Apparatus for Enabling Ships to Clear Harbour Bars and similar Obstacles to their Course.
Year: 1896

page_text: Date of Application, 21st Jan., 1896
Complete Specification Left, 21st Oct.. 1896-Accepted, 28th Nov., 1896
PROVISIONAL SPECIFICATION.
Apparatus for Enabling Ships to Clear Harbour Bars and similar
Obstacles to their Course.
I, WILLIAM HENRY WRIGHT, of No. 8 Beauclerk Road, Hammersmith, in the
County of Middlesex, Master Mariner, do hereby declare the nature of this
invention to be as follows:-
My invention relates to apparatus for enabling ships to clear harbour bars and
similar obstacles to their course, and the object of it is to enable a ship to be taken
over a bar in any state of the tide.
In carrying it into effect, I provide closed air and water tight tanks of a proper
shape to fit to the ships sides fore and aft and of a sufficient capacity to diminish her
draught by increasing her buoyancy, as much as may be required, after they have
been made fast to her skin at a suitable level for the purpose, and their water contents
replaced by air.
The tanks may be of lighter or other shape adapted to move easily through the
water. Suitable provision is made for holding them to the ship by means of chains
or the like passed from each tank to its fellow on the opposite side of the ship, as well
as from each tank to the one behind or before it. They are, preferably, divided into
water and air tight compartments.
Suitable pumping machinery is provided for the purpose of replacing the water in
the compartments, with air.
Dated this 21st day of January 1896.
PHILLIPS & LEIGH,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Apparatus for Enabling Ships to Clear Harbour Bars and similar
Obstacles to their Course.
1, WILLIAM HENRY WRIGHT late of No. 8 Beauclerk Road, but now of
No. 169 The Grove, Hammersmith, in the County of Middlesex, Master Mariner,
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:-
My invention relates to apparatus for enabling ships to clear harbour bars and
similar obstacles to their course and the object of it is to produce improved apparatus
for enabling a ship, by diminishing its draught, to be taken over a bar at any state
of the tide.
The invention consists in improved apparatus for so applying the buoyancy of
enclosed volumes of air to a vessel, that the latter and the said volumes of air shall
become practically one and the same floating body.
Referring to the accompanying figures which are to be taken as part of this
specification and read therewith:-
Figure 1 is a side elevation illustrating the application of the invention to a screw
steamer.

page_text: Figure 2 is a transverse section, taken on the line 2-2 of Figure 1, and
illustrating the capacity of the invention for enabling the same steamer to cross a
barbour bar.
Figure 3 is a sectional end elevation of the apparatus detached from the steamer.
A, A are the shells of buoyancy tanks of the same dimensions and shape,
consequently of the same total capacity. They are, preferably, circular in cross
section. Each one is destined to fit up to and to be held tightly against the
respective side of the vessel to be floated over the bar or other obstacle, and for that
reason is fitted with a chock a, along the respective side. As far as the invention is
concerned, it is a matter of indifference whether there is only one, or more than one,
tank for each side of the vessel. The requirement in this respect is that there be the
same capacity and the same draught on both sides of the vessel. Convenience in
handling the apparatus may be depended upon to decide how many tanks there are to
be on a side. Figure 1 illustrates the use of two.
6 is a ballast chamber extending along the bottom of each tank. Its function is to
keep the tank steady in the water.
e are two bulk heads establishing a central pumping chamber d in the middle of
each tank and two water ballast chambers c', c, one on each side of the pumping
chamber. d is a steam pump fixed in each chamber d and adapted to either pump
water, say from the sea, into both the water chambers el c, or to pump water out of
them. d is a steam supply pipe, from any convenient source to each pump d. fis
an air vent in the top of each shell A adapted to allow the air to escape from the
respective chamber c while water is being pumped into the latter, and to admit air
into the said chamber to take the place of the water being pumped out of it. The
floor of each chamber c¹ is dished from the sides towards the centre and from each
end towards the pump. is a coaming along the top of each tank. It serves to
carry the respective winding gears and to prevent any wash of the sea getting down
into the ballast chambers, e through the air vents. g, y are the winding gears by
which the pairs of buoyancy tanks, (that is one tank on one side and its fellow tank
on the opposite side of the vessel) are, in combination with their own buoyancy, held
to the vessel. They are fixed at equal distances upon the top of the respective
coaming e, those on one tank of a pair, interspacing those on the opposite tank of the
same pair when both tanks are in working position against the sides of the vessel.
Each winding gear consists of any suitable kind of winch preferably, having a chain
pulley instead of a drum. The type illustrated consists of a double winch bandle
carrying a worm gearing with a worm wheel axially fast to a chain pulley and
turning with the latter in bearings in a pair of standards. h, h are the gear chains.
Each tank of a pair is held to its fellow by the gear chains common to them both. For
this purpose, the end of each chain is made fast to an eye i projecting from the
bottom of a tank strengthening hoop a standing half way between two of the winding
gears g, g on the same tank. The other end of the same chain is led across to the
fellow tank and upwards through a chain pipe; to the winding gear g which it finds
there on the top of the coaming e. It engages with the chain pulley thereof, the
slack hanging down therefrom through the respective vent into the chamber c¹.
Each chain pipe extends upwards through the tank from the bottom to the top shell.
It is water tight throughout its length, as are both its junctions with the tank shell A.
When the tanks of a pair are in the proper position up against the sides of a vessel,
each is opposite its fellow, a strengthening hoop and eye i on one tank being
opposite to a chain pipe j and a winding gear g on the other of them.
The invention is used and acts as follows.
The pairs of hallasted tanks with their winding gears and chains in the working
position are towed out to the vessel waiting outside the bar for the apparatus, till one
tank or set of tanks is on one side and the other on the other side of it, the
chains h, h hanging under the keel. The steam supply pipes d', d', are connected
to the steamer's boiler, the pumps d d started to empty the chambers el, el and all
the winding gears 9, 9 started winding in their respective chains h, h. The water
in the chambers c¹, c, and the chain pipes j,j, is omitted from Figure 3, to

page_text: prevent its presence obscuring the chains h, h. As the chambers c² c' are emptied
of water, they tend to rise, but the winding in of the chains h, h pulls them down
into the water thereby bringing their buoyancy to bear, through the chains upon
the vessel's bottom. The maximum buoyancy of the combined tanks must be more
than the additional buoyancy required to float and support the vessel's keel at a level
above that of the harbour bar. This latter is indicated in Figure 3 by the line k.
When the vessel has no further need of the apparatus, the latter can be detached
from the hull of the former, by pumping enough water into the chambers c' to sink it
away from the hull.
With reference to the steam supply to the pumps, it must be pointed out that
the particular means by which the pumps are worked is not a feature of the
present invention. If the apparatus is to float a sailing vessel, it must find its
own steam or provide a substitute means for working its pumps.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The combination of a pair or pairs of tanks, ballasted chambers, water chambers,
pumps, winding gears and gear chains, as and for the purpose set forth in connection
with the accompanying figures.
Dated this 21st day of October 1806
PHILLIPS & LEIGH,
22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.