the rise or fall of pontoon as to open
Another method is to place a
and shut the valves, as in the former case.
quantity of mercury or quicksilver in a tube of an ascertained length or form
fitted for such a purpose, and so poised or arranged that by the rise or fall of
pontoon the mercury would alternately change its position, and so open or
close the valve. A third plan is to effect the same result by placing a small
heavy ball within a larger ball, which finding its centre of gravity the pontoon
is in an horizontal position to cause it to so act upon a valve by its own
weight as to open or shut it with the rise or fall of pontoon, as before nien-
tioned. It must be understood, however, that I do not confine myself to these
forms of pontoon balance or regulator, as my Invention consists in the appli-
cation as well as the mode of balancing the pontoon; for I have discovered, in
addition to the above, various methods of obtaining the same result, although
I believe the above to be on the best principle, on account of their cheapness,
simplicity, and certainty of action. Or the pendulums may be so constructed
as to work either on their own axes or by means of a lever or connecting rod
In addition to above, I also make use of
arranged at the top of the same.
a powerful buoy or other floating body placed by a line over a pulley at cach
end of pontoon, which buoy is particularly applicable to the raising of vessels
in a sloping position.
:
Thirdly, my improvement consists in placing the tubes or pipes, through
which the suspending chains pass in an inclined or slanting position in the
direction of its breadth, by which means the diagonal compartments in
pontoons are retained in the same position when sunk, and attached to the
sunken body as when afloat and upright, thus equalizing as nearly as possible
the weight of water in all parts of the pontoon.
The Invention consists, fourthly; in the adaptation of a radial tube or other

page_text: valve. In order to prevent the closing of the valve at the bottom by the
intervention of sand or mud, I force the water upwards and out at the top of
the tube instead of at the bottom; or I construct a circular tube going all
round the inside circumference of tlie pontoons; a certain portion of this tube
at the bottom part I open for the outlet for the water, and a weighted pen-
dulum suspended at the centre or elsewhere is so arranged with a valve on
the top of the weight that no portion of the circular tube but the valvo
outlet finds admission for the water, which finds its way out through the top
of the tube outside the pontoon.
Fifthly, the improvements consist in attaching a buoy to pontoons by means
of a line, which passes over a pulley and a weighted indicator or spring
balance, which will indicate any undue increase of buoyancy, and enable the
attendant to control it by means of the self-acting balance, or should it be
out of order to turn off the tap communicating with the air pumps.
My improvement, consists, sixthly, in grappling the sunken vessel or other
body, which I effect by an arrangement of chains and other apparatus in the
following manner, or as near thereto as circumstances admit:-Having per-
manently fixed through the pontoons a strong cross bar or bars properly
secured and strengthened by stays in a diagonal position, that is, in a direct
line or nearly so with the chains, I attach to it a hook ring or sheave pulley,
which is attached to the side of pontoon, and is enclosed or not, as needed, in
a hollow socket to protect the side of pontoon or sunken body from injury.
The chain which grapples the vessel is hooked on to the pontoon at the part
when either afloat or sunk, as most convenient, and is in the form of a V
round the stern or head of the vessel. Any number of chains or length of
chain may be hooked on in this form, and by means of shackles the chains
can be adjusted to any required length; where the chains are exceedingly
heavy I-attach them to a number of buoys or one single buoy of the peculiar
form of the V above mentioned, and so cause them to sink gradually, and
enable the. diver to move them in any required direction, or by means of a
boat containing a small windlass with a hooked chain passing through the
centre of the boat may enable the diver to lift the chain over any obstruction.
In order to prevent the chain slipping out of the grapple, I attach another
chain at each extreme end where the grappling chain comes to a point. This
additional chain is made to hook on to the grappling chain at one end, and to
the edge of the top of the vessel at the other end; or, in place of this, the
large buoy, before mentioned, may be attached by a line to the grapple, which
it is impossible to pull over the top of the sunken vessel. By the above-

page_text: mentioned methods and improvements I am enabled to raise sunken vessels
immersed in deep water, or when operating from the shore, and in most
cases without the aid of windlasses or capstans, except so far as lowering the
pontoons.
My seventh improvement consists in the form of the pontoon, which I have
discovered, may with advantage be in the shape of a partial, say, a half or
two-thirds cylinder with bevil, rounded, flat, or hollow sides; and when required
for towing purposes, the sides of each pontoon may be lashed or hooked
together, thus forming an appearance somewhat like one oblong cylinder. The
advantages of this form are that the pontoon clips the vessel at a greater
number of points than if it was made in one complete cylinder, and also
without much less capacity or lifting power. I. am enabled by having the
arched part of pontoon made of india-rubber to enter narrow confined spots,
as, for instance, a harbour, or near perpendicular rocks.
The flat sides
My eighth improvement consists in the material used for the construction
of the pontoons. In order to secure the greatest strength with the least
weight I propose to have the pontoons made in some cases of steel, as now
adapted to many forms of boats, but I believe not to pontoons.
of pontoons may be strengthened by having them made of steel
the other portion be composed of wrought-iron plates, or in
india-rubber, or gutta percha, or other light material; these steel sides I
propose to make use of as a flat surface has not the same strength as a
rounded, bevilled, or arched form.
only, although
some cases of
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Henry Hopwood in the Great Seal Patent
Office on the 7th November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HENRY HOPWOOD, of Hulme, in the City of Manchester, in the County of
Lancaster, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of
Her reign, did,. for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Henry Hopwood, Her special license, that I, the said
Thomas Henry Hopwood, my executors, administrators, and assigns, or such
others as I, the said Thomas Henry Hopwood, my executors, administrators,

page_text: and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for CERTAIN IMPROVEMENTS IN THE MEANS OR APPARATUS TO BE
EMPLOYED FOR THE PURPOSE OF RAISING SUNKEN VESSELS OR OTHER SUBMERGED
BODIES, AND ALSO IN THE APPLICATION. OF A SELF-ACTING BALANCE AND REGULATOR
To THE PONTOON3 USED THEREIN," upon the condition, amongst others, that I
the said Thomas Henry Hopwood, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,.and.cause
the saine to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
:
NOW KNOW YE, that 1, the said Thomas Henry Hopwood, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement and accompanying Drawings (that is to say):
:-
My Invention relates to a novel arrangement and application of pontoons
or air cylinders for raising sunken or stranded vessels, or other submerged
bodies, or for raising vessels in dock for repair, and further for the use and
addition of a balance and regulator to such pontoons to retain them in any
position required whilst submerged.
My improvement consists, first, in dividing the air cylinders, which I call
the pontoons used for raising sunken vessels into three, four, or more compart-
ments or chambers in vertical, diagonal, spherical, or other forms for the
following objects :-I place at any portion of the pontoon (although I prefer
them at each extreme end), one, two, or more compartments of such a
capacity that when the other compartments or chambers within the pontoons
are filled with water, they will have buoyancy sufficient to allow the pontoons
whatever may be their actual weight, to sink horizontally, gradually, and with
no inconvenient strain on the tackle by which they are suspended and lowered.
These compartments may be made of sufficient strength to resist external
pressure, or a tube and a valve may be fixed in connection with the air pump
so as to regulate the pressure of air to the pressure of water externally. The
other portion of the pontoon I divide into any number of compartments
according to the size and nature of construction of the pontoon, but in order
to prevent any uncontrollable buoyancy at either end of the pontoon, I prefer
the compartments.to to. be made of a diagonal form, so as to confine the water

page_text: to a more limited space, and thus be more under control. These compartments
may be in whole or in part, that is to say, they may each and every one of
them be closed at the top and bottom to the exclusion of any other compart-
ment, or they may be connected by a portion being left open at top or
bottom resembling a wall, or they may be made to communicate (as I prefer
them to be) consecutively with each compartment, with valves or taps at the
top for the escape of the air when sinking, and valves also at the lowest
defined point, the advantage in this arrangement being that one compart-
ment would be nearly emptied of water before the air would enter into the
next compartment. The air can be made to enter by having additional tubes into
each compartment separately or simultaneously, but I prefer in some cases to
commence pumping into the centre compartments, which prevents the sudden
rise of the pontoons at either end by the greater lever power naturally existing
in greater ratio as diverging from the centre. By the above-mentioned
arrangement I am enabled to raise a vessel lying in a sloping direction, the
air being prevented from escaping by the interposition of the compartments.
My improvements consist, secondly, in the use and application of the
duplex self-acting pontoon balance" and regulator, for the purpose of pre-
venting the pontoon rising in a vertical or irregular position without any
material waste of lifting power. I fix or adapt to any of the compartments
inside or outside the pontoon, two or more weighted pendulums, or any other
cquivalent contrivance, which on the pontoon rising out of the level, imme-
diately opens a valve, tap, or other outlet, and causes a flow of air either to
escape altogether, or force its way into the heaviest end, at the same time
another pendulum shuts off the outlet of water at the lightest end of the pon-
toon, thus bringing it by the combined action to its original level. The motion
of this weight and rod; or pendulum is limited in one direction by means of a
stopper or pin, which prevents it from swinging from the centre, except in one
direction as needed. This self-actor can be set or locked at pleasure; and
the pendulums may be so constructed as to work either on their own axis, or
by means of a lever or connecting rod arranged at the top of the same.
In
addition to the above, I also make use of a powerful buoy or other floating
body, placed (by a line over a pulley) at each end of pontoon, which buoy is
particularly applicable to the raising of vessels in a sloping position.
Thirdly, my improvement consists in placing the tubes or pipes through
which the suspending chains pass in an inclined or slanting position in the
direction of its breadth, by which means the diagonal compartments in pon-
toons are retained in the same position when sunk and attached to the sunken

page_text: body as when afloat and upwright, thus equalizing as nearly as possible the
weight of water in all paris of the pontoon.
The Invention consists fourthly, in the adaptation of a radial tube or other
valve. In order to prevent the closing of the valve at the bottom by the inter-
vention of sand or mud, I force the water upwards, and out at the top of the
tube instead of at the bottom, or I construct a circular tube going all round
the inside circumference of the pontoons. A certain portion of this tube at
the bottom part I open for the outlet for the water, and a weighted pendulum
suspended at the centre or elsewhere, is so arranged with a valve or tap on the
top of the weight, that no portion of the circular tube but the valve outlet finds
adinission for the water, which finds its way out through the top of the tube
outside the pontoon.
Fifthly, my improvement consists in attaching a buoy or pontoon by means
of a line, which passes over a pulley, and a weighted indicator or spring
balance, which will indicate any undue increase of buoyancy, and enable the
attendant to control it by means of the self-acting balance, or should it be out
of order, to turn off the tap communicating with the air pumps.
My improvement consists, sixthly, in grappling the sunken vessel or other
body, which I effect by an arrangement of chains, &c. in the following manner,
or as near thereto as circumstances admits:-Having permanently fixed through
the pontoons a strong cross bar or bars, properly secured and strengthened by
stays, &c. in a diagonal position, that is, in a direct line, or nearly so, with
the chains, I attach it to a hook, ring, or sheave pulley, which is attached to
the side of pontoon, and is enclosed or not as needed in a hollow socket to
protect the side of pontoon or sunken body from injury. The chain which
grapples the vessel is hooked or shackled on to the pontoon at this part when
either afloat or sunk as most couvenient, and is in the form of a V round the
stern or head of the vessel. Any number of chains or length of chain may be
hooked on in this form, and by means of the shackles the chains can be adjusted
to any required length. Where the chains are exceedingly heavy I attach
them to a number of buoys, or one single buoy of the peculiar form of the V
above mentioned, and so cause them to sink gradually, and enable the diver to
move them in any required direction; or by means of a boat containing a
small windlass with a hooked chain passing through the centre of the boat,
may enable the diver to lift the chain over any obstruction. In order to prevent
the chain slipping out of the grapple, I attach another chain at each extreme
end where the grappling chain comes to a point. This additional chain is
made to book on to the grappling chain at one end, and to the edge of the top

page_text: of the vessel at the other end; or in place of this, the large buoy before men-
tioned may be attached by a line to that part of the grappling chain which it
is impossible to pull over the top of a sunken vessel. By the afore-mentioned
methods and improvements I am enabled to raise sunken vessels immersed in
deep water, or when operating from the shore, and in most cases without the
aid of windlasses or capstans, except so far as in lowering the pontoons.
In order that the Invention may be better understood and explained in
detail, I have hereunto attached a Sheet of Drawings, similar. letters of
reference being marked upon corresponding parts in all the Figures.
:
Fig. 1 is a sectional view, representing a pontoon divided vertically into six
compartments or chambers (as an example), and exhibits the water as partly
expelled from the middle chambers, and the two ends as occupied by air.
In
this Figure the tubes and apparatus for discharging the water from the pontoon
only are shewn; by such arrangement the rolling of the water is confined to
two compartments only, irrespective of the number into which the pontoon
may be divided; Fig. 2 is also a longitudinal sectional view, in which the appa-
ratus for regulating the admission and pressure of air is exhibited alone; Fig. 3
exhibits the adaptation and arrangement of the " duplex pontoon balance!
for causing the submerged pontoon to rise in a horizontal position; Fig. 4
represents a longitudinal sectional view of a pontoon complete, with the com;
bination of apparatus shewn separately in the aforesaid Figures (for their better
illustration). In this Figure the pontoon is shewn filled with water, excepting
the end chambers, and is in a condition to be lowered down to the submerged
body required to be raised, such arrangement ensuring the sinking of the
pontoon horizontally; Fig. 5 is an enlarged view of the flexible or pendulous
end of the outlet pipe, which is supported by a flexible attachment upon a
ball or wheel, and so arranged as to keep continually in and convey away the
water so long as any remains in the chamber in which it moves; Fig. 6 is an
enlarged view of the duplex pontoon balance," consisting of a weight and
double-hinged lever, constructed so as to open or close the water and air
passages according to the position or movement of the pontoons, by means of
.the weight, in a self-acting manner.
In Figs. 1, 2, 3, 4, a, a, a, are the bulkheads or partitions dividing the
pontoon into chambers c', c, c³; and d', d, d³, are flexible, radiating, or
pendulous outlets for the water d', conveying the water from c¹ to c, and com-
municating with. the main outlet or discharge pipe e, the passage of the water
being indicated by the arrows. The air tubes f, f, have two openings, one
into chamber c', and the other into chamber c', which is closed by means of

page_text: the ball valve g which floats upon the water; the course of the air is also
indicated in this Figure by arrows, the outlet pipe d³ serves also to convey
away any water that may have escaped into the chamber c. The self-acting
balance or regulator of the pontoon consists of a weighted lever h supported
by a pin in the bearing e, which may be also hinged, thus the lever and ball
may swing from the two centres vertically and laterally to adapt itself to the
position of the pontoon, a stop being employed to limit its upward movement;
this lever his connected at one end to the tap i, by which the discharge of
water is regulated, and the other end projects so as to be locked at will by
means of the clip k. A similar regulator is applied to the air valves p, but
without a stop to limit its action.
Having described the various parts, I will now proceed to explain the
method of sinking and raising the pontoon.
:
Water having been admitted to the middle chambers by the valves ?, 1,
sufficient to sink the pontoon, and the pontoon having been made secure to
the body to be lifted, the air is first forced into the pipes f. f, it then passes
into the chambers, and through pipes d³ into chambers e¹, opening the
valves m, m, the water therein is thus discharged through pipes into
chambers c, c, and as the water sinks in c¹, c', the ball valves opens and
admits air direct to such chambers, thus the two end and the two centre
chambers become empty, which tends to preserve the equilibrium, and
regulate the pressure of air in all parts of the pontoon; the pressure of air
being continued, the water passes up the pipes d³, and is finally discharged
from the main pipes, which may be closed with a valve opening outwardly,
the pontoon then being in a state of buoyancy. When one end of a pontoon
has a tendency to rise first, from the irregular weight of the sunken body, or
other cause, the levers and pendulums governing the water valves assume a
different angle in relation to the pontoon, and close the tap, and immediately
prevent the discharge of water from the lightest end of the pontoon simulta-
neously, also the pendulum governing the air valve p is opened by similar
means, and admits air from the lightest half into the heavier, thus their com-
bined action re-establishes the horizontal position of and balances the pontoon.
I also employ in connection with the pontoon a powerful buoy attached to
each end of the pontoon by means of a line, and sunk a few inches. below the
surface, to check any undue buoyancy when the pontoon reaches the surface:
Having now described the nature of the said Invention, together with the
method of carrying the same into practical effect, I wish it to be distinctly
understood that I claim,-

page_text: First, the novel arrangement and construction of pontoons, or other such
vessels.
And, secondly, balancing or regulating pontoons or air vessels by means of
self-acting valves to shut off or admit air and water as required to maintain
its horizontal position, as herein-before described, set forth, and fully illustrated
in the Drawings attached.
In witness whereof, I, the said Thomas Henry Hopwood, have hereunto
set my hand and seal, this Fifth day of November, in the year of our
Lord One thousand eight hundred and sixty-two.
THOMAS HENRY HOPWOOD. (L.S.)
Witnessed by,
JNO. L. DAVIES, Office for Patents,
4, St. Ann's Square, Manchester.