Improvements in and connected with Temporary Supports for Tunnels, Sewers, and the like.
Year: 1893

page_text: Date of Application, 20th May, 1893
omplete Specification Left, 20th Feb., 1894-Accepted, 24th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in and connected with Temporary Supports for
Tunnels, Sewers, and the like.
I, FRANK ARTHUR WILLETT, of 10 Victoria Street, Westminster, Contractor,
do hereby declare the nature of this invention to be as follows:-
In the construction of tunnels through soft or loose ground it is necessary to
support the roof and sides in position until the permanent structure is completed.
This temporary support is usually secured by means of timber carefully fixed by
skilled workmen. After the permanent structure is completed the temporary
supports are as far as possible withdrawn and used in a fresh position. The object
of this invention is to supply improved means of supporting the roof and sides, the
arrangement being such that excavation and construction may be practically carried
on continuously and this with the aid of practically unskilled labour; the necessity
of a top advance gallery or heading being also rendered unnecessary when the
present invention is employed. The arrangement consists of a series of telescopic
supporting bars which when placed together form the shape or configuration of the
desired excavation. These bars are supported by means of supporting frames
carried on telescopic foot blocks and capable of being raised and lowered and of
being advanced or withdrawn as occasion may require. The supporting frames
are used in pairs, each capable of being separately lowered on to an independent
rail section which in turn is capable of being advanced as occasion may require.
The side sections may be held in position by a pivoted frame capable of being
actuated by screw or like power from a main cross frame.
With this general
construction of parts the operation of advancing the telescopic bars and supports
would be as follows:-The second vertical or side frame of a pair would be raised
or extended by screw or like pressure until practically taking the entire pressure at
that particular point. The first frane would then be slackened until clear of the
telescopic bars and resting upon its rail. It would then be advanced forward by
screw or like power and would then again be raised so as to take in its turn
practically the entire pressure thercon, when the second support would be lowered
on to its independent rail and advanced to a position close to that of the first, the
carrying rails being also from time to time advanced and the frame work carrying
the screws or lifting devices being also advanced. In fact, the parts would be
moved forward in a manner analogous to that of a man walking. The telescopic
supporting bars may be provided with projecting pieces or lugs against which
hydraulic or like power may be applied for the purpose of advancing them
into the earth to be excavated, the strain of such forward motion being eventually
taken up upon that portion of the tunnel or wall already completed. If desired
the bars may be forced forward by a series of hydraulic motors carried in the
end of a radial arm moving or rotating about a centre or otherwise and supplied
with the requisite power by water under pressure in any of the well-known ways.
When using this invention it is judged that it will be convenient to have the
advanced supports of less height than that required for the full size of the tunnel

page_text: desired; the supporting bars or frames gradually increasing in depth depending
upon the number of pairs until the desired size is attained.
Dated this 20th day of May 1893.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, W.C., Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in and connected with Temporary Supports for
Tunnels, Sewers, and the like.
I, FRANK ARTHur Willett, of 10 Victoria Street, Westminster, Contractor,
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement :-
In the construction of tunnels and the like through soft or loose ground it is
necessary to temporarily support the "roof," and sides, and sometimes also to
maintain the bottom of the excavation in position until the permanent structure is
completed.
"
""
and "bars are
This temporary support is usually secured by means of timber "bars" and
polling-boards
carefully fixed by skilled workmen, and during the time that
each portion (or "length as it is technically termed) of the permanent structure
is heing built and after its completion-such "polling boards
withdrawn, or so much of them as possible for use in future "lengths."
The object of this invention is to supply improved means of supporting and
maintaining the roof and sides and sometimes the bottom of the excavation in
position the arrangement being such that the use of timber is not required, while
Further the
the necessary work can be done by ordinary labor in place of skilled.
usual top heading is not necessary and there is less liability to accident while the
rate of progress is increased by making it possible by this method of construction
that the excavation, construction of side walls and construction of arch can all be
progressing simultaneously, and by the employment of frames of less height at the
front the difficulties of keeping up the front of the excavation-or as it is usually
called "the face are decreased while little or no settlement of the roof or the
surface above will take place.
The proposed arrangement may be said to consist of a series of supporting
franies placed at right angles to the centre line of the tunnel said frames working
in pairs and supporting two or more sets of metallic sliding or drawing bars placed
around such supporting frames and moveable in the direction of the line of the
tunnel independently of each other sucb bars maintaining the excavation in position
as required.
In the accompanying drawings which illustrate my invention-
Fig. 1 is a sectional elevation of a tunnel in process of being excavated, provided
with the temporary supports in accordance with my invention.
For convenience
of illustration this figure is divided into two parts one being shown on Sheet 1 and
the other on Sheet 2 of the drawings the right hand end of the latter being a
continuation of the left hand end of the former.
Fig. 2 is a half cross section on line X X Fig. 1 looking from rear to front.
Fig. 3 is a balf cross section on line Y Y Fig. 1 looking from rear to front.
Fig. 4 is a half cross section on line Z Z Fig. 1 looking from front to rear.
Fig. 5 is a half cross section showing the construction of a tunnel with an invert.
Fig. 6 is a detail shewing the parts of the telescopic foot blocks, hereinafter
referred to, separately.
Two sets of what I term telescopic supporting bars of any suitable section are
employed the rear set C being shown as of T iron-the rear end of each bar
resting on the top of the completed tunnel and supported at other points by the

page_text: pairs of frames F, F' and F F. Such bars can be moved forward as required
longitudinally over these frames and can slide under the leading bars C which are
shown as being of channel iron. The leading bars C can also be moved forward
longitudinally as required. They are supported at their rear ends on the rear
bars C 1 and at other points by the pairs of frames F and F and F and F'. The
two sets of bars may work entirely independently one of the other-the object.
being that whilst the front bars are being moved forward more or less continuously
as the excavation is proceeding the rear bars are required to be moved forward at
intervals only as the respective lengths of arch are completed.
The pairs of frames F 1, F 2, F3, F4, F5, F6, and F7, F8 are generally
similar in construction but vary slightly in height and details, the intention being
that generally the front frames shall be less in height than the rear frames so that
the depth from ZZ to QQ in the extreme front shall be as small as possible thus
lessening the depth of the excavation and its liability to fall in. These frames are
strongly constructed and are shaped to suit the shape of the tunnel to be
constructed. At their bases they are provided with screw-jacks D for the purpose
of raising or lowering them as required-these jacks rest on metallic telescopic
footblocks B and B 1-(shown separately in Fig. 6) the footblocks B which support
the rear frame of each pair of frames being smaller than the footblocks B 1. which
support the front frame of each pair and which latter, as it were, bridge over B, so
that whilst each footblock can be of considerable length to get a good bearing on
the timber packing P.-the frames of each pair are enabled to be set very close
together. The foot-block B 1. as shown is formed of two side plates connected
together by a narrow top plate which bridges over the foot-block B. Each frame
is also provided with wheels D 1. which, when the frames are lowered, rest upon
the short lengths of rails E, upon which they can travel forward carrying the
frames with them. Each pair of frames is also connected together by 4 horizontal
screws, G, provided with suitable handles which serve the purpose of maintaining
vertically and moving forward the frames as will be hereinafter described. These
frames 1. &c. are solid in their upper portion with the exception of parts which
are cut away, but at the sides have wing pieces W, pivotted at W1, and actuated at
the lower end by the screws S, which screws enable the wing pieces to be drawn
inwards towards the centre of the frame or forced outwards from it tightly against
the sliding bars C, C 1. The rollers R, shown in the sections of the frames in
Fig. 1. are employed for the purpose of reducing friction when moving forward the
bars. The three front pairs of frames carry on the front side of the front frame
of each pair what may be described as an angle iron tramway consisting of angle
bars TT curved to the shape of the frames and the tunnel, supported and connected
together at intervals by angle bars T 2. Upon the bars T T and supported on a
suitable carriage capable of sliding on same is a hydraulic jack J. Figures 1 and 4,
the rams J1 of which press against projections J2 carried by the sliding bars C
and C 1. for the purpose of moving the bars forward as required. Each jack is
capable of being moved around on the bars TT so as to act on the projections J 2
of the bars in order, so that they are successively forced forward, its various
positions being regulated by a chain J 3 (Fig. 4) or in other convenient ways.
A, A1, A2, are telescopic supplementary thrust stays the rear ends of A pressing
against a baulk of timber N 1, or other arrangement fixed in the completed portion
of the tunnel to serve as an abutment, these stays are of channel iron and slide one
within another, but can be bolted and clamped together when required, the various
frames being clamped to them as required by the clamps H. A 3 and A4 are
further stays held in clamps H and abutting against a baulk N 2. The object of
the supplementary stays is to assist when needed to retain the frames in their
position and assist them to resist the backward thrust of the hydraulic jacks when
they are working and forcing forward their respective bars.
K. are supports for carrying the longitudinal planks L, which in turn carry
the slack blocks or wedges M supporting the "centres" N which support the
planking O. upon which the arch in course of construction is being built.

page_text: The manner in which the arrangement is worked may be thus described :-The
earth or other material at the face of excavation is first removed from the under
sides of the front bars, first at the top and then at both sides-the leading bars C
being at the same time forced forward by the hydraulic jacks, their sharp points
cutting away and forcing inward any earth not already removed-after this
operation has been carried out round the whole interior of the bars and they have
been advanced a sufficient distance it will be desirable to advance the pair of
frames F 1, F 2.-with this view frame F 2 will be screwed up as tight as possible
under the bars by means of the jack and its wings W extended tightly against the
bars at the sides, then the frame F 1 has its wings W drawn in and is itself lowered
till the wheels D1 bear on the rails E. The screws G are then rotated in the
proper direction simultaneously, and frame F1 is pushed forward towards the
front when sufficiently advanced, it is again screwed up from off the rails tight
under the bars, and its wings W are extended tightly against the bars at the sides
-this done F 2 in turn has its wings drawn in, and it is lowered until its wheels
rest on the rails-then the screws G are rotated in the proper direction and it is
drawn forward as close as possible to F 1. It is then again screwed up off the rails
tightly to the under side of the bars and its wings extended tightly against the bars
at the sides, after which F 1. can again be lowered and moved as before, and so on,
the operations being repeated as the work progresses.
It will be understood that the packing blocks P. will be put in as required, and
that the foot blocks and rails are moved forward as required-the rails when the
wheels are not bearing on them and the footblocks when the wheels are on the
rails.
The rear bars C1 and frames are moved in a similar manner-but whereas the
leading bars C are continually being moved forward at frequent intervals--the rear
bars and frames are only moved as each respective length of arch is completed.
Fig. 5 shows a modified form adapted for use when the bottom of the excavation
also requires to be kept in position in this case instead of the wood packing P.,
foot blocks and rails and wheels, an invert foot block is used to carry the frames,
which foot block itself slices forward on the bars underneath.
It will be understood the hydraulic jacks may be employed in place of the screws
mentioned above.
I am aware of the Specification of James Nobbs No. 7394 of 1890 and I make
no claim to anything both described and claimed therein.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. As a temporary support for tunnels and the like, moveable frames constructed
substantially as described adapted to support moveable bars substantially as
described.
2. The employment of moveable frames arranged in pairs and provided with
wheels and raising and moving appliances adapted to support moveable bars
substantially as described.
3. The employment with a moveable frame constructed substantially as described
of means for carrying a jack and enabling it to be moved to operate successively on
the sliding bars substantially as and for the purpose described.
4. A moveable frame provided with a screw G or the like, wheels, and anti-
friction rollers and jacks for raising same, and pivotted wing pieces W substantially
as and for the purpose described.
5. The combination with a pair of moveable frames constructed substantially as
described of the telescopic blocks B. B 1. substantially as and for the purposes
described.
6. The employment in conjunction with moveable bars of a set of moveable
frames constructed substantially as described, the forward frames being of less
heighth than the rear frames substantially as and for the purpose described.

page_text: 7. The employment in conjunction with moveable frames constructed substantially
as described of moveable bars constructed or arranged to slide telescopically one
within another substantially as and for the purpose described.
8. The general arrangement and construction of the improved temporary
5 supports for tunnels, sewers, and the like substantially as described and illustrated.
Dated this 20th day of February 1894.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Chartered Patent Agent,
For the Applicant.