IMPROVEMENTS IN FLOATING DOCKS
Year: 1864

page_text: LETTERS PATENT to James Campbell, of No. 6, Founders Court, in the City
of London, Civil Engineer, trading under the Firm of Campbell, Johnson,
& Company, for the Invention of "IMPROVEMENTS IN FLOATING DOCKS."
Scaled the 18th November 1864, and dated the 29th August 1864.
PROVISIONAL SPECIFICATION left by the said James Campbell at the
Office of the Commissioners of Patents, with his Petition, on the
29th August 1864.
I, JAMES CAMPBELL, of No. 6, Founders Court, in the City of London,
Civil Engineer, trading under the Firm of Campbell, Johnson, & Company,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
FLOATING DOCKS," to be as follows:-
My Invention has for its object economy in the chief design and con-
struction, combined with efficiency in the working of docks adapted for the
largest class of ships or vessels, and it is also intended to provide the means
of floating off the next and smaller class of ships or vessels into shallow
docks or elsewhere when considerable repairs are required to be done.
The dock for the larger class of ships or vessels is preferred to consist of
twenty compartments (ten on each side of the keel), each composed of a
Jower or floating chamber, a balance chamber, and an upper tank, and it is
made with its inner skin to a shape fitting within a few feet to the amidship
section of the largest sized ship at the bottom, with sides either vertical or
battering out one in six. The external skin is parallel to the internal at a
distance of about one-fifth of the internal width of the dock. The dock is
sunk ready for lifting by the weight of water admitted into the upper tanks,
and when the large ship or vessel has been admitted into the dock, and the

page_text: water let off from the upper tanks, the whole rises out of the water to the
extent of about nine or ten feet. Caissons of the kind herein-after described
are then put at each end of the dock, and sunk or otherwise fixed in their
places, and the water within the dock is allowed to sink into the lower or
floating chambers by means of valves, when the ship or vessel which has been
shored up from the sides of the dock can be examined, cleaned, or repaired,
as may be required. When this is done the external water can be admitted
inside the dock until the water is level inside and out, when the caissons may
be removed, and the vessel floated out. Then before taking on another ship
or vessel the water has to be pumped out of the floating chambers into the
upper tanks, and the surplus water got rid of. By means of the above-
described arrangement the necessity for working any machinery, engines,
boilers, or pumps during the whole process or processes of raising and
lowering the vessel is obviated.
The form of the caissons above referred to is as follows:-The floating
power is confined to the top, and the remainder is composed of water-tight
thicknesses of plates with stiffening ribs. For the smaller class of ships or
vessels there is inserted in the dock a tray or pontoon of the kind herein-after
described, on which tray or pontoon the vessel rests, and by the rising of
which it is raised by letting the water out of the upper tanks, and also out of
the tray. Then on admitting the external water into the lower chambers the
dock is caused to sink, leaving the tray floating with the vessel on it. The
form of the tray or pontoon above referred to is made to correspond as nearly
as convenient to the shape of the lower part of the inside of the dock. This
form of tray or pontoon may be used either in combination with the dock
constructed as above described, or it may be otherwise used. For repairing
the dock I employ an iron belt or trough which has three sides, but is open
at the top, and floated at each end by ordinary tanks, to which it is fixed.
The top of the said belt or trough corresponds in form, or nearly so, with that
of the dock, and can be moved along it to the part requiring repairs, when
by sinking the dock a little, or preferably by pumping water out of the end
tanks, it can be made to spring tight to the dock, and to make a water-tight
joint if properly packed. The water may then be pumped out of the belt or
trough, when the repairs can be proceeded with. A cutwater may be adapted
and applied to each end of the dock, so as to allow of its being propelled by
means of a propeller, and the rudder may be placed pro tempore with its axis
in the centre of the dock, being secured at the top on a transverse beam. *

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Campbell in the Great Seal Patent Office on the
27th February 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
CAMPBELL, of No. 6, Founders Court, in the City of London, Engineer,
trading under the Firm of Campbell, Johnstone, and Company, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of August, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Campbell, Her special license that I, the said James Campbell,
my executors, administrators, and assigns, or such others as I, the said
James Campbell, my executors, administrators, 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 "IMPROVEMENTS
IN FLOATING DOскs," upon the condition (amongst others) that J, the said
James Campbell, by an instrument in writing under my band 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 same 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 I, the said James Campbell, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
:-
My Invention of "Improvements in Floating Docks" has for its object
economy in the chief design and construction, combined with efficiency in
the working of docks adapted for the largest class of ships or vessels, and it is
also intended to provide the means of floating off the next and smaller class of
ships or vessels upon trays or pontoons into shallow docks or elsewhere when
considerable repairs are required to be done.
The dock for the larger class of ships or vessels is preferred to consist of
twenty compartments (ten on each side of the keel), each composed of a
lower or floating chamber, a balance chamber, and an upper tank, and it is
made with its inner skin to a shape fitting within a few feet to the midship

page_text: section of the largest sized ship at the bottom, with sides either vertical or
battering out, say, about one in six. The external skin is about parallel to
the internal at a distance of about one-fifth of the internal. width of the
dock. The dock is sunk ready for lifting by the weight of water introduced
into the upper tanks, and when the large ship or vessel has been admitted into
the dock and the water let off from the upper tanks, the whole rises out of
the water to the extent of, say, about ten feet. Caissons of the kind herein-
after described are then put at each end of the dock, and sunk or otherwise
fixed in their places, and the water within the dock is allowed to sink into the
lower or floating chambers by means of valves, when the ship or vessel which
"has been shored up from the sides of the dock can be examined, cleaned, or
repaired, as required. When this is done the external water can be admitted
inside the dock until the water is level inside and out, when the caissons may
be removed, and the vessel floated out. Before taking on another ship or
vessel the water has to be pumped out of the floating chambers into the upper
'tanks, and the surplus water got rid of. By means of the above-described
arrangement the necessity for working any machinery, engines, boilers, or
pumps during the whole process or processes of raising and lowering the vessel
is obviated.
The form of the caissons above referred to is as follows:-The floating
power is confined to the top, and the remainder is composed of water-tight
thicknesses of plates with stiffening ribs. For the smaller class of ships or
vessels there is inserted in the dock a tray or pontoon, upon which the vessel
rests. By letting the water out of the upper tanks until the bottom of the
tray or pontoon rises above the external water, so as to be thoroughly emptied,
and then lowering the dock by admitting the water into the lower chambers of
the dock, the tray or pontoon with the vessel on it is floated off into shallow
basins or elsewhere, as required. The form of the tray or pontoon above
referred to is made to correspond as nearly as convenient to the shape of the
lower part of the inside of the dock. This form of tray or pontoon may be
used either in combination with the dock constructed as above described, or
it may be otherwise used. For repairing the dock I employ an iron belt or
trough which has three sides, but is open at the top, and floated at each end
by ordinary tanks, to which it is fixed. The top of the said belt or trough
corresponds in form, or nearly so; with that of the dock, and can be moved
along it to the part requiring repairs, when by sinking the dock a little, or
preferably by pumping water out of the end tanks, it can be made to spring
tight to the dock, and to make a water-tight joint if properly packed. The
'water may then be pumped out of the belt or trough, when the repairs can be

page_text: proceeded with. A cutwater may be adapted and applied to each end of the
dock, so as to allow of its being propelled by means of a propeller, and the
rudder may
be placed pro tempore with its axis in the centre of the dock,
being secured at the top on a transverse beam.
Having thus stated the nature of the said Invention, I will proceed to
describe more particularly in what manner the same is to be performed by the
aid of the accompanying Drawings, in which are represented a dock as
adapted for the largest class of ships or vessels, and also a dock containing
one of the trays or pontoons for the next and smaller class of ships or
of ships or vessels; and Figures 9 to 14 represent the dock as containing :
tray or pontoon for the next and smaller class of ships or vessels. In
these several Figures the same letters of reference indicate corresponding
parts.
Fig. 1 is a longitudinal vertical section through the centre of the dock;
and Fig. 2 is a horizontal section of the same, taken in a line passing through
the upper tanks. A, A, are the several compartments of which the dock is
composed (preferred to be twenty in number, ten on each side of the keel),
cach compartment consisting of a lower or floating chamber B, a balance
chamber C, and an upper tank D, as shewn in the transverse sections, Figs.
3, 4, 5, 6, 7, and 8. The general dimensions of the dock represented in the
Drawings and the proportions preferred are, entire length four hundred and
twenty feet, that is to say, forty-two feet for cach of the ten compartments on
each side, inside depth forty-nine feet from the top of the lower or floating
chamber, and fourteen feet for the depth of this chamber. A dock of these
dimensions is capable of lifting a dead weight of ten thousand tons. There
are forty pumps intended to be worked by ten engines of ten-horse power
cach; but the dock be fitted for self-propulsion, the four pairs of engines
that drive the propellers can be made also to work the pumps.
The general mode of constructing the dock is represented in the Drawings,
but is too well understood to require description. It may, however, be
stated that there is a water-tight bulkhead between each chamber in the
several compartments.
Fig. 3 represents a section of the dock after it has been sunk and has
received a large vessel. When the vessel has been admitted into the dock,
and the water let off from the upper tanks D, D, the whole rises out of the

page_text: water, say, about ten feet, as represented in Fig. 4. Then when the caissons
E, E, (Figs. 1 and 2) are sunk, or otherwise put in place, the water in the
dock is allowed to flow into the lower or floating chambers B, B, and the
vessel is left dry, as shewn in Fig. 5. After the examination and repairs of
the vessel the external water is allowed to flow into the dock, by the weight
of which it is caused to sink, when the vessel is floated off, as shewn in Fig. 6.
And when the water in the lower or floating chambers B, B, is pumped up
into the upper tanks D, D, and the surplus is pumped overboard, the dock is
ready for lifting another vessel, as shewn in Fig. 7. In this Figure also the
trussing for the frames is shewn. From the foregoing description of the
working of the dock it will be seen that during the whole process or processes
of raising and lowering the vessel there has been no machinery, engines,
boilers, or pumps at work, thereby removing much cause of anxiety during
these delicate operations. The caissons E, E, (Figs. 1 and 2) consist of
water-tight thicknesses of plates G, G, with stiffening ribs, the floating power
being confined to the top, as shewn.
In Fig. 8 is represented an iron belt H for repairing the dock. This belt
is also shewn in Fig. 1. It consists of a three-sided tank open at the top,
and floated at each end by ordinary tanks I, I, to which it is fixed by rivets
or otherwise. The top of this tank H is made to correspond as nearly as may
be to the shape of the bottom of the dock, and can be moved along to the part
thereof requiring repairs, when either by sinking the dock a little, or pre-
ferably by pumping water out of the end tanks J, J, it can be caused to
spring tight. to the dock, and to make a water-tight joint if properly packed
with wood and vulcanized india-rubber or otherwise. The water can then be
pumped out from between the three sides of the tank H and the bottom of
the dock, and men and materials for repairs introduced. It has been before
stated that there are forty pumps in the dock, which are intended to be
worked by ten engines of ten-horse power each; but if the dock is to be
capable of self-propulsion, it would be preferable to make four of the com-
partments into wells, wherein the water from the other compartments can be
allowed to flow at pleasure through pipes K, K, say, of six inches diameter,
the valves of which can be reached through tunnels L, L, see Figs. 1 and 8.
Figures 9 and 10 are similar views to Figs. 1 and 2, but shewing the tray
or pontoon adapted for the smaller class of ships or vessels. A is the tray or
pontoon, which is shewn as about three hundred and twenty feet long by
sixty-six feet six inches in its greatest width, and consists of eight com-
partments on each side, united by intermediate chambers and framing. This
tray or pontoon is shewn in the above Figures, and also in the sections, Figs.

page_text: 11, 12, 13, and 14, as contained within the dock, from which it will be seen
to be shaped so as to be parallel, or nearly so, with the inside of the dock.
These Figures correspond with the sections herein-before described, and it
will be understood from them.that the vessel is raised on the tray or pontoon
by letting the water out of the upper tanks D, D, until the bottom of the tray
or pontoon rises above the external water, so as to be thoroughly emptied, and
that then on lowering the dock by admitting the water into the lower
chambers B, B, the tray or pontoon with the vessel on it is floated off into
shallow basins, or elsewhere, as required.
Having thus described the nature of the said Invention, and in what
manner the same is to be performed, I would remark that I do not claim
as of my Invention the parts represented and described otherwise than as
herein-after stated; but what I do claim as of my Invention is,-
First, the general design, proportions, and construction of the dock as
represented and described, so as to adapt it for use with the largest class of
ships or vessels.
Secondly, the mode herein-before described of either partially or totally
getting rid of the water inside the dock.
Thirdly, the use of caissons of the particular form and construction repre-
sented and described.
Fourthly, the use of trays or pontoons of the form and construction repre-
sented and described, whether alone or in combination with the dock, and in
the manner herein-before described.
And, lastly, the belt represented and described, by means of which access
is afforded to the bottom of the dock for repairing the same when required.
In witness whoreof, I, the said James Campbell, have hereunto set my
hand and seal, the Thirty-first day of January, in the year of our Lord
One thousand eight hundred and sixty-five.
30 Witness,
G. W. R. WAINWRIGHT,
Staple Inn, Sol.
JAMES CAMPBELL. (L.S.)