Improvements in the Method of and Apparatus for Making Tunnels.
Year: 1889

page_text: Date of Application, 5th Dec., 1889
Complete Specification Left, 31st July, 1890-Accepted, 4th Oct., 18.90
PROVISIONAL SPECIFICATION.
Improvements in the Method of and Apparatus for Making Tunnels.
I, MATHEW JAMES JENNINGS, of High Street, Mortlake, in the County of Surrey
Civil Engineer, do hereby declare the nature of my said invention for "IMPROVEMENTS
IN THE METHOD OF, AND APPARATUS FOR, MAKING TUNNELS," to be as follows:-
My invention is intended to facilitate the making of tunnels, more especially in
cases where it appears desirable to afford support to the superincumbent earth, whether
the same arises from the nature of the soil, or from the tunnel passing under a river
or other water, or from proximity to the surface, or some of these, or other circum-
stances, and my invention provides special means which may be used when tunnelling
beneath water. My invention is also specially applicable to the construction of
tunnels which have to pass under buildings, roads, and the like, or otherwise where it
is necessary to prevent subsequent subsidence of the surface.
"
According to my invention I provide a series of bars or needles," preferably of
iron or steel, which I arrange side by side within the excavation so as to form a com-
plete temporary lining and support to the roof and sides thereof, immediately under
and within which series of needles the brick, iron, or other lining arch of the tunnel
is to be built. The needles may conveniently be of considerably greater breadth than
depth, and be provided with longitudinal grooves, rabbets, or the like by means of
which each needle may be linked to the next one, but so as to admit of their separate
longitudinal motion.
When the construction of the tunnel is in progress, it will be understood, the
needles lie on and without the brick or other arch, and under and against the earth or
other roof and sides, that is to say, between the lining arch and the earth, and as the
work proceeds the needles are, one by one, driven forward, so as to pierce the earth
in front of the excavation, and when all are thus advanced, to form a complete lining
under and within which the earth may be excavated with facility and the lining arch
advanced.
The needles may conveniently be driven forward one at a time by hydraulic power,
screw-jacks, or the like, butting against the end of the lining arch already built, or
other sufficiently stable fulcrum, and against projections, or into recesses, on, or in,
the needles but any other convenient means or apparatus may be adopted for driving
the needles forward.
The needles should be of sufficient length to be supported with tolerable accuracy
in their proper direction, and to project preferably some feet in advance of the lining-
arch and into the solid earth in front.
The needles may be provided with longitudinal tubular cavities with side openings,
or other cavities or channels through which cement or other filling material may be
introduced from time to time, to fill the space left vacant by the advancing needles
between the top of the lining-arch and the earth above and around, and thus prevent
any subsidence.
In tunnelling beneath water, when there is any reason to fear that the water may
penetrate into the workings, I provide an apron which I spread on the bottom of the
river, lake, sea, or other piece of water under which it is desired to drive the tunn⚫l;
over the line of the intended tunnel, and such apron may be of very considerable
width so as to extend many, say for instance fifty or more feet on each side of the
central line. The material of which such apron should be constructed depends on the
conditions to be fulfilled in each case but preferably it should be of waterproof or
water resisting materials either rigid or pliable, such for instance as sheet iron laths
jointed together, waterproof textile fabric, or any other material that may lend itself

page_text: readily to the requirements of the particular case, such apron extending longitudinally
over the tunnel, in the direction of its length.
.
By this means I am able when making sub-aqueous tunnels more particularly when
driving them in the manner before described, to exclude the water very effectually
and to enable the tunnel to be made at a less depth, that is to say, at a less distance
beneath the water, than could otherwise be done, and to keep the works comparatively
dry and safe.
The pressure of the superincumbent water on the upper surface of the apron, when
the water beneath it has been to some extent removed by being drained into the
tunnel, brings the apron into close contact with the mud or other bottom, and thus
prevents the ingress of more water, and in some cases I prefer to load the apron with
a coating of sand, or gravel, or the like, so as to imbed it in the bottom.
Dated the Wirth date of Dhoomban 1000
NEWNHAM BROWNE,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Making
Tunnels.
I, MATHEW JAMES JENNINGS, of High Street, Mortlake, in the County of Surrey,
Civil Engineer, do hereby declare the nature of my said invention for "IMPROVEMENTS
IN THE METHOD OF, AND APPARATUS FOR, MAKING TUNNELS," 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 accompanying sheet of
drawings and to the figures and letters of reference marked thereon:-
My invention is intended to facilitate the making of tunnels, subways, sewers &c.,
more especially in cases where it appears desirable to afford support to the super-
incumbent earth, whether the same arises from the nature of the soil, or from the
tunnel passing under a river or other water, or from proximity to the surface or
some of these or other circumstances, and my invention provides special means which
may be used when tunnelling beneath water.
My invention is also specially applicable to the construction of tunnels, subways,
and sewers which have to pass under buildings, roads, and the like, or otherwise,
where it is necessary to prevent subsequent subsidence of the surface and further by
its use a saving is effected of the timber which is usually built in and which is not
required in working in this manner.
According to my invention I provide a series of bars or "needles" preferably of
iron or steel, which I arrange side by side within the excavation so as to form a
complete temporary lining and support to the roof and sides thereof, immediately
under and within which series of needles the brick, iron, or other lining-arch of the
tunnel is to be built. The needles may, conveniently, be of considerably greater
breadth than depth, and be provided with longitudinal grooves, rabbets, or the like
by means of which each needle may be linked to the next one but so as to admit of
their separate longitudinal motion.
When the construction of the tunnel is in progress, it will be understood, the
needles lie on and without the brick or other arch, and under and against the earth
or other roof and sides, that is to say, between the lining-arch and the earth, and
as the work proceeds the needles are, one by one, driven forward as the earth is
excavated, and in some cases, as for instance when the soil is very loose and treacherous
or full of water, they may be driven into the earth in front of the excavation and when
all the needles are thus advanced they form a complete lining under which the brick-
work can be built in, and when driven into the earth in front as above mentioned
they form a shield under and within which the earth may be excavated and the arch
advanced.
The needles may conveniently be driven forward one at a time by bars, jacks, or

page_text: the like, from the end of the lining-arch already built, or other sufficiently stable
fulcrum, butting against projections on, or attached to, or into recesses, 'in the needles,
but any other convenient means or apparatus may be adopted for driving the needles
forward.
The needles must be of sufficient length to be supported with tolerable accuracy in
their proper direction and to project if required some feet in advance of the lining-
arch and to or into the solid earth in front.
1
The needles may be provided with longitudinal cavities or channels through which
cement grouting or other filling 'material may if necessary be introduced from time
to time to fill the space left vacant by the advancing needles between the top of the
lining-arch and the earth above and around and thus prevent any subsidence.
In order that my invention may be fully understood I shall now, proceed to describe
how the same may be carried into effect in a particular case which will serve as an
example and sufficiently explain its application to works of other dimensions and
circumstances, and for that purpose shall refer to the accompanying sheet of drawings
in which Fig, 1 represents a longitudinal vertical section of a tunnel in process of
construction according to my said invention. Fig. 2 represents a transverse vertical
section taken on the line'x. y in Fig. 1 looking towards the advanced end, and Fig. 3
represents a similar section taken on the line . w. Fig. 4 represents one of the
needles drawn to a larger scale, a small portion being shewn in section, and Fig. 5 is a
half-size transverse section of the same. A, is the brickwork of an already completed
portion of a tunnel. B, is a portion of the tunnel which has been excavated but is not
yet lined. C, C, are timbers supporting the needles and the sides and roof of the
excavation, and D, D, are polling-boards supporting the face of the earth at the end
of the excavation. E, E are the needles that is to say, strong bars, preferably of
iron, or steel, one of which is shown separately in Fig. 4 and which are the principal
feature of novelty in this invention. The needles may be made of any convenient
section, but that which I consider most convenient and best adapted for the purpose
is shown in Fig. 5 in which three of the needles are represented in transverse section
and in which it will be seen that they are so shaped that the edges of two adjacent
needles overlap each other and preferably partially hook together, or interlock in
such wise that while free to slide on or against each other longitudinally they
mutually support and guide each other, against any transverse movement, but such
overlapping and linking together is not necessary in all cases and the needles may b
made of simple rectangular or other section, some play-room must be allowed between
the joints of the needles in order to allow them to accommodate themselves to the
curve, as circumstances may require. On one side of each needle I generally provide
a longitudinal groove or channel F extending the whole length of the needle on that
side of the needle which is intended to be next the brickwork and, consequently, as
each needle is the opposite way upwards to the preceding one about half the needles
have the channel on one side and half on the other side. These channels serve to
facilitate the introduction of cement grouting or the like to fill up the small space left
behind the needle as the latter is moved forward as hereinafter described.
1
In constructing a tunnel a length is first excavated equal to, or slightly greater than,
the length of the needles to be used, and a series of the needles are then placed in
position completely lining the roof of the excavation and as much of the sides as may be
required according to the nature of the soil and other circumstances and are there
supported by appropriate timbers such for instance as those shown in Fig. 2 and
marked C. C. A length of the brick or other permanent lining of the tunnel is then
built as represented at A in Figs. 1 and 2 and is carried to as near the end of the
excavation as conveniently may be; or when the circumstances admit of it a length
of the brickwork may be first built and then the needles placed thereon. The needle
are then to be driven forward and when all have been advanced they form a complete
-roof or shield under which the workmen can safely push forward the works, supporting
the needles with additional timbers as often as necessary, and carrying forward the
brickwork under the needles, which latter are again advanced as soon as the lining
brickwork approaches their front ends.

page_text: The needles may be pierced by a series of holes marked r. r into any of which
the end of a crow-bar, or lever, may be inserted in order to prize the needle
forward or into or by means, of which a boss or bracket shown in Fig. and
marked G may be attached, against which a screw-jack or hydraulic ram or the
like may be made to act so as to force the needle forward as required.
As each needle is moved forward it will obviously leave vacant the space it has
occupied between the brick arch and the earth above; this space may be filled by
cement or grouting which may be introduced through the channel F in the needle
into and through which it may be forced either by ramming it, or by pumping
it through an appropriate nozzle made to fit into and between the channel in the
needle and the brickwork.
If the work under consideration be such that it is desirable to advance the
lining brickwork by lengths of say 6 feet at a time as is represented in the
drawings the needles may, conveniently, be of the following lengths that is to say
there may be about seven central or upper ones which may be 10 feet 6 inches
long and the remainder may be 9 feet long or such other lengths as the nature
of the soil and circumstances of the work require, such needles may be about
6 inches wide and one and a half or 2 inches thick, but obviously the dimensions
must be controlled and determined by the particular case in which they are to be
used and if a greater length be required to be excavated at one time the needles
must be proportionately longer but the length, as well as the thickness and
breadth must depend on the requirements of each particular case and more par-
ticularly on the nature of the soil to be passed through and the superincumbent
weight. The timber centres on which the arch is turned, and the timbers for
supporting the face of the earth at the end or face of the excavation are not shown
in the drawings as they do not differ in any respect from those ordinarily in use in
similar cases.
It will be obvious that in constructing tunnels according to this invention it is
practicable to avoid the possibility of any settlement of the superincumbent earth.
or any buildings above. The earth above the needles will not be disturbed and
the small space left by the withdrawal of the needles can be filled up as each
needle is advanced thus leaving absolutely no room for any settlement, disturbance
or damage above.
In tunnelling beneath water when there is any reason to fear that the water may
penetrate into the workings, I provide an apron which I spread at the bottom of the
river, lake, or other piece of water under which it is desired to drive the tunnel, over
the line of the intended tunnel, and such apron may be of very considerable width so
as to extend many say for instance fifty or more feet on each side of the central line.
The material of which such apron should be constructed depends on the conditions to
be fulfilled in each case but preferably it should be of waterproof or water resisting
materials either rigid or pliable such for instance as tarpaulin or any other material
that may lend itself readily to the requirements of the particular case, such apron
extending longitudinally over the tunnel in the direction of its length.
By this means I am able when making sub-aqueous tunnels, more particularly when
driving them in the manner before described, to exclude the water very effectually and
to enable the tunnel to be made at a less deptu, that is to say, at a less distance
beneath the bottom of the water than could otherwise be done, and to keep the works
comparatively dry and safe.
The pressure of the superincumbent water on the upper surface of the apron, when
the water beneath it has been to some extent removed by being drained into the
tunnel or otherwise brings the apron into close contact with the mud or other bottom
and thus prevents the ingress of more water, and in some cases I prefer to load the
apron with a coating of sand, gravel or the like so as to imbed it in the bottom.
.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I wish it to be understood that my
invention is not limited to the dimensions described or the shapes shown in the

page_text: drawings, which are given by way of example but may, and in fact must be
varied to meet the requirements as various cases arise, but I declare that what I
claim is :
1. In constructing tunnels, subways, sewers and the like the use of needles in the
manner and for the purpose described.
2. In constructing tunnels, subways, sewers and the like beneath water, the use of
an apron spread at the bottom of the water so as to check or lessen the flow of water
into the workings substantially as described and set forth.
3. Constructing needles for use in the formation of tunnels substantially as and for
the purpose described and set forth.
ሳለ
1
1
1000
MATHEW JAMES JENNINGS.