IMPROVEMENTS IN THE CONSTRUCTION AND MODE OF WORKING AND EMPLOYING FLOATING PLATFORMS, PONTOONS, OR DOCKS, FOR SUPPORTING SHIPS OR OTHER VESSELS
Year: 1860

page_text: LETTERS PATENT to George Banks Rennie, of the Firm of George Rennie
and Sons, Holland Street, Blackfriars, Civil Engineer, for the Invention
of "IMPROVEMENTS IN THE CONSTRUCTION AND MODE OF WORKING AND
EMPLOYING FLOATING PLATFORMS, PONTOONS, OR DOCKS, FOR SUPPORTING SHIPS
OR OTHER VESSELS."
Sealed the 19th September 1860, and dated the 22nd March 1860.
PROVISIONAL SPECIFICATION left by the said George Banks Rennie
at the Office of the Commissioners of Patents, with his Petition, on
the 22nd March 1860.
I, GEORGE BANKS RENNIE, of the Firm of George Rennie and Sons, Holland
Street, Blackfriars, Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION AND MODE OF WORKING AND
EMPLOYING FLOATING PLATFORMS, PONTOONS, OR DOCKS, FOR SUPPORTING SHIPS OR
OTHER VESSELS," to be as follows :-
This Invention relates to a novel mode of constructing floating platforms,
pontoons, or docks, for supporting ships or other vessels, and in the mode or
method of arranging the parts of the same, and in the mode of working or
employing apparatus so constructed, by which greater facilities than heretofore
possessed by such contrivances are attainable or secured.
It consists in constructing a water-tight platform, rectangular on the plan, of
a depth suited to the purpose for which it is intended, and dividing such

page_text: hollow platform by longitudinal and transverse bulkheads into any convenient
number of parts or sections. Upon each side of such hollow platform, from
end to end thereof, a hollow wall or longitudinal chamber is carried from end
to end, each having an internal capacity sufficiently great so that the upper
half being divided from the lower portion of such chamber by means of an air-
tight horizontal division or floor leaves sufficient floatative balancing and
supporting power to enable the degree of immersion of the whole structure
or apparatus to be regulated. The lower half of each hollow longitudinal wall
is fitted with valves for the admission of water thereinto, and the water con-
tained therein as well as that which is contained in an angular chamber
abutting upon the inner face of each hollow longitudinal wall and extending
along the whole length thereof and to about one half its height, may be
discharged without pumping by means of outlet valves in proportion to
the amount of water pumped or forced out of or otherwise withdrawn from
the hollow platform or pontoon. A suitable balk or longitudinal block piece
of timber is laid along the top side or floor of the hollow platform or pontoon
upon which the keel of the vessel is intended to be received, and this in turn is
supported by a longitudinal girder forming a bulkhead from end to end, and
by means of diagonal bracing and trussing pieces the whole of the hollow
water and air tight structure forming the hollow platform or pontoon and the
two vertical walls and angular chambers abutting thereon are strengthened and
their form preserved.
In such floating platform, pontoon, or dock, I have no fixed or moveable
ends or gates or pontoons for the purpose of enclosing the vessel and the water
in which she has floated, and which water would require to be pumped out or
otherwise discharged therefrom, but I make the floatative power of the bottom
and side walls amply sufficient to support the weight of the structure and also
of the heaviest vessel which can be drawn within it or carried by it.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Banks Rennie in the Great Seal Patent Office on the 3
19th September 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
BANKS RENNIE, of the Firm of George Rennie and Sons, Holland Street,
Blackfriars, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her Letters 3
Patent, bearing date the Twenty-second day of March, in the year of our Lord

page_text: One thousand eight hundred and sixty, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
George Banks Rennie, Her special licence that I, the said George Banks
Rennie, my executors, administrators, and assigns, or such others as I, the
said George Banks Rennie, 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 THE CONSTRUCTION AND MODE OF WORKING AND EMPLOYING
FLOATING PLATFORMS, PONTOONS, OR DOCKS, FOR SUPPORTING SHIPS OR OTHER
VESSELS," upon the condition (amongst others) that I, the said George
Banks Rennie, my executors or administrators, 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 George Banks Rennie, 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 and accompanying Sheet of Drawings:
:-
This Invention relates to a novel mode of constructing floating platforms,
pontoons, or docks, for supporting ships or other vessels, and in the mode or
method of arranging the parts of the same, and in the mode or method of
working or employing apparatus so constructed, by which greater facilities than
heretofore possessed by such contrivances. are attainable or secured.
It consists in constructing an iron water-tight hollow platform of a rectangular
or other convenient form, of a depth and capacity suited to the purpose for.
which it is intended, and in the division of such hollow platform by longitudinal
and transverse bulkheads into any convenient number of parts or chambers.
On the upper part and towards each side of such hollow, platform, a hollow
iron water-tight longitudinal chamber is carried from end to end, of a convenient
form, having an internal capacity sufficiently great, so that the upper part being
divided from the lower part by means of an air-tight horizontal division or
floor sufficient floatative, balancing, and supporting power is obtained to enable
the greatest degree of immersion of the whole structure or apparatus to be safely
effected. The lower part of each hollow wall or longitudinal chamber is fitted
with valves for the admission and exit of water, and the water contained

page_text: O
therein may be allowed to flow out or in as the structure is raised or lowered.
The hollow walls or longitudinal chambers as well as the basement or hollow
platform or pontoon are divided into chambers by means of transverse water-
tight bulkheads, so that by means of valves the water may be let out or admitted
at pleasure in one or several of the chambers, thus enabling the base of the
dock to be kept in a horizontal or level position. Suitable balks of timber are
laid along the top, side, or floor of the hollow platform or pontoon upon which
the keel of the vessel is intended to be received, and these are supported by
longitudinal and transverse girders, thus distributing the weight so as not to
alter the form of the hollow platform or pontoon; the side walls are also
strengthened by girder frames. On the top of the side walls or hollow
chambers steam power may be placed for the purpose of discharging the water
from the basement portions of the apparatus for the purpose of performing
other work or operations in connection with the dock, such as raising, lowering,
hauling, or removing materials, and other similar operations, and also, for
working air exhausting and air compressing pumps, as well as those for the
raising and discharging of water. The pipes connected with the various pumps
are carried along in any convenient manner to the various chambers, sections,
or divisions of the dock, and in turn the different chambers are connected by
means of pipes and sluices or other valves which are capable of being acted
upon independently.
In such floating platform, pontoon, or dock, fixed or moveable ends or gates
or caissons for the purpose of enclosing the vessel can be dispensed with and
are not needed, and the water in which the vessel has floated, and which water
would, in case of using gates, &c., have to be pumped out or otherwise discharged,
will leave the vessel during the time the dock and vessel are being raised, but
the floatative power of the bottom or basement, when the water is forced or
drawn out by pumps or forced out by means of compressed air or otherwise
discharged therefrom, is made sufficiently ample to support the weight of the
structure and also of the largest and heaviest vessel which can be drawn within
it or otherwise placed on it.
The sluice cocks are so arranged that they may be worked from the deck
formed on the top of each hollow side wall, and by this means either one or
any greater number of chambers may be filled or discharged at pleasure, and
thus any irregularity in the disposition of the load, or any inequality in the
stowage of the weights of the ship which is being docked, may be compensated
for. In addition to the longitudinal and transverse plate-iron bulkheads, the
poutoon as well as the side walls are strengthened by means of open or lattice
girder frames formed of diagonal iron braces and trusses, and similar iron

page_text: trussings are applied in a longitudinal direction, and diagonal iron frames are
introduced between each system of girder frames to strengthen the iron
plating.
On the exterior surface of each wall wooden fender planks or timbers should
be fixed and suitably deep angle irons should be securely rivetted along the
side plates for the purpose of affording the means of readily fixing such
wooden fender planks or timbers.
In the accompanying Drawing I have shewn various views of a floating
platform, pontoon, or dock, constructed according to my present Invention.
Figure 1 is a longitudinal elevation thereof, shewing a vessel in position and
resting on the floor of the floating platform or pontoon dock; Figure 2 is a
longitudinal sectional elevation, illustrating more particularly the mode of con-
structing and equipping such floating platform or pontoon docks, as herein-
before described; Figure 3 is a sectional plan of the hollow platform forming
the basement of such floating dock, and shewing the suitable arrangement and
disposition of the pipes, valves, &c., by means of which the water is admitted
into or discharged from the water-tight bulkheads or compartments into which
the basement and hollow side walls of the floating dock are divided, and thus
allow of the structure being raised or lowered as circumstances require;
Figure 4 is an end elevation of Figure 1, aud Figure 5 a transverse section of
the same.
In these several views the same letters of reference are employed for
like or corresponding parts. A, B, C, D, represents the hollow platform
forming the basement of the structure; A, E, F, G, the hollow side walls or
longitudinal chambers of the structure; the lower part of the interior face of
cach side wall being inclined as at I, so as to form a buttress or support to the
side walls, and also thus giving a form of dock best suited for the purpose of
securing a vessel within the same, in the usual manner (this will be more
readily seen on reference to Figures 4 and 5); E, F, G, H, are the hollow air
and water-tight longitudinal compartments forming the tops of the hollow
side walls A, E, F, G, and extending from end to end of the dock, and by
means of which the structure is supported, as previously herein described;
K, L, &c., the series of longitudinal and transverse plate bulkheads or par-
titions, by which the structure is divided into so many water-tight compartments;
M, N, represent a steam engine and boiler fitted upon a strong platform or
floor, which is formed on the tops of the balancing chambers E, F, G, H,
(shewn more distinctly in Figure 5,) and employed for working the pumps for
discharging the water, or for raising the same, as well as for working air-
exhausting and compressing pumps, and for performing any other necessary

page_text: work in connection with the dock; O, O' are the pumps, and P, Q, R, the
series of pipes, valves, and sluices for the admission and discharge of water. A
similar engine and set of machinery or apparatus may be fitted on the top side
of the other hollow side wall, or more than one such engine and apparatus may
be fitted on each side; sheds or small workshops and similar erections may
(as shewn in the accompanying Drawing) be constructed on the platform or
top of the balancing chambers.
The following is the mode or method of working or using floating platforms,
pontoons, or docks constructed according to my Invention, and, which I have
for the purpose of illustrating my said Invention shewn in the. accompanying
Drawing, and herein-before described in detail, as being a form and general
arrangement of parts which, by preference, I have adopted.
Let the basement or hollow platform A, B, C, D, as well as the lower part
of the side walls A, H, I, G, contain no water, and the valves in communication
with the water in which the structure floats be closed. The structure would
then have an immersion depending on the amount of water displaced by its
weight alone. The valves in communication with the water are then opened,
and the dock allowed to sink to the depth necessary and according to the class
of vessel to be raised or docked. The valves are then closed, the vessel hauled
into the dock and "shored up," the engines and pump set to work, and the
water pumped out of the different chambers of the basement or hollow plat-.
form, so as to preserve its level and raise the dock and vessel until the keel of
the vessel is well out of the water, the structure being so arranged that the
top or floor of the basement would be a convenient height above the level of
the water when floating and supporting the largest and heaviest vessel for
which it is adapted.
To lower the vessel into the water the valves in communication with the
water in which the structure floats are opened, and the structure together with
the vessel upon it sinks until the vessel floats, when it may be hauled out.
Should in any case the valves in communication with the outside water be kept
open by accident, neglect, or from any other cause, the dock is prevented from
entirely sinking by means of the permanent floating or air chambers on the
upper part of the hollow walls or longitudinal chambers, which, as herein-before
stated, are so constructed that their capacity or floating power is sufficient to
prevent the structure from sinking.
Having now described and ascertained the nature of my said Invention and
in what manner the same may be used or carried into effect, and having also
illustrated it in the accompanying Drawing, wherein I have shewn an arrange-
ment of parts and details suited to the form and dimensions of the dock

page_text: therein shewn, and for the purpose for which the same is intended, I wish it
to be understood that I do not restrict myself to the precise arrangement and
disposition of the parts or mode of framing and strengthening shewn in the
accompanying Drawing; but what I claim as my Invention is, constructing
the shell or external surfaces of floating platforms, pontoons, or docks of iron
or steel plates, and of the form and in the manner described; the whole being
divided longitudinally and transversly, by which the structure is formed into
several air and water-tight compartments, and also framing together and
strengthening such hollow structures by means of diagonal bracings, trellis-
work, and truss girders, composed of bars of iron or steel; in the manner
described and as herein set forth.
In witness whereof, I, the said George Banks Rennie, have hereunto
set my hand and seal, this Twenty-seventh day of July One thousand
eight hundred and sixty.
GEORGE BANKS RENNIE. (L.S.)