IMPROVEMENTS IN PNEUMATIC RAILWAYS
Year: 1878

page_text: LETTERS PATENT to Thomas Webster Rammell, of 17, Pall Mall, London, in the
County of Middlesex, Civil Engineer, for the Invention of "IMPROVEMENTS IN
PNEUMATIC RAILWAYS"
Sealed the 17th June 1879, and dated the 23rd December 1878.
PROVISIONAL SPECIFICATION left by the said Thomas Webster Rammell
at the Office of the Commissioners of Patents on the 23rd December 1878.
THOMAS WEBSTER RAMMELL, of 17, Pall Mall, London, in the County of Mid-
dlesex, Civil Engineer. "IMPROVEMENTS IN PNEUMATIC RAILWAYS."
In the working of pneumatic railways it is desirable that the pneumatic pressure
employed should be brought to bear upon the train within the tubular-way at the
right moment, and should be afterwards when necessary similarly withdrawn from
it; that is to say, that the terminal-doors and the valves controlling the application
should be opened and closed with great precision, and this will be better effected
mechanically than by manual means. In a former Patent I proposed to open
automatically the terminal-doors for the delivery of the train; I now make the
train act automatically in closing the terminal-doors behind it after it has passed
from the station into the tubular-way, and also in opening and closing the valves by
which the pneumatic pressure is applied to it, and is afterwards shut off.
I effect these objects by receiving the action of the moving train upon suitable
bars and levers properly placed and set for the purpose in the line of way, and then
transmitting this action through other suitable bars, levers, and cranks, or where
advisable through hydraulic or pneumatic pressure to the spindles of the doors and
valves in question, being means the application of which is already well under-
stood.
With pneumatic railways inconvenience is experienced from the present plan of
affixing the sail-plate to one of the ordinary carriages of the train. These carriages
are necessarily fitted with springs too easy to allow of an accurate fit of the plate to
the contour of the tubular-way; their width of body will not leave a sufficiency

page_text: of space at the sides for the proper play of the wings, while additional accommoda-
tion beyond what can be thus obtained is required for the driver and the necessary
appliances of the train.
I therefore now place the sail-plate upon a separate carriage, which I call a piston-
carriage, specially constructed to receive it, and of width and length to leave suffi-
cient space for the proper play of the wings, and to insure stability and the requisite
accommodation. This carriage is so far stiffened in the springs as to prevent undue
loss from windage around the periphery of the plate, and besides carrying the sail
plate and its supports space is provided in the carriage for the brake apparatus, and
also for suitable receivers for compressed air to be used for giving motion to the
train after rest at stations in the manner to be described under the next head of
my Inventions.
With pneumatic railways the train when brought to rest at a station is in a
position in which the pneumatic pressure employed in the tubular-way cannot be
made available for again putting it in motion. Several means have been devised
for giving motion to the train when so placed, but all are more or less open to
objection. I now therefore endow each train with a limited faculty for locomotive
action, enabling it to move from the station into the tubular-way in the manner
in which an ordinary locomotive train is moved. The distance to be thus travelled
over being only a score or two of yards, and the gradients at command being always
favourable, the power required for the purpose will be extremely small, and I prefer
to provide it in the shape of air compressed to the necessary degree, and made to
act upon the wheels of the piston-carriage as steam does on those of the locomotive
engine, rather than by the use of steam. To this end I provide a reservoir for
compressed air in the piston-carriage, and this I fill to the proper degree either by
pumps affixed to the carriage and put in action during the transit of the train
between station and station, or charge it from time to time at stationary reservoirs.
By these means motion may be readily communicated to the train when at rest at
any station precisely as it is given to any ordinary locomotive train, and by the act
of the driver alone without extraneous assistance. To facilitate the movement
prefer to lay the ways at stations with an inclination downwards, say, of 1 in 100,
into the section of tubular-way to be entered.
With pneumatic railways it is necessary that the source of pressure should be
readily available at each station where it is to be employed, and the transmission
of a compressed or rarified current from a distance being impracticable it follows
that there should be the means of producing on the spot the rarefaction or com-
pression required. To produce the compression or the rarefaction of the air I make
use in each case, by preference, of a centrifugal machine, by preference of that form
which I have described in previous Patent, No. 2718 of 1860, but it is not necessary
that these machines should be driven by steam power produced on the spot. They
may be acted upon by steam or by compressed air conveyed from a distance, or by
water under pressure produced elsewhere, and led through proper pipes to suitable
receivers at each station for its better application. Water may be thus raised or
put under pressure by steam power in any convenient locality, and led without
much loss of power to the several stations of a pneumatic railway, and I consider
this fluid as the preferable medium to be employed for communicating power to the
pneumatic ejectors, especially in the interior of a large city where space is valuable
and the use of steam on the spot is open to objection.
To economise the consumption, and also for the compactness of the apparatus, I
prefer to use the water under the pressure of a considerable head, and I apply it,
according to the case, either through the intervention of the turbine or the recipro-
cating engine, both being formns of application well understood, as may appear
advisable. In cities I so arrange the pneumatic and hydraulic machinery that
the entire apparatus for a station may be placed below ground, whether at the
side of or beneath the station, as may be found preferable in each case.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Webster Rammell in the Great Seal Patent Office on the
19th June 1879.
THOMAS WEBSTER RAMMELL, of 17, Pall Mall, London, in the County of Mid-
dlesex, Civil Engineer. "IMPROVEMENTS IN PNEUMATIC RAILWAYS."
In the working of pneumatic railways it is desirable that the pneumatic
pressure employed should be brought to bear upon the train within the tubular-
way at the right moment, and should be afterwards when necessary similarly
withdrawn from it, that is to say, that the terminal-doors and the valves controlling
the application of the pressure should be opened and closed with great precision in
point of time, and this will be better effected mechanically than by manual means.
In a former Patent I proposed to open automatically the terminal-doors for the
delivery of the train from the tubular-way into the station; I now make the train
act also automatically in closing the terminal-doors behind it on passing from the
station into the tubular-way, and also in opening and closing the valves by which
the pneumatic pressure is applied and is afterwards shut off.
I effect these objects by receiving the weight of the moving train upon suitable
bars and levers properly placed and set for the purpose along the line of way, and
then transmitting this action through other bars, levers, and cranks, and where
advisable through hydraulic or pneumatic pressure, applied through proper pipes,
valves, pistons, and cylinders to the spindles of the doors and valves in question,
being means the use and arrangement of which is already well understood.
In applying this part of my Invention I prefer to communicate the action
through one of the hindermost wheels of the entering train, which I make with a
tire broader or a flange deeper than the rest in order that it may press down a bar
or lever, which the other wheels will clear, such bar or lever having been previously
set for the purpose, and so as to transmit the motion in the manner already
described. On the "up" line of way I thus make use of say the left-hand hinder-
most wheel, placing the bar or lever along the left-hand rail, and on the "down"
line I make use of the hindermost right-hand wheel, placing the bar or lever along
the right-hand rail, by which arrangement, when the position of the train is
reversed, the bars and levers of the "up" line are cleared by the wheel intended to
act on the "down" line, and so vice-versa.
As to their position, I prefer to place the bars or levers in connection with the ter-
minal-doors at a short distance, say 20 feet, within the tubular-way, so that the closing
of these doors and securing them with proper bolts or cams may take place
immediately on the complete entry of the train. The bars and levers in connection
with the main air valves I place, according to the case, at those points of the
tubular-way where it is fit that the pneumatic pressure should be turned on or
afterwards shut off, having regard to the gradients to be travelled over. The bars
or levers are to be set anew at each passage of a train.
With pneumatic railways inconvenience is experienced from the present plan of
affixing the sail-plate to one of the ordinary passenger carriages of the train. These
carriages are necessarily fitted with springs too easy to allow of an accurate fit of
the plate being maintained to the contour of the tubular-way, while the great
width of their body interferes with the space required for the proper play of the
wings of the plate. Additional room too beyond what can be obtained in a portion
only of an ordinary carriage is required for the accommodation of the driver of the
train and the necessary appliances.
I therefore now place the sail-plate upon a separate carriage, which I call a piston-
carriage, specially constructed to receive it, and of width and length proper for the
play of the wings of the plate, and for the accommodation of the driver and the
requisite appliances. This carriage is so far stiffened in the springs as to prevent
an undue vertical movement, and the consequent loss from windage around the

page_text: periphery of the plate, and besides the room for the sail-plate and its supports, space
is provided in the carriage for the brake apparatus, and also for suitable receivers
for compressed air to be used for giving motion to the train after it has been brought
to rest at stations, in the manner to be described under the next head of my
Inventions.
In dimensions I prefer to make the piston-carriage about 7-feet in width by
about 15 feet in length, and in the form of an ordinary open wagon. The sail-
plate I place in the middle between the two pairs of wheels, its position being
vertical and transverse to the line of way. It is stiffened with proper ribs and
braces, and a balanced door in the middle gives communication from front to back.
The wings of the plate are hung on vertical spindles, and fold back each to the
extent of about 2 ft. 6 inches in a tubular-way of the diameter of 12-feet. The
piston-carriage is placed at the head or the tail of the train, or one is placed at each
end, as required.
With pneumatic railways the train when at rest at a station is in a position
in which the pneumatic pressure is ordinarily employed in the tubular-way
cannot be made available for again putting it in motion, and although various
means have been devised for giving motion to the train when so placed, all are
more or less open to objection. I now, therefore, endow each train with a limited
faculty of locomotive action, in order to enable it to move from its place of rest at
a station into the next section of tubular-way precisely as an ordinary locomotive
train is moved. The distance to be thus travelled over being, however, but a few
yards, and a favourable gradient being always at command, the power required for
this movement will be extremely small, and I prefer to provide it through the
medium of air compressed to the necessary degree and made to act upon the wheels-
of the piston-carriage as steam acts on those of the locomotive engine, rather than
by the use of steam, although I do not debar myself from the use of steam for the
purpose. With this object, I provide one or more suitable reservoirs for compressed
air in the piston-carriage, which I charge to the proper degree either by pumps
affixed to the carriage itself, and put in action during the transit of the train
between station and station, or refill from time to time at stationary reservoirs. By
these means motion may be very conveniently communicated to a train at a
station by the act of the driver alone without extraneous assistance. To facilitate
the starting of the train, I prefer to lay the way with an inclination downwards
from the station into the section of tubular-way to be entered, at the rate, say, of
1 in 100.
As regards this part of my Invention, I do not confine myself to the use of com-
pressed air, or of steam, for giving motion to the train at a station, but I claim the
combined use of high and low pressures applied as described, the former at stations,
the latter in the tubular-way in the working of pneumatic railways.
With pneumatic railways it is an indispensable condition that the source or
supply of pneumatic pressure should be readily available at each station where it is
to be employed, and the transmission of a compressed or a rarefied current from at
distance being impracticable, it follows that there should be the means of producing
on the spot the rarefaction or compression required. To produce the required
compression or rarefaction of the air, I prefer to make use in each case of a centri-
fugal machine of the form which in previous Patents I have called an "ejector," but
it is not necessary that these machines should be driven by steam power produced
on the spot. They may be acted upon by steam or by compressed air conveyed
from a distance, or by water under compression produced elsewhere, and led
through proper pipes into suitable receivers at each station for its application.
Water may be thus raised or put under compression by steam power in any con-
venient locality, and be led without much loss of head to the several stations of a
pneumatic railway where it is required for use, and I consider this fluid as the
preferable medium to be employed for communicating power to the pneumatic
ejectors or other machines adopted for the compression or rarefaction of the air,

page_text: especially in the more central parts of large cities where sites are costly and the
use of steam on the spot is open to objection.
To economise its consumption and also for the compactness of the apparatus
employed, I prefer to use the water under a considerable pressure, say, of that due
to a head of from 1000 feet to 1500 feet, and I apply the medium, according to the
case, either through the intervention of the turbine or of the reciprocating engine,
both being forms of application well understood. In cities where space is limited,
I so arrange the pneumatic and hydraulic engines and machinery that the entire
apparatus for a station may be placed in chambers underground, such chambers
being provided either at the level of or below the main station, as may be found
practicable in each case.
In witness whereof, I, the said Thomas Webster Rammell, have hereunto
set my hand and seal, this Ninth day of June, in the year of our
Lord One thousand eight hundred and seventy nine.
T. W. RAMMELL. (L.S.)