IMPROVEMENTS IN LOCOMOTIVE ENGINES AND CARRIAGES AND PERMANENT WAY FOR THE SAME
Year: 1872

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN LOCOMOTIVE ENGINES AND CARRIAGES AND PERMANENT
WAY FOR THE SAME."-A communication from abroad by Jean
Larmanjat, of Paris, Engineer.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 26th April 1872.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
3 County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN LOCOMOTIVE ENGINES AND CARRIAGES
AND PERMANENT WAY FOR THE SAME," to be as follows:
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 26th April 1872.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
3 County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN LOCOMOTIVE ENGINES AND CARRIAGES
AND PERMANENT WAY FOR THE SAME," to be as follows:-
In the construction of a locomotive engine the chief aim is to obtain
such an amount of adhesion that the weight of the train shall never

page_text: overcome the adhesion of the driving wheels and cause them to slip or
revolve without advancing. Thus a locomotive of the ordinary con-
struction and weight has a maximum of tractive power which cannot
be exceeded on an ordinary railway except some practical means be
provided to prevent slipping in conjunction with a means of multiplying
the power without increasing the weight.
The method of increasing the tractive power beyond that obtained by
the adhesion of the wheels on the ordinary smooth rails proposed by
the present Inventor consists in the employment of a single toothed
rail or rack placed alongside the ordinary rail and secured in a similar
manner. A ring of teeth carried by one of the driving wheels of the
locomotive is caused to gear with the toothed rail, which is laid at points
where increased tractive power is required, the speed of the locomotive
being also reduced by a system of gearing provided for the purpose
when ascending steep gradients. Since the toothed rack serves merely
as an auxiliary to the rail it will form no impediment to the passage of
the train in the contrary direction, as the gearing is placed on one side
only of the engine which is turned round for returning. The rack rail
would be placed now on one and now on the other side of the line
according as the ground rises or falls, but when descending the train
can travel at any speed desired, as the rack at those places is always on
the opposite side to the gearing on the engine.
By these improvements railways in which two rails are employed
may be laid in localitics having steep gradients, but where it is not
desired to communicate with an ordinary line of railway it is preferable
to employ the single rail system hercin-after referred to, in which the
same method of obtaining adhesion at the expense of speed is applied
although in a different manner. The single rail system allows of curves
of very small radius, whereby the expense of the road is greatly
reduced, and even on curves of a fourth of a chain radius the tractive
effort required is not increased, and the use of turntables is dispensed
with.
Vehicles are employed for use on such lines having four wheels, one
at each end, placed centrally or in the longitudinal axis of the vehicle,
and one at cither side at mid length. The two first mentioned wheels
are grooved to run on the rail, and are mounted on pivots. They serve
to guide the vehicle and they also sustain a greater portion of the load.
The other two wheels serve merely to maintain the equipoise of the

page_text: :
vehicle by bringing the weight on the central rail. The vehicle is
entered at either end and has longitudinal central seats.
A single
central buffer is placed at each end of the framing, which is curved to
an arc of a circle, and beneath it is placed the coupling link, which
connects to a radiating bar pivoted to a transverse lever placed at a
.certain distance from the end of the carriage, on which the bar moves as
a centre. The fulcrum of this lever may be movable and connected
to a spring. The other extremity of the lever is connected with the
corresponding end of the lever at the opposite end of the carriage by
a screw coupling adjusted by a worm shaft, operated by a ball lever
at either side of the carriage. By this means the strain is sustained
by the draw bars and does not effect the carriage framing. The springs
on which the carriage is supported are located in the hollow central
back of the passengers' seats and connected by suitable yokes with the
bearings of the central guide wheels. The vehicle is constructed for use
on ordinary roads by making the fore and rear grooved guide wheels
removable and attaching shafts. This system of traction is also appli-
cable for towing barges or vessels on canals by laying the rail along the
towing path. The locomotive applicable for single rail lines is also
provided with four wheels, one at front and one at rear running on the
rail, forming guide wheels, while the other two are driving wheels
running on the ground or on trams for obtaining adhesion and arè
furnished with india-rubber tires.
A further means of preserving both the rubber surface and the roadway
3 is obtained by making the driving wheels bear more or less thereon
according to the tractive power required by the aid of an adjusting
screw which causes the engine to preponderate cither on the side wheels
or on the central rail. The engine is arranged to work at two different
speeds and so as to double the tractive power when working on inclines
). or drawing heavy loads.
The chief feature of novelty in the construction of the locomotive
consists in the method of varying the speed. In order to adapt the
locomotive to turn curves of small radius one of the driving wheels is
loose on its axle (which is not the cranked axle), and each is provide.l
with a toothed wheel or circle on the boss of the wheel for high speeds,
while for low speeds a larger toothed circle concentric with the other is
placed within a ring fixed on the driving wheel, both toothed circles
being capable of turning loosely. A pinion is keyed at either end of

page_text: the crank axle and placed between the inner and outer toothed circle
to gear with both at once. It will be evident that by fixing one or
other of the toothed circles to the driving wheels the engine may be
driven at a high or low speed as desired. The toothed circles may
be fixed by means of locking wedges or keys, and by fixing those of t
the one driving wheel to which only the power would be applied the
engine may be turned on the other driving wheel as on a pivot.
The bearings of the wheel axle and cranked driving shaft are made
in one piece, so that the two will always preserve their relative positions
and keep in gear notwithstanding the vertical movements of the engine 1
caused by the yielding of the springs.
For double rail lines I employ a locomotive with two pairs of wheels
which may be coupled. One pair is provided with the system of gearing
above described and is driven by a separate cranked shaft. One wheel
of this pair is also provided with an outer ring of teeth fixed inside the 1
tire of the wheel to gear with the rack laid alongside the rail as before
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 25th October 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of April, in the year of:
our Lord One thousand eight hundred and seventy-two, in the thirty-fifth
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville:
Clark, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN LOCOMOTIVE ENGINES AND CARRIAGES, AND PERMANENT
WAY FOR THE SAME," a communication to me from abroad by Jean
Larmanjat, of Paris, Engineer, upon the condition (amongst others)
that I, the said Alexander Melville Clark, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their
hands and scals, 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 I, the said Alexander Melville Clark, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, reference being had to the
Sheet of Drawings hereunto annexed, and to the letters and figures
marked thereon (that is to say) :-
In order to work local or branch railways having steep gradients the
locomotive if of the ordinary type would have to be of such power and
weight and the permanent way of such an expensive character that in
most cases the expenses would exceed any possible returns.
This Invention relates to the construction of locomotive engines
capable of working at two different speeds according to the requirements
of the traffic, and therefore peculiarly adapted for service on such lines.
An engine so constructed weighing between 13 and 14 tons and capable
of hauling a dead weight of 118 tons on inclines of about 1 in 80 (when
arranged to run on rails in the ordinary manner and the weight of the
engine being sufficient to obtain the necessary adhesion) may by simply
changing the speed be used for hauling a train of the same weight up
inclines of about 1 in 40. The tractive power which is equal in the
first case to about 2 tons becomes doubled in the second case owing
to the change in the speed of the locomotive, thus power is gained at
the oxpense of speed.
In the construction of a locomotive engine the chief aim is to obtain
such an amount of adhesion that the weight of the train shall never
overcome the adhesion of the driving wheels and cause them to slip or
revolve without advancing. A locomotive of the ordinary construction

page_text: and of a certain weight has a maximum tractive power which cannot be
exceeded (as it would however require to be in order to ascend a steep
incline) unless some means be provided to prevent slipping, in conjunction
with a means of multiplying the power and diminishing the spoed
without increasing the weight.
}
The method of increasing the adhesion beyond that of the wheels on
the smooth rails of an ordinary railway proposed by the present Inventor
consists in the employment of a single toothed rail or rack placed along-
side the ordinary rail and secured in a similar manner. A ring of teeth
carried by one of the driving wheels of the locomotive is caused to gear 1
with the toothed rail, which is laid at points where increased tractive
power is required, the speed of the locomotive being reduced to 6 or 7
miles an hour by a system of gearing provided for the purpose when
ascending steep gradients. Since the toothed rack serves merely as an
auxiliary to the rail it will form no impediment to the passage of the 1
train in the contrary direction, as the gearing is placed on one side only
of the engine which is turned round at the end of the line. The rack
rails would therefore be placed now on one and now on the other side
of the line according as the ground rises or falls, but when descending
the train can travel at any speed desired, as the gearing on the engine
is always at the opposite side to the rack provided at those places for
engines travelling in the contrary direction.
By these improvements railways in which two rails are employed as
usual may be laid in localities having steep gradients, but where it is
not desired to form a junction with an ordinary line of railway it is
preferable to employ the single rail system hercin-after referred to, in
which increased adhesion is obtained by partly running on the ordinary
roadway, and the same method of obtaining greater tractive power at
the expense of speed is applied although in a different manner.
The single rail system which facilitates the laying of lines alongside
of roads allows of curves of very small radius, whereby the expense of
the line is greatly reduced, and even on curves of a fourth of a chain
radius the tractive effort required is not increased and the use of turn-
tables is dispensed with.
The vehicles, both locomotives and carriages, employed on such lines
have four wheels, one at each end, placed centrally or in the longitudinal
axis of the vehicle, and one at either side. The two first mentioned
wheels are grooved to run on the rail and are mounted in pivoted frames,

page_text: They serve to guide the vehicle and also sustain the greater portion of
the load, while the other two wheels serve to maintain the equipoise of
the vehicle by throwing the weight on the central rail.
I have taken as an example an engine of the comparatively light
weight of 14 tons, although it will be found that in the majority of
cases engines weighing from 5 to 8 tons only and capable of hauling
a train of four or five trucks carrying from 15 to 20 tons of goods up
inclines of 1 in 25 will suffice for local purposes. With light engines
heavy rails and sleepers are not required and but little ballast, while by
the adoption of these gradients the heavy expenses inseparable from
the construction of ordinary lines are not incurred.
This system of traction is also applicable for towing barges or vessels
on canals by laying the rail along the towing path. The locomotive
applicable for single rail lines is illustrated in the accompanying
Drawings, Figure 1 of which shows a longitudinal vertical section
thereof; Figure, 2 is a transverse section taken through the fire-
box and tender; Figure 3 is a longitudinal section below the boiler;
Figure 4 shows a face view on a larger scale of the driving wheel with
gear for changing the speed; Figure 5 is a section of same, while
Figures 6 and 7 show a part sectional elevation and plan of the crank
shaft and driving axle detached. The same reference letters serve for
all these Figures.
The locomotive is provided with four wheels, of which one a is placed
at front and one b at rear, running on the rail, forming guide wheels,
while the other two c, c, are driving wheels running on the ground or
on trams for obtaining adhesion and are furnished with india-rubber
tires to prevent damage to the trams or road, and which serve to reduce
the weight on the square inch to less than 26 lbs. The driving wheels
are made capable of adjustment so as to bear more or less on the track
according to the tractive power required by the aid of an adjusting
screw d by which the engine may be caused to preponderate either on
the side wheels or on the central rail e, Figure 2.
The engine is arranged to work at two different speeds so as to double
the tractive power when working on inclines or drawing heavy loads.
The locomotive shown in the Drawing is so geared that for the higher
speed the crank makes three revolutions for one of the driving
wheel, and for the lower speed five revolutions to one of the driving
wheel.

page_text: The chief feature of novelty in the construction of the locomotive
consists in the method of changing the speed. In order to adapt the
locomotive to turn curves of small radius one of the driving wheels c
is loose on its axlof (which is not the cranked axle), and each is provided
with a toothed wheel 9 or circle on the boss h of the wheel for high
speed, while for low speed and increased tractive power a larger toothed
circle concentric with the other is placed within a ring j, fixed on the
driving wheel, both toothed circles being capable of turning loosely
when not fixed or keyed. A pinion is keyed at either end of the crank
axle k and placed between the inner and outer toothed circles g, i, to
gear with both at once. It will be evident that by fixing one or other
of the toothed circles to the driving wheels the engine may be driven
at a high or low speed as desired. Sufficient space is left between the
two toothed rings g, i, for the insertion of a hooked or locking bolt m,
which passes through the body or web of the wheel, and is provided
with a handlen and nut o. If it is desired to run at a low speed the larger
toothed ring i is locked against the wheel c by the bolt m and nut o,
while on the contrary for running at a high speed the key m is unlocked
and reversed by its handle n, so as to lock the smaller toothed ring g
against the wheel. Turntables are not required with an engine of this
construction, and in order to turn it within a circle of 5 or 6 yards radius
the toothed rings of the inside wheel are unlocked by releasing the
bolt m, so that the wheel which runs on the outside curve only will be
driven (one of the wheels being loose on the axle), and the engine may
therefore be turned sharp round, as at the corner of a road for example.
The bearings p of the wheel axle ƒ and cranked driving shaft are made
in one piece, so that the two will always preserve their relative positions
and keep in gear notwithstanding the vertical movements of the engine
caused by the yielding of the springs.
In double rail lines having gradients higher than 1 in 80, I employ
a locomotive with two pairs of wheels coupled and capable of working
at either of two speeds. The arrangement of gearing is the same as
that for the single rail locomotive before described and the same
reference letters serve to indicate the same parts.
Figure 8 shows a longitudinal vertical elevation of the mechanism;
Figure 8 the continuation of the incline shown at Figure 8, while
Figures 9 and 9 show plans of Figures 8 and 8" respectively.
general arrangement of the engine is shown at A; r, r, c, c, two pairs
The

page_text: of driving wheels coupled together, the latter pair being provided with
the system of gearing before described for changing the speed; f, wheel
axle; g, small ring of teeth for high speed; h, nave of driving wheels;
j, circular rib or flange within which is carried the large toothed ring
for low speed; 1, pinion fixed on each end of the crank axle k; m, bolt,
and o nut for locking one or other of the toothed rings; n, handle of
same; 8, 8, pair of rails with a rack & placed at one side, on inclines
only. With this rack gears a ring of teeth u on one of the driving
wheels c.
Figure 10 shows a longitudinal vertical section of a passenger carriage
adapted for the single line railway before referred to, Figure 11 ȧn
end view, and Figure 12 a transverse section of same, while Figure 13
shows a plan of the under framing, the flooring being removed. The
same reference letters apply to all theso Figures.
The following are the features of novelty in this vehicle:-The vehicle
if for passenger service is entered at either end from platforms a¹, a', and
has longitudinal central seats b₁; a single central buffer c' is placed at
each end of the framing. The face of the buffer is curved in a horizontal
but not in a vertical direction, and the ends of the framing are also
curved to an arc of a circle. Beneath the framing is placed the coupling
link which connects to a radiating bar pivoted at d to a transverse lever
placed at a certain distance from the end of the carriage on which the
bar moves as a centre. The fulcrum of this lever is at e', which may
be movable within fixed limits and connected to a spring. The other
extremity f¹ of the lever is connected by rods g' with the corresponding
end of a similar lever at the opposite end of the carriage, a screw
coupling being provided in said rods 9' for tightening up when
required. The coupling is adjusted by a worm shaft & operated by a
ball lever at either side of the carriage. By this means the strain
is sustained by the draw bars alone and does not affect the carriage
framing. The springs on which the carriage is supported are located in
the hollow central back of the passengers' scats and connected by
suitable yokes with the bearings of the central guide wheels. The
vehicle is constructed for use on ordinary roads by making the fore
and rear grooved guide wheels removable and attaching shafts.
Having described the nature of the Invention, and in what manner
the same is to be performed, I declare that what I claim as the Inven-
tion to be protected by the herein-before in part recited Letters Patent

page_text: is, the system of locomotive constructed as set forth to work either
at a high speed or at a low speed when increased tractive power is
required whether for a single rail line or for an ordinary line, the latter
being provided with a rack rail at steep gradients, also the improved
construction of passenger carriage for single rail lines, the whole 5
constituting improvements in railways based on the novel means of
traction above specified, and illustrated in the Drawings.
In witness whereof, I, the said Alexander Melville Clark, have
hercunto set my hand and seal, this Twenty-fifth day of October,
in the year of our Lord One thousand eight hundred and seventy- 1
two.