AN IMPROVED METHOD OF LIFTING OR LIGHTENING SHIPS FOR ENTERING SHALLOW HARBOURS, OR DOCKING AND OTHER PURPOSES
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by Robert Bushby at the Office of the
Commissioners of Patents, with his Petition, on the 5th May 1862.
I, ROBERT BUSHBY, of Little Hampton, in the County of Sussex, do hereby
declare the nature of the said Invention for "AN IMPROVED METHOD OF LIFTING
OR LIGHTENING SHIPS FOR ENTERING SHALLOW HARBOURS, OR DOCKING AND OTHER
PURPOSES," to be as follows:-
Observing that there may be great difficulty in docking the Warrior,
and other ships of her large draught of water, in consequence of there not
being docks to obtain water of sufficient depth to float ships of her large
draught into them in many of the ports in the United Kingdom, it has
occurred to me that a power might be applied to bring up the ships, or lift
them up sufficiently out of the water to enable them to enter some of the
present docks without alteration, and also to take ships of larger draught into
shallower harbours in cases of emergency. To accomplish this, I should
propose to apply either of the following powers, namely, to form iron tanks or
buoys of sufficient buoyancy for each side of the ship, with a chain to pass
under the ship, and through the buoys or tanks, by forming a water-tight
trunke through them to admit the chain. I. should then propose to immerse
the tanks, by admitting water into them to bring them down to nearly the
weight of the water, by having a water-tight compartment. The water could
be admitted by a screw-down valve, and when sufficiently full, screw down the
valve, take in the slack of the chain, and make it fast, or, if thought more
desirable, the chains of the buoys could pass under the ship, and fasten with

page_text: shackles on deck, or in any other mode thought desirable, and then apply a
pump to pump out the water; this might be done by a hose, with a brass
union to connect to an iron pipe, which should be made and fixed to each
tank, and then leading the hose or suction pipe to a small steam engine, or
any other power for pumping out the water, there must be a small air pipe. to
each tank. These tanks or buoys could be made to suit the dimensions of the
ducks, and the power used for applying them; they could be made sınall enough
to be bousted down with luff tackles, in a man-of-war, having plenty of men;
for example, suppose the ship "Warrior" to have, say a bearing of 340 feet
each side, where the buoys or tanks could be applied, say I want to lift her
3 feet, and the superficial area at the load-water line would be, say for example,
15,000 feet, that would be about 430 tons at one foot deep, I want to raise
her 3 feet, which would be, say 1,290 tons, that would require 45,350 feet of
buoyancy, which would require a sectional area of 75 feet for the 340 feet
each side. The dimensions of the buoys or tanks could be made to come
under the power for applying them, supposing they are to be bousted down
by tackles. Experience would tell what weights, and consequently what
dimensions could be applied by that power, there could be a series of powers
applied on the plan of the old-fashioned screw jacks, with multiplying pinion
"wheels, say, for example, 650 tons power would be required on each side.
To raise the Warrior 3 feet, would require, say, 50 screw jacks or multi-
plying pinions and wheels each side of 15 tons each, 3 men could work each
of thein, and they could obtain 1,500 tons power. This would answer to
make the tanks of any dimensions or buoyancy, the same as immersing them
by water, if the whole of the jacks or multiplying pinions and wheels were
worked simultaneously, which could be done in a man-of-war, or any place
where men are plentiful, the chains could be made to lead through the bottom
of the tanks or buoys, in a water-tight tube, with friction rollers, and under
"the bottom of the ship, to the top of the tanks, with a chain made with a link
to work on the pin of the wheel. For adapting or applying these tanks to the
ship, I'should propose to have moorings to moor the tanks to in deep water,
and sufficient distance apart, that the ship may be hauled in between them,
the chains being suspended at a sufficient depth for the draught of the ship.
The tanks could then be brought alongside, immersed by either of the powers
before mentioned, and made fast; there could then be a chain run through
rings in the tanks fore and aft to keep them together. This power could be
used for many other purposes, namely, for raising sunken ships or raising
ships for bar or shallow harbours. There might be tanks constructed of one
or two hundred tons, or any other, dimensions required, and moored in the

page_text: manner before described, in order that a ship might be hauled between them,
and the tanks or buoys immersed by either of the powers before described.
The mode of applying the power for lifting sunken ships would be, to have
tanks or buoys of sufficient buoyancy to lift the sunken body, the weight of
which could be ascertained and worked according to circumstances, then sink
the buoy or tank, by admitting just sufficient to overbalance the water, sling
the sunken body by chains (or means thought more desirable) by divers, or
others, connect the suction pipe to the sunken buoy or tank, admitting also an
air-pipe, pump out the water, then, if there is a sufficient buoyancy, the sunken
body will rise and float with the tank or buoy. It would be found desirable
to make the buoy for lightening small ships of somewhat different shape in
section, and they might be made sufficient to lighten a ship of 300 or 400 tons
burthen two or three feet, by having them of a sufficient buoyancy to be
baving one or two tanks or buoys on each side of the ship, whichever may
be thought most desirable. This mode of lightening ships of these dimensions
would save a great deal for merchants, such as the expence and loss of time
of taking out grain or other merchandize. At a port like Galatz, a ship of
400 tons burthen would at times cost £150 to lighten, beside the loss of time.
By this mode it could be done at any time; say, for example, I want to lighten
a 400 ton ship 2 feet, suppose the probable area at load-water line to be about
1,800 feet, that would be about 50 tons each side, therefore, by applying two
buoys of 50 tons each, the amount of power could be obtained; this could be
done in a most easy manner, and with little expence; for example, a boat or
buoy made of 50 tons buoyancy, could be built for two men to live on board,
by having water-tight compartments, and immersing with water. These two
men could pump out the water by hand in 2 hours, and the time could. be
reduced by having any number of pumps. The pinion and wheel would
answer the purpose, if strength could be obtained, which no doubt, could be
from a ship of 400 tons, for about 16 men, working altogether, could obtain
the power, and do it in a few minutes, the buoy could then be used for any
other purpose; for burthen there could be a propelling power introduced into
the buoys, such as a small screw, the engine could then be used for pumping
out the water. This mode applied to lightening or raising a ship could also
be carried into effect by having a steamboat with a tank or water-tight
compartment, and to immerse the steamboat by admitting. water, as before
proposed, with a screw-down valve. I should then propose to have a
series of chains to go down through the centre of each steamboat, by having a
water-tight trunk from the centre of the keel to the deck, (or in any other
direction that gravitation may direct), with friction rollers top and bottom.

page_text: It
The chains to be laid from the deck of one steamboat, under the bottom of the
ship to be lightened, and raised up thro' the other steamboat, leading to the
deck, and when the boat is immersed, the slack of the chain to be taken in
and made fast. There could be almost any amount of power obtained by
adopting the power of the screw jack as before mentioned, and as the latter
mode would not interfere with the capacity of the steamboat, it might be
thought possibly more desirable. Two steamboats, with chains slung in this
way, could run alongside of a ship, with the chains dropping under the ship;
the boats made fast fore and aft to the ship to be lifted. The steamboats then
immersed by either of the powers before-mentioned, would lift a ship of any
weight according to the power applied. It would be necessary to apply wood
fenders, of different thicknesses, between the steamboats and the ship to be
lifted, in order that the bearing might be as equal as possible, or, if thought
desirable, the steamboats could be built with a curve, and vertical pieces of
wood on the side, sufficiently thick to admit the chains for lifting; or the
steamboats could be made of any suitable form if found more desirable.
will be necessary to have the boats or buoys very strong and well supported,
to sustain the pressure of lifting. Other apparatus could be used, if the
steamboats were immersed with water, because there would be no friction in
bauling down; such as old canvass, or matting, in packing out the fenders,
when the water is being pumped out for lifting; and this power applied to a
man-of-war, or any other ship aground, would be very desirable, as the whole
of the steamboats might be fitted for this apparatus by adding the chain trunks
as before described, and by strengthening the bearing points of the ship in a
manner thought most advisable, without in any way interfering with the con-
struction or capacity of the ship. There are two other powers that might be
applied for immersing the buoys or steamers without admitting the water,
namely, the hydraulic power, or powerful screws, the screw to be worked on
the principle of a capstan. By having a quantity on either of these principles,
any amount of power might be obtained, for example, say, (the Warrior is to
be raised 3 feet, as before stated), to go into dock or harbour, any number of
tanks or buoys that would take up 750 tons, each side would raise her 3 feet,
assuming my calculations as to dimensions to be correct. My object in cal-
culating, is to show the principle for working the power. It appears to me,
therefore, that by applying this power, it would save the Lords of the Admi-
ralty a great outlay in altering the docks, and give them an opportunity, in
many cases, of having docks in harbours where they would not think of having
them, on account of the depth of water. There may be a difficulty in not
having docks of sufficient width to admit the buoys, but to alter to give.

page_text: sufficient width, would be a small matter in comparison with making new
-docks. If a dock or a basin could be made sufficiently wide to take up a ship
in this way by two powerful steamers, a ship-of-war might be fitted, equipped
for a voyage or expedition (although there might not be water enough to
float her), taken up by the powerful steamboats, taken out of dock, and to sea
if required. Other modes or plans might be applied, by having buoys and
docks made suitable to take up a ship 3 or 4 feet, or any weight that may be
required. The buoys or tanks could remain in the sides of the docks, to form a
platform each side of the dock for nien to work on, if thought desirable, by floating
them from the ship, for the purpose of staging, or any other operation required;
or, if thought more desirable, the buoys might be made suitable for either, or
all of the docks, floated out, and moored to buoys, or in any other modo
thought more desirable. As before proposed, in reference to the chains for
the slings, there could be a strong shoe of iron for the keel to drop into, with
an eye, for a chain to be shackled to it from each steamboat or buoy. In
order that the chain might not rub the keel with friction, it would also be
advisable to make a portion of the chain as a belt, covered, in order that the
chain may not rub the ship at the bilges, or any other part. I should then
propose to haul the lifting chains on slack through the trunk, and when
wanted to be used, they should be sent down through the trunk, with a buoy
and a piece of rope sufficient for the buoy to float to the surface. The rope
should be taken in on deck, to haul in the end of the chains in both steam-
boats or buoys, and then made fast or shackled to the shoe. If steamboats
are fitted and adapted for the lifting power, the steam could be used or applied
for working either of the above powers. This mode of lifting ships would be
a great advantage in war times, as by applying the lifting power, ships of war,
transports, or merchants' ships, could enter small harbours. It would be a
great advantage to take in tow a disabled ship. There may be a question
as to the propriety of taking a ship-of-war into a basin, and fitting and
equipping her as before stated, because it would be desirable to have the ship
floating to ascertain ber trim. To obviate this, I should propose (when found
necessary), when a large ship could not be floated, to heighten the walls of the
basin or dock; pump water sufficient with pumps worked by steam to float her;
she could then be taken up by the powerful steamers, if fitted with the
lifting powers; the water could then be let out of the dock or basin to the
level of the tidal waters. This would be a great advantage, if ships were
required to be taken out of dock at neap tides, when otherwise, there would
only be water at spring tides. These lifting steamers would be useful for
many purposes, as there would be the advantage of taking up a ship, and

page_text: taking her into almost any harbour; and docks or basins could be constructed
in the manner before proposed, so that a ship of the largest draught could be
made to float by the lifting power; by building up the walls, for damming up
the water to a sufficient depth. To enumerate further the number of matters
this power could be applied to, would not, I think, be of any great advantage,
as I have laid down the principle, and as the composition of machines for
mechanical powers are well known; science will direct their application, I will,
therefore, conclude by enumerating the powers I have herein recommended,
namely, 1st, by luff tackles; 2nd, by admitting water and pumping out; 3rd,
multiplying pinion wheel; 4th, bydraulic pressure; 5th, the powerful screw.
The above powers can be worked by steam, or not, according to circum-
stances, the entire object being to employ sufficient power to overcome the
resistance.