IMPROVEMENTS IN THE ROLLING STOCK OF RAILWAYS AND TRAMWAYS: ALSO IN TRACTION ENGINES AND OTHER VEHICLES
Year: 1868

page_text: LETTERS PATENT to Thomas Claxton Fidler, of Ventnor, in the Isle
of Wight, Civil Engineer, for the Invention of "IMPROVEMENTS IN
THE ROLLING STOCK OF RAILWAYS AND TRAMWAYS: ALSO IN TRACTION
ENGINES AND OTHER VEHICLES."
Sealed the 11th June 1869, and dated the 16th December 1868.
PROVISIONAL SPECIFICATION left by the said Thotnas Claxton Fidler
at the Office of the Commissioners of Patents, with his Petition, on
the 16th December 1868.
I, THOMAS CLAXTON FIDLER, of Ventnor, in the Isle of Wight,
Civil Engineer, do hereby declare the nature of the said Invention of
"IMPROVEMENTS IN THE ROLLING STOCK OF RAILWAYS AND TRAMWAYS; ALSO
IN TRACTION ENGINES AND OTHER VEHICLES," to be as follows, that is
to say:
This Invention relates to improvements in the rolling stock of railways
and tramways, in traction engines, and other vehicles, the object being
to enable sharp curves to be traversed with case and safety, and to
enable engines and carriages of longer wheel base to be employed on
curves of ordinary radius to avoid the lateral slipping of wheels and the

page_text: sinuous oscillations of engines and carriages, and the consequent wear
and tear and destruction of rolling stock and permanent way, and the
great increase of resistance on curves.
Arrangements are employed whereby each pair of wheels is allowed.
free lateral play to adjust itself to the curvatures of the rails, the axle of
each pair of wheels being at the same time maintained in à line radial
to the curve traversed, whatever its radius, or at right angles to the rail
below it, or nearly so. With this object each pair of wheels is mounted
on a separate frame or truck (except in cases where, as herein-after
cxplained, it is expedient to mount two or more pairs in any one truck),
and any number of such trucks, not less than three (and by preference
three), are connected together to form one articulated frame. One such
-articulated-frame_may_form the frame of a locomotive or traction engine
or engines, of-an-engine_and_tender, of an engine and carriage-or
carriages, or a carriage or carriages, or any wagon or wagons.
For-
the purpose of coupling two or more pairs of wheels, or for the purpose
of preventing vertical oscillations, or for the purpose of diminishing the
load on each pair of wheels, two or more pairs of wheels may be mounted
in any of the trucks; and when this is done all the wheels in one truck,
except one pair, may be without flanges.
In the following description of the arrangements of apparatus
comprised under this Invention it is assumed, for the sake of clearness
and brevity, that each truck has only one axle. When any truck has
more than one axle the centre of its wheel base or the axle of that pair
of wheels which is flanged may be taken to represent the axle herein-
after referred to.
The apparatus or mechanism comprised under this Invention is so
arranged that of the three trucks composing one articulated frame the
two end trucks are able to deflect to any required extent, and on either
side from the line of the middle truck, but always both on the same side,
and that the amount of angular deflection of the centre line of one end
truck from the centre line of the middle truck produced, or the supple-
ment of the angle contained between those centre lines, always bears
that proportion to the angular deflection of the centre line of the other
end truck from the centre line of the middle truck that the distance
from the centre of the axle of the middle truck to the centre of the axle
of the first-named end truck bears to the distance from the centre of the
axle of the middle truck to the centre of the axle of the second-named

page_text: end truck, or nearly so, so that whatever may be the relative position
laterally of the three pairs of wheels, the centre lines of their respective
trucks shall form tangents to that circular curve which may be
described, passing through the three points in the middle of the three
axles, and shall touch the said curve at those three points, and the axles
themselves being perpendicular to the said centre lines shall form
normals or radial lines to the said circular curve. One method of
connecting the three trucks composing one articulated frame so as to
maintain the axle of each radial to the curve traversed or nearly so is to
joint the three trucks together consecutively, that is, the first with the
second and the second with the third, by centres situated in their
centre lines and midway between the axles of the two adjacent trucks,
or nearly so, and further to connect the first and third, or the two end
trucks, over, or under, or between, or outside the frame of the middle
truck, and at a point in the length of the middle truck which divides
that length (measured between the joints) inversely in proportion to the
length of each end truck from its connection with the middle truck to
its axle, or nearly so. This connexion between the two end trucks may
consist of two toothed segmental arcs gearing together, and with smooth
edges touching one another at their pitch circles, the radii of the two
arcs dividing the length between the centres in the proportion above
mentioned; or of two smooth segmental arcs touching one another, and
of the radii above mentioned, and one large tooth in the centre long
enough never to come out of the recess in the opposite arc; or one of
the smooth segmental arcs may carry two half teeth or epicycloidal arms
placed at a convenient distance apart and working between two jaws
carried by the other arc; or two straight or curved rods or bars may be
carried upon one arc sliding in sockets or guides carried upon the other;
or one arc may carry one or more pins, rollers, or blocks working in
guides carried by the other; or the two arcs may be bound together by
flexible bands of thin steel, or leather, or other material, or. by chains, or
by connecting rods crossing each other, and the segmental arcs may
when necessary be tongued and grooved, or may be formed of a V
section, or with a number of V grooves.
Another method is to connect the three trucks consecutively, as above
described, and to carry an arm or a pair of arms at a convenient distance
apart on the inner end of each end truck, the arms of one truck carrying
rods or bars sliding in sockets or guides carried by the other, or pins,

page_text: rollers, or blocks working in guides carried by the other, the object in all
cases being to prevent any lateral or vertical play between the connected
ends of the two end trucks, but to allow angular play.
Another method is to connect the two end trucks by pins or
segmental joints with radius bars, and to connect the two ends of the
middle truck to the two end trucks at distances determined as above
explained, or nearly so, by pins or other joints, the necessary longi-
tudinal play being allowed in one or both such joints; or the middle
truck may be connected at one end or both ends to the corresponding end
truck or trucks by an arm or pair of arms carried on the middle truck,
and the said arm or arms connected with the end truck by rods or bare
carried on the one and sliding in sockets or guides carried on the other;
-or-by-pins, rollers, or blocks carried on the one, and working in guides
carried-on-the-other. The ends of the two end trucks may be carried
on the middle truck; also when the end trucks have more than one pair-
of wheels the ends of the middle truck may for certain purposes
be
carried on the end trucks, so as to increase the load on the end trucks,
and the weight in either case may be borne by the pin or bogie con-
nection, which may be spherical or of other forin, and may be provided
with india-rubber or steel springs of any form; or the weight may be
borne partly or wholly by rollers arranged radially to the centres of
motion, and placed in any convenient part of either truck. The rollers
may also be provided with springs, and the roller path may either be
horizontal or inclined both ways. Any of the rollers may also be pro-
vided with screws and hand wheels or other suitable. means for varying
the load upon them. Horizontal springs may be applied to any of the
connections which have longitudinal play, also screws, keys, or other
appliances may be adapted to the sliding or turning parts to adjust the
friction. When an engine occupies one of the trucks, and its tender or
a carriage carrying water occupies another, the water connection may be
taken through the centre or centres of motion. When twin engines
occupy two of the trucks their reversing gear may be connected at or
near the centre or centres of motion. To traction engines and vehicles
intended to run upon common roads the same principle is applied, and
the radius and direction of the curve to be traversed may be fixed by
means of a screwed shaft carried in bearings transversely on the middle
truck, having a nut working upon it connected to the joint between the
two end trucks, or to a point on one or both of them situated near their

page_text: inner ends, or by means of an endless screw and worm wheel carried
near the end of one end truck, and actuating a pitch chain attached at
both ends to the middle truck, or the chain may be attached to the end
truck or trucks or the joint between them, and the wheel and screw
carried upon the middle truck, or other similar methods of fixing the
deflection may be adopted.
be adopted. Any of the trucks composing the frame of a
traction engine or other common road vehicle may have one central
wheel in place of a pair of wheels.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Claxton Fidler in the Great Seal Patent
Office on the 15th June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
CLAXTON FIDLER, of Ventnor, in the Isle of Wight, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of December, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Claxton Fidler, Her special
license that I, the said Thomas Claxton Fidler, my executors, adminis-
trators, and assigns, or such others as I, the said Thomas Claxton
Fidler, my executors, administrators, or 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
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN THE ROLLING STOCK OF RAILWAYS AND TRAMWAYS; ALSO IN
TRACTION ENGINES AND OTHER VEHICLES," upon the condition
the condition (amongst
others) that I, the said Thomas Claxton Fidler, by an instrument
in writing under my hand and seal, 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 Thomas Claxton Fidler, do hereby
declare the nature of my said Invention, and in what manner the samié

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:
This Invention relates to improvements in the rolling stock of railways
and tramways, in traction engines, and other vehicles, the object being
to enable sharp curves to be traversed with ease and safety, and to
enable engines and carriages of larger wheel base to be employed on
curves of ordinary radius to avoid the lateral slipping of wheels, and the
sinuous oscillations of engines and carriages, and the consequent wear
and tear and destruction of rolling stock and permanent way, and the
increase of resistance on curves. Arrangements are employed whereby
-each-pair of wheels is allowed free lateral play to adjust itself to the
Turvatures-of-the rails, the axle of each-pair of wheels being at the same
time maintained in a line radial to the curve-traversed, whatever its
With this
radius, or at right angles to the rail below it, or nearly so.
object each pair of wheels is mounted on a separate frame or truck
(except in cases where, as herein-after explained, it is expedient to
mount two or more pairs in--any one truck), and any number of such.
trucks, not less than three (and by preference three), are connected
together to form one articulated frame. One such articulated frame
may form the frame of a locomotive or traction engine or engines, of an
engine and tender, of an engine and carriage or carriages, of a carriage
or carriages, or of any wagon or wagons. For the purpose of coupling
two or more pairs of wheels, or for the purpose of preventing vertical
oscillations, or for the purpose of diminishing the load on each pair of
wheels, two or more pairs of wheels may be mounted in any of the
trucks; and when this is done all the wheels in one truck, except one
pair, may be without flanges.
In the following description of the arrangements of apparatus comprised
under this Invention it is assumed, for the sake of clearness and brevity,
that each truck has only one axle. When any truck has more than one
axle the centre of its wheel base, or the axle of that that pair of wheels
which is flanged, may be taken to represent the axle herein-after
referred to.
The apparatus or mechanism comprised under this Invention is so
arranged that of the three trucks composing one articulated frame, the

page_text: two end trucks are able to deflect to any required extent, and on either
side from the line of the middle truck, but always both on the same side,
and that the amount of angular deflection of the centre line of one end
truck from the centre line of the middle truck produced, or the supple-
ment of the angle contained between those centre lines, always bears
that proportion to the angular deflection of the centre line of the other
end truck from the centre line of the middle truck that the distance
from the centre of the axle of the middle truck to the centre of the axle
of the first-named end truck bears to the distance from the centre of the
axle of the middle truck to the centre of the axle of the second-named
end truck, or nearly so, so that whatever may be the relative position
laterally of the three pairs of wheels, the centre lines of their respective
trucks shall form tangents to that circular curve which may be described
passing through the three points in the middle of the three axles, and
shall touch the said curve at those three points, and the axles themselves
being perpendicular to the said centre lines shall form normals or radial
lines to the said circular curve. One method of connecting the three
trucks composing one articulated frame so as to maintain the axle of
cach radial to the curve traversed or nearly so is to join the three trucks
together consecutively, that is, the first with the second and the second
with the third, by centres situated in their centre lines and midway
between the axles of the two adjacent trucks, or nearly so, and further to
connect the first and third, or the two end trucks, over, or under, or
between, or outside the frame of the middle truck, and at a point in the
length of the middle truck which divides that length (measured between
the joints) inversely in proportion to the length of each end truck from
its connection with the middle truck to its axle, or nearly so.
This
connection between the two end trucks may consist of two toothed
segmental arcs gearing together, and with smooth edges touching one
another at their pitch circles, the radii of the two arcs dividing the
length between the centres in the proportion above mentioned; or of two
smooth segmental arcs touching one another, and of the radii above
mentioned, and one large tooth in the centre, long enough never to come
out of the recess in the opposite arc; or one of the smooth segmental arcs
may carry two half teeth or epicycloidal arms placed at a convenient
distance apart, and working between two jaws carried by the other arc;
or two straight or curved rods or bars may be carried upon one arc,
sliding in sockets or guides carried upon the other; or one arc may carry
one or more pins, rollers, or blocks working in guides carried by the

page_text: other; or the two arcs may be bound together by flexible. bands of thin
steel or leather, or other material, or by chains, or by connecting rods
.crossing each other; and the segmental arcs may when necessary be
tongued and grooved, or may be formed of a V section, or with a number
of V grooves.
Another method is to connect the three trucks consecutively, as
above described, and to carry an arm or a pair of arms at a convenient
distance apart on the inner end of each end truck, the arms of one
truck carrying the rods or bars sliding in sockets or guides carried by the
other, or pins, rollers, or blocks working in guides carried by the other,
the object in all cases being to prevent any lateral or vertical play
between the connected ends of the two end trucks, but to allow angular
Another method is to connect-the-two-end-trucks_by_pins or segmental
joints with radius bars, and to connect the two ends of the middle truck
to the two end trucks at distances determined as above explained, or
nearly so, by pins or other joints, the necessary longitudinal play being
allowed-in-one or both such joints; or the middle truck may be connected
at one end or both ends to the corresponding end truck or trucks by an
arm or pair of arms carried on the middle truck, and the said arm or arms
connected with the end truck by rods or bars carried on the one and
sliding in sockets or guides carried on the other; or by pins, rollers, or
blocks carried on tlie one and working in guides carried on the other.
The ends of the two end trucks may be carried on the middle truck; also
when the end trucks have more than one pair of wheels the ends of the
middle truck may for certain purposes be carried on the end trucks so as
to increase the load on the end trucks, and the weight in either case may
be borne by the pin or bogie connection, which may be spherical or of other
form, and may be provided with india-rubber or steel springs of any form,
or the weight may be borne partly or wholly by rollers arranged radially
to the centres of motion and placed in any convenient part of either truck.
The rollers may also be provided with springs, and the roller path may
either be horizontal or inclined both ways. Any of the rollers may also
be provided with screws and hand wheels or other suitable means for
varying the load upon them. Horizontal springs may be applied to any
of the connections which have longitudinal play, also screws, keys, or
other appliances may be adopted to the sliding or turning parts to adjust
the friction.

page_text: And in order that my said Invention may be properly understood I now.
proceed more particularly to set forth the system, mode, or manner in or
under which the same is or may be used or practically carried into effect,
reference being had to the accompanying Drawings, and to the letters
and figures marked thereon, that is to say:-
In Sheet 1, Figure 1 is a diagram plan of an articulated frame of three
trucks with three axles equally spaced shewing the position of the
various parts upon a curve; Figure 2 is a diagram plan shewing the
position of the parts with the three axles unequally spaced. In both
these Figures a, b, is the centre line of one end truck, and c, d, the
centre line of the other end truck, which are connected together at their
inners ends b and c by apparatus or means herein-after more particularly
described, and in such a manner as to allow of no lateral play between
them. m, n, is the centre line of the middle truck, which is swivelled
at the ends me and n to the points m and n in the centre lines of the end
trucks a, b, and c, d, e, o, f, is the centre line of the axle of the truck
a, b; g, s, h, the centre line of the axle of the truck m, n; and k, p, l,
the centre line of the axle of the truck c, d,
In Figure 1 the distances o, m, m, s, s, n, n, p, are all equal, the axles
being equally spaced, and the length m, b, is therefore made equal to
the length n, c, so that whatever the curve of the rails e, g, h, f, h, l, may,
be the angle b, m, n, which represents the angular deflection of the truck
a, b, from the line of the middle truck m, n, or the supplement of the
angle a, m, n, contained between the centre lines of those trucks is always
equal to the angle c, n, m, which is the angular deflection of the other
end truck c, d, so that the centre lines of the three trucks a, b, m, n, c, d,
always form tangents to the circular curve o, s, 2, which is the centre line
of the railway if the curve is continuous through the length o, p, and is
always nearly the centre line of the railway, and the axles e, o, f, g, s, h,
k, p, l, being fixed at right angles to the three centre lines at the points
0, 8, 2, always form radial lines to the said circular curve.
In Figure 2 the axles are unequally spaced. The length o, m, is equal
to the length m, s, and the lengths, n, is equal to the length n, p, but
the length m, s, is greater than the length s, n. In this case the
length m, b, is made equal to the length s, n, and the length c, n,.
equal to the length m, s, so that the angle b, m, n, bears the same
proportion to the angle c, n, m, that the length m, s, bears to the
lengths, n, or nearly so, and the three centre lines form tangents to

page_text: the truck a, b, being fixed parallel to the axle e, f, and at equal
. distances from it. Moreover, as the only consequence of departing
slightly from the proportions as above determined would be to throw
some of the axles slightly out of the radial position, and as it
may be advantageous for other reasons to choose other proportions,
therefore I do not confine myself to these or any proportions or
dimensions; thus in Figure 1 the length of the middle truck may
be made shorter, as at m₁, n₁, throwing the end axles in the position
e₁, fi, and k₁, l₁.
Figure 3 is a side elevation, and Figure 3a a plan of the articulated
-frame-of-a-carriage or other vehicle. The elevation is drawn as it would
appear on a straight-line, and-the-plan-as-it-would appear_on_a_curve,
and the same letters are used in both Figures to indicate the same
parts, and the same principles are followed in all the Drawings referring
to any modification of this Invention contained in the Sheets hereunto
appended, and the details of the framing and other parts are often
omitted for the sake of clearness. a and c are the two end trucks
forming the frames of two half bodies of a carriage or other vehicle;
b is the middle truck swivelled. by the ends to the end trucks at the
centres d and e and supporting the inner ends of the end trucks
by the rollers n, n, n, n, arranged radially to the centres of motion
d and e; also volute or other springs may be inserted between the
middle truck and the end trucks at the centres d. and e, as shewn
in Figure 3, to carry a portion of the load and permit a vertical
deflection of the articulated frame in passing over an uneven track.
The inner headstocks f and g of the end trucks are formed near the
middle as segments of circles from the centres d and e, and touch
each other in any position of the frame so as to take through
them the bufling strain, but they may also be of any other form
and kept apart, and the bufling strain taken through the middle
truck. The headstocks are connected together so as not to allow
any lateral play between them by the pin or block carried by
the headstock g and working in a slot in the guide iron k attached to
the headstock f and allowing longitudinal play.
Figures 4, 5, 6, 7, 8, and 9 show other methods of connecting the
headstocks and g or inner ends of the end trucks a and c in Figure 4

page_text: by means of toothed segments & and e gearing together in Figure 5 by
the bands of thin steel or leather d, e, and k, l, which are wrapped in
opposite directions round the rolling segments of the alternative head-
stocks, and strained in tension in Figure 6 by the diagonal connecting
rods d and e crossing each other, and also strained in tension in Figure 7
by the large tooth a working in a recess in the opposite headstock in
Figure S by the two arms or half teeth e, e, working between the jaws d
and d₁, and in Figure 9 by the pins, rollers, or blocks e and e, working
in the guides d and d₁.
Figure 10 and Figure 11 are longitudinal sections shewing how the
segmental headstocks f and g of the end trucks a and c may be tongued
and grooved to prevent any vertical play between them.
Figure 12 is a side elevation, and Figure 12a a plan shewing how the
end trucks a and c may be connected by a segmental joint f and radius
bar g. The middle truck bis centred at d to the end truck a, and at e to
the end truck c, and a certain amount of longitudinal play is allowed
at e. The rollers n, n, n, n, supporting the inner ends of the end trucks
may also be carried near the ends of the middle truck, as shown in the
Figures, or in any intermediate position, and two pairs of wheels may be
mounted in the middle truck to equalize the distribution of the load.
•
Figure 13 is a plan shewing the ends of the end trucks a and c
connected by a joint k in two bars 7, 7, which slide in strong guides g, 9,
fixed to the headstocks. India-rubber or steel springs s, s, are applied
to the bars, and may be cottered up so as to put the bars in initial
tension. These springs give to the combination an elasticity or tendency
to preserve or return to the straight position. The draw bar t may also
be attached to the bars 7, so as to pass the tensile strains directly
through them. The buffing strains may be taken through the middle
truck, of which a, b, e, is the centre line, or through ordinary buffers
applied between the trucks a and c.
Figure 14 is a side elevation and Figure 14a a plan of an articulated
frame supporting an engine and tender. a is the engine occupying one
end truck, which may have two or more pairs of wheels coupled, and I
prefer to flange the leading wheels, and leave the other wheels of this
truck without flanges; c is the tender occupying the other end truck,
and connected to the engine at f by a pin, or by a segmental joint and
radius bar, as shown in Figure 12a; b is the middle truck swivelled to

page_text: the engine at d and to the tender at e, and longitudinal play may be
allowed at either of the joints d or e, and springs of any form may be
applied at the joint, which has longitudinal play to take up the longitu-
dinal strains, which springs are omitted in the Drawing for the sake of
clearness. Also the longitudinal play may be allowed for in the joint f,
as shewn at k in Figure 3a, or any of the modifications shewn in Figures
4 to 13 inclusive may be applied to this or any other modification of
this Invention shewn in the accompanying Drawings. The middle
truck supports the tender by the rollers n, n, and it may also support
the engine by rollers. Also either of the trucks may have two or more
pairs of wheels, and instead of a tender a carriage or wagon may occupy
the truck c.
In Sheet 2, Figure 1 is a side elevation, and Figure la a plan of a
-locomotive engine and tender for working steep gradients arranged-on-
an articulated frame, the middle truck carrying an auxiliary pair of
cylinders. a is the tender occupying one end truck; c is the boiler of
the engine occupying the other end truck, and having a pair of cylinders
at p fixed in the ordinary way, and working the two or more pairs of
coupled wheels attached to that truck; bis the middle truck carrying
an auxiliary pair of cylinders k, k, driving the coupled wheels attached
to that truck; the middle truck is swivelled to the truck c by the
centre e, through which the steam pipe may pass for the supply of the
cylinders,, and the joint of the exhaust pipes may be made by
stuffing boxes at m, m, to allow for the motion of the trucks b and c.
The two end trucks are connected together at f by a pin, the middle
truck is also connected to the end truck a at the joint d, which may
have longitudinal play, the tensile and buffing strains being taken up by
the spring g.
The middle truck supports the end of the boiler, and
derives load for the adhesion of its wheels by the rollers n, n, also a part
of the weight of the tender may be carried by the middle truck. The
reversing gear r, r, r, of the forward cylinders ? is carried upon the
truck c, the lever being fixed at the side of the fire-box, and the
reversing gear 1, 1, of the auxiliary cylinders k, k, may be carried at
the side upon the foot plate carried by the middle truck, so that the
motion of the trucks in going round curves does not affect the position
of the gear.
Figure 2 is a side elevation. and Figure 2a a plan of a pair of twin

page_text: engines with a tender between them connected together upon an
articulated frame. a and care the engines, placed fire-box to fire-box,
and occupying the two end trucks, and connected together at i under
the tender by rolling segments, and y, and by any of the types of
connection previously described; b is the tender, occupying the middle
truck, and swivelled to the two engines at d and e. Any portion of the
weight of the tender, except as much as may be left on the wheels of
the middle truck for guiding that truck, may be transferred to the
trailing wheels of the two engines for adhesion, either through the
joints d and e or by the intervention of rollers.
Figure 3 is a side elevation, and Figure 3a a sectional plan of a com-
bination of engine and carriages or steam carriage especially adapted
for working a limited passenger traffic on branch lines, light railways,
and street tramways, and upon heavy gradients and sharp curves.
a and c are two carriage bodies occupying the two end trucks of an
articulated frame, and connected together at by a pin or other pre-
viously described connection allowing for the longitudinal play; b is
the middle truck, carrying a small locomotive tank engine, having by
preference a vertical boiler; the middle truck is swivelled to the two
end trucks by the centres d and e, through which the propulsion is
effected, and carries the inner ends of those trucks by the rollers n, n, n, n,
placed near the ends of the middle truck, and also by the rollers 7 placed
nearer to the centre of the middle truck and to the ends of the end
trucks; these rollers 7 work upon paths s fixed to the middle truck, and
are carried by bearings provided with screwed shafts and hand wheels o, o,
so that they can be raised from the paths for the purpose of throwing a
larger portion of the weight of the carriages upon the middle truck for
ascending steep gradients, which is effected by allowing the carriages to
rest upon the rollers n, n, which are nearer the centre of gravity of the
carriages than the rollers r. For the purpose of this modification I
prefer to employ carriages with entrance at the ends, and seats arranged
longitudinally, as shewn in Figures 3 and 3a, and with the floor or
footway placed between the wheels, as shewn more particularly in
Figure 3b, which is a cross section taken through the centre d and the
rollers n, n. In this way I propose to lessen the height from the rails
or roadway to the floor of the carriage, and also the height of the roof,
so that the driver who is stationed upon an elevated platform, shewn in

page_text: dotted lines in Figure 3, can easily see over the carriages in both
directions. But in this and in all the modifications of this Invention
shewn in the Drawings I do not confine myself to any particular type
of carriage or engine, nor to inside or outside cylinders, nor to inside or
outside bearings, nor to any particular number of wheels in each truck,
and the form of connection between the several trucks shewn in any one
of the Figures is applicable to the modification shewn in any other

page_text: Sixth. The arrangement or combination of an engine and two
carriages upon the three trucks of an articulated frame, as herein-before
described and illustrated at Figures 3, 3a, and 86, Sheet 2 of the
annexed Drawings.
In witness whereof, I, the said Thomas Claxton Fidler, have here-
unto set my hand and seal, this Twenty-sixth day of May, One
thousand eight hundred and sixty-nine.
described and illustrated at Figures 3, 3a, and 36, Sheet 2 of the
nnexed Drawings.
In witness whereof, I, the said Thomas Claxton Fidler, have here-
unto set my hand and seal, this Twenty-sixth day of May, One
thousand eight hundred and sixty-nine.
In witness whereof, I, the said Thomas Claxton Fidler, have here-
unto set my hand and seal, this Twenty-sixth day of May, One
thousand eight hundred and sixty-nine.
THOMAS CLAXTON FIDLER. (L.S.)