CERTAIN IMPROVEMENTS IN ATMOSPHERIC RAILWAYS
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I CONRAD
HAVERKAM GREENHOW, of the City of London, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Thirteenth day of
January, One thousand eight hundred and forty-nine, in the twelfth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Conrad Haverkam Greenhow, my exors, admors, and assigns,
Her especial license, full power, sole privilege and authority, that I, the
said Conrad Haverkam Greenhow, my exors, adiñors, and assigns, or such
others as I, the said Conrad Haverkam Greenhow, "my exors, admňors, or
assigns, should at any time agree with, and no others, from time to time and
at all times during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, and in the Islands of Jersey, Guernsey, Alderney,
Sark, and Man, and also in all Her said Majesty's Colonies and Plantations
abroad, my Invention of "CERTAIN IMPROVEMENTS IN ATMOSPHERIC RAILWAYS;"
in which said Letters Patent is contained a proviso, that I, the said Conrad
Haverkam Greenhow, shall cause a particular description of the nature of my
said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her said
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as in

page_text: and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said Conrad
Haverkam Greenhow, hereby declare that my Invention has reference to atmo-
spheric railways of the kind for which Letters Patent for England were granted
on the Twenty-third day of June, One thousand eight hundred and forty-five,
to Thomas Clarke, of Hackney, Engineer, and John Varley, of Poplar,
Engineer, namely, atmospheric railways, in which the traction tube is yielding
or resilient, and fitted on the inner or opposite faces of the longitudinal slit
with continuous lip or valve pieces, and the longitudinal slit is closed before
and after each passage of the train by the action of the tube and lip pieces
themselves;
and that the nature of my Invention consists in an improved
method of fixing the said resilient tube, and in addition thereto of certain
appliances whereby the efficiency of the same is greatly increased. And
I declare that the manner in which the said Invention is to be performed, is
exhibited in the Drawings hereunto annexed, reference being thereunto had,
and in the following description thereof, that is to say :-
Figure 1 is a horizontal section of a traction tube and plan of a piston
embodying my improvements. Figure 2 is a vertical section of the tube and
side elevation of the piston, as also a side elevation of a railway traction
carriage fitted to the tube. Figure 3 is a transverse section of the tube on
the line A, B, of Figures 1 and 2. Figure 4, a transverse section on the
line C, D, of Figures 1 and 2. And Figure 4 is a plan of the piston head.
I propose that the tube (N) shall be suspended at intervals of six feet in a
sling C, of malleable iron one eighth of an inch in thickness, and three inches
broad, in such a manner as to avoid damaging the tube by rivetting (sce
Figure 3). The sling is to be rivetted to upright supports D, D, one on each
side, which are bolted down to the sleeper E. The sling must embrace the
tube on each side to within twenty-five degrees of the longitudinal slit H on
the vertex of the tube, and be rivetted to the upright supports D, D, within
the perpendicular lines F, F, which touch the tube at the extremities of its
horizontal diameter G. By this means the weight of the tube in the sling
will have a tendency to draw the points of the standards or upright supports
D, D, together, and their pressure on the tube will assist its elasticity in
closing the longitudinal slit H, after the passing of the coulter. To facilitate
the opening of the longitudinal slit H on the vertex of the tube, for the
passage of the coulter L, I attach to an iron plate P, placed parallel with the
horizontal diameter of the tubes, and at right angles with the coulter L, four
horizontal wheels 0, 0, 0, 0, two inclined towards one side of the tube, and

page_text: two towards the other (see Figure 1). The distance between the extreme edges
K of the wheels O, should be one half of an inch greater than the internal
diameter of the tube, so that as the wheels advance through the inside of the
tube they increase its horizontal diameter, and cause the slit H to open to
twice the distance of the increase in the horizontal diameter (the transverse
section becoming then slightly spheroidal). The coulter L is secured to the
top of the plate P, and the intervention of that plate prevents the coulter from
coming in contact with the wheels O, O, as it passes between the parted edges
of the longitudinal slit H. To ensure that the wheels O, O, shall remain
precisely parallel with the horizontal diameter, and thus prevent the coulter L
from oscillating out of the perpendicular, which might cause an abrasion
between it and the edges of the slit, I attach to the side of the coulter a
wheel M, with grooved periphery, which fits and runs upon a rigid rail N,
rivetted to the top of the tube on one side of the slit, and extending through
its entire length, so that any tendency which the coulter might have to swerve
is corrected by the rigidity of the guide rail N. To attach the coulter L to
the piston S, I make use of a tube of malleable iron R, three inches in
diameter, which passes quite through the piston S, and is fixed at the other
end in the plate P, to which the wheels O, for opening the slit are secured.
Care must be taken to have sufficient distance between the wheels O and the
piston S, to prevent the opening in the slit from extending as far as the piston.
The coulter L, which consists of a plate of steel thrce eighths of an inch in
thickness and three feet long, is secured to the plate P directly above the
wheels O, in order that it may pass through the opening made in the slit by
the wheels (see Figure 4). Immediately behind the coulter L there is a
valve V in the tube which forms the piston rod, and by opening this valve air
will pass through the piston rod R into the exhausted tube before the piston S,
and so assist in retarding the train by destroying the vacuum in case of any
emergency occurring to render it necessary to do so. To strengthen the con-
nection of the tube R and piston S with the coulter and plate P, I place an
iron bar T, quarter inch thick and four inches broad, under the wheels O, and
make it fast at one end to the piston, as shewn at T'.
ing the coulter L to this leading carriage is shewn in Figure 2, and further
illustrated in Figures 5 and 6. To each end of the coulter L are secured by
three links, two wedge-shaped pieces of iron W, W, which are drawn
through a strong plate of iron a in the perch of the leading carriage, where-
upon another wedge-shaped piece of iron attached to a lever z is forced in
between them. When in this position the two pieces attached to the coulter
cannot fall out or be withdrawn, and consequently the attachment of the
The manner of attach-

page_text: coulter and piston to the perch of the leading carriage remains perfect. By
raising, however, the levers z the wedges fixed to them are withdrawn, and
those attached to the coulter being released fall through the plate x (see
Figure 6), and the carriage is instantaneously freed from the coulter in case of
need. As the vertical tube requires an exit valve which will adapt itself to
the altered shape which the tube assumes on the passing of the wheels O
and reopening of the slit, I propose to construct that valve in the manner
shewn in Figures 7, 8, 9, and 10. Figure 7 is an elevation of the cylinder
in which the valve is placed; Figure 8, a transverse section on the line a, b;
Figure 9, a longitudinal section on the line c, d; and Figure 10, a vertical
section exhibiting the piston in the act of passing the valve. The cylinder x
is made of malleable iron with a longitudinal slit similar to that in the tubes,
and is of a diameter as much more than twice that of the tube y as is
necessary to allow the valve A, which is suspended in the centre of the
cylinder to revolve on an axis B and to fall clear of the line P, when laid
horizontally for the passing of the piston S, as shewn in Figure 10. The
valve A is a circular piece of malleable iron of the same diameter as the inside
of the tube, having a small tube of vulcanized india rubber inserted into a
groove round its periphery, so that, when it is in the perpendicular position
shewn in Figure 9, its whole circumference may come into perfect contact
with every point in the inside circumference of the tube or cylinder. A
perfectly air-tight valve is thus obtained, because when the air is withdrawn
from one side the flexible lip is pressed against the inside of the cylinder, and
prevents the air passing from the other side, while the valve, being sustained
at two points diametrically opposite to each other, has consequently an equal
pressure on each side of its axis (as indicated by the arrows C and D in
Figure 9, and therefore has no tendency to open, whilst the equilibrium is
easily destroyed, and the slightest pressure of the bow E on the piston head S,
against the spring F on the valve, will cause it to revolve on its axis and
assume the horizontal position shewn in Figure 10, and so allow the piston
and coulter to pass through. The valve is then restored to its perpendicular
position, and the cylinder closed again, as shewn in Figure 9, by the action of
a strong spring enclosed in a case G (see Figure 7), which spring is secured
by a hook H to the lever J, placed at the outside of the cylinder a, and at
right angles with the valve and attached to its axis B. When the valve,
therefore, is moved in the direction of the arrows M, the lever J moves in the
same direction, and when the valve becomes horizontal, as in Figure 10, the
ever becomes perpendicular, having drawn the rod K out of the case G, and
compressing the spring at the back by the other end of the lever g, is at the

page_text: same time unhooked from the rod K on the opposite side. When the valve
is released from the pressure of the rod of the piston the spring acting on the
lever J, through the medium of the rod K drawn out of the case G, returns the
valve to its perpendicular position, as shewn in Figure 9. A similar action
occurs with the opposite spring should the valve be opened from the other
side; and thus the valve is in effect self-acting, in whichever direction it may be
opened, requiring no attention saving only what is necessary to keep it in order.
To produce the requisite degree of rarefaction in the traction tube, I
propose to connect it with vacuum chambers exhausted in manner following:
-Figure 11 is a plan of my arrangements for this purpose, and Figure 12 a
vertical section of them on the line E, F. A, A, are two chambers of equal
size, each of cubic contents equal to those of the length of tube intended to be
exhausted at one time. M, M, are two pipes that lead from the chambers
A, A, to one common connecting tube S, which terminates by two branches in
the railway tube or atmospheric main N. R, R, W, W, are two sets of
valves by which the communication between the pipes M, M, and S is
regulated. The chambers A, A, are made of boiler plate, and set in brick-
work up to the point B, from which point the roof is the section of a sphere
supported by eight stays C, C, springing from a strong circular ring D, which
rests on perpendicular supports Y. The stays C, ring D, and supports Y, are
all made of malleable iron tubes of a thickness proportional to the size of the
chamber. In the centre of the roof there is a circular opening a packed all
round with felt on which the lid H rests when closed. At the bottom of the
chamber there is a pipe o for the escape of the water by opening the valve T.
The mode of operation is as follows:-The valve T in the escape pipe O is
closed, and the water allowed to flow into the opening until the chamber A
is full. The lid H is then closed, and also the valve R in the connecting pipe
M. The valve T in the escape pipe O is next opened, when the water flows
off, escaping at the outlet P, which must be 34 feet below the level of the
bottom of the chamber. The water will now, by the natural effect of gravity,
leave the chamber and the pipe O until it is balanced by the atmospheric
pressure at the outlet P, and will stand in the pipe O at a height equal to the
amount of vacuum created in the chamber A, which in ordinary cases will be
equal to a column of water of about twenty-eight feet, making due allowance
for the air which will escape from the water into the vacuum chamber. Now,
by closing the valve T in the escape pipe O, and opening the valve R in the
connecting pipe M, the air in the tube N will expand into the exhausted
chamber and thus rarefy the air in the tube N, and give motion to the piston
by the atmospheric pressure on the outside of A. When the greatest effect

page_text: has been obtained from one chamber the valve R in the connecting pipe M
may be closed, and a like operation be performed with the other chamber, and
by this means a great amount of pressure on the piston will be obtained. By
closing the valve V on the tube N, and opening either of the valves W in
the connecting pipe S, the effect of the vacuum may be communicated in either
direction.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that the improvements in
reference to the atmospheric system of Clarke and Varley, which I claim as of
my Invention, are as follows:-
First, I claim the suspending of the tube in slings, as before described.
Second, I claim the employment of horizontal wheels within, and of greater
diameter than the traction tube, in order to widen the horizontal slit for the
passage of the coulter, as before described.
Third, I claim the employment of the grooved wheel M and rigid guide rail
N to prevent the swerving of the coulter, as before described.
Fourth, I claim the modes of attaching the coulter to the piston and to the
leading carriage, each as before described.
Fifth, I claim the employment of an exit valve of the peculiar construction
before described. And
Sixth, I claim the obtaining of a vacuum by causing water to fall from an
air-tight vessel or vessels to its barometrical level, as before described.
In witness whereof, I, the said Conrad Haverkam Greenhow, have here-
unto set my hand and seal, this Eleventh day of July, in the year of
our Lord One thousand eight hundred and forty-nine.
C. H. (L.s.) GREENHOW.
AND BE IT REMEMBERED, that on the Twelfth day of July, in the
year of our Lord 1849, the aforesaid Conrad Haverkam Greenhow came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Thirteenth day of July, in the year of our Lord One
thousand eight hundred and forty-nine.