Improvements in Raising Sunken Vessels and other Bodies, and in Apparatus therefor.
Year: 1896

page_text: Date of Application, 15th Sept., 1896-Accepted, 17th Oct., 1896
COMPLETE SPECIFICATION.
Improvements in Raising Sunken Vessels and other Bodies, and in
Apparatus therefor.
We, NATHANIEL SHEPARD KEITH of the Sandycroft Foundry and Engine
Works, Hawarden in the County of Flint, Electrical Engineer, and JOSEPH
WALWYN WHITE of Widnes in the County of Lancaster, Engineer, 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:-
According to this invention the lifting ropes are attached to sunken iron or steel
vessels or bodies by means of electro-magnets thus enabling attachments to he
made when the vessels, or bodies are too deeply submerged in water to permit of
divers descending to make the necessary connections.
The lifting machinery consists wholly, or in part, of hydraulic rams, all or part
of which are connected together, and also with an accumulator, which we style the
balance, the object of this arrangement being to maintain an equal pressure on all,
or any part of the lifting ropes, so that no particular rope gets more than its due
strain upon it. And the balancing accumulator also acts as a spring to prevent
any undue shock, owing to the action of the waves, or other causes.
The lifting machinery can be carried on any vessel, tank or hulk, having the
necessary displacement, or floating power, but preferably we use pontoons having
one or more wells passing completely through them, and through which the magnets
and lifting ropes can be lowered and operated with suitable crane or cranes
associated with each for convenience of handling.
Each electro-magnet can have one or more lifting ropes attached, depending of
course on the adhesive power of the magnet and strength of the ropes.
Each rope is attached directly, or otherwise, to a hydraulic ram in such a
manner that when the rams are forced out of their respective cylinders, the required
"lift" is given to the ropes, which thus raise the vessel.
.
We now describe in detail one way of raising a vessel, though we do not confine
ourselves to this particular method.
One or more pontoons, having in the aggregate the requisite floating power,
necessary to raise the vessel, are moored by sea anchors, or otherwise, directly over
the vessel or body to be raised-each pontoon having the necessary number of
(preferably four,-one near each corner) electro magnets of the required aggregate
adhesive power.
The pontoons are supplied with sufficient steam, or other power, to operate the
hydraulic rams, the cranes, and the electric generating machines for supplying
electricity to the electro-magnets.
Each magnet with its lifting rope, and electric cable attached, is now lowered
through its well, and a relatively small electric current passed through it, so that it
has only a relatively small lifting capacity.
On its touching the bottom, vessel or body, a lift is given to the rope by means
of the crane, to which is attached a dynamometer, so that the strain on the rope is
known.
If the magnet has made good contact with the iron body to be raised, it will of
course stand the testing strain on the rope, but if it has failed to touch the wreck,
or has contact with a weak part of it, it will rise, when it can be again lowered,
and slightly moved, this operation being repeated until every magnet has taken a
good hold of the wreck-the electric current being meanwhile maintained.

page_text: Each of the lifting ropes or hawsers is now passed over a sheave or pulley over
the well, and connected to the head of a hydraulic ram, all the cylinders on each
pontoon being connected together, and fed from an omnibus main from the force
pumps, which main is also connected to the balancing accumulator.
The full electric current is now turned on, so that each magnet will exert its
maximum holding power, and the hydraulic pump or pumps are started, with the
result that each ram is forced out, and gives the corresponding "lift " to its rope.
As the rams are all of the same size, it follows that no rope can exert any greater
lifting power than ench of its fellows, and therefore no extra strain can be given
to any one magnet, more than that which it is capable of lifting, because should
the pumps by any means force the water at any higher than normal pressure, the
surplus power would merely lift the ram of the balancing accumulator which is
suitably weighted, and thus acts as a safety valve. In addition ordinary hydraulic
relief valves, can be placed on the omnibus main, to effect the same object.
A further advantage gained by the balancing accumulator, is, that should a swell
arise on the surface of the water, and lift the pontoon, and so put a sudden pressure
on the ram heads greater than the magnets could safely 'stand, the balancing
accumulator would at once rise, because the water from the hydraulic cylinders,
would be forced back into it, and thus the strain on the ropes be instantly and
automatically relieved. On the other hand if the swell on the water should cause
the pontoon to suddenly depress and so tend to slacken the strain on the ropes, the
accumulator would fall, and the water in it be forced into the hydraulic cylinders,
enabling them to at once take up the slack of the rope without unnecessary shock.
Instead of relying on a single accumulator more may be used, and placed in
different parts of the system, but be all so connected as to act in the above
described manner.
As soon as the hydraulic rams have made their full stroke, the ropes may be
held in position by suitable gripping apparatus, preferably by being wedged or
bolted to short hydraulic rams, in connection with the balancing accumulator,
which last would still act as a spring to them-the water connections to the lifting
rams are then cut off and the rams returned to their original position, in readiness
to make another lift, as soon as the lifting ropes are again attached to them.
In this way successive lifts can be given to the wreck, until it is sufficiently
raised toward the surface of the water to be salved in the usual manner, or the
wreck, still supported by the pontoons, can be towed to ground at less depth of
water, and the operation described be repeated until in position to be salved by
ordinary means.
If it be preferred to haul the lifting ropes, continuously, instead of the
alternating motion of the hydraulic rams-steam winches, or other suitable, power
driven capstans, or such like winding gear can be used, which will constantly haul
the ropes.
In this case the pulleys carrying the lifting ropes over the wells, can be attached
to the cross heads of hydraulic rams, the cylinders of which are all connected
together, and with the balancing accumulator as before mentioned. These
cylinders are kept normally half full of water, under a pressure corresponding to
the strain on the ropes, the accumulator being suitably weighted as before. The
same action now takes place, in case of any undue strain being put on any of the
ropes, either through rise and fall of the waves, or through any of the winches
being driven too fast or too slow, or from any other cause.
If the strain on the rope is increased above normal, the pressure on the ram is
increased, and the water driven out of the cylinder, into the balancing accumulator,
or to waste through the relief valve, the "return" of the ram thus reducing the
pressure on the rope. Or if the strain on the rope is reduced, the pressure on the
ram is lessened, and the higher pressure water in the balance, instantly flows into
the cylinder and forces the ram outwards until the strain on the rope is increased
to the normal.
If desired these water borne pulleys or sheaves can be used with the hydraulic

page_text: rope lifting, as first described, and thus render the whole of the lifting gear very
sensitive to shocks or undue strains.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is an elevation partly in section of an apparatus constructed according
to this invention.
A is a pontoon having a well B.
C is an electro magnet, in contact with hull H, to be raised.
D is a pulley over which the lifting rope E passes.
F is a hydraulic lifting cylinder, with ram G, having a cross bead J, the bottom
of which slides in the guide K, and to the top of which the lifting rope E is
attached.
K is a guide for the cross head J, and having notches or holes in it, to engage
the end of a lever, for forcing back the ram G.
L is an omnibus pipe carrying the high pressure water to the cylinders &c.
M is a relief valve suitably weighted to prevent any undue strain on G.
N is a balancing accumulator, connected to the omnibus pipe L, and having its
relief valve O, to prevent shock.
P is a pressure pump, for forcing the water into the hydraulic cylinders.
Q is a crane for convenience in manipulating magnets and lifting ropes.
R is any source of electricity, and,
S are insulated electric conducting cables.
In Figure 2 the pulley D is placed on the ram T of a hydraulic cylinder U and
the weight is lifted by a winch V. In other respects the arrangement is similar to
that shown at Figure 1 and the remaining parts bear the same letters.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The combination with the lifting ropes of magnets for making the necessary
connections substantially as described.
2. The combination with the lifting ropes of means for equalising the strain
upon them substantially as described.
3. The combination with the lifting ropes of hydraulic cylinders and an
accumulator all on an omnibus main substantially as described.
4. Apparatus for raising sunken ships and other bodies substantially as described
and shown at Figure 1.
5. Apparatus for raising sunken ships and other bodies substantially as described
and shown at Figure 2.
Dated this Twelfth day of September 1896.
N. D. KEITH.
J. W. WHITE.