IMPROVEMENTS IN TUNNELLING AND EXCAVATING AND APPARATUS THEREFOR."
Year: 1881

page_text: LETTERS PATENT to Thomas Russell Crampton, of No. 4, Victoria Street, in
the City of Westminster, for an Invention of "IMPROVEMENTS IN TUNNELLING
AND EXCAVATING AND APPARATUS THEREFOR."
PROVISIONAL SPECIFICATION left by the said Thomas Russell Crampton at
the Office of the Commissioners of Patents on the 28th October 1881.
THOMAS RUSSELL CRAMPTON, of No. 4, Victoria Street, in the City of West-
minster. "IMPROVEMENTS IN TUNNELLING AND EXCAVATING AND APPARATUS
THEREFOR,"
This Invention has for its object improvements in tunnelling and excavating,
and apparatus therefor.
In a convenient place at a distance from the working face in the open I provide
pumping machinery or mechanism for the supply of water at considerable pressuro,
or where convenient I obtain water at sufficient pressure by gravitation.
This water I lead by pipes to the working face where I provide an bydraulic
motor engine or engines which it drives.
The hydraulic engine actuates a mining or excavating machine or machines
suited to the rock or material in which the tunnel is being formed.
The motor engine or engines driven by the water also actuates mills or crushers
by which the debris brought down by the mining or excavating machine, or it may
be by manual labour, is reduced or broken down.
In some cases the debris from the mining or excavating machine may be so fine
as not to require to be passed through a mill or crusher.
The crushed or reduced debris is mixed with the water discharged from the
bydraulic motor or motors. In this state of admixture with water the debris is
passed into an exit pipe which is led back to the place of discharge. If the
distance is very long the pressure water or water from the main led into the tunnel
is also made to actuate pumps near the working face to propel the stream of debris

page_text: and water through the exit pipe. Or in place of or in conjunction with pumps,
jets of the pressure water may be applied at one or more points upon the exit pipe
to propel the stream laden with debris to the outfall.
For shorter distances the suction of pumps at the bottom of the shaft rising to
the surface will suffice. In some cases the tunnel may be at such an inclination
that the debris mixed with water will flow out by gravitation. When necessary in
tunnelling I cause the water to pass into the pressure or inlet main charged with
air, which air it liberates when the pressure is relieved on the water passing out
of the hydraulic motor engines, and thereby air is supplied to ventilate or assist in
ventilating the tunnel, and for cooling the tunnel, especially at the part where the
work is in progress.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Russell Crampton in the Great Seal Patent Office on the
28th April 1882.
THOMAS RUSSELL CRAMPTON, of No. 4, Victoria Street, in the City of West-
minster. "IMPROVEMENTS IN TUNNELLING AND EXCAVATING AND APPARATUS
THEREFOR."
This Invention has for its object improvements in tunnelling and excavating and
apparatus therefor.
In practice when a mining gallery or tunnel has to be excavated it has hitherto
been usual to make use of waggons or trollies in order to remove the debris of rock
produced by the excavation. In tunnels of great length, as the distance to run
over from the base of operation increases as the work advances, it is a very costly
operation, and involves great loss of time.
The Invention which is the object of the present Patent purposes to supply
means for an automatically acting and continuous process of removing the débris
of rock as the work is carried on. The debris is reduced by being mixed with water
to a state of cream or sludge so that it will flow through pipes or channels at
moderate velocities. I further purpose in some cases to utilise, in order to effect
that conveyance, the water which passes away from the hydraulic motors which
are employed for working the excavating and other machinery.
In a convenient place at a distance from the working face in the open I provide
pumping machinery or mechanism for the supply of water at considerable pressure,
or where convenient I obtain water at sufficient pressure by gravitation.
This water I lead by pipes to the working face, where I provide an hydraulic
motor engine or engines which it drives.
The hydraulic engine actuates a mining or excavating machine or machines
suited to the rock or material in which the tunnel is being formed.
The motor engine or engines driven by the water also actuates mills or crushers
by which the débris brought down by the mining or excavating machine, or it may
be by manual labour is reduced, or broken down.
In some cases the débris from the mining or excavating machine may be so fine
as not to require to be passed through a mill or crusher.
The crushed or reduced debris is mixed with the water discharged from the
hydraulic motor or motors. In this state of admixture with water the débris is
passed into an exit pipe which is led back to the place of discharge. lf the
distance is very long the pressure water or water from the main led into the tunnel
is also made to actuate pumps near the working face to propel the stream of débris
and water through the exit pipe. Or in place of or in conjunction with pumps,
jets of the pressure water may be applied at one or more points upon the exit pipe
to propel the stream laden with debris to the outfall. For shorter distances the
In
suction of pumps at the bottom of the shaft rising to the surface will suffice.
some cases the tunnel may be at such an inclination that the debris mixed with
water will flow out by gravitation. When necessary in tunnelling I cause the
water to pass into the pressure or inlet main charged with air, which air it liberates
when the pressure is relieved on the water passing out of the hydraulic motor
engines, and thereby air is supplied to ventilate or assist in ventilating the tunnel,
and for cooling the tunnel, especially at the part where the work is in progress.
In order that my said Invention may be more fully understood I will proceed
to describe more in detail the arrangements which are suitable for producing a long
tunnel in chalk.

page_text: Near the mouth of the tunnel it in chalk 1 establish steam engines or other
convenient motors of suitable power, for the case of a cylindrical tunnel of 8 feet
diameter 100 horse power would be adequate, but the power provided may be
varied within wide limits, depending upon the quality of the material acted on and
the rate at which it is removed, and the length of travel and height to which the
mixture has to be lifted.
The engines are made to work pumps to force water into a main in connection
with which a regulating accumulator is provided. I also, in order to ventilate the
tunnel, cause air to be passed into the main to the extent which the water will
This air is
conveniently carry, and so as to partly charge the water with air.
liberated in the tunnel when the water is let out. The main enters the tunnel
and is carried along the same to the vicinity of the working face.
The pressure and the speed of flow to be maintained in this main may also
vary within wide limits, but a pressure of 700 lbs. per square inch and a speed of
four feet a second will be suitable.
I also lay along the tunnel another larger pipe to serve as the exit for the water
and the debris, the speed of flow maintained in this pipe I prefer not to be less
than about two feet per second.
The whole of the working parts by which the rock is cut and the débris disposed
of I arrange upon a platform or bed to move forward within the tunnel as the
work progresses. A pair of rams of considerable length are fixed to the back of
the platform or bed; they are inserted the one into the water inain and the other
into the exit pipe. The joints-around-the-rams-are-rendered tight by ordinary
means. The pressure in the pipes acting against the rams serves to urge the
platform or bed forward as the work progresses.
The rams serve also to maintain the connection with the pipes laid within the
tunnel; one ram conveys the water from the pressure main to hydraulic motors
upon the platform or bed, and the other conducts away the water and débris.
When the work has progressed a distance nearly equal to the length of the rams
it is stopped, valves are closed, and additional lengths of pipe are laid.
For cutting the rock there are several well known tunnelling machines which
may be employed, or it may be cut down by hand, but I prefer to use a machine
having a rotating head armed with cutters to operate against the cutting face, such
a machine for example as that known as Brunton's tunnelling machine or
Beaumont's machine.
The axis is driven by an hydraulic motor, preferably of the type in which the
water is made to act upon pistons or plungers moving to and fro in cylinders.
The cutting head carries buckets which scoop up the débris and deliver it into a
trough. This trough conducts the débris continuously into a mill or mixer, and a
portion of the waste water from the motors may be admitted to the trough to
carry the débris forward; or carrying screws or like mechanism may be fitted in
the trough. In the mill or mixer the débris is reduced with water to a creamy
state.
A mixture of equal weights of chalk and water will flow, but it is preferable,
and it will be convenient to employ more water even to G of water and 1 of chalk,
the more water the better if conveniently obtained, particularly if tlie débris has
to be conveyed to long distances.
The mill or mixer is a plain metal cylinder about four feet in diameter and
three feet long; it is mounted upon an horizontal axis and has perforated ends; the
perforations are numerous, and about of an inch across. There is an opening
about fifteen inches diameter around the axis at one or both ends to admit the
débris and water. The water from the motors or so much of it as may be required
for assisting in reducing the chalk is also discharged into the mill or mixer, the
balance passing into and mixing with it outside the drum before entering the exit
pipes. This mill or mixer is driven by an hydraulic motor at about 32 revolutions
per minute. The mill or mixer should be kept charged so that nothing may pass
out but by the perforations; any material which cannot escape in this way must

page_text: be cleared out from time to time when the apparatus is temporarily stopped. Tho
chalk creain runs out from the mill or mixer into a tank beneath, from which it is
drawn by pumps worked by another hydraulic motor. These pumps force the
whole of the débris and water from the motors into the exit main, which is con-
tinued to the outfall. It will be obvious that one motor for all the work may
be applied, but I prefer where convenient to have separate motors for each
operation.
As already stated, ejectors may be employed in place of pumps to force the
débris and water along the exit main.
In order to regulate the forward travel of the platform or bed, I provide upon it
a pinion or worm geared with the main shaft so as to maintain such relative
speeds as may be desired; this pinion or worm is made to engage with a rack
firmly fixed in the tunnel, and so arranged to assist the rain if not sufficiently
powerful, or retard it if too powerful.
The exit pipe may in some cases be most conveniently led direct to the outfall,
in other cases it may be caused to deliver it to pumps or other apparatus which
will lift the semi fluid mixture to the surface.
Where the tunnelling or hewing machine is adapted to cut the material
sufficiently small the mill or mixer may be dispensed with, in such cases the débris
as raised by the scoops and the water may be pumped at once into the exit main.
In cases where the tunnel is at a considerable inclination the débris and water can
be delivered to the foot of the shaft by gravitation.
This can be done wherever the inclination of the tunnel and the quantity of
water is such as to maintain a stream capable of carrying the débris along with it,
and the débris should be reduced more or less according to the velocity of the
stream which is to convey it. Any water leaking into the tunnel will add to the
volume of the stream; in other cases water leaking into the tunnel may be forced
into the exit pipe by ejectors or by pumps at intervals worked by hydraulic
motors supplied with water from the pressure main.
I prefer to ventilate the tunnel where the air liberated from the water is
insufficient by forcing air into the tunnel through pipes.
For the conveyance of men and materials along the tunnel I prefer to employ
compressed air locomotives.
Having thus described the nature of my said Invention and the manner of
performing the same, I would have it understood that I do not confine myself
to the exact details described, but what I claim is,
First. The construction of tunnels or other underground passages by the employ-
ment, substantially as herein described, of my improved system of operation,
wherein the materials when excavated are mixed with water, and are then as the
work progresses carried by water power through suitable pipes or channels along
the excavated passage, and delivered by pumping machinery or otherwise to the
required receiving stations outside.
Second. The use in the construction of tunnels or other underground passages of
water under pressure conveyed as required to the place where the excavation is
carried on with or without air conveyed there with for ventilating purposes, the
water being used for driving hydraulic machinery, and then mixed with the débris
60 as to reduce the débris to a semi-liquid state, and then used for carrying it in
that state through suitable pipes or channels laid along the tunnel as the work
progresses, and ultimately delivering it by pumping machinery or otherwise at
suitable receiving stations outside, substantially as herein described.
Third. The method or process, substantially as described, for making tunnels,
consisting in leading water at high pressure into the tunnel under construction,
and in applying such water to work machinery by which the rock is hewn reduced
sufficiently small mixed with water and forced into an exit pipe by which it is
conveyed away.
Fourth. The method or process, substantially as described, for making tunnels
by the aid of machinery worked by bydraulic motors, consisting in disposing of

page_text: the waste water from the motor and the débris by mixing them together by the
aid of a mill or mixer, and conducting the mixture away through an exit pipe or
channel.
In witness whereof, I, the said Thomas Russell Crampton, have hereunto
set my hand and seal, this Twenty eighth day of April, in the year of
our Lord One thousand eight hundred and eighty two.
T.
1. K. CRAMPION. (L.S.)