IMPROVEMENTS IN THE MODE OF PROPELLING TRAMWAY,, CARS AND OTHER VEHICLES
Year: 1875

page_text: LETTERS PATENT to Andrew Nicol Porteous, Engineer, and George
Cadell Bruce, Civil Engineer, both of Edinburgh, Scotland, for the
Invention of "IMPROVEMENTS IN THE MODE OF PROPELLING TRAMWAY,,
CARS AND OTHER VEHICLES.”
Sealed the 21st January 1876, and dated the 18th September 1875.
PROVISIONAL SPECIFICATION left by the said Andrew Nicol Porteous
and George Cadell Bruce at the Office of the Commissioners of
Patents, with their Petition, on the 18th September 1875.
We, ANDREW NICOL PORTEOUS, Engineer, and GEORGE CADELL'
BRUCE, Civil Engineer, both of Edinburgh, Scotland, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MODE OF
PROPELLING TRAMWAY CARS AND OTHER VEHICLES," to be as follows:-
―
Our Invention has for its object the combination of a steam engine
with one or more air or gas engines in the propulsion of a tramway car.
or other vehicle, in such a manner that the power of the steam engine
is-stored in the form of compressed air or gas in tanks or a series of

page_text: pipes placed underneath the seats or bottom of the car or vehicle, or
in other convenient place, which compressed air or gas-is-passed-to-the
-propelling engine or engines in such-volume_as_may_be_required.-For
-this-purpose the steam engine is connected directly to the pump or
condenser, and the air or gas propelling-engine-or-engines-is or are
connected directly to the wheels of-the-car or vehicle, no gearing being
required.
The products of combustion from the furnace are forced downwards
by means of an air jet into the fire-box underneath the body of the car
or vehicle, and the feed pipe leading to the air or gas engine or engines 1
is conducted along this fire-box for the double purpose of utilizing the
waste heat, and expanding the air or gas before it reaches the propelling
engine or engines.
1 The steam engine is of a slightly greater power than would be
required for the compressing or condensing of the air or gas necessary 1
to propel the car or vehicle at the required rate on a level, and is kept
continually working at its full power or nearly so. The surplus power
so obtained while running on a level and descending gradients, or when
the car or vehicle is stationary is stored in the form of compressed air or
gas, and when accumulated in the receivers can be employed to supply 2
the extra power required for overcoming gradients.
By means of the above described combination only a small steam
engine and boiler are required (thereby ensuring lightness in the car or
vehicle), and at the same time a high uniform power is obtained.
Also by the steam engine constantly working at the same power, an 2
uniform consumption-of-water-and-fuel takes place.
• Also by the products of combustion being passed through the fire-box
underneath the body of the car or vehicle all annoyance from smoke or
dust is prevented.
Also steam is not required to be blown off when stopping. or 3

page_text: 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 17th March 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ANDREW
NICOL PORTEOUS, Engineer, and GEORGE CADELL BRUCE, Civil
Engineer, both of Edinburgh, Scotland, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of September, in the
year of our Lord One thousand cight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Andrew Nicol Porteous and
George Cadell Bruce, Her special licence that we, the said Andrew
Nicol Porteous and George Cadell Bruce, our executors, administrators,
and assigns, or such others as we, the said Andrew Nicol Porteous and
George Cadell Bruce, our executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN THE MODE OF PROPELLING TRAMWAY CARS AND
OTHER VEHICLES," upon the condition (amongst others) that we, the said
Andrew Nicol Porteous and George Cadell Bruce, our executors or ad-
ministrators, by an instrument in writing under our, or their, or one of
their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
•
NOW KNOW YE, that we, the said Andrew Nicol Porteous and
George Cadell Bruce, do hereby declare the nature of our said Inven-
tion, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, referenco
being had to the Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say):
Our Invention of "Improvements in the Mode of Propelling Tramway

page_text: Cars and other Vehicles," has reference to a mode of propelling tramway
cars and other vehicles, whereby-aro_obtained.a.high-uniform-power, an
uniform consumption of water and fuel, freedom from_all_annoyance-by
noise, smoke, or the issue of steam, and lastly, economy in working.
For these purposes our Invention-consists-in-the-combination of a
condensing steam engine with an air or gas engine or engines, the steam
engine being used in working one or more air or gas pumps for the
compressing of air or gas into-receivers placed underneath the seats or
bottom of the car or vehicle or in other convenient place therein, which
compressed air or gas is passed to the propelling engine or engines in
such volume as may be required. For this purpose the steam engine is
connected directly to the compressing pump, and the air or gas pro-
pelling engine or engines is or are connected directly to the wheels of
the car or vehicle, no gearing being required.
The steam boiler constructed as herein-after described is specially
adapted for preventing the annoyance that would arise from the omission
of smoke fumes and the gases of combustion (commonly emitted from
the flues of steam boilers), as these are passed through the fire-box
underneath the body of the car or vehicle.
By means of the above stated combination of a steam engine with an
air or gas engine or engines, a high uniform power is obtained for a
small steam engine. The steam engine need not be of greater power
than is necessary to drive the car or vehicle at the required rate of speed
along a level railway, tramway, or road, and according to the gradients
on the tramway or road, this power may be increased or diminished.
The steam engine is kept continually working up to its full power in
compressing the air or gas by which the car or vehicle is propelled, and
the compressed air or gas is only admitted to the propelling engine or
engines in such volume as may be required. The car or vehicle is fitted
with receivers or tanks in which the air or gas is stored, and starting on
its journey with these full, the required pressure is maintained by the
constant working of the steam engine; also when the car or vehicle is
brought to a stand still either at a station or while taking up or setting
down passengers or goods, as also when traversing a descending gradient,
the means of propulsion are being increased as the same power is not
-being-expended as when the car or vehicle is travelling on a level

page_text: railway, tramway, or road. The power thus accumulated is available
for overcoming the ascending gradients. Hence it will be seen that the
power required for any particular railway, tramway, or road, on which it
is proposed to run the car or vehicle can be readily calculated.
By means of the said combination and the said specially constructed
steam boiler, all annoyance from noise, smoke, or the issue of steam is
prevented, whether the car or vehicle be run on a level road, or
tramway, or railway, or on a road, or tramway, or railway with steep
gradients.
On a road, or tramway, or railway with steep gradients on it, the
extra power required to overcome the ascents is acquired while traversing
level portions and descending gradients, or while the car or vehicle is
stationary, and is stored in the form of compressed air or gas. In the
case of a comparatively level road or tramway, or railway, the power
required to propel the car or vehicle is comparatively small, and the
steam boiler is of itself sufficient to accomplish this without the aid of a
secondary agent, such as compressed air or gas. In both cases any
surplus steam that may be generated is blown off into the condenser,
and thus rendered noiseless and invisible. In order however that our
Invention may be fully understood and readily carried into effect, we
will proceed to describe it more particularly by the aid of the accom-
panying Drawings, in which are represented the entire combination of
parts above referred to, and also the specially constructed steam boiler.

page_text: It forms-a bogie on which the-front-portion-of-the-car-is-carried,-and-in-
it are placed the propelling engines C which are thus-always kept at-a
high temperature.
The upper plate or lid of the "smoke-box is fixed to the under
surface of the body of the car, in order that the car may turn or revolve
on the bogie: The feed pipe D-and the exhaust pipe pass through a
hole in the centre of this plate or circular lid C; E represents the steam
engine for working the air pump F. The air so compressed by the air
pump being stored in the-receiver G placed underneath the seats of
the car.
These receivers may either be a series of tubes, or one or more
large tubes or cylinders. From these receivers G the compressed air or
gas is admitted to the feed pipe D of the propelling engine C, and by
being passed through the heated air in the smoke box A, the air or gas
is thus expanded before it reaches the propelling engine. The exhaust
pipe from the steam engine is passed to the surface condenser H, which
consists of a series of tubes or cylinders made of copper or other con-
ducting metal, with a current of atmospheric air continually passing
through them, caused by the heated air continually escaping at the top,
and the cold air entering at the bottom. By this means the steam is
condensed, and thus rendered noiseless and invisible, a partial vacuum
being at the same time formed. The exhaust pipe from the air engine
is led into the ash-pit of the furnace, and constitutes the blower for the
furnace.
In order to prevent the heat from the boiler B passing into the
interior of the car, two partitions K-and-Irare-placed-between-the-boiler
casing or front portion of the car and the interior or passenger portion of
the same, with an air space between them, open at the top and the
bottom, so that all heat ascends at once into the atmosphere, and is
prevented from passing into the inside of the car.
The hindmost pair of wheels M, M, are trailing wheels, and are hung
from the body of the car.
The car is rendered reversible by being made to revolve on the centre
of the bogie in the following manner :-The wheel N at the extreme
back of the car, the axis of which is placed at right angles to the axis of

page_text: the other wheels on the car, is lowered by means of the screw O, until
the trailing wheels M, M, are lifted off the rails, and the car is then
run round on the wheel N, the bogie being the centre upon which it
turns.
turns.
In Sheet III., Figures 1, 2, and 3, represent three different forms of
the steam boiler above referred to, which is constructed in the form of
three or more tubes of a small diameter.
Figures 1 and 2 represent a boiler constructed of three tubes, two of
which, P, T, are placed perpendicularly, and one Q horizontally, con-
necting the tubes P, T, at the top, and in order to complete the
circulation, the tubes P, T, are also connected at the bottom by a pipe
or tube R; Fig. 3 represents a boiler constructed of four tubes, three of
which P, T, T, are placed perpendicularly, and one Q horizontally,
connecting the tubes P, T, T, at the top. The tubes P, T, T, are also
connected at the bottom in order to complete the circulation by the
pipes or tubes R, R. The small internal tubes 2, along which the flames
and hot gases are taken from the crown of fire-box S, thence up the
perpendicular tubes P through the horizontal tube Q, and thence down
the perpendicular tube T into the smoke box underneath. An air jet or
blower is introduced into the furnace to produce rapid combustion.
Having thus described the nature of the said Invention and in what
manner the same is to be performed, we wish it to be understood that
we do not confine or restrict ourselves to the precise forms or arrange-
ments of the parts represented and described, neither do we claim as of
our Invention many of the details of mechanical constructions which we
have had occasion to describe for the purpose of making our Invention
properly understood, but what we consider novel and original, and
therefore claim as the Invention secured to us by the herein-before
recited Letters Patent is,-

page_text: either in combination with a steam and air or gas engine or engines, or
with a steam engine alone.
-
In witness-whereof, we,-the-said-Andrew-Nicol-Porteous-and-
George Cadell Bruce, have hereunto set our hands and seals,
the Fifteenth day of March, in the year of our Lord One
thousand eight hundred and seventy-six.
In witness-whereof, we,-the-said-Andrew-Nicol-Porteous-and-
George Cadell Bruce, have hereunto set our hands and seals,
the Fifteenth day of March, in the year of our Lord One
thousand eight hundred and seventy-six.
ANDREW NICOL PORTEOUS. (L.S.)
GEO. C. BRUCE.
(L.S.)
Witness,
JAMES BURNETT,
17, Dundas Street,
Edinburgh,
Civil Engineer.