IMPROVEMENTS IN THE CONSTRUCTION OF STEAM TRAMWAY CARS AND OTHER VEHICLES, AND IN BOILERS AND ENGINES FOR THE SAME
Year: 1877

page_text: LETTERS PATENT to Andrew Nicol Porteous, Engineer, and George Cadell.
Bruce, both of Edinburgh, Scotland, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF STEAM TRAMWAY CARS AND OTHER VEHICLES, AND IN
BOILERS AND ENGINES FOR THE SAME."
Sealed the 20th November 1877, and dated the 23rd May 1877.
PROVISIONAL SPECIFICATION left by the said Andrew Nicol Porteous and
George Cadell Bruce at the Office of the Commissioners of Patents on the 23rd
May 1877.
ANDREW NICOL PORTEOUS, Engineer; and GEORGE CADELL BRUCE, both of Edin-
burgh, Scotland. "IMPROVEMENTS IN THE CONSTRUCTION OF STEAM TRAMWAY CARS.
AND OTHER VEHICLES, AND IN BOILERS AND ENGINES FOR THE SAME."
Our Invention has reference to the general combination and arrangement of the
parts' constituting a steam tramway car, herein-after described, and also the parti-
cular construction of the boiler and engines for the same, and to the special means
employed for getting rid of the exhaust steam and products of combustion.
The general arrangement of the car is in its main features similar to that described
in the Specification of the Patent granted to us, and bearing date 18th September
1875, No. 3264, but differing from it in respect of the boiler and engines and the
means employed for getting rid of the exhaust steam and products of combustion.
The car is divided into two parts, the front part forming the boiler, and the
hinder portion the passenger compartment; these two parts are separated by two
partitions, with an air space between them, by which heat is prevented from passing
from the boiler enclosure to the passenger carriage
The car or vehicle is carried on six wheels, the foremost four of which are con- -
nected to the engines and their framework, and form a bogie on which the front
part of the car rests; these four wheels are the driving wheels, the two binder
wheels supporting the back portion of the car.
The method of turning the car is the same as that described in the Specification,
of the Patent, No. 3264 (1875), above referred to.
When the car or vehicle is required to run for a short distance off the rails in
order to pass any obstruction, the driving or bogie wheels are run on to an iron

page_text: chain belt carried for the purpose. One side of the belt is made to fit the wheels,
and the other is covered with a soft material, such as india-rubber or leather, in
order to grip the road, thereby forming a new tyre for the said wheels, and enabling
them to run on any ordinary road surface. The two wheels on each side are enclosed
by the same belt.
The hinder wheels of the car are lifted off the rails by the turning wheel, which
is itself turned to run along with the bogie wheels in front. The direction of the
car is in such a case under the complete control of the driver owing to the bogie
arrangement in front; or, the bogie being fixed, the turning wheel can be used for a
guide.
The boiler is of the locomotive type, but with a fire-box of a conical form, the
narrow or upper end of which leads into a circular combustion chamber, one end of
which is formed by the tube plate, and the other is closed by a fire-brick, per-
forated so as to admit of a small quantity of hot air (heated by passing through the
perforations in the said fire-brick) entering the combustion chamber, and mixing
with the gases therein, in order to facilitate the consumption of the carbonic oxide
gas. By the removal of the said fire-brick easy access is obtained to the tube plate
when required.
From the combustion chamber the products of combustion pass along the tubes
into the chimney, which is carried both upwards and downwards.
The upper branch of the chimney is only used in raising steam, and when this is
accomplished it is removed, and the neck or part to which it is connected is com-
pletely closed.
The exhaust steam from the engine is introduced into and forms a powerful blast
in the lower branch of the chimney, thereby maintaining the combustion in the
furnace, and forcing the products of combustion downwards underneath the body of
the car or vehicle.
The engines with their framework are specially adapted for forming a complete
bogie, on which the car rests. They are four-cylinder single-acting engines, with
two pistons connected to the front wheels and two to the back wheels of the bogie,
the wheels being coupled with side rods.
The valve casing forms the centre of the bogie; on which the car is turned.
The slide valve is made to revolve, the exhaust ports and steam ports being alike.
The slide valve carries with it an expansion valve, one side of which is cast with
a D shaped port, forming the exhaust port; the other side thereof is fitted with
ordinary steam ports. This expansion valve is under the control of the driver, and
by turning it half a revolution the engines can be reversed as required. Steam can
also be cut off at any part of the stroke from one-eighth to full steam.
The means employed for getting rid of the exhaust steam and products of com-
bustion consists of the arrangement, herein-after described, for mixing the same
with proportionate quantities of atmospheric air, so that the whole may be allowed
to escape, after being thoroughly mixed, at the temperature required for condensing
the vapour with which the air is saturated by the said mixture.
The ratio of weight of the exhaust steam producing the blast in the chimney in
relation to that of the air drawn through the furnace at a high temperature becomes
reduced. by the further supply of air being drawn into the chimney by the force of
the blast or other mechanical blower, the temperature at the same time being
reduced, and this process continues until the temperature of the whole is reduced to,
The air so
say, one-fourth of that of the air originally drawn through the furnace.
reduced in temperature and thoroughly saturated with moisture is allowed to
escape under the car, and is thereby brought into immediate contact with the
external atmosphere, becoming entirely invisible by the time that the car or vehicle
has passed over it.
In dry weather the moist air will be rendered invisible by absorption, and in
damp weather by condensation, a smaller quantity of air being required in the
chimney in the former case than in the latter.
The products of combustion are also entirely dissipated by this process..

page_text: The feed water tanks for the boilers are or may be made of sufficient size to carry
a supply for eight hours if required, and a portion of the exhaust steam is led into
them for the purpose of heating the feed water and assisting the process for the
dissipation of the exhaust steam in unfavourable weather, or when traversing
important thoroughfares; this could be regulated by the drivers of the car.
•
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Andrew Nicol Porteous, and George Cadell Bruce in the Great Seal
Patent Office on the 22nd November 1877...
ANDREW NICOL PORTEOUS, Engineer, and GEORGE CADELL BRUCE; Civil Engi
neer, both of. Edinburgh, Scotland. "IMPROVEMENTS. IN THE CONSTRUCTION OF
STEAM TRAMWAY CARS AND OTHER VEHICLES, AND IN BOILERS AND ENGINES FOR
THE SAME."
Our Invention of "Improvements in the Construction of Steam Tramway Cars
and other Vehicles, and in Boilers or Engines for the same," has reference to the general
combination and arrangement of the parts constituting a steam. tramway car, herein-
after described, and also the particular construction of the boiler and engines for the
same, and to the special means employed for getting rid of the exhaust steam and
products of combustion.
'
The general arrangement of the car is in its main features similar to that described
in the Specification of the Patent granted to us, and bearing date Eighteenth Sep-
tember One thousand eight hundred and seventy-five, No. 3264, but differing from
it in respect of the boiler and engines and the means employed for getting rid of the
exhaust steam and products of combustion..
"
The car is divided into two parts, the front part forming the boiler, and the
hinder portion the passenger compartment; these two parts are separated by two
partitions, with an air space between them, by which heat is prevented from passing
from the boiler enclosure to the passenger carriage.
:
The car or vehicle is carried on six wheels, the foremost four of which are.con-
nected to the engines and their framework, and. form a bogie on which the front
part of the car rests; these four wheels are the driving wheels, the two hinder
wheels supporting the back portion of the car.
The method of turning the car is the same as that described in the Specification
of the Patent, No: 3264 (1875), above referred to.
When the car or vehicle is required to run for a short distance off the rails in
order to pass any obstruction, the driving or bogie wheels are run on to an iron
chain belt carried for the purpose. One side of the belt is made to fit the wheels,
and the other is covered with a soft material, such as india-rubber: or leather, in
order to grip the road, thereby forming a new tyre for the said wheels, and enabling
them to run on any ordinary road surface. The two wheels on each side are enclosed
by the same belt.
:
"
The hinder wheels of the car are lifted off the rails by the turning wheel, which
is itself turned to run along with the bogie wheels in front. The direction of the
car is in such a case under the complete control of the driver, owing to the bogie
arrangement in front; or, the bogie being fixed; the turning wheel can be used for a
guide.

page_text: The boiler is of the locomotive type. The fire-box is of a conical form," the
narrow or upper end of which leads into a circular combustion chamber, one end of
which is formed by the tube plate, and the other is closed by a fire-brick, per-
forated so as to admit of a small quantity of hot air (heated by passing through the
perforations in the said fire-brick) entering the combustion chamber, and mixing
with the gases therein, in order to facilitate the consumption of the carbonic oxide
gas. By the removal of the said fire-brick easy access is obtained to the tube plate
when required.
From the combustion chamber the products of combustion pass along the tubes
into the chimney, which is carried both upwards and downwards.
The upper branch of the chimney is only used in raising steam, and when this is
accomplished it is removed, and the neck or part to which it is connected is completely
closed.
The exhaust steam from the engine is introduced into and forms a powerful blast
in the lower branch of the chimney, thereby maintaining the combustion in the
furnace, and forcing the products of combustion downwards underneath the body of
the car or vehicle.
The engines with their framework are specially adapted for forming a complete
bogie, on which the car rests. They are four-cylinder single-acting engines, with
two pistons connected to the front wheels and two. to the back wheels of the bogie,
the wheels being coupled with side rods.
The valve casing forms the centre of the bogie, on which the car is turned.
The slide valve is made to 'revolve, the exhaust port being placed on the one side
and the steam ports on the other, these steam ports being alike.
The slide valve. carries with it an expansion valve, one side of which is cast with
a D shaped port, forming the exhaust port, and the other side thereof is fitted with
ordinary steam ports. This expansion valve is under the control of the driver, and
by turning it half a revolution the engines can be reversed as required. Steam can
also be cut off at any part of the stroke from one-eighth to full steam.
The means employed for getting rid of the exhaust steam and products of com-
bustion consists of the arrangement, herein-after described, for mixing the same
with proportionate quantities of atmospheric air, so that the whole may be allowed
to escape, after being thoroughly mixed, at the temperature required for condensing
the vapour with which the air is saturated by the said mixture.
The ratio of weight of the exhaust steam producing the blast in the chimney in
relation to that of the air drawn through the furnace at a high temperature becomes
reduced by the further supply of air being drawn into the chimney by the force of
the blast or other mechanical blower, the temperature at the same time being
reduced, and this process continues while the temperature of the whole is reduced
to, say, one-fourth of that of the air originally drawn through the furnace. The air
so reduced in temperature and thoroughly saturated with moisture is allowed to
escape under the car, and is thereby brought into immediate contact with the
external atmosphere, becoming entirely invisible by the time the car or vehicle has
passed over it.
In dry weather the moist air. will be rendered invisible by absorption, and in
damp weather by condensation, a smaller quantity of air being required in the
chimney in the former case than in the latter.
The products of combustion are also entirely dissipated by this process.
The feed water tanks for the boilers are or may be made of sufficient size to carry
a supply for eight hours if required, and a portion of the exhaust steam is led into.
them for the purpose of heating the feed water and assisting the process for the
dissipation of the exhaust steam in unfavourable weather or when traversing
important thoroughfares; this could be regulated by the driver of the car.
Having thus stated the nature of the said Invention we will proceed to describe
more particularly in what manner the same is to be performed by the aid of the
accompanying Drawings, in which are represented a steam tramway car with boiler
and engines for the same constructed in the manner above referred to.

page_text: Fig. 13, Sheet III., represents a plan of the valve seat on the engines. o' is the
exhaust port, and p¹, p', the steam ports.
Figures 20, 21, and 22 (Sheet III.) represent the downward branch of the
chimney g and its connections for dissipating the exhaust steam, products of com-
bustion, and vapours. G represents the exhaust steam pipe introduced into the
chimney g'. The force of the blast induces a current of air into the circular tubes
H, H, wherein the whole exhaust steam, products of combustion, and air are mixed
together in their downward journey, escaping underneath the car through the
narrow slit K.
"
Fig. 23 (Sheet III.) represents the air tubes of the chimney surrounded by a
box L, into which air may be forced by any mechanical blower through the.
pipe M.;
Fig. 19 (Sheet III.) represents the under portion of the car with the bogie wheels
fitted with the chain bolt N to enable it to run off the rails when required. P is the
turning wheel by means of which the car can be reversed as required.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, we hereby declare that what we claim as of our Inven-
tion is,
First. The combination of parts constituting the steam tramway car represented
and described, consisting of a boiler house, or enclosure and passenger carriage,
with a double partition and air space between them, together with an engine and
bogie, as described; also with adaptation of parts to render the car reversible and
capable of being guided when not running on rails; also the arrangement for running
the car off and on to rails in order to clear obstructions, and the other parts of the
car combined therewith, all as herein-before described.
Secondly. The boiler, as represented in Figures 9, 10, 11, and 12, and herein-
before described.
Thirdly. The engines with their framework, as described, adapted to form a bogie
having the valve casing for its centre of motion, such engines being fitted with
valves of the kind represented and described.
Fourthly. The adaptation and application to steam tramway cars of valves of the
kinds represented in Figures 13, 14, 15, 16, 17, and 18, and described.
And, lastly. The means and apparatus adapted for getting rid of the exhaust
steam and products of combustion, represented in Figures 20, 21, and 22, and herein-
before described..
: In witness whereof, we, the said Andrew Nicol Porteous and George Cadell
Bruce, have hereunto set our hands and seals, the Twentieth day of November,.
in the year of our Lord One thousand eight hundred and seventy-seven.
+
GEO. C. BRUCE,
Witness,
JAMES BURNET,
17, Dundas Street,
Edinburgh,
Civil Engineer.
(LA.D.)
(L.S.)