IMPROVEMENTS CONNECTED WITH THE PROPULSION OF STEAM TRAM CARS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER SIMILAR PURPOSES
Year: 1878

page_text: LETTERS PATENT to Astley Paston Price, of 47, Lincoln's Inn Fields, in the
County of Middlesex, for the Invention of "IMPROVEMENTS CONNECTED WITH
THE PROPULSION OF STEAM TRAM CARS, WHICH IMPROVEMENTS ARE ALSO
APPLICABLE TO OTHER SIMILAR PURPOSES." A communication from abroad by
Alexandre Arson, of Paris, in the Republic of France, Civil Engineer.
PROVISIONAL SPECIFICATION left by the said Astley Paston Price at
the Office of the Commissioners of Patents on the 13th May 1878.
ASTLEY PASTON PRICE, of 47, Lincoln's Inn Fields, in the County of Middlesex.
"IMPROVEMENTS CONNECTED WITH THE PROPULSION OF STEAM TRAM CARS, WHICH
IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER SIMILAR PURPOSES." A commu-
nication from abroad by Alexandre Arson, of Paris, in the Republic of France, Civil
Engineer.
This Invention relates to the arrangement and construction of a steam motor for
tram cars or vehicles travelling upon rails with a view to obviating the numerous
disadvantages which have attended the systems hitherto employed, and which have
militated against the general adoption of this description of tractive force. These
disadvantages arise chiefly from the large dimensions of the engine and boiler, the
inadequate provision for consuming the smoke, the noise of the escaping steam,
and the complex appliances for controlling the working of the engine and boiler.
Now by means of this Invention the whole of these defects are remedied in the
following manner :-
The boiler, placed in a corner of the platform, occupies scarcely as much space as
would be required for two passengers, leaving room for carrying four passengers
besides the engine driver or attendant on the unoccupied part of the platform; and
the furnace is supplied before starting with sufficient fuel to last twice as long as
the time occupied by the journey.

page_text: The apparatus for feeding the boiler, which is provided with a corresponding
supply of water, is in permanent communication with the boiler, and an annular
float provided with a cock, having a plug or valve of the construction herein-after
described, regulates the feed automatically in a most practical and infallible
manner, so that no attention is required on the part of the stoker on this head.
The engine, nominally of, say, 4 horse-power, but capable of working at, say,
6 horse-power in case of need, is on the principle of a compound engine, and con-
structed in such a manner as to be able to change suddenly from working at 4
horse to working at 6 horse-power without discontinuing to work economically on
ordinary occasions.
The engine, adjusted to work at, say, 5 atmospheres, uses the steam expansively,
and discharges it into the open air.
In the first cylinder the steam enters under a pressure of, say, 5 atmospheres, and
this pressure is maintained during the first half of the stroke. At this moment
expansion commences, so that on reaching the end of the stroke the pressure only
amounts to, say, 2 atmospheres. The steam is discharged from the first cylinder
into an intermediate space, in which a constant pressure of 21 atmospheres is
maintained.
The second cylinder, which is of the same length as the first, but twice its sectional
area, receives the whole of the steam escaping from the first half of its stroke by :
means of a full-pressure slide valve during the first half of its stroke. The expansion
takes place during the second half of the stroke, and the steam escapes at a pressure
of, say, one and a quarter atmospheres, a small excess of power which serves to create
a draft in the boiler flue, and renders a chimney unnecessary.
Vehicles in general require a considerable amount of tractional force to move
them at the moment of starting, involving the expenditure of a supplementary force
which it is not necessary to maintain after the vis enertia has been overcome, and
the apparatus is running at its normal rate of speed. This supplementary force is
also required on ascending inclines, and in order to provide for this increase of
power the engine is fitted with a special appliance enabling high-pressure steam to
be introduced into both cylinders of the compound engine simultaneously, which
then work as in an ordinary engine, exerting under these conditions a force equi-
valent to 6 horse-power. This result is obtained by means of a slide valve of the
peculiar construction herein-after described.
The boiler has an evaporating capacity relatively greater than that of ordinary
boilers, and the whole of its heating surface is exposed to the radiation from the
incandescent fuel. The beating surface is further augmented by the passage of the
flue through the feed-water reservoir, and by means of this arrangement the gases
resulting from combustion are deprived of a considerable portion of their heat before
being discharged into the atmosphere.
It is evident that a very small area of fire-grate is required for a motor of this
power and description; for example, it may be formed by one or two annular fire-
bars surrounding an unperforated cone with a wide base which occupies the contre
of the fire-grate underneath a central tube, through which the supply of coke is fed
automatically into the furnace, being intended to impede the draft of the air and
consequent abnormal combustion of coke in the foed tube.
The supply of fuel is contained in a bunker, which delivers it through the vertical
central tube, extending nearly to the fire-grate. The vibration of the vehicle while
running will be sufficient to ensure the descent of the fuel from the bunker through
the tube with suitable regularity.
The principle of the compound engine, which consists in expanding this steam
from a small cylinder into a larger cylinder, is applied in such a manner as to allow
of high-pressure steam being admitted into both cylinders at once in order to pro-
vide temporarily for the extra power required for starting the vehicle.
The peculiarly constructed slide valve, before referred to, which enables this result
to be obtained is actuated directly and independently of the mechanism of the
engine by the engine driver by moving, to the extent of, say, half a revolution, a

page_text: small hand wheel placed in a convenient position. This slide valve, which is situate
in the intermediate space between the two cylinders, serves to place the outlet port
of the small cylinder in direct communication with the atmosphere through the
ordinary steam exhaust pipe, without thereby in any way affecting the steam outlet
or exhaust of the second cylinder.
The same valvo also performs another function distinct from the preceding by
admitting steam direct from the boiler to the intermediate space through a channel
and special ports, independent of those herein-before referred to.
The engine is provided with two eccentrics for running forwards or backwards,
and an ordinary link motion, which enable the engines to be either stopped com-
pletely or reversed by means of a lever. A single lever capable of occupying certain
calculated positions is sufficient for all the necessary manipulations, thore being no
necessity for the engine driver to attend to any of the details of the boiler and
engine; and the means for controlling the motion of the car are completed by an
ordinary brake operated by the foot of the engine driver.
The steam is generated in a cylindrical boiler, through the centre of which is
passed the hollow column before mentioned, surmounted by the bunker containing
the fuel, which is delivered automatically on to the fire-bars around the cone situate
at the base in the centre of the furnace.
The products of combustion ascend in an annular space or chamber enclosing and
surrounding respectively annular water spaces, from which combustion chamber
leads a flue which conducts the products of combustion into a central fluo in a cylin-
drical column, forming the reservoir for the feed water. On passing through this
column the smoke and heated gases part with a portion of their caloric, which is
absorbed by the feed water, the temperature of which becoines perceptibly elevated;
the smoke and gases are then discharged into the atmosphere underneath the body
of the vehicle through a flue, also containing the steam discharge or oxhaust pipe.
The small surplus amount of pressure under which the steam is discharged expels
the smoke and gases resulting from the combustion, and creates a draft without the
necessity for the use of an elevated chimney.
The reservoir for the feed water, which is calculated to contain double the quantity
of water that is considered to be requsite for a double journey, supplies the boiler
continually, either by means of a feed pump worked by an eccentric placed upon
the axle of the driving wheels, or by a rotary pump of continuous action without
valves, which draws the hot feed water from the reservoir and forces it into the
boiler.
In order that the engine driver may never have to attend to the supply of water
during the journey, and that this most important function may be regularly per-
formed, an annular float is employed, placed within the boiler at the required point
indicated by the normal level of the water which it should contain, the said float
being connected to a fixed point on one side of the boiler by a hinge joint, and
connected at the other side of the boiler by a jointed connecting link to a lever on
the hollow plug of a cock.
When the water in the boiler stands at its normal level the cock is closed, but
when the water falls below this level the float sinks and opens the cock, so that the
water which is constantly supplied in the feed pipe under sufficient pressure is
admitted to the boiler.
When the cock is closed by the rising of the level of the water in the boiler, the
feed water continually supplied by the pump having no other outlet opens a valve
and is re-admitted to the reservoir. This valve is retained on its seat by a small
spring of a power somewhat greater than that of the pressure generated in the
boiler.
This apparatus thus ensures an automatic and certain supply of water to the
boiler, and with the generator, herein-before described, enables steam power to be
applied on tramways without the necessity for attending to the fire; without hand
feeding and without complex appliances for controlling the working of the appa-
ratus; in short, without requiring any special attention on the part of the engine

page_text: driver or attendant, who is consequently at liberty to devote the whole of his
attention to working the car.
In order to avoid the agitation and disturbance produced by the contact of the
steam with the feed water, a bent or corrugated partition of sheet metal is provided
within the boiler, being detached from the same and extending in a polygonal shape 5
round the annular spaces, so as to forin separate vertical passages, along which the
water descends on one side, whilst the steam ascends on the other.
The several features of the Invention are also applicable either separately or in
combination to other similar purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Astley Paston Price in the Great Seal Patent Office on the 11th
November 1878.
ASTLEY PASTON PRICE, of 47, Lincoln's Inn Fields, in the County of Middlesex.
." IMPROVEMENTS CONNECTED WITH THE PROPULSION OF STEAM TRAM CARS, WHICH
IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER SIMILAR PURPOSES." A commu-
nication from abroad by Alexandre Arson, of Paris, in the Republic of France, Civil
Engineer.
The said Invention relates to the arrangement and construction of a steam motor
for tram cars or vehicles travelling upon rails with a view to obviating the
numerous disadvantages which have attended the systems hitherto employed, and
which have militated against the general adoption of this description of tractive
force. These disadvantages arise chiefly froin the large dimensions of the engine
and boiler, the inadequate provision for consuming the smoke, the noise of the
escaping steam, and the complex appliances for controlling the working of the
engine and boiler.
Now by means of this Invention the whole of these defects are remedied in the
following manner :-
The boiler, placed in a corner of the platform, occupies scarcely as much space as
would be required for two passengers, leaving room for carrying four passengers
in addition to the engine driver or attendant on the unoccupied part of the platform;
and the furnace is supplied before starting with sufficient fuel to last twice as long
as the time occupied by the journey.
The apparatus for feeding the boiler, which is provided with a corresponding
supply of water, is in permanent communication with the boiler, and an annular
float provided with a cock, having a plug or valve of the construction herein-after
described, regulates the feed automatically in a most practical and infallible manner,
so that no attention on the part of the person in chargo is required for the purpose
of feeding the boiler.
The engine, nominally of, say, four horse-power, but capable of working at, say,
six horse-power in case of need, is on the principle of a compound engine, and con-

page_text: structed in such a manner as to be able to change suddenly from working at four
horse-power to working at six horse-power without discontinuing to work econo-
mically on ordinary versions.
The ongine, adjusted to work at, say, five atinospheres, uses the steam expan-
sively, and discharges it into the open air.
In the first cylinder the steam enters under a pressure of, say, five atmospheres,
and the pressure is maintained during the first half of the stroke. At this moment
expansion commences, so that on reaching the end of the stroke the pressure only
amounts to, say, two and a half atmospheres. The steam is discharged from the
first cylinder into an intermediate space, in which a constant pressure of two and a
half atmospheres is maintained.
The second cylinder, which is of the same length as the first, but twice its sectional
area, receives the whole of the steam escaping from the first cylinder by means
of a full-pressure slide valve during the first half stroke. The expansion takes
place during the second half of the stroke, and the steam escapes at a prossure of,
say, one and a quarter atmospheres, a small excess of power which serves to create
a draft in the boiler flue, and renders a chimney unnecessary.
Vehicles in general require a considerable amount of tractional force to move
them at the moment of starting, involving the expenditure of a supplementary force
which it is not necessary to maintain after the vis inertia has been overcome, and
the apparatus is running at its normal rate of speed. The supplementary force is
also required on ascending inclines, and in order to provide for this increase of
power the engine is fitted with a special appliance enabling high-pressure steam to
be introduced simultaneously into both cylinders of the compound engine, which
then work as in an ordinary engine, exerting under these conditions a force equi-
valent to six horse-power. This result is obtained by means of a slide valve of the
peculiar construction herein-after described.
The boiler has an evaporating capacity relatively greater than that of ordinary
boilers, and the whole of its heating surface is exposed to the radiation from the
incandescent fuel. The heating surface is further augmented by the passage of the
flue through the feed-water reservoir, and by means of this arrangement the gases
resulting from combustion are deprived of a considerable portion of their heat before
being discharged into the atmosphere.
It is evident that in the case of motors of this power and description a very
limited area of fire-grate should be employed. It is preferably formed by one or
two annular fire-bars surrounding an unperforated cone with a wide base which
occupies the centre of the fire-grate underneath a central tube, through which the
supply of coke is fed automatically into the furnace, the said coke being intended
to impede the draft of air, and consequent abnormal combustion of coke in the feed
tube.
The supply of fuel is contained in a bunker, which delivers it through the vertical
central tube, extending nearly to the fire-grate. The vibration of the vehicle while
running will be sufficient to insure the descent of the fuel from the bunker through
the tube with suitable regularity.
And in order that the said Invention may be fully understood I shall now proceed
more particularly to describe the same, and for that purpose shall refer to the several
Figures on the annexed Sheet of Drawings, the saine letters of reference indicating
corresponding parts in all the Figures.
Figure 1 of the accompanying Drawing represents a side elevation of a tram car
provided with a compound engine and boiler in accordance with the said Invention.
Figure 2 is a plan of the under frame of the car corresponding to Figure 1.
Figures 3, 4, and 5 illustrate details of the compound engine, drawn to a larger
scale.
Figure 6 is a sectional elevation of the boiler and feed reservoirs for fuel and
water, and
Figures 7, 8, and 9 represent various details of the feed valve; also an arrange-

page_text: .
:
ment provided in the boiler for the purpose of establishing a circulation in order
. to prevent the disturbances occasioned by the contact of the feed water with the
steam.
In carrying out the said Invention the principle of the compound engine, which
consists in expanding the steam from a small cylinder (as, for example, the cylinder
C) into a larger cylinder (as, for example, the cylinder C'), is applied in such a
manner as to allow of high-pressure steam being admitted into both cylinders simul-
taneously in order to provide temporarily for the extra power required for starting
the vehicle.
A peculiarly constructed slide valve T (Figures 3, 4, and 5) enables this result to
be obtained, the said valve being actuated by the engine driver directly and inde-
pendently of the mechanism of the engine by the act of moving, to the extent of,
say, half a revolution, a small hand wheel placed in a convenient position, and con-
nected to one end of a shaft c, the other end of which is provided with an eccentric cl
working in a recess formed in one end of the valve T. This slide valve, which is 1
situate in an intermediate space R between the two cylinders, serves to place the
outlet port a of the small cylinder C in direct communication with the atmosphere
through an ordinary steam exhaust pipe I, without thereby in any way affecting
.the steam outlet or exhaust a¹ of the second cylinder C'.
The same valve also performs another function distinct from the preceding by 2
admitting steam direct from the boiler to the intermediate space R through a special
channel t and port l.
The engine is provided with two eccentrics for running forwards or backwards,
and an ordinary link motion, known as Stephenson's link motion, which enable the
-engines to be either stopped completely or reversed by means of a lever. A single 2
lever capable of occupying certain calculated positions is sufficient for all the
necessary manipulations, there being no necessity for the engine drivor to attend to
any of the details of the working of the boiler and engino; and the means for con-
trolling the motion of the car are completed by an ordinary brake operated by the
foot of the engine driver.
The steam is generated in a cylindrical boiler A, through the centre of which
passes a hollow column B, Figure 6, surmounted by a bunker b containing the fuel,
which is delivered automatically on the fire-bars around an unperforated conc D
situate at the base in the centre of the furnace. The cone D is surrounded at its
base by one or more annular fire-bars d, serving to support the fuel, which has been 3
placed previously to starting in the bunker b, and which is caused to descend
automatically, through the column B by the vibration of the vehicle.
The products of combustion ascend in an annular space E, whence they are con-
ducted along a horizontal flue F into a vertical flue F arranged in the centre of a
cylindrical column G, forming the reservoir for the feed water. On passing through 4
this column the smoke and heated gases part with a portion of their caloric, which
is absorbed by the feed water, the temperature of which becomes perceptibly
elevated; the smoke and gases are then discharged into the atmosphere underneath
the body of the vehicle through a flue H, containing the steam discharge pipe I.
The small surplus amount of pressure under which the steam is discharged expels 4
the smoke and gases resulting from the combustion, and creates a draft without the
necessity for the use of an elevated chimney.
By dispensing with a chimney on a level with the roof an important improvement
is effected in the comfort of the passengers, who, without the arrangement herein-
before described, would be frequently enveloped in a cloud of smoke and steam.
5
The reservoir G for the feed water (which is constructed of sufficient capacity to
contain double the quantity of water that is considered to be requisite for a double
journey) supplies the boiler continually, either by means of a feed pump worked by
an eccentric placed upon the axle of the driving wheels, or by a rotary pump of
continuous action without valves, which draws the hot feed water from the reservoir 5
G, and forces it into the boiler A.

page_text: In order to obviate the necessity for any attention on the part of the engine
driver to the supply of water during the journey, and at the same time to ensuro
the regularity of such supply, an annual float J (see Figures 6, 7, 8, and 9) is
employed. This float is placed within the boiler A at the required part indicated
by the normal level of the water which it should contain, and is connected to a
fixed point on one side of the boiler by a hinge joint j, and connected at the other
side of the boiler by a jointed connecting link k to a lovor k on the hollow plug
of a cock K, which forms the. communication between the boiler A and a feed
pipe w.
"When the water in the boiler stands at its normal level the cock K is closed, but
as the water falls below this level the float sinks and opens the cocks, so that the
water which is constantly supplied in the-feed pipe w under sufficient pressure is
admitted to the boiler.
When the cock K is closed by the rising of the level of the water in the boiler,
the feed water continually supplied by the pump having no other outlet opens a
valve a and is remitted to the reservoir. This valve is retained on its scat by a
small spring of a power somewhat greater than that of the pressure generated in
the boiler.
8
This apparatus thus ensures an automatic and reliable supply of water to tho
boiler, and with the generator, herein-before described, enables steam power to be
applied on tramways without the necessity for attending to the fire; without hand
feeding and without complex appliances for controlling the working of the appa-
ratus, that is to say, without requiring any special attention on the part of the
engine driver or person in charge, who is consequently at liberty to devote the whole
of his attention to the management of the car.
In order to obviate the agitation and disturbance produced by the contact of the
stean with the feed water, there is provided within the boiler, but detached there-
from, a bent or corrugated partition L of sheet metal (see Figures 6 and 9), which
forms separate vertical passages, along which the water descends on one side, whilst
the steam ascends on the other.
The apparatus may be constructed of any suitable form and dimensions, according
to the power required.
It is obvious that although the apparatus is represented on the Drawing as applied
to a tramway car with a platform at each end, it may, if required, be adapted to
vehicles having only one platform, such, for example, as the ordinary omnibuses, by
providing a small space in front of the vehicle for the apparatus and engine
driver.
Having now described and particularly ascertained the nature of the said In-
vention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-before
in part recited Letters Patent is,―
First. The general arrangement and combination of parts forming apparatus for
effecting the propulsion of vehicles running on rails, substantially as herein-before
described, and illustrated by the accompanying Drawings.
Second. The furnace with a continuous and automatic supply of fuel descending
through a central pipe, substantially as herein-before described, and illustrated by
the Drawings.
Third. The obtaining an automatic and continuous supply of water to the boiler
by means of a feed pump or a rotary pump with continuous action without valves,
and the employment of a cylindrical cork with a hollow plug, which is opened
or closed by a float according to the variations in the level of the water in the
boiler, substantially as herein-before described, and illustrated by the Drawings.
Fourth. The application and use to and in the steam boiler of a bent or corrugated
metal partition, forming passages for the circulation of steam and water, for the
purpose of obviating the agitation and disturbance occasioned by the contact of the

page_text: steam with the water, substantially as herein-before described, and illustrated by the
Drawings hereunto annexed.
In witness whereof, I, the said Astley Paston Price, have to this my Speci-
fication set my hand and seal, the Fifth day of November, One thousand
eight hundred and seventy-eight.