IMPROVEMENTS IN FLOATING DOCKS
Year: 1868

page_text: LETTERS PATENT to James Campbell, of No. 6, Founders Court,
Lothbury, in the City of London, Engineer, for the Invention of
"IMPROVEMENTS IN FLOATING DOCKS."
Sealed the 28th August 1868, and dated the 7th March 1868.
PROVISIONAL SPECIFICATION left by the said James Campbell at
the Office of the Commissioners of Patents, with his Petition, on
the 7th March 1868.
I, JAMES CAMPBELL, of No. 6, Founders Court, Lothbury, in the City
of London, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN FLOATING Docкs," to be as follows:-
My Invention has reference, in the first place, to trays or pontoons
described in the Specification of a Patent granted to me, and bearing
date 29th Aug. 1864, No. 2118, and consists as herein-after mentioned
in the construction of such trays or pontoons with the transverse ribs
sufficiently close to allow of a deck of stout planking to be laid thereon,
so that a vessel can be securely shored as in a stone dock with the keel
resting on proper docking blocks over the ribs at a sufficient height
to admit of the men working under the bottom of the ship. Such of the

page_text: My Invention consists, in the third place, in employing docks of
similar construction to the docking of river steamers of light draught
which require a dock of considerable width, and when the greater amount
of water required to be pumped out is not relatively important. In
these docks it will be advisable to use the belt described in the Specifi-
cation of the Patent herein-before referred to for repairs, as, owing to
their great proportionate width and having no load chambers, they
cannot be conveniently made to heel over.
My Invention has reference, in the fourth place, to improvements in
the belt above referred to, and consists, first, in enlarging the tanks at
the ends thereof, and making, say, two or any requisite number of
bulkheads transversely in each, so as to enable the water-tight joints of
the belt proper to be raised out of the water for adjustment and repairs
without docking. These improvements consist, secondly, in the mode
of securing the vulcanized india-rubber to the woodwork of the water-
tight joints by inserting a stout band thereof in a dovetailed groove
formed in the woodwork, which has been made to correspond as nearly
as possible to the form of the bottom of the dock. This band may be
of about four inches in depth and one inch in thickness, and made to
project about one inch out of the groove, and may be kept in its place
by pieces of hard wood driven in for the purpose.
And my Invention consists, in the last place, in the use of a water
guage composed of a reservoir of compressed air at, say, 40 to 50 pounds
pressure per square inch, communicating by suitable taps with small
pipes branching off to the lower parts of the various compartments
wherein it is required to ascertain the level of the water. Each of these
pipes is intended to have a pressure guage divided, not in pounds but
in feet and inches, shewing the head of water corresponding to the
pressure. By this arrangement when one of the small pipes has received
through its tap a sufficient supply of air from the reservoir, its guage
will indicate the head of water above its lower extremity. By making the
reservoir sufficiently large in proportion to the capacity of the small pipes,
and taking reasonable care to avoid leakage and waste, no inconvenient
amount of pumping of air into the reservoir will be required either during
the docking or undocking. It is preferred that each side of the dock
should have its reservoir and pipes, all the guages on either side being
together in a small office for the purpose.

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 28th August 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
CAMPBELL, of 6, Founders Court, Lothbury, in the City of London,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of March, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said James Campbell, Her special licence, that
I, the said James Campbell, my executors, administrators, and assigns,
or such others as I, the said James Campbell, my executors, adminis-
trators, 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
Docкs," upon the condition (amongst others) that I, the said James
Campbell, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, 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 performed, 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 reference,
in the first place, to trays or pontoons described in the Specification of a
Patent granted to me and bearing date Twenty-ninth August One
thousand eight hundred and sixty-four, No. 2118, and consists, as
herein-after mentioned, in the construction of such trays or pontoons
with the transverse ribs sufficiently close to allow of a deck of stout

page_text: planking to be laid thereon, so that a vessel can be securely shored as in
a stone dock, with the keel resting on proper docking blocks over the
ribs, and at a sufficient height to admit of the men working under the
bottom of the ship. Such of the transverse ribs as are designed to be
water-tight are to be continued so up to the keel of the vessel, but the
part thereof above the deck is to be constructed so as to admit of being
readily moved several inches, and to consist of plates on edge nearest
the vessel in order to prevent interference with the repairs of the vessel.
Such upper continuations of the ribs or upper bulkheads are by pre-
ference constructed not directly over the ribs but, say, two feet off, so
as not to interfere with the docking blocks. In order to render the
tray capable of being trimmed as required by water forward and aft so
as to adapt the upward pressure of the tray along its length to the
varying weight of the vessel, it is proposed to make the sectional area
of the tray to the height of the water-tight continuations of the ribs
under the keel of the vessel at least 1-4 S (S being the immersed
sectional area of the vessel to be docked on such tray) and the width of
the tray at least 2 V, S. By means of these proportions the required
trimming will be provided for and a margin left for security against
accidents. In order to adapt the trays for carrying ships with their
cargoes over shallows and up rivers, or, say, through the Isthmus of
Suez canal before its final completion, they are constructed with conical
ends or cutwaters so as to facilitate their being towed as required. It
is also intended to make the outer or upper edges of the trays cylindrical
so as to combine stiffness with lightness.
My Invention consists, secondly, in constructing docks capable of
taking the larger class of vessels over shallows, and adapted for the use
of trays for large ships, which docks should be as light as possible, and
must be of great width. For this purpose it is intended to employ a
dock with only two chambers transversely, one on each side of a centre
partition, from which the water will have to be pumped when raising
the vessel. In this form of dock the upper or load chambers and the
lower or air chambers are dispensed with altogether. By this arrange-
ment, although the power of pumping at any time or using the load
chambers as an accumulator is lost, and although a large body of water
has to be pumped out which cannot escape from balance chambers, yet
there is much less pressure of water to contend with, and a considerable
saving in the weight of the dock. The safety of the dock is provided

page_text: for by making several of the transverse ribs water-tight, and it is
preferred that there should not be less than sixteen water-tight ribs on
each side of the keel.
My Invention consists, in the third place, in employing docks of
similar construction for the docking of river steamers of light draught
which require a dock of considerable width, and when the greater
amount of water required to be pumped out is not relatively important.
In these docks it will be advisable to use a belt for repairs, such belt
consisting of a three-sided tank open at the top, and floated at each end
by ordinary tanks, as, owing to their great proportionate width and having
no load chambers, they cannot be conveniently made to heel over.
My Invention has reference, in the fourth place, to improvements in
the belt above referred to, and consists, first, in enlarging the tanks at
the ends thereof, and making, say, two or any requisite number of
bulkheads transversely in each, so as to enable the water-tight joints
of the belt proper to be raised out of the water for adjustment and
repairs without docking. These improvements consist, secondly, in
the mode of securing the vulcanized india-rubber to the woodwork of.
the water-tight joints by inserting a stout band thereof in a dovetailed
groove formed in the woodwork, which has been made to correspond as
nearly as possible to the form of the bottom of the dock. This band may
be of about four inches in depth and one inch in thickness, and made
to project about one inch out of the groove, and may be kept in its place
by pieces of hard wood driven in for the purpose.
And my Invention consists, in the last place, in the use of a water
gauge composed of a reservoir of compressed air at, say, forty to fifty
pounds pressure per square inch, communicating by suitable taps with
small pipes branching off to the lower parts of the various compart-
Each
ments wherein it is required to ascertain the level of the water.
of these pipes is intended to have a pressure gauge divided, not in
pounds but in feet and inches, shewing the head of water corresponding
to the pressure. By this arrangement when one of the small pipes has
received through its tap a sufficient supply of air from the reservoir its
gauge will indicate the head of water above its lower extremity. By
making the reservoir sufficiently large in proportion to the capacity of
the small pipes, and taking reasonable care to avoid leakage and waste,
no inconvenient amount of pumping of air into the reservoir will be
required either during the docking or undocking. It is preferred that

page_text: on either side being together in a small office for the purpose.
I will now proceed to describe the accompanying Drawings, in which
are represented the improvements in floating docks above referred to.
DESCRIPTION OF DRAWINGS.
In order to avoid confusion no shores have been shown on the
Drawings.
Figures 1 to 5 inclusive represent the tray as adapted to vessels of
the unarmoured screw sloop "Eclipse" class. Fig. 1 is a sectional
elevation through the centre of the tray; Fig. 2 is a plan; Fig. 3 is a
transverse section; Figures 4 and 5 shew the construction of the tray,
A, A, being the water-tight transverse ribs, of which there are four-
teen, making twenty-six water-tight compartments (thirteen on each side
of the keel); B, B, are the upper bulkheads; C, the intermediate trans-
verse ribs of which there are thirty-eight; D, the water-tight keel; E, E;
are the longitudinal girders, and F, F, the cutwaters; the deck G is
supported on the transverse ribs A and C, which are four feet six inches
apart; H, H, are the outer or upper edges. The draughts of this tray
with the unarmoured screw sloop "Eclipse" at her load displacement
of one thousand eight hundred tons on it vary from seven feet to eight
feet nine inches according to the quantity of water admitted forward and
aft for trimming.
Figures 6 to 10 inclusive represent the dock as adapted for large trays,
the tray shewn being suitable for the Indian transport "Euphrates."
Fig. 6 is a sectional elevation through the centre of the dock;
Fig. 7 is a plan; Fig. 8 is a transverse section showing the vessel
grounded on the blocks of the tray; Fig. 9 is a section showing the tray
lifted up and drained out; Fig. 10 is a section showing the tray floating
off with the vessel on it. The letters of reference on this tray indicate
corresponding parts to those in Figures 1 to 5 inclusive.
The tray is composed of twenty-one water-tight transverse ribs,
making forty water-tight compartments (twenty on each side of the
keel) and sixty-two transverse ribs. The draughts of this tray with the
Indian transport "Euphrates" at her load displacement of six thousand
two hundred and eleven tons on it vary from ten feet three inches to
twelve feet eight inches according to the quantity of water admitted
forward and aft for trimming. I is the dock, which is composed of a

page_text: water-tight keel and twenty-seven water-tight bulkheads, making fifty-
two water-tight compartments (twenty-six on each side of the keel);
J, J, are the cutwaters.
Figures 11 to 14 inclusive represent the same dock showing its
capability of taking the larger class of vessels, such as the "Minotaur,"
over shallows. Fig. 11 is a sectional elevation; Fig. 12 is a plan;
Fig. 13 is a transverse section showing the vessel grounded on the
blocks of the dock; Fig. 14 is a section showing the vessel lifted up
ready for being taken over shallows. The draught of the dock with
the iron-clad "Minotaur" at her load displacement of ten thousand two
hundred and thirty tons on it is seventeen feet seven inches.
Figures 15 to 18 inclusive represent a dock suitable for docking river
steamers of light draught. Fig. 15 is a sectional elevation; Fig. 16 is
a plan; Fig. 17 is a transverse section showing the vessel grounded
on the blocks of the dock; Fig. 18 is a section shewing the vessel
lifted up. This dock is composed of forty-two water-tight compartments
(twenty-one on each side of the keel).
Figures 19 to 22 inclusive represent an iron belt K for repairing the
dock. Fig. 19 is a sectional elevation; Fig. 20 is a plan; Fig. 21 is a
transverse section to a larger scale. L, L, are the tanks at the ends,
the under side of the tank is shewn six feet lower than the water-tight
joint; M, M, are the transverse bulkheads in the tanks; N, N, is the
woodwork of the water-tight joints, and O, O, the india-rubber for the
same.
Having thus described the nature of the said Invention, and the
mode of carrying the same into practical effect, I hereby declare that
I claim as follows:-
First. The general design, proportions, and construction of the tray as
represented and described.
Secondly. The deck for shoreing upon as applied to trays.
Thirdly. The upper transverse water-tight and moveable bulkheads.
Fourthly. The use of cutwaters as applied to trays.
Fifthly. The general design, proportions, and construction of the
docks as represented and described.
Sixthly. The large end tanks to the belt proper, with one or more
transverse bulkheads in each.

page_text: Seventhly. The mode herein-before described of securing the vul-
eanized india-rubber to the woodwork of the water-tight joints of the
belt proper.
And, lastly. The use of the water gauge, as described, when applied to
floating docks.
In witness whereof, I, the said James Campbell, have hereunto set
my hand and seal, the Eighteenth day of August, in the year
of our Lord One thousand eight hundred and sixty-eight.
10 Witness,
G. W. R. WAINWRIGHT,
Staple Inn,
Sol*.
JAMES CAMPBELL. (L.S.)