IMPROVEMENTS IN TUNNELLING, AND IN MACHINERY AND APPARATUS THEREFOR
Year: 1870

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert
and Company, Patent Agents, of 67, Strand, in the City of West-
minster, for the Invention of "IMPROVEMENTS IN TUNNELLING, AND
IN MACHINERY AND APPARATUS THEREFOR."-A communication from
abroad by William Sykes, of Toronto, in the Dominion of Canada,
Civil Engineer.
COMPLETE SPECIFICATION filed by the said Herbert John Haddan at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 27th August 1870, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HERBERT
JOHN HADDAN, of the Firm of Herbert and Company, Patent Agents,
of 67, Strand, in the City of Westminster, send greeting.
WHEREAS I am in possession of an Invention for " IMPROVEMENTS
IN TUNNELLING, AND IN MACHINERY AND APPARATUS THEREFOB," and have
petitioned Her Majesty to grant unto me, my executors, administrators,

page_text: and assigns, Her Royal Letters Patent for the same, and have made
solemn Declaration that the same is a communication made to me from
abroad by William Sykes, of Toronto, in the Dominion of Canada, Civil
Engineer.
NOW KNOW YE, that I, the said Herbert John Haddan, 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, that is to say:
-
The improvements consist in the construction and application of a
subaqueous isolating apparatus or shield, in which excavation may be
-performed and masonry or brickwork be built, the shield forming in
whole or in part permanent sheathing-for-the same, the apparatus being
so constructed that it can be built up in convenient lengths in suitable
docks or other convenient sites, and floated or otherwise taken to the
intended site and sunk or fixed.
The improvements may be carried into effect by making the isolating
shield a bottomless structure corresponding in form and dimensions with
the particular tunnel for the building of which it is employed and may
be made in lengths with turrets at each end. These turrets being of
sufficient height to reach above the level of high water when the shield
is sunk to its full depth. The lower edges being supported laterally by
a grid, the under edges of which may, if deemed necessary, be sharpened
and hardened to facilitate the cutting into the ground as it is sunk.
In the accompanying Drawing Figures 1ª and 1 show an elevation of
the turrets, the portions a conforming to the external contour of the
brickwork are put together with bolts and nuts, and are also secured to
the upper portions in the same manner in order to facilitate their
removal at the proper time; g, Figures 1 and 3, show an elevation and
plan of a portion of the shield in place and sunk, and also the manner
in which the adjoining lengths are brought nearly to it. The spaces
between the turrets of the respective lengths being enclosed with sheeting
piles of timber or iron or with caissons, as shown at e. Figure 4 shows
a transverse section of the shield d; and Figure 5 a portion of longi-
tudinal section of same with the internal fittings which form part of the
Invention. It will be seen that these fittings consist of a series of trans.
verse and longitudinal sills with posts and pontoons c, the pontoons
being connected together in each line by proper pipes (having air pipes

page_text: attached), these pipes being furnished with screw sluices at the ends in
each turret, so that they may be opened or closed from the top thereof.
The position of these pontoons may be varied, as also the construction
of the upper part of the shield d, which may be made in chambers so
as to act instead of pontoons. The shield may be made to conform
strictly to the contour of the brickwork. Figures 1, 2, and 3 show a
method of floating and sinking the several portions of the shield. This
may however be varied according to circumstances.
A convenient mode of building, transporting, sinking, and using the
apparatus and shield is as follows:-The character and dimensions of
the desired tunnel being determined, the shield is built in sections, as
stated, of the preferred material or materials, the building being per-
formed in suitable docks near the proposed site of the work. Each
section is here fitted up complete with its sills, posts, centreing, and
pontoons, or chambers as equivalent of pontoons. The turrets are also
constructed and fitted with moveable ends and upper parts, in whole or
in part attached; these turrets are also fitted with air-tight chambers,
so that if necessary the pneumatic system either of plenum or vacuum
may be used in sinking. The water being admitted into the dock the
section of the shield is floated to its place, it is then secured either by
piling, or by barges f, or other suitable means. The sluices of a
sufficient number of the tiers of pontoons c being then opened to admit
the water the shield will gradually sink. The sinking, if necessary, may
be controlled with tackle from the barges, as shown. When the shield
has been thus sunk into the trench which has been previously dredged
to receive it. All the pontoons must then be filled with water to give
weight to it, so that it will cut into the clay. The water must then be
pumped out from the shield, and any excavation that may be required
to let it down to the proper depth must then be done, and the material
thus excavated sent out through the turrets, which will act as shafts.
It is here to be remarked that if the skin friction is so great that the
shield will not readily sink, then air-tight covers must be put on the
chambers referred to in the turrets, and the air within the shield must
in whole or in part be exhausted, by which means sufficient pressure will
be brought upon the shield to sink it. Should, however, the material be
soft and the shield tend to sink more rapidily than is desirable the
reverse operation must then be resorted to, that is, the air within the
shield must be sufficiently compressed to effectually counteract such

page_text: endency; all the material of the excavation and the building materials
for the tunnel being then passed through the turrets which will then be
used as air locks. When the shield has sunk to its proper depth, and
the excavation removed, the building of the brickwork is then proceeded
with and the internal fittings removed, as they may be dispensed with.
On one section being sunk to its place, or during the operation of sinking
it, another may be brought into line and as nearly as possible to it, and
sunk in the same manner as the first. On both reaching the desired
level they are connected by piling or caissons. The water in the space
thus enclosed may then be pumped out and the temporary ends in the
turrets removed, and the brickwork then continued from one shield to
the other. The brickwork through these spaces and also through the
widths-of_the_tunnel may then be covered with boiler plate. The body
of the shield forms a permanent covering-at-all_other_points. The
tunnel being completed the upper portions of the turrets are then
removed, the piles or caissons are removed or cut off at the bed of
the river, which is then left perfectly free and clear.
The foregoing will serve to illustrate my Invention and to show how
the improvements may conveniently be performed, but it is obvious that
the details may be varied considerably without departing from the
spirit or nature of the said improvements.
In witness whereof, I, the said Herbert John Haddan have
hereunto set my hand and seal, this Twenty-sixth day of
August, in the year of our Lord One thousand eight hundred
and seventy.
H. J. HADDAN. (L.S.)