IMPROVEMENTS IN THE CONSTRUCTION OF CAISSONS, COFFER DAMS, AND SIMILAR STRUCTURES USED WHEN FORMING FOUNDATIONS UNDER WATER
Year: 1864

page_text: LETTERS PATENT to Josiah George Jennings, of Palace Road, Lambeth,
in the County of Surrey, Sanitary Engineer, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF CAISSONS, COFFER DAMS, AND
SIMILAR STRUCTURES USED WHEN FORMING FOUNDATIONS UNDER WATER."
Sealed the 7th October 1864, and dated the 21st April 1864.
PROVISIONAL SPECIFICATION .left by the said Josiah George Jennings
at the Office of the Commissioners of Patents, with his Petition, on the
21st April 1864.
I, JOSIAH GEORGE JENNINGS, of Palace Road, Lambeth, in the County of
Surrey, Sanitary Engineer, do hereby declare the nature of the Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF CAISSONS, COFFER DAMS, AND SIMILAR
STRUCTURES USED WHEN FORMING FOUNDATIONS UNDER WATER," to be as
follows:
This Invention has for its object improvements in the construction of
caissons, coffer dams, and similar structures used when forming foundations
under water.
In constructing coffer dams and similar structures according to this
Invention, I drive side by side into the earth piles or plates.formed of
corrugated sheet metal. Each pile is composed of two corrugated plates
placed together face to face in such manner that the ridges of one plate come
against the ridges of the opposite plate, and where the plates thus come
together they are attached together by means of' rivets. The corrugations of

page_text: Section of plate or pile.
or
the plates run vertically in the direction of the length of the pile, and the
pile is made of such a length that after its lower end has been forced
into the earth to the requisite extent its upper edge shall project sufficiently
above the highest water line. The lower ends of the combined plates are
furnished with shoes or points for entering the earth, which shoes may be
attached to the plates. any
suitable manner. On the upper end of the
combined plates is also placed a head or block by which the piles or plates
may be driven or forced into the earth. In constructing a coffer dam or
similar structure, after having forced into the earth one of the piles plates
constructed as above described, another plate is forced down so that the side
edges of the two plates shall be in close connection with each other. The
lower end of another plate is then similarly forced down into the earth and so
on until the length of dam required is-constructed. The joints between the
neighboring ends of two plates may be made water-tight by the side edges of
the combined plates being each made so that they would appear thus in
section;
A half tube would thus run from top to
bottom of the edge of each side of the pile. Thus when two of the
piles or plates are placed, together edge to edge, the two half tubes will
meet together, and so, between them, form a complete tube. Into this may
be inserted a tube of india-rubber, which may then be inflated, and the
joint between two plates so made water-tight, or in place of the tubes of india-
rubber, the joint may be made water-tight merely by filling or ramming in
the space between two tubes with clay, cement, or, other suitable material.
In forcing the plates down into the earth they may be guided by piles of
timber previously driven in, or they may be otherwise guided; the side. edges
of the piles or plates may also have projecting pieces formed upon them, so
that after a pile has been driven into the earth the pieces projecting from its
side may serve as guides to guide the plate next to it as it is being driven into
the ground; the end of one plate may also be connected to the end of the
next plate by the open portion of a corrugation at the edge of. one plate being
made to slide over or into the open portion of a corrugation at the edge of
another plate. Connecting one plate into another in this manner would also
aid in guiding each plate as it is being driven into the ground. Caissons may
also be constructed of corrugated sheet metal, the sheets of metal being all
connected together to form the requisite caisson or tube before the caisson or
tube is sunk into its place, the lower end of the caisson would then be forced
into the earth in the usual manner.

page_text: SPECIFICATION. in pursuance of the conditions of the Letters Patent, filed
by the said Josiah George Jennings in the Great Seal Patent Office
. on the 21st.October 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSIAH
5 GEORGE JENNINGS, of Paláce Road, Lambeth, in the County of Surrey,
Sanitary Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date: the Twenty-first day of April; in the year of our
Lord One thousand eight hundred and sixty-four, in the twenty-seventhi
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me; the said Josiah George Jennings, Her spécial licence that I;
the said Josiah George Jennings, my executors, administrátors, and assigns,
or such others as I, the said Josiah George Jennings, 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 OF CAISSONS, COPPER DAMS,
AND BIMILAR STRUCTURES USED WHEN FORMING FOUNDATIONS UNDER WATER," upon.
the condition. (amongst others) that I; the said Josiah George Jennings; my
executors or administrators; by an instrument in writing under my; or théir,
or one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the, sanie was to be
performed, and cause the sanid 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 Josiah George Jennings, do hereby.
declare the nature of the said Invention, and in what manner, the samé is
to be performed, to be particularly described and ascertained in and by the
following statement thereof; that is to say:
This Invention has for its object improvements in the construction of.
caissons, coffer dams, and similar structures used when forming foundations.
under water.
In constructing coffer dams and similar structures according to this Inven-
tion I.drive side by side into the earth piles or plates formed of corrugated
sheet metal; each pile is composed of two corrugated plates placed together
face to face in such manner that the ridges of one plate come against.
the ridges of the opposite plate, and where the plates thus come together

page_text: they are attached together by means of rivets; the corrugations of the plate
run vertically in the direction of the length of the pile, and the pile is made
of such a length that after its lower end has been forced into the earth to the
requisite extent, its upper edge shall project sufficiently above the highest
water line. The lower ends of the combined plates are furnished with shoes
or points for entering the earth, which shoes may be attached to the plates in
any suitable manner; on the upper end of the combined plates is also placed
a head or block, by which the piles or plates may be driven or forced into the
earth. In constructing a coffer dam or similar structure, after having forced
into the earth one of the piles or plates, constructed as above described,
another plate is forced down, so that the side edges of the plate shall be in
close connection with each other, the lower end of another plate is then.
similarly forced down into the earth, and so on, until the length of dam
required is constructed; the joints between the neighbouring ends of two,
plates may be made water-tight by filling or ramming in the space between: 1
two tubes with clay, cement, or other suitable material. In forcing the plates
down into the earth they may be guided by piles of timber previously driven.
in, or they may be otherwise guided. The side edges of the piles or plates
may also have projecting pieces formed upon them, so that after a pile has;
been driven into the earth the pieces projecting from its side may serve as a
guides to guide the plate next to it as it is being driven into the ground; the
end of one plate may also be connected to the end of the next plate by the.
open portion of a corrugation at the edge of the plate being made to slide,
over or into the open portion of a corrugation at the edge of another plate..
The connecting one plate into another in this manner would also aid in
guiding each plate as it is being driven into the ground. Caissons may also be
constructed of corrugated sheet metal, the sheets of metal being all connected.
together to form the requisite caisson or tube before the caisson or tube is
sunk into its place, the lower end of the caisson would then be forced into the
earth in the usual manner.
And in order that my said Invention may be most fully understood and.
readily carried into effect, I will proceed to describe the Drawings hereunto
annexed,
section; and Figure 4, a horizontal section of a pile constructed according to
my Invention.
The corrugated plates a, a, are laid the one on the other so that the ridges are:

page_text: of
in contact, and they are rivetted through, as is shown, at short distances. apart.
At the upper part, of the pile there is fixed; either permanently or temporarily.
until the pile is driven, a wrought-iron trough 6, in which a piece of timber is
fixed to receive the blows of the pile-driving monkey; at the lower end of the
pile.there is fixed a shoe made of cast iron with a stem entering up between
the plates of the pile, and secured by rivets or bolts. The piles may be made
any convenient. breadth, I believe, from two to three feet to be the most
convenient in ordinary cases. The length will of course vary with the circum-
stances under which the piles are to be employed, and where it exceeds the
length to which corrugated plates can be readily obtained, as will frequently
be the case, the plates are joined by rivets end to end to make up the required
length. The size of the corrugations and the thickness of the plates also will
vary according to the length of the pile and other circumstances; but for a
pile of medium size, say, 25 feet long, it is convenient that the corrugations
should be six inches from ridge to ridge, and the metal, wrought iron, about 1
thick. The most convenient way of connecting the piles edge to edge to make
a coffer dam, when this is required, is that shown in side view at Figure 5,
and in horizontal section at Figure 6; here there is the greater part of a
corrugation of each sheet left extending beyond the line of joints, and these
projecting portions of the sheet are bent slightly either inwards or outwards,
so that projecting edges of the one pile may enter down between the corre-
sponding edges of the next pile. These interlocking edges will form very
efficient guides for the piles in driving, the pile last driven serving to guide
the next into its place, and usually but little other guiding will be necessary.
If found requisite, however, the pile last driven may have guiding cheeks
bolted to it, between which the next pile is placed for driving. The joints
between the piles are conveniently made tight by filling the space or passage
'enclosed by the projecting edges of the piles with tempered clay; and where
the depth of water is great, and there is danger of this clay being washed
through, it may be enclosed in bags of stout fabric. In some cases, especially
where a travelling crane is required over the line of metal piling, it is con-
venient to drive timber piles to carry the way for the traveller, and to use
these to some extent to guide the corrugated piles.
Figure 7 is a side view, and Figure 8, a portion of a plan of a caisson,
constructed of corrugated iron according to my Invention; it will usually be
convenient to construct it about six or eight feet in diameter, and for this size
metal thick, with corrugations measuring four inches from ridge to ridge is
suitable; cross ties are employed within the caissons at convenient distances
apart. The caisson is conveniently sunk by weighting it at the top, and

page_text: excavating from the interior when the water has been, got out by pumping;
additional lengths are bolted on at the upper end of the caisson as it sinks,
so as to keep its upper end well above the water level: as the work progresses.
In witness whereof, I, the said Josiah George Jennings, have hereunto
set my hand and seal, this Twenty-first day of October, in the year
of our Lord One thousand eight hundred and sixty-four.
JOSIAH GEORGE JENNINGS. (L.S.)