Improvements in and in connection with Electrical Signalling Apparatus for Preventing Collisions between Trains on Railways.
Year: 1889

page_text: Date of Application, 27th Aug., 1889
Complete Specification Left, 23rd May, 1890-Accepted, 26th July, 1890
PROVISIONAL SPECIFICATION.
Improvements in and in connection with Electrical Signalling
Apparatus for Preventing Collisions between Trains on Railways.
A communication to me from abroad by THEODOR VERLS, of Würzburg, in the
Empire of Germany.
I.EDMUND EDWARDS, of the firm of Edwards and Co., Patent Agents and Engineers,
of 35, Southampton Buildings, Chancery Lane, in the County of Middlesex.dohereby
declare the nature of this invention to be as follows:-
This invention has for its object the prevention of collisions between locomotive
engines or trains travelling in the same or opposite directions upon the same line of
rails, and also to give notice at the right time of the threatening danger to the drivers
of both locomotives by means of electrical bells.
In order to put the invention into operation pairs of conducting wires are arranged
near the main rails of the railway between and parallel with the latter,one pairbeing
arranged near each rail. These conducting wires are carried by supports upon the
wooden transverse sleepers, or if iron sleepers are used they are carried by the latter
with the intervention of suitable electrical insulators.
These wires serve as conductors for a current of electricity, the left hand ones of
each pairbeing continuous, and therebeing nobreak or interruption in theirlength for
the distance over which they extend, whilst the right hand wire of each pair is inter-
rupted at regular distances by a non-conductor inserted into them. The interruptions
in these two wires are not opposite one another, those in each wire being intermediate
between those of the other wire.
The apparatus upon the locomotive is constructed as follows:
Upon the footplate, or near it, is arranged in a convenient position an electrical
battery of one or more elements, insulated covered wires being connected to the poles
of the battery, and carried along the right hand side of the boiler to two helical
terminals which pass through an opening in the bottom or front of the smoke box, to
a small double disc or wheel. The circumference of one part of this double disc is in
electrical contact with the wire from the negative pole or battery, whilst the circum-
ference of the other part is in electrical contact with the wire from the positive pole.
The two parts of the double disc are separated by an insulator and are carried by
au axle so that their circumference can run, when the engine is in movement, upon,
and in electrical connection with, the right hand pair of the wires carried by the
sleepers as described. In order to keep the wires clean a cleaning bar or brush is
carried by the axle in front of the rollers but insulated from them.
A conducting wire also passes from the negative pole of the battery to the binding
screw of an electric bell (of the kind ordinarily used in dwelling houses) and from the
binding screw, as well as from the other side of the bell apparatus, pass two insulated
wireswhich leadalong the left hand side of the engine to two helical terminals similar
to those upon the right side, and leading through an opening in the smoke box
to a double dise orwheel similar to that describedupon theright hand side,and having
the circumference of its two parts running upon the left hand pair of wires carried by
the sleepers.
In the second locomotive (which is accidentally running upon the same line as the
firstone,)similar apparatus to that described upon thefirst locomotive is alsoarranged,
two insulated wires running from the electrical bell to the front of the engine,
upon its left side, to two helical terminals connected with the circumference of a
double wheel, running upon the right hand pair of wires carried by the
sleepers.
From the first binding screw of the bell is also carried a conducting wire to the

page_text: negative pole of a battery, and from this, as well as from the positive pole of
the same battery, two insulated wires pass to the front of the locomotive on its
right side to two helical terminals, connected like those already described, to the
rim or circumference of a double wheel, which runs upon the left hand pair of
insulated wires carried by the sleepers.
As already explained the right hand wires of each pair are interrupted by non-
conducting insulators, arranged alternately at determined distances apart, in such
manner that the two locomotives cannot run upon the same section or length
of conducting wires without a signal being automatically given by means of the
electrical apparatus.
Should both locomotives be approaching one another upon the same section, in
which the wire of the right hand pair has its continuity interrupted, the left
hand wire of the right hand pair, and both wires of the left hand pair conduct
the current.
As soon as the locomotives are so near together that the right hand wire of the
right hand pair is no longer interrupted, the electrical bells upon both locomotives
will be sounded by the current passing through both wires of the right hand pair and
the left hand wire of the left hand pair.
In the case of a locomotive which is running in the opposite direction, (that is to
say, is running backwards.) without having been turned round, a slight alteration in
the electrical apparatus is necessary, the connection of the wires being altered to suit
the altered circumstances.
All locomotives which are running in a determined direction must have the wires
between the bells and the batteries connected to correspond, whilst all those running
in the opposite direction must have the arrangement altered to correspond with the
different conditions, with the exception of those engines which run backwards, the
bells and their connections in both locomotives being arranged to come into operation
in the proper way.
In order to give signals between two locomotives, where one is either meeting or
following the other on the same line of rails, the wires laid between the rails are
so arranged that one is in the centre and the others at equal distances at each
side of it, one to the left and two to the right of the central one, and five contact
rollers are arranged in front of each locomotive, four of them being in contact
with the four wires and the left hand one running free. Of the four wires the right
hand and the central ones are continuous through the section of the line on
which they are laid, whilst the other two are interrupted by insulators as already
described.
These interruptions are not situated onthe same sleeperbut areintermediate between
one another, as already described.
Upon or near the footplates of the locomotives, electrical batteries are arranged.or
generators actuated by the movement of the engine.
From the positive and negative poles of the generating apparatus two insulated
wires are carried along the rightside of the engine and end inhelical terminalswhich
passthrough an opening in thebottom ar front of the smoke box, and are in electrical
contact with the rim or circumference of the rollers running uponthe centraland left
hand conducting wires below, the central roller being in contact with the wire from
the positive pole,and the roller to the left of it being in contactwith thewire fromthe
negative pole. Moreover a wire connects the positive pole to one of thebinding screws
of an electrical bell; and from the second binding screw of the bell iwo wires pass
along the left hand side of the engine to two helical terminals (similar to those
upon the right hand side) which are in electrical contact with the rim or
circumference of the two rollers which run upon the two right hand conducting
wires below.
Before the extreme right hand wire joins its helical terminal a second wire is
connected to it which passes to a helical terminal which is in contact with the rim of
the extreme left hand roller which runs free as above described.
In the other locomotive. which is accidentally running upon the same line

page_text: as the first, is arranged apparatus in every way similar to that upon the first
locomotive.
The centralrollers of both locomotives which are meeting one another run upon the
central conducting wire below, the extreme left hand roller of one engine and the
extreme right hand roller of the other engine running free.
The central conducting wire is in communication with the positive pole, and
the wires on each side of it with the negative pole, whilst the extreme right handcon-
ducting wire is neutral and serves to connect the bells of both locomotiveswhenthey.
accidentally approach one another on the same line of rails.
As already explained the two conducting wires upon each side of the central one
are alternately interrupted by non-conductors, these interruptions being alternate as
otherwise the signals between the two electrical bells would not be given.
Moreover the interrupted wires are so connected that always a little before each
interruption of the right hand one, a connectingwire passes from it to a point one and
a half sections distant, and communicates with a point just in advance of the next
interruption but one onthe otherwire. The operation of this connectingwire is not for
the purpose of indicating if two engines are meeting one another onthe sameline, but
to showif one engine is catching upthe otherwhen following upon the same line,and
bythe signal bells to prevent a collision, the positive anduegative poles of an electric
generator being connected so as to close the circuit. If two engines are meeting in
oppositedirections, the negative pole of the first engine at the timewhen the left hand
conducting wire below, through the approach of the two meeting locomotives, is no
longer insulated by a break, is connected with the second binding screw of the bell of
the second engine, whilst the positive poles of the two batteries are connected
together, and that of the second engine with the first binding screw of its bell.
The bell on the second engine rings, and at the same time the neutral or extreme
right hand conducting wire is connected to the negative pole, and the positive pole
of the battery of the first engine is connected with the first binding screw of its bell
which rings as the currentpassesfrom the second binding screw of the secondengine,
through the right hand conducting wire to the other binding screw of the bell on the
first engine, to the battery of the same engine,and from the positive pole of the latter
back to the bell on the first engine.
The operation is analogous if the alternate conducting wire is the one which
comes into operation. The current then passes from the negative pole of the
second engine to the second binding screw of the first engine, and to the positive
pole of the battery of the latter, the current from the negative pole passing through
the central lower conducting wire, to the bell in the second engine which sounds at
the same time as that in the first. In this case the connecting wires which always
connect the alternate wires, which are insulated at intervals as described, do not
influence the operation of the current. These connecting wires are only of service if
two trains are accidentally following one another on the same line and come so near
that it is necessary to prevent the chance of a collision.
In this case if the engine of the hindermost train is just approaching an interrup-
tion inthe left hand lower interrupted conductingwire, and theleading engine is just
in advance of an interruption in the right hand lower interrupted conducting wire,
connection is made so that the bells on both engines ring. The current passes from
the negative pole of the battery on theleading enginethroughthe two interrupted con-
ducting wires, and the connecting wire which connects two of their sections, to the
binding screw of the bell in the hindermost engine, the other binding screw of which
is connected with the positive pole of its battery and causes its bell to ring.
The negative pole of the leading engine is connected with the other binding screw
of the bell in the rear engine, and then through the extreme left hand conducting
wire, back to the second binding screw of the bell in the leading engine, so that both
bells sound.
The same signals may also be made to sound in the neighbouring stations upon
the line.
For this purpose the central conducting wire and that which has been called the

page_text: neutral one,are made to pass the current through electric bells similar to those upon
the engines. These operate immediately after the bells upon both locomotives have
been sounded, because the lower wire is put into circuit with them, the stations
therefore are signalled at the same time as the engines.
Each station must have as many bells as there are sections of line, respectingwhich
it is to receive signals.
The insertion of an electric battery or generator in the wires connected with these
bells is only necessary if the station to which the signals are to be given is to be put
into communication with both trains.
Any necessary information can follow by telegraph for which it is necessary that
the electrietelegraphing apparatus found in every station should be used, and inboth
the neighbouring stations as well as in the two locomotives the two broken or
interrupted conducting wires can be used for telegraphing in the usual way.
The drivers of the engines can thus not only be put into communication with the
neighbouring stations but also with one another.
In the principal stations the separate sections of wire may be arranged closer to
one another so that the signals are given within very short distances, or the
interruptions may be omitted altogether.
The operation of the signal apparatus on both engines when meeting one another
depends upon the arrangement of conducting wires, interrupted or broken by non-
conductors at alternate points, and maybe made notonlyio ring thebells mechanically
but to act upon the steam regulating valves of the engines.
It may be added that by the means described the danger arising from the near
approach of two engines or trains upon the same line can be notified, not only
to neighbouring stations, but also to any other trains upon the same line.
Dated this 27th day of August 1889
COMPLETE SPECIFICATION.
Improvements in and in connection with Electrical Signalling
Apparatus for Preventing Collisions between Trains on Railways.
A communication to me from abroad by THEODOR PERLS, of Wurzburg, in the
Empire of Germany.
I, EDMUND EDWARDS, of the firm of Edwards & Co., Patent Agents and Engineers,
of 35,Southampton Buildings, Chancery Lane, in the County of Middlesex,dohereby
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 and
accompanying drawings, that is to say:-
This invention has for its object the prevention of collisions between locomotive
engines or trains travelling in the same or opposite directions upon the same line of
rails, and also to give notice at the right time of the threatening danger to the drivers
of both locomotives by means of electrical bells or equivalent signalling devices.
The accompanying drawings are in illustration of the invention, Figure 1 being a
plan of part of a railway shewing the arrangement of the electrical conductors.
Figure 2 a plan shewing two engines meeting upon the same line of rails, the engines
being represented bya simple parallelogram only. Figure3 is a similar plan shewing
one engine catching another up upon the same line of rails.
The same letters of reference indicate similar parts in the several figures.
In order to put the invention into operation four conducting bars, rods, or
wires bed and e are arranged between and parallel with the main rails A, A, of the
railway. These electrical conductors are carried by supports upon the wooden
transverse sleepers, or if iron sleepers are used they are carried by the latter with
the intervention of suitable electrical insulators.

page_text: The conductor c is situated centrally between the rails A.A, the conductors band d
at equal distances from c and the conductor e between and the main rail A.
These bars, rods, or wires. serve as conductors for a current of electricity, those
marked cand e being continuous, and there being no break or interruption in their
length for the distance over which they extend, whilst the other bars, rods, or
wires band d are interrupted at regular distances at a¹ by a non-conductor inserted
into them. The interruptions in these two conductors are not opposite one another,
those in each conductor being intermediate between those of the other conductor as
shewn in Figure 1.
The apparatus upon the locomotive is constructed as follows:-as illustrated in
figures 2 and 3 (engines and 3). Upon the footplate or near it, is arranged in a
convenient position an electrical generator or battery B of a suitable number of
elements, the insulated wires i,and k, being connected to the poles or terminals of the
battery and carried along the side of the engine to two helical or other terminals
which pass through an opening in the bottom or front of the smoke box to dises or
wheels or to brushes or equivalent devices war which are insulated from the body of
the engine and run upon the conductors be below and in electrical contact with
the latter, as shewn in end view in figure 8.
An insulated conducting wire o (engines 1 and 3) also passes from one of the poles
of the battery to the binding serewt of an electrical bell C (of the kind ordinarily
used in dwelling houses) and from the binding screw or terminal at the other side
of the bell apparatus, pass two insulated wires and which lead along the side of
the engine to two helical terminals similar to those upon the other side, and leading
through an opening in the smoke box to discs, wheels, or brushes y and z
similar to those described upon the other side, and running in contact with the
conductors d and e.
From the insulated wire another insulated wire passes to a helical terminal
which is in contact with the roller or brush likewise insulated from the body of
the engine and which is running free as described below.
These five brushes, rollers or equivalent devices are arranged upon each engine
(as shewn in figure S) a being the central one running always upon the conductor c,
and wand y are those upon each side of it, running upon the conductors and d.
One of the outer ones or runs upon the conductor e according to the direction in
which the engine is running upon the line, the other one running free, as shewn
at in figures 2, 3, and S.
In order to keep the conducting bars rods or wires clean a cleaning bar or brush
may be carried by the axle in front of the dises rollers or brushes but insulated from
them.
In the second locomotive 2 or 4 (figures 2 and 3) which is accidentally running
upon the same line as the first one in the same or opposite directions a similar
apparatus to that described upon the first locomotive is also arranged.
From the first binding screw of the bell C'is also carried an insulated conducting
wire o'to the pole gl of the battery B', and from this, as well as from the other pole
of the same battery two insulated wires and pass to the front of the locomotive to
two helical terminals, connected like those already described to discs, wheels, or
brushes of which runs always upon the conductor e carried by the sleepers,
and of which sometimes runs upon the conductor d (figure 2) and sometimes
upon b (figure 3) according to the direction of the engine. Two insulated wires p' q'
also run from the binding screw or terminal of the electrical bell C' to the front of
the engine to two helical terminals connected with the circumference of discs wheels
or brushes y¹¹ adjusted to run upon the conductor or conductors below carried by,
the sleepers.
From the insulated wire ' passes also another insulated wire to a helical
terminal which is in contact with the disc, roller, or brush, which is running on the
conductor e as shewn in engine 2, or which is running free when the engine is
running in the same direction as engines 1 and 3 (as shewn in engine 4).
As already explained the conductors band d are interrupted by non-conducting

page_text: insulators at a arranged alternately at determined distances apart. (as shewn in
figure 1) in such manner that the two locomotives cannot run upon the same section
or length of conducting wire without a signal being automatically given by means of
the electrical apparatus.
The central uninterrupted conductor e is in communication with the positive poles
and the conductors band d on each side of it with the negative poles, whilst the
extreme outer conductor e serves to connect the bells of both locomotives when they
accidentally approach one another on the same line of rails as shewn.
Should both locomotives be approaching one another, upon the same section
(as shewn in figure 2 and diagram 4,) in which the conductor d has its continuity
interrupted, the conductors band and serve to conduct the current. Should,
however, (as shewn in diagram 5) the conductor 6 have its continuity interrupted
then the conductors c, d, e, serve to conduct the current.
As soon as the locomotives are so near together that (as shewn in diagram 4) the
conductor b. or (as shewn in diagram 5) the conductor d is no longer interrupted, the
electrical bells C, C', upon both locomotives will be sounded by the current passing
through the conductors b. c, e, or c, d, e, as the case may be.
As already explained the two conductors bd, upon each side of the central one c,
are alternatelyinterrupted by non-conductors at a¹. These interrupted conductorsb,d,
are so connected that always a little before each interruption on one conductor an
insulated connecting wire, or preferably cable. f. passes from it to a point just after
the interruption on the other conductor, one and a half sections (or lengths of
uninterrupted bar, rod, or wire) distant from it. The operation of this connecting
wire is not for the purpose of signalling if two engines are meeting one another
on the same line as shewn infigure 2,but if one engine is catching up the otherwhen
following upon the sameline as shewn in figure and if by the signal bells a collision
is to be prevented, the positive and negative poles of an electric battery or generator
being connected so as to close the circuit as already explained.
In the case of a locomotive which is running in the opposite direction to the usual
one (that is to say) running backwards without having been turned round, a slight
alteration in the electrical apparatus is necessary, the connection of the wires being
altered to suit the altered circumstances.
If two engines are meeting in opposite directions (as shewn in figure 2, and in
diagram figure 4) at the time when the conductor through the approach of two
meeting engines. is no longer interrupted, a current passes from pole g of the
battery B on engine 1, through the wire k. brush .r, wire e, brush wires and o¹.
to and through the bell (" on engine 2 and through a' and the wire p³, brush y' b.
and brush we wire i to the other pole h of the battery B on engine 1, and the bell on
engine 2 will ring. At the same time, part of the current from g passes through o, t.
and the bell C on engine 1 through u, q. z, e, and through to so that the hell
on engine 1 also rings.
The operation is analogous if the alternate conductor d is the one which comes into
operation instead of bas shewn in the diagram 5. (which also relates to the engines
in the position shewn in figure 2).
In this case the current passes from pole g₁ on engine 2, through the wire Al
brush to c, brush .r and wire k to g, and through o, t, and bell C on first engine and
through u, p, y, d, ', and i' to the other pole ', on engine 2, and the bell (' on
engine 1 rings. Part of the current also passes from g¹ through o't', and bell c¹ on
engine 2. through u', r¹, el, and e, to z. and w, so that bell C on engine 2 also
rings.
ان
In these two cases the connecting wires f which always connect the alternate
conductors which are interrupted at intervals as described, do not influence the
operation of the current. These connecting wires are only of service if two trains are
accidentally following one another on the same line and come so near that it is
necessary to prevent the chance of a collision. In this case (as shewn in figure 3 and
by a diagram in figure 6) if the engine 3 of the bindermost train is just approaching
an interruption a' in the lower interrupted conductor d and the leading engine 4

page_text: (or the rollers or brushes upon it) is just in advance of an interruption in the lower
interrupted conductor (as shewn) connection is made so that the bells on both
engines ring.
The current passes from the pole gl of the battery in engine 4 through the wire kt
brush and conductor c. to brush, wire k. pole g of battery B in engine 3 thence
through o tot, bell C and u, and wire to brush y, connecting diagonal wire f, and
brush and through wire to the other pole h' of battery B in engine 4. Part of
the current also passes from gl through o, t, and the bell Cupon the leading
engine 4, and through ', q', and e, to z. q. and #, and both bells C C' ring.
It is to be understood that in the differentarrangements describedsuitablyadjusted
resistance coils or equivalent devices are inserted in the insulatedconductingwires on
the engines wherever it is necessary that part of the current should pass in one
direction and the remainder be diverted into a different direction.
Figurest, 5 and 6 arediagrams illustrating more clearlythe course of the electrical
current, the course of the main current being indicated by plain arrows, and that of
the supplementary currents, as described. by dotted arrows.
The same signals may also be made to sound in the neighbouring stations upon the
line. For this purpose (as illustrated in figure 7) the central conducting bar, rod, or
wire and the outer one c are made to pass the current through electric bells CC' in
the stations SS', similar to those upon the engines. These operate immediately after
the bells upon both locomotiveshavebeen sounded, the uninterrupted conductorscande
being put into circuit with them, and a part of the current diverted through them,so
that the stationstherefore are signalled at the same time asthe engines. Eachstation
must have as many bells as there are sections of line respecting which it is to receive
signals.
The insertion of an electric battery or generator (as shewn in station S¹) in the
wires connected with these bells is only necessary when signals are to be sent from
such station as well as received.
Any necessary information can follow by telegraph for which it is necessary that
the electric telegraphing apparatus found in every station should be used.and in both
the neighbouring stations as well as in the two locomotives the two uninterrupted
conductors e and e can be used for telegraphing in the usual way. The drivers of the
engines can thus not only be put into communication with the neighbouring stations
but also with one another. Or telephones can be used, instead of electric telegraphing
apparatus.
The electric current may be made not only to ring the bells mechanically but to act
upon the steam regulating valves of the engines, or upon any brake with which the
engines are fitted.
It may be added that by the means described the danger arising from the near
approach of two engines or trains upon the same line can be notified, not only to
neighbouring stations but also to any other trains upon the same line as for instance,
if another engine fitted with the apparatus described were upon the line where either
of the stations S and S are shewn in figure 7.
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 I
claim is:-
1. The combination of the five dises rollers or brushes r, ... or e¹, w³‚àª¹‚y'‚z',
on the locomotives, with the four conducting bars rods or wires b, c, d, e, arranged
between the rails A. A, the conductors e, and e being continuous and the con-
ductors L,and being alternately interrupted, and the diagonal wires f,substantially
as and for the purpose described and shewn.
2. In combination with the arrangement of discs, rollers or brushes and the four
conductors,two of which are continuous and two interrupted, and the diagonal wires,
as claimed in the first claim, the electrical batteries or generators B. B', upon the
locomotives, the bells or signalling devices C, C, and the insulated connecting

page_text: wires i, , k, k, o, o¹, p, p¹, q, q', and r, r¹, and resistance coils or equivalent devices,
substantially as and for the purpose described and shewn.
3. In combination with the four conductors b, c, d, and c, of which the con-
ductors c and are continuous and the conductors band d alternately interrupted, the
bells or other signalling devices connected with the wires cand e, in the stationsS,S',
with or without batteries or other electrical generating apparatus in such stations
substantially as and for the purpose described and shewn in figure 7.
Dated this 23rd day of May 1890.
EDWARDS & Co.,
35, Southampton Buildings, Chancery Lane, London, Agents for the Applicant.