AN IMPROVED METHOD OF RAISING SUNKEN VESSELS
Year: 1876

page_text: LETTERS PATENT to Pryse Protheroe, of Surbiton, in the County of Surrey,
for the Invention of "AN IMPROVED METHOD OF RAISING SUNKEN VESSELS."
PROVISIONAL SPECIFICATION left by the said Pryse Protheroe at the Office
of the Commissioners of Patents on the 10th March 1876.
PRYSE PROTHEROE, of Surbiton, in the County of Surrey.
METHOD OF RAISING SUNKEN VESSELS."
"AN IMPROVED
My Invention relates to the raising from a moderate depth of water vessels that
may have sunk in consequence of damage to their bottoms or other causes.
Usually vessels in this condition lie on their bottom, or it may be on their side
or bilge. When they are not sunk beyond a depth accessible to divers I cause the
masts and other deck hamper to be removed, and I then by means of ropes, chains,
or cables, made fast to one side of the vessel and attached to other vessels anchored
afloat at some distance from the sunken vessel, applying hauling force to turn the
sunken vessel over so that it may lie bottom upwards. In cases where great
force is necessary for so turning over the vessel I apply spars to act as levers,
inserting them through portholes or other suitable openings in the vessel's side,
and I apply the hauling power to these spars.
When the vessel is turned over, as above described, I repair, if necessary, damages
to the bottom of the vessel, making it as nearly as possible sound and air tight.
I then, by means of air pumps and hose connected therefrom pump air into the
hull so as to expel the water therefrom, until the vessel, being thus placed in the
condition of a diving bell, rises to the surface or nearly so. While the vessel is
rising it may be kept steady in position by means of chains or cables attaching its
sides to vessels floating above, the slack of these chains or cables being taken up as
the vessel rises so as to prevent it from canting over in consequence of unequal
loading.
When the vessel has been thus raised I tow it into shallow water, and I then
draw under its deck one or more sails so as to make a partial and temporary
closure of the deck openings. The vessel may then be righted by hauling it over.
It will be seen that the peculiarity of the method which I have described
consists in employing the bottom of the vessel, which is the strongest and tightest
part of the structure, as the receptacle for the air that is pumped in to float the
vessel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Pryse Protheroe in the Great Seal Patent Office on the 6th September
1876.
PRYSE PROTHEROE, of Surbiton, in the County of Surrey.
METHOD OF RAISING SUNKEN VESSELS."
"AN IMPROVED
My Invention relates to raising from a moderate depth of water vessels that
may have sunk in consequence of damage to their bottoms or other causes.
Usually a vessel that has sunk lies on its bottom, or it may be on its side or
bilge. When it is submerged to a depth that is not beyond the reach of divers
it may be raised according to the novel method which I will describe, referring to
the accompanying Drawings as illustrating the application of that method under
ordinary circumstances.
I will suppose that the sunken vessel is lying as shewn at A, in Fig. 1. The
inasts and other deck hamper are in the first place removed, and cables are made
fast to one side of the deck as at B; or where it is possible to spars C introduced
through portholes or other openings in the side of the vessel, the lattor arrange-
ment being preferred as giving greater leverage. These cables are carried up
to one or more vessels D floating on the surface of the water, and moored to
anchors or otherwise. The cables secured to the sunken vessel A or those which
noor the vessel D being hauled in by a windlass, capstan, or other hauling
apparatus, the sunken vessel will be caused to turn over on its side, and the
operation being continued after making such change as may be necessary in the
fixing of the cables to the sunken vessel, securing them to the keel, when it is
sufficiently exposed, the vessel will ultimately be turned bottom upwards, as
indicated by the dotted lines E. In this position the bottom of the vessel if it
has been injured or leaky can be made sound by divers preparatory to the raising
operation, which is illustrated in Fig. 2. Four bottom moorings F are provided
either by sinking masses of ballast or other heavy material, or by piles or anchors
where the bottom will admit of their use, and to each of these moorings is secured
a pulley or block G. Spars H are fixed across the keel of the vessel A, one near the
bow and one near the stern, and from the ends of these spars cables are led over
the pullies G and up to vessels K. moored above. From either of those vessels or
from an intermediate vessel L an air pipe M is carried down to the sunken vessel,
and either made good to the bottom, or it might be carried down the side and
introduced through a porthole or a deck opening so as to communicate with the
interior of the hull. Air is then by a forcing pump forced through this pipe
into the hull of the vessel A, displacing water therefrom, so that the vessel is thus
placed under the conditions of a diving bell, being so far lightened by the dis-
placement of the water that it will tend to rise. The cables from the vessel K
are now equably paid out so as to let the vessel rise evenly, the spars H each held
by two cables governing its position laterally, and the equal paying out of the
cables from the two vessels K. governing the position of the vessel longitudinally.
As a guide in paying out the cables from the vessels K I prefer to attach to each
end of the sunken vessel a line of floats or buoys N at equal short intervals.
These buoys being distinguised by different colours, the depth of each end of
the vessel A can be known by observing the particular buoy that comes to the
surface, and the paying out of the cables from the vessels K can be regulated
accordingly. There might also be provided, an insulated electric conductor ex-
tending from the paying out apparatus on one of the vessels K to that on the
other, with an indicating instrument shewing to the operators on each vessel the
extent of cable paid out from the other end, so enabling the two sets of operators
to keep pace with each other. It is obvious that regular and equal action in that
respect is of great importance, otherwise if the vessel A were permitted to rise more
at one end than at the other, the air within the hull, acting like shifting ballast,
but in an inverse manner, would render the higher end more buoyant and so
throw undue strain on the releasing cables and pullics, or their moorings at that

page_text: end. If, however, the vessel A be prevented from taking an inverse position, a
very moderate strain will suffice to retain it in that position. The releasing
cables from the vessels K, instead of being in each case in duplicate and secured
to the ends of spars H, might be single and secured simply to the stem and to the
stern of the vessel A, a single spar O being fixed about the middle of the vessel,
and connected by cables with the vessel L above for the purpose of steadying
laterally the vessel A as it rises.
The vessel A being by the means above described raised wholly or partially
to the surface can be towed in its inverted position into shallow water, or to a
convenient locality where means can be applied to turn it over.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim,
The method, substantially as herein described, of raising sunken vessels by
inverting them, making good their bottoms, pumping air into their hulls while
inverted so as to displace water therefrom, and guiding their ascent equably.
In witness whereof, I, the said Pryse Protheroe, have hereunto set my hand
and seal, this Fourth day of September, in the year of our Lord One thousand
eight hundred and seventy-six.
PRYSE PROTHEROE. (L.S.)