An Improved Method of Preventing the Pollution or Fouling of the Atmosphere in Railway Tunnels by the Emission of Steam and the Products of Combustion from Locomotive Engines.
Year: 1893

page_text: Date of Application, 16th May, 1893
Complete Specification Left, 15th Feb., 1894-Accepted, 24th Mar., 1894
PROVISIONAL SPECIFICATION.
An Improved Method of Preventing the Pollution or Fouling of the
Atmosphere in Railway Tunnels by the Emission of Steam and
the Products of Combustion from Locomotive Engines.
I CHRISTOPHER ANDERSON of Lane House Hunslet in the City of Leeds
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention is more especially adapted to underground railways constructed
upon the shield system, but it is applicable to any railway tunnel in which from
the nature of the strata in which it is constructed or from the method of its
construction air can be kept at a given pressure above that of the outer
atmosphere.
My invention is supplemental to certain parts and in substitution for other parts
of that of Alice Anderson described in Letters Patent numbered 10851 of the
year 1888. Instead of having pumping engines or other suitable means for creating
a partial vacuum to draw or carry off the products of combustion and waste steam
through the service pipe and main trunk as described in the Specification of the
said Alice Anderson, I use forcing engines to force air into the tunnel and keep
the air in the tunnel outside the service pipe at a sufficient pressure above that of
the outer atmosphere to prevent any escape of steam or products of combustion
between the trunk valve and the service pipe and instead of drawing away all
the waste steam and products of combustion to the exhaust station and there
discharging them into the outer air, I make use of numerous connections or
ventilating shafts or tubes between the service pipe or the main trunk and the
outer atmosphere to allow of the waste steam and products of combustion passing
freely away or being driven away by the force of the blast from the engine. By
this means I avoid the great expenditure of power required to draw away the
waste steam and products of combustion in the manner practised by the said Alice
Anderson. In other respects I make use of the aforesaid invention of the said
Alice Anderson. In order to keep up the pressure of air in the tunnel I provide
at all stations or places of ingress or egress whether for passengers or engines or
otherwise by means of doors or other suitable appliances what I may describe as
air locks so as to prevent any direct communication with the outer atmosphere.
I do not intend by this Specification to confine myself to any particular method
of providing an air lock, but I may give the following as an illustration of my
meaning. Passengers desiring to go by train would assemble in a waiting room
between which and the platform would be closed doors. Inside the waiting room
the air pressure would be normal. On the platform the pressure would be greater.
At a given time the entrance doors to the waiting room would be closed and the air
pressure of the room increased to that in the tunnel. The platform doors would
then be opened and the passengers go out and into the train. Passengers arriving
would enter the waiting room and the platform doors would then be closed.
the pressure in the room would be reduced to that of the outer air, the entrance
doors would be opened and the passengers allowed to go away.
Dated this 15th day of May 1893
Then

page_text: An Improved Method of Preventing the Pollution or Fouling of the
Atmosphere in Railway Tunnels by the Emission of Steam and
the Products of Combustion from Locomotive Engines.
I CHRISTOPHER ANDERSON of Lane House, Hunslet in the City of Leeds,
Engineer, 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:-
My invention is more especially adapted to underground railways constructed
upon the shield system but it is applicable to any railway tunnel in which from the
nature of the strata in which it is constructed or from the method of its construction
air can be kept at a pressure above that of the outer atmosphere.
My invention is supplemental to certain parts and in substitution for other parts
of that of Alice Anderson described in Letters Patent numbered 10851 of the year
1888. Instead of having pumping engines or other suitable means for creating a
partial vacuum to draw or carry off the products of combustion and waste steam
through the service pipe and main trunk as described in the Specification of the
said Alice Anderson, I use forcing engines to force air into the tunnel and keep
the air in the tunnel outside the service pipe at a sufficient pressure above that
of the outer atmosphere to prevent any escape of steam or products of combustion
between the trunk valve and the service pipe, and instead of drawing away all the
waste steam and products of combustion to the exhaust station and there dis-
charging them into the outer air, I make use of numerous connections or ventilating
shafts or tubes between the service pipe or the main trunk and the outer
atmosphere to allow of the waste steam and products of combustion passing freely
away or being driven away by the force of the blast from the engine. By this
means I avoid the great expenditure of power required to draw away the waste
steam and products of combustion in the manner practised by the said Alice
Anderson.
In order to keep up the pressure of air in the tunnel I provide at all stations or
places of ingress or egress whether for passengers or engines or otherwise (by
means of doors or other suitable appliances) what I may describe as air-locks so as
to prevent any direct communication with the outer atmosphere. I do not intend
by this Specification to confine myself to any particular method of providing an
air lock, but I may give the following as an illustration of my meaning. Passengers
desiring to go by train would assemble in a waiting room or as I prefer to call it the
transit room between which and the platform would be closed doors. Inside the
waiting room the air pressure would be normal. On the platform the pressure
would be greater. At a given time the entrance doors to the waiting room would
be closed and the air pressure of the room increased to that in the tunnel. The
platform doors would then be opened and the passengers go out and into the train.
Passengers arriving would enter the waiting room and the platform doors would then
be closed. Then the pressure in the room would be reduced to that of the outer air,
the entrance doors would be opened and the passengers allowed to go away. With
the variations hereinbefore mentioned I adopt the same means to carry out my
invention as does the said Alice Anderson and I adopt the drawings attached to
her Specification as illustrative also of the method of using my invention and I do
not consider it necessary to add thereto. The main trunks will under my
invention be connected with the ventilating shafts instead of being as under the
invention of the said Alice Anderson connected with exhausting stations.
So far as my invention is additional (as distinguished from substitutional) to that
of the said Alice Anderson it consists only of the provision of air locks so as to keep

page_text: up the given pressure of air in the tunnels. The air lock is formed in all essential
particulars like a water lock on a river or canal and consists of valves or sluices
for and to regulate the inlet and outlet of air. These may be placed in any
position and operated by any suitable means. I lay no claim to any form of valve
or sluice or the means of actuating the same. For these reasons 1 do not regard it
as necessary to accompany this my Specification by any drawings. But it is of
course essential that in the transit rooms there should be no fire place or other
opening save the valve openings for regulating the inlet and outlet of air and the
doors for the ingress and egress of passengers. It is likewise essential that tunnels
in which my invention may be used shall not communicate with the open air
except by means of air locks so that any engine or other vehicle running in a tunnel
to which iny invention is applied cannot run out into the open except by first going
through an air lock. It is furthermore essential that there be no shafts or other
openings in tunnels communicating with the outer air except the ventilating shafts
in connection with the main trunk m.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is
1. The use in railway and other tunnels of air at a pressure greater than that of
the outer atmosphere and produced by artificial means as a means of preventing
the pollution or fouling of the atmosphere in such tunnels in manner hereinbefore
and in the Specification of the said Alice Anderson so far as the same is
incorporated herewith described.
2. The use in railway and other tunnels of air locks as a means of keeping up in
such tunnels a pressure of air greater than that of the outer atmosphere so as by
means thereof in combination with ventilating shafts connected with the main
trunks m and other the method employed by the said Alice Anderson so far as is
incorporated herewith to prevent the pollution or fouling of the atmosphere in
such tunnels and as and for other the purposes herein before mentioned.
Dated this Fourteenth day of February 1894.