A CHAMBERED FLOATING DRY DOCK.
Year: 1860

page_text: LETTERS PATENT to James Campbell, of No. 44, Adelaide Road,
Haverstock Hill, in the County of Middlesex, Ship Builder, for the
Invention of "A CHAMBERED FLOATING DRY DOCK.".
Sealed the 4th December 1860, and dated the 21st September 1860.
PROVISIONAL SPECIFICATION left by the said James Campbell at the
Office of the Commissioners of Patents, with his Petition, on the 21st
September 1860.
I, JAMES CAMPBELL, of No. 44, Adelaide Road, Haverstock Hill, in the
County of Middlesex, Ship Builder, do hereby declare the nature of the said
Invention for "A CHAMBERED FLOATING DRY DOCK," to be as follows:-
My Invention consists in the construction of floating docks with the base
composed of air and water-tight chambers, so as to afford the required degree
of buoyancy to the dock, such chambers being separated from each other by
water-tight partitions, in order to prevent the stability of the dock when
immersed from being endangered by any excessive rolling of the water
internally, and also to prevent its safety from being endangered by the external
plating of one or more of the chambers becoming injured so as to admit the
water from without. The upper chambers which form the sides of the dock
are only intended to give it stability when the lower chambers (on which
alone in ordinary cases its buoyancy depends) are immersed. The upper
chambers are separated from the lower by a water-tight deck over which the

page_text: external water is allowed to flow in or out according as the dock is being
lowered or raised. In most cases it is preferred that the upper chambers
should not be continuous, but formed by means of square towers, or vertical
projections at each corner of the various sections. The engine and pumps for
withdrawing the water from the lower chambers, being contained in a small
water-tight portion of such upper chambers, the remaining portion of the same
allowing free ingress or egress to the water during the lowering or raising of
the dock.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Campbell, in the Great Seal Patent Office on the
19th March 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
CAMPBELL, of No. 44, Adelaide Road, Haverstock Hill, in the County of
Middlesex, Ship Builder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of September, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth 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 "A CHAMBERED FLOATING DOCK,"
upon the condition (amongst others) that I, the said James Campbell, by an
instrument in writing under my hand 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):

page_text: My Invention of "A Chambered Floating Dock," consists in the construction
of floating docks with the base composed of water-tight chambers so as to
afford the required degree of buoyancy to the dock, such chambers being
separated from each other by water-tight partitions, in order to prevent the
stability of the dock from being endangered by any excessive rolling of the
water internally, and also to prevent its safety from being endangered by the
external plating of one or more of the chambers becoming injured so as to
admit the water from without. The upper chambers which form the sides of
the dock are only intended to give it stability when the lower chambers (on
which alone in ordinary cases its buoyancy depends) are immersed. The
upper chambers are separated from the lower by a water-tight deck over
which the water is allowed to flow through regulating valves in or out
according as the dock is being lowered or raised. In most cases it is
preferred that the upper chambers should not be continuous, but formed by
means of rectangular towers or vertical projections, for instance at each corner
of the various sections. The engine and pumps for withdrawing the water
from the lower chambers being contained in a small water-tight portion
of such upper chambers, the remaining portion of the same allowing
free ingress or egress to the water during the lowering or raising of
the dock.
Having thus stated the nature of the 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 is represented the dock with the
arrangements applicable to the reception of vessels of different sizes.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a transverse sectional elevation of the dock shewing on one side
the section of a small class vessel on an arrangement of cradles for the
purpose of removing her ashore, and on the other side the half section of
a large class ship with the arrangement of cradles adapted for the same
purpose; Fig. 2 is a plan or horizontal view of the dock, different parts
of the Figure shewing the surface thereof at different points of elevation;
Fig. 3 is a side elevation shewing a series of sections of the dock connected
together for the purpose of receiving a vessel of great length; and Fig. 4
is a plan or horizontal view of the same. In all these Figures the same letters
of reference indicate corresponding parts.
a, a, are the twelve lower water-tight chambers in each section on which
the buoyancy or bearing power of the dock entirely depends; b, b, are the
water-tight divisions to ensure the stability and safety of the dock; c, c, are

page_text: connecting tubes with shut off valves between the various compartments a, a,
for the purpose of allowing the water to be drawn off from any one of the lower
chambers, as required, by means of any of the sets of pumps fixed in a small
water-tight compartment in either of the upper chambers or towers_d, d, the
remaining portion of the upper chambers or towers allowing free ingress and
egress to the water whenever the dock is lowered or raised. By this arrange-
ment of connecting tubes less inconvenience will arise from any disarrangement
of a set of pumps; e, e, are the pumps fixed on the top of the water-tight deck
over the lower chambers a, a. These pumps communicate with the lower
chambers by means of the vertical pipes f, f, and the horizontal connecting
tubes c, c, so as to be capable of drawing the water therefrom when required;
9, 9, are the discharge pipes with shut off valves at the sides of the upper
chambers; h is the engine for working the pumps supplied with steam from
the boiler k. The engine and pumps are by preference so proportioned that
the lifting of a vessel out of the water would not occupy more than three
quarters of an hour or thereabouts.
Such being the general arrangement and construction of the parts of the
dock, I would remark that when the width thereof is sufficient to ensure the
requisite amount of stability I prefer that the sides should not be made con-
tinuous, but that the upper chambers should be formed by rectangular towers,
as, for instance, at each corner of the various sections, as shewn in the Drawing,
the engine and pumps for removing the water from the lower chambers being
placed in a small portion of the tower or upper chamber, as shewn in the
Drawing, and above referred to. This arrangement of towers would be adopted
in all cases wherein it is practicable, that is to say, when the width of the
dock can be made sufficiently great. The advantages gained thereby would
be the admission of daylight to the lower parts of the dock, and the facility
for unloading barges containing materials for repairs brought alongside, which
barges could be unloaded elsewhere than at the ends without the necessity of
lifting such materials over the sides of the dock, and then lowering them on the
inside thereof. Again, when there is a great width of dock, and consequently
a great excess of stability, the central division b shewn on the Drawing as under
the keel of the large class ship had better not be made water-tight, but of
open or lattice work, the central water-tight chambers thus formed being also
made sufficiently large that the whole. of the water (or nearly so) that has to
be drawn off may be drawn off by the pumps direct from these central chambers.
It is obvious that by this method the trim of the dock will be more easily
maintained than by pumping out from the lateral chambers. By forming
the base of the dock in various lower chambers they may be pumped out

page_text: according to the buoyancy required, so that those chambers which have to
carry the greatest weight may have their buoyancy increased beyond those
which carry the least weight, (say, for instance, the stem and stern of the vessel)
thereby avoiding the danger of throwing an undue strain on any part of the
vessel lifted. The dock being flat on the bottom can be grounded with safety
and the vessel if required can be drawn ashore by means of cradles placed
underneath as shewn in Fig. 1.
Having thus described the nature of the said Invention,, and in what
manner the same is to be performed, I hereby declare that what I claim as
of my Invention is the construction of floating docks with the base or lower
part composed of water-tight chambers whereon the whole buoyancy of the
dock depends, such chambers being so arranged and divided or separated by
water-tight partitions as to prevent such degree of rolling about of the
internal water as would disturb the stability of the dock, and also to obviate
the danger that would occur by the external plating of one or more of the
chambers or divisions being injured so as to admit the external water. The
upper chambers or towers not being used to give buoyancy to the dock, but
only for the purpose of giving it stability when immersed. The water is
allowed to flow through regulating valves in or out during immersion or emersion
respectively.
I also claim the arrangement of the lower central chambers as described
above, and the formation of the upper chambers or sides in detached towers
as herein-before described.
In witness whereof, I, the said James Campbell, have hereunto set my
hand and seal, the Thirteenth day of March, in the year of our
Lord One thousand eight hundred and sixty-one.
JAMES CAMPBELL. (L.S.)
Signed, sealed, and delivered by the
within-named James Campbell, in
the presence of
D. SUTTON,
Clerk to Messrs. Combe & Wainwright, Solicitors,
Staple Inn.