IMPROVEMENTS IN CONSTRUCTING SUBMERGED WORKS
Year: 1861

page_text: LETTERS PATENT to Joseph Gibbs, of Brentford, in the County of
Middlesex, Civil Engineer, for the Invention of "IMPROVEMENTS IN
CONSTRUCTING SUBMERGED WORKS."
Sealed the 15th March 1861, and dated the 12th January 1861.
COMPLETE SPECIFICATION filed by the said Joseph Gibbs at the Office
of the Commissioners of Patents, with his Petition and Declaration,
on the 12th January 1861, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
GIBBS, of Brentford, in the County of Middlesex, Civil Engineer, send
greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
CONSTRUCTING SUBMERGED WORKS," and have petitioned Her Majesty to grant
unto me, my executors, administrators, and assigns, Her Royal Letters Patent
for the same, and have made solemn declaration that I am the true and first
Inventor thereof:

page_text: NOW KNOW YE, that I, the said Joseph Gibbs, do hereby declare that
the following Complete Specification under my hand and seal fully describes
and ascertains the nature of the said Invention, and in what manner the same
is to be performed, in and by the following statement and accompanying
Drawings (that is to say):-
This Invention is for an improved method of constructing breakwaters,
harbours, piers, jetties, bridges, forts, defences, and other submerged works
under water level by means of cassoons formed of distinct water-tight cells,
which cassoons may be floated to the proper site, and sunk by admission of the
water into them, and the cells may be afterwards separately emptied of water,
and filled with concrete, or other permanent building material.
To construct a breakwater or other submerged work, I cause a vessel or
cassoon of sheet iron or other suitable material to be built of a dimension and
of a breadth nearly in the form of a cube or a prismatic triangle, or other
convenient form, and to rise above high-water mark when placed on its site;
this cassoon is divided into cellular compartments, as shewn at Fig. 1, Sheet 1,
where A, B, C, D, E, F, G, and H, form separate cells or compartments;
each of these cells may be strengthened to resist the pressure of water by
being lined on the sides and bottom with, well-burned and vetrified bricks or
other adequate materials laid in strong cement or asphaltum or other
cementaceous material, or removable stays may be used for the same purpose.
After a casscon has been built, launched, and lined or stayed in the manner
stated, it may be floated over the proper site, the cells may be gradually filled
with water, which will cause it to subside until it has taken the ground on the
proper site. The cells one by one may then be emptied of the water, and
filled with concrete, which concrete may be composed of clean shingle and
bydraulic cement or other suitable material until the whole with the external
casing forms one solid block. The cells may be sufficiently numerous to
prevent the cassoon from having any tendency to float or change position when
any one cell is emptied of its water. These cassoons may be joined and also
laid parallel to each other so as to cover any requisite area; or they may be
placed in such a manner as to form parallelogram or circles, or other figures,
leaving an area within, and which area may be filled with rubble or shingle,
and on which any superstructure or work may be wholly or partially raised.
When these cassoons are placed on banks where there is a probability of the
current moving the shingle or sand, it will be expedient to place groins at
right angles to the face of the work, or a foot may be built on the cassoon, as
shewn at A, B, Fig. 8, Sheet 1, which will indent in the sand or shingle, and

page_text: serve the purpose of sheet piling. The depth of the foot will depend on the
nature of the material on which the cassoon will have to be placed. Theso
cassoons may also be constructed of brick, stone, or other hard material, so as
to form solid or cellular blocks (dispensing with the casing before described),
but which must be well bonded with hoop iron ties, and an iron or wooden
foundation plate must be placed below it at its lower side, and the block must
be carried to its destination and lowered to its place by a floating derrick or
other suitable means, to which suspending rods are fixed, but when the weight
is very great, and in order to carry and deposit these brick or combined stone
blocks or cassoons in a convenient and rapid manner, I construct a trans.
porting cassoon, as described Fig. 6, Sheet 2. A, A, A, A, is the foundation
on which a cellular transporting cassoon B, B, is placed at a few feet above
low water; this cassoon divides in two parts at C, C, Fig. 5, for the purpose
which will be hereafter described. It is also provided with sluices to each
cell, so that the water may flow in and out of it; it is also supplied with two
powerful latticed girders to keep the two parts in line with each other. The
brick or stone cassoon which is to be carried and deposited as shewn at D, D,
and D, D, Fig. 5 and 6, Sheet 2, and in the prospective Drawing, Fig. 7
and 8, Sheet 3, is bulged or joggled, as shewn at E, E, Fig. 6, Sheet 2, and
Fig. 7 and 8, Sheet 3; this bulge rests on the sides of the transporting cassoon
which is properly shaped and strengthened in this part to receivo so great a
weight. When the brick or stone cassoon is to be moved, the sluices of the
transporting cassoon are shut; the flow of the tide will then lift the whole,
and the brick or stone cassoon may be taken and deposited on its intended
site. By filling with water the cells of the transporting cassoon, it will
gradually sink (the brick or stone cassoon taking ground first), the trans-
porting cassoon will in the act of sinking glide down the slope of the brick or
stone cassoon, and the girder being so constructed as to allow the two parts to
separate a short distance, so as to part from the joggles or bulges, air may
again be pumped into the transporting cassoon to displace the water, and the
cassoon will rise to the surface, and may be taken to its place for the purpose
of again transporting other like structures.
I use also a cylindrical cellular coffer dam for the foundations of bridges,
piers, and other works.. This cylinder has an outside case of iron or wood,
wider at the bottom than at the top, and lined with brick, and bonded and
girded with iron; the lower edge is constructed at a sharp angle, so as to fit
it for penetration, as shown at A, A, Fig. 4, Sheet 1. The cylinder being
brought to its site, the inside gravel, sand, or clay must be scooped out, and

page_text: the cylinder will then sink by the pressure of the slope B, B, and when suffi-
ciently deep the space scooped out may be filled with cement concrete in the
usual manner.
In order to construct a foundation in deep water for a fortress, or a jetty,
or other work of considerable extent, the separate cassoons may be placed in a
manner to form intervals between them equal to their width, as is shewn at
Fig. 2, Sheet 1, where A, B, C, D, represent four of a series of cassoons, and
E, F, G, H, I, K, dams, piles, or coffers, for retaining such material as is
intended for filling the space E, F, G. The cassoons in this case form the abut-
ments for supporting the dams or coffers, and in order to fill the spaces in the
most effectual manner, I sometimes enclose in sacks recently formed concrete
before it is set, and pile the sacks properly within the spaces, by which means
a solid mass will be formed to abut against the dams. In case it is considered
desirable to build a wall or pier or parts of a pier, or other submerged work,
and then to remove the outer casing or coffer dam which has been used to
protect it (and after the work or part of the work is completed), I proceed
to build in iron or wood a cellular cassoon or cofferdam, open at one end,
as shewn at A, A, Fig. 10, Sheet 3, and at Fig. 5 and 6, Sheet 2, which
cassoon or cofferdam is divided into cells or compartments horizontally and
vertically, to give it stability. A floor is placed under it, as shewn in section
at A, Fig. 9, and at B, Fig 10, Sheet 3. This cassoon or cofferdan is
constructed of a height and depth to reach from the foundation to 6 or 8 feet
above high-water mark. The floor is fastened to the cassoon by screws on the
inner side; in that state it is brought to the intended site, and sunk by letting
in water, as before described. If it is the first commencement of a work, a
pile dam is to be driven across the open end from A to A, Fig. 10, but if
some of the masonry work has already been constructed, then a small portion
of piling need only be done at C, C, to shut out the water between the cassoon
and the finished pier, dotted off at D; the water may be pumped from the
space marked E, and the masonry work may proceed by building upon the
floor (of course the water must be kept in the cells of the cassoon to resist
floatation, and also to give stability to the work in case a sea strikes it during
the construction of the masonry within it). After the masonry is finished the
screws which fasten the floor to the cassoon must be withdrawn, the cassoon
emptied of water, the piles taken up, and the cassoon or cofferdam floated
away to receive a new floor for the purpose of allowing another length of
masonry to be constructed within it.
Having now described the nature of my said Invention, and in what

page_text: manner the same is to be performed, I wish it to be understood that what
I claim in the Invention whereof the exclusive use is intended to be secured
by the said Letters Patent is, the constructing submerged works by means of
cellular cassoons arranged and worked as above described.
In witness whereof, I, the said Joseph Gibbs, have hereunto set my
hand and seal, this Twelfth day of January, in the year of our Lord
One thousand eight hundred and sixty-one.
JOSEPH GIBBS. (L.S.)