Frictional Contact between the Wheels and Rails in Railways.
Year: 1888

page_text: Frictional Contact between the Wheels and Rails in Railways.
A communication from ELIAS ELKAN RIES, of Baltimore, State of Maryland, United
States of America, Electrician.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
My invention is based upon the fact that a strong adhesive effect between metallic
conductors in contact with each other is produced when an electric current is
passing from one to the other. This adhesion I have found to increase in proportion
to the quantity of current passing between the conductors; and this effect is
particularly noticeable when the frictional contact is a rolling one, as distinguished
from sliding frictional contact, although it is also noticeable in the latter case.
In the operation of electric railways I have found that when the current is
supplied to the motors on the cars through the rails upon which the wheels travel,
increased friction is caused by the passage of the current from the rails to the
wheels, and this increases the traction of the motor; but I have also found that
this result, although beneficial in some cases, is detrimental to the operation of the
system in other cases, for the increased traction will manifest itself at all times so
long as the current passes, i.e. so long as the motor is supplied with current and
moves. The mount of traction in a system of the kind indicated is, therefore,
not controlled by the operator or engineer, but fluctuates without regard to the
momentary requisitions of the system, and in most cases, in a manner contrary to
these demands.
Precisely the same thing I found to happen in such systems of electrical loco-
motion where the current is supplied to the motor through separate conductors, and
is returned through the wheels and traction rails; for as long as current is passing
to the motor in the manner indicated there will be increased traction due to the

page_text: increased friction between the wheels and rails at their points of contact, produced by
the current. The increased traction will, therefore, be present whether at a given
moment it may be desirable or not.
Now it is the object of my invention, to utilize the phenomenon of increased
friction produced by the passage of an electric current between the wheels of a 5
moior-car and the rails upon which it travels, for increasing the traction of the
moving vehicle at the will of the operator or driver so as to have it entirely
under control and adjustable according to the demand of the system from moment
to moment.
I accomplish this object in a variety of ways, all of which, however, have this in i
common, that I establish a self contained electric circuit travelling with the motor-car
or with any other car, upon the rails and including two or more wheels of the vehicle
and the rails extending between the same, and that I charge this circuit with an
electric current independently of the current passing through the electric motor, if
such motor be used. In case of steam propulsion the self contained circuit including 1
the rails and wheels and travelling with the vehicle, which circuit I shall herein-
after call the traction circuit, naturally independent of the steam motor, and an
electric current of any desired quantity may be passed through the same without
in any way or manner affecting the motive power. Thus, in both cases, the motive
power may be increased or diminished; and the motor may be run fast or slow, or it
may be stopped entirely while the frictional contact of the wheels with the rails may be
variably increased as desired, or as the circumstances may require.
In practising my novel method of increasing the traction of motors in general it is
preferable to employ a current of large volume and comparatively low tension in fact
the current must be such as to produce considerable heating effect at the points of
contact of the wheels with the rails, and unless such heating effect is produced to an
appreciable extent, there is no increase of traction.
I desire to emphasize this point, so that it may be understood that the current
ordinarily employed for signalling and other purposes will be entirely insufficient to
produce a perceptible trace of increased traction. The current therefore which must
be employed to have the beneficial effects aimed at, I shall hereinafter call a traction
current which will be understood to be such as produces a perceptible heating effect at
the juncture of two metallic conductors through which it passes.
The apparatus which I employ for practising my novel method may assume a
great number of forms, some of which I have illustrated in the accompanying drawings,
in which
Fig. 1 represents an elevation of a steam locomotive and a car attached to it, both
equipped with my invention.
Fig. 2 an electric motor-car similarly equipped.
Fig. 3 a plan view of a vehicle travelling upon conducting rails, with the source of
the traction current on the vehicle.
Fig. 4 a similar view of a slightly modified form of the arrangement shown in
figure 3, and
Fig. 5 is a diagrammatical view of an electric railway system in which the traction
current is derived from the main propelling current, being a modification of the
arrangement shown in figure 2.
Referring to figure 1, there is shown upon the locomotive a dynamo electric
generator A adapted to furnish an effective traction current; it is preferably driven
by a small steam engine B which is independent of the driving engine of the loco-
motive, and is supplied with steam from the steam chest of the latter. The dynamo
can thus be operated at any desired speed whether the locomotive is running or not,
and the circuits C C of this dynamo includes an adjustable rheostat F located in the
cab of the engineer, and the driving wheels of the locomotive as shown.
In the drawing, the circuit wires are shown as terminating at the axles of the
driving wheels, and it will be understood that they make contact with these axles
by brushes, or in any other suitable manner; the circuit may be traced with reference
to unfeathered arrows marked along the conductors. If it is desired to increase the

page_text: traction of a locomotive, the engineer closes the traction circuit at the rheostat by
means of a switch-lever, as shown, and he can increase or decrease the resistance of.
the traction circuit at will, and can thereby decrease or increase the amount of current
passing through the same. The current from the dynamo thus passes through the
wires CC and from one driving wheel or set of driving wheels to the other driving
wheel or set of driving wheels, through the intervening section of rails.
In figures 3 and 4 this arrangement of circuits is indicated with reference to an
apparatus in which any suitable source H of electricity is carried upon the loco-
motive or car; the two axles there shown may be supposed to be the driving axles
of a locomotive and one of these axles must be insulated from the body of the
locomotive. In figure 3 the circuit extends from one pole of the source of electricity
to a brush E bearing upon a collar D, fixed to one of the axles; at this point the
current divides and passes by the two wheels mounted upon that axle, and by the
rails on both sides of the wheels on the other axle, upon the collar D₁ of which the
current unites again and continues by a brush E and wire C to the rheostat F back to
the other pole of the source of electricity.
The circuit connections indicated in figure 4 presuppose that one of the wheels
is insulated from its axle as indicated at C; the circuit is then from one pole of the
source of electricity, by wire C', to brush d, bearing upon one of the wheels; then by
the rail on this side of the track to the wheels on the other axle, through that axle, and
by the wheel at the other end of said axle, through the rail on that side of the track,
to the insulated wheel of the first axle, and by brush d¹, bearing upon said wheel,
and by conductor to the rheostat F back to the other pole of the source of
electricity. Unfeathered arrows marked along the conductors facilitate the tracing of
these circuits.
Thus we see that the traction current may be sent in multiple arcs, composed
each of a section of rails on one side of the track and the two wheels bearing upon
the same, or it may be sent through four wheels of a truck in series with the inter-
vening rails in each case the current passes between four wheels and the rails and the
traction is considerably increased.
The circuits thus far described may be arranged upon the locomotive shown in
figure 1 in the manner indicated, in which case the dynamo A takes the place of the
generator H shown in figures 3 and 4.
Instead of driving the dynamo by a separate steam engine mounted upon the loco-
motive the same may be driven by suitable gearing connected with an axle of one of
the vehicles of the train.
This arrangement is shown in figure 1 as applied to the tender G ; but in order
to enable the engineer to control the traction independently of the motion of the train
the traction circuit is in this case not charged directly from the dynamo, but from
a secondary battery charged by the dynamo. The driving pulley I of the dynamo A
is connected by a belt J (shown in dotted lines) with a pulley K upon one of the
axles of the tender and the circuit L L which is the external circuit of the dynamo
charges the secondary battery H preferably in series while the traction circuit M M into
which the secondary battery discharges preferably in quantity includes an adjustable
rheostat Flocated in the cab of the engineer and the driving wheels of the
locomotive.
This circuit is easily traced by means of feathered arrows marked along the con-
ductors and it will be understood may pass either in multiple arc or in series through
the wheels and the rails between the same; substantially in the manner shown in
figures 3 and 4.
Thus it will be seen that when the source of electricity is mounted upon the
vehicle, the traction circuit may be made or broken, and more or less resistance
included in the same, without in any way or manner affecting the driving power;
the degree of traction employed is thus absolutely under the control of the
operator.
If a secondary battery is employed as in the case where the same is carried
upon the tender G, this secondary battery may be charged by a dynamo driven

page_text: rom an axle of the vehicle, as shown in figure 1, or it may be charged separately
at the starting station by independent dynamos there located and figures and 4
may be supposed to represent such system. If the charging dynamo is driven from
an axle of the vehicle, a great saving is accomplished, since in that case the
dynamo will be made to charge the secondary battery when the train is coming to
a stop or running on a down grade thus making use of the momentum of the train;
and the current stored during this process can be used to increase the traction when
the train is starting or when it is running upon an ascending grade, when it is
mosily needed.
In addition to charging the traction circuit the source of current upon the
locomotive or other vehicle may also be used for the operation of magnetic brakes or
electric head lights; such brake is conventionally indicated in figure 1 at N and the
circuit wires n proceeding from the same will be understood to be properly connected
with the source of electricity. In the drawing this connection has been omitted for
the sake of clearness of illustration, and because this use of the current does not
constitute a part of my invention.
In electric locomotion where the motor current is supplied through separate
conductors extending parallel with the track either in a channel between the rails,
or overhead, the traction current is derived from the main current either directly or
indirectly according to the nature of this current.
Figure 2 illustrates such system when a current of comparatively low tension
and great volume is employed for propulsion. Line conductors 00 one of which
only is shown in the drawing, are provided in a trench or channel, extending
between the rails QQ and a current collector composed of rollers R R takes the
current from the line conductors to the electric motor S which is geared to the
driving wheels as indicated in the drawings. A system of levers and rods actuated
by a crank under the control of the driver or engineer, is connected with the current
collector, whereby the latter may be brought to hear upon the line conductor, or to
break contact with the same, as is usual in such systems.
The motor circuit is indicated at t t etc., extending from one contact roller to the
motor and from the latter to the platform of the car or vehicle, where it includes
a resistance t', and from whence it returns, to the other contact roller; the drawing
clearly illustrates this circuit, which can be traced without difficulty. The means
for varying the power of the motor are not shown in the drawing; they may be
of any ordinary or improved construction and form no necessary part of the present
invention. The traction circuit embraces a shunt around the resistance t¹; it is
composed of the conductors gq etc.; the adjustable rheostat I, the contact brushes mm
bearing upon the driving wheels and the portions of the rails which extend between
these wheels.
The switch lever shown as a part of the rheostat F2 enables the engineer to open
and close the traction circuit and to introduce more or less resistance in the same
according to the requirements at a given moment; if increased traction is required,
the traction circuit is closed and is charged more or less according to the lesser or
greater amount of resistance introduced. This operation of the traction circuit does
not perceptibly affect the operation of the motor, for the two are in multiple arc
branches from the line, which line is charged by dynamos regulated according to the
demands of the system, the same as in systems of incandescent electric lighting; the
traction produced is therefore under the control of the operator and is independent of
the power supplied to the motor. It will be understood that the traction circuit will
be arranged as shown in figures 3 and 4 to include the wheels either in multiple arc
or in series.
If the motor current is one of high tension and small quantity which could not be
effectively used for the purpose of increasing frictional contact between the wheels of
the vehicle and the rails I convert the currents intended for the traction circuits
into currents of the required tension and volume and employ the arrangement shown
in figure 5.
. The line conductors OO may be arranged overhead or underground, and the
.

page_text: contact rollers R R are understood to be under the control of the engineer; the high
tension current is supplied to the motor S by conductors t t and a branch 77 including
an adjustable rheostat and switch lever which in this instance is not directly
connected with the traction circuit proper, but includes a commutator T designed to
render the continuous current derived from the motor circuit alternating or inter-
mittent. This commutator is composed of two flat cylinders T¹ T² each having a
crown of segmental teeth cut into one face with segmental spaces alternating with the
same. The two cylinders are each mounted upon a separate shaft u u² respectively
and are united together with their segmental teeth and spaces in mutual engagement
but insulated from each other as indicated in heavy lines.. The two shafts are in
alignment so that they have the effect of a single shaft constituting the commutator
and the latter is rotated about its shaft by any suitable means. Brushes bearing
on diametrically opposite sides of the commutator upon the segmental portions of the
same, establish each electrical connection alternately with one and the other of the
cylinders T T and these brushes are connected by wires c c with the terminals of
the fine wire coil U of the inductorium V the coarse wire coils H' of which is
connected with the traction circuit proper, composed of conductors W W rheostat F
the wheels of the vehicles, and the rails Q' between the latter.
The operation of this apparatus will now be easily understood. If it is desired to
increase the traction, the switch at rheostat F is manipulated, and the circuit through
commutator T, and coil U of the inductorium is enclosed with the desired resistance;
it will be apparent without further description that the current of high tension derived
from the motor circuit will traverse the high resistance or primary coil of the
inductorium as a series of alternating impulses following each other with great
rapidity and that similar alternating impulses of low tension will be generated in the
low resistance or secondary coils of the inductorium and will traverse the traction
circuit. The immediate source of current for the traction circuit is therefore the
coarse wire coil H¹ and the traction circuit will be arranged upon the vehicle
substantially in the manner shown in figures 3 and 4.
Both rheostats and switches F and F should be arranged within convenient reach
of the operator or engineer and in this form of my apparatus the same as in the forms
hereinbefore described, the traction circuit is self-contained upon the train or vehicle,
including the rails between the wheels and travelling with the same; at the same
time, the traction is completely under the control of the operator, and is independent
of the power supplied to the latter.
It is apparent that the principles of my invention may be embodied in apparatus
widely differing from the specific construction herein shown and described, and that
the methods of operation may be also variously changed without departing from the
fundamental idea which underlies my invention; I am for this reason not limited
to the identical features of details set forth in this specification.
It is obvious that the traction circuits need not necessarily be arranged in the
manner shown in figures 3 and 4 to include four wheels of the vehicle since it is
quite practicable to pass the traction current between two wheels only on one side of
the track; figures 1, 2 and 5 illustrate this mode of operation if no reference is made
to figures 3 and 4, and in the arrangement shown in figure 3 this will be the mode of
operation if the car or vehicle should be on a section of the track where the adjoining
rails on one side are accidentally insulated from each other at the fish plates as
frequently happens.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is :-
1. The method of increasing the traction of a wheeled vehicle moving upon a
metallic track, which consists in establishing and maintaining a traction circuit which
moves with the vehicle and includes two or more wheels and that portion of the rails
which extends between the same, and charging said circuit with a low tension current
of electricity; substantially as described.

page_text: 2. The method of increasing the traction of a wheeled vehicle moving upon a
metallic track which consists in establishing and maintaining a traction circuit which
is independent of the motive power moves with the vehicle and includes two or more
wheels and the portion of the rails extending between the same, and charging said
circuit with a low tension current of electricity; substantially as described.
3. The method of increasing the traction of a wheeled vehicle moving upon a
metallic track which consists in establishing .and maintaining a traction circuit which
moves with the vehicle and includes two or more wheels and the portion of the rails
extending between the same and variably charging said circuit with currents of low
tension; substantially as described.
4. The method of increasing the traction of a wheeled vehicle moving upon a
metallic track which consists in establishing and maintaining a traction circuit
which moves with the vehicle and includes two or more wheels and the portion of
the rails extending between the same in series, and charging said circuit, with a low
tension current or currents of electricity; substantially as described.
5. The combination of a closed electrical circuit moving with a railway car or
vehicle, including that portion of the track rails lying immediately below the said
vehicle, or between the driving wheels thereof; with a source of low tension electricity
for charging said circuit substantially as described.
6. The combination of an electrical circuit moving with a railway car or vehicle
including that portion of the track rails lying immediately below the said vehicle, or
between the driving wheels thercof; with a circuit controller for said circuit and a
source of low tension electricity for charging said circuit; substantially as described.
7. The combination of an electrical circuit moving with a railway car or vehicle
including that portion of the track rails lying immediately below the said vehicle;
with means for varying the resistance of said circuit and a source of low tension
electricity, for charging said circuit; substantially as described.
8. The combination with a wheeled vehicle adapted to travel upon an electrical
conducting surface or surfaces; of an electrical generator furnishing currents of low
tension and great quantity mounted upon the vehicle, and a traction circuit formed
in part by two or more wheels of the vehicle the rails extending between the same
and the generator; substantially as described.
9. The combination with a wheeled vehicle adapted to travel upon an electrical
conducting surface or surfaces; of an electrical generator furnishing currents of low
tension and great quantity mounted upon the vehicle and a traction circuit formed
in part by two or more wheels of the vehicle the rails extending between the same,
the generator and an adjustable rheostat; substantially as described.
10. The combination with metallic track rails of a motor car mounted thereon
having two connected pairs of driving wheels an electrical generator of currents of
low tension and great quantity mounted upon the motor car and an electrical circuit
including said generator each of the said pairs of driving wheels and the portion of
the conducting rails between the pairs of wheels; substantially as described.
11. The method of increasing the traction of electrically propelled vehicles, which
consists in establishing a traction circuit including two or more wheels of a vehicle
and the rails extending between the same and charging said circuit with currents
of low tension derived from the circuit supplying the motor; substantially as
described.
:
12. The method of increasing the traction of a wheeled vehicle moving upon a
metallic track which consists in transforming currents of high tension passing upon
the vehicle into currents of low tension and then passing such low tension currents
through a traction circuit including two or more wheels and the rails extending
between the same; substantially as described.
13. The method of increasing the traction of a wheeled vehicle moving upon a
metallic track which consists in establishing and maintaining a traction circuit
moving with the vehicle and including two or more wheels and the portion of the
rails extending between the same and charging said circuit with alternating electrical
currents of low tension; substantially as described.

page_text: 14. The combination of a wheeled vehicle moving upon metallic rails and an electric
motor mounted upon the vehicle for propelling the same; with a traction circuit
derived from the circuit supplying the motor including two or more wheels of the
vehicle and the rails extending between the same; substantially as described.
15. The combination of a wheeled vehicle moving upon metallic rails and an
electric motor mounted upon the vehicle for propelling the same; with a traction
circuit derived from the circuit supplying the motor, including two or more wheels
of the vehicle and the rails extending between the same, and an adjustable resistance
and switch in the traction circuit; substantially as described.
16. The combination of a wheeled vehicle moving upon a metallic track, and an
electric motor actuated by currents of low tension and high quantity mounted upon
the vehicle for propelling the same, with a circuit derived from the motor circuit
charging inductively with currents of low tension and great quantity a traction
circuit including two or more wheels of the vehicle and the rails extending between
said wheels; substantially as described.
17. The combination with a track composed of conducting rails; of a wheeled
vehicle mounted thereon; an electric circuit traversed by a current of high tension
for propelling said vehicle; a transformer or secondary generator having one of its
coils included in said circuit, and a traction circuit including the other coil of said
transformer two or more wheels of the vehicle and the rails extending between the
same; substantially as described.
18. In an apparatus for increasing the traction of railway vehicles, the combination
of a motor circuit traversed by the current of high tension, with a circuit derived
from the motor circuit provided with means for rendering said current alternating
and intermittent, including the high resistance coil of a transformer and a traction
circuit including the low resistance coil of the transformer, two or more wheels of the
vehicle and the rails extending between the same; substantially as described.
Dith: 504 M 1000