Improvements in Signalling Systems adapted for Railway Use.
Year: 1893

page_text: Date of Application, 12th June, 1893-Accepted, 29th July, 1893
COMPLETE SPECIFICATION.
Improvements in Signalling Systems adapted for Railway Use.
A communication from abroad by JOSEPH Boss STEWART, Electrician, of
Haverstraw, and WILLIAM GRAFTON WATTSON, Electrician, of Tappan,
both in Rockland County, State of New York, United States of America.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56 Chancery Lane in the County
of Middlesex, Fellow of the Chartered Institute of Patent Agents, 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:-
This invention relates to railway signalling systems, and has special reference to
providing means for properly signalling to trains in passing through tunnels, and
the like, and it consists in the various features of construction, arrangement, and
mode of operation, substantially as hereinafter more particularly pointed out.
Referring to the accompanying drawings,
Fig. 1 is a diagram illustrating the general principles of the invention:
Fig. 2 is a diagram showing more in detail a manner of carrying out the inven-
tion; and
Fig. 3 is a view showing an instrument which is used in making the connections.
It is well known that it is imperative for any railroad where a number of trains
are run at comparatively short intervals, to provide some sort of a signalling device,
the signals of which shall be controlled either automatically by the train or by
means of signalmen at the stations along the line, and many and various schemes
have been proposed for accomplishing the desired purpose.
Most of these systems involve the use of signals in the form of semaphores or
lamps showing various colors, which shall control the running of the trains. While
some of these systems are very complete and satisfactory in most respects, it has
been found exceedingly difficult to provide a satisfactory system of signals, which
shall be perfectly safe and thoroughly control trains running through long tunnels
or similar dark places. It has been found that owing to the smoke and for other
reasons, it is practically impossible for an engineer to distinguish the color of a
signal in a tunnel, to tell whether it is a white light for safety, or red, green or
other color, and accidents have happened, owing to the impossibility of distin-
guishing one colored signal from another. It. has been common to have signals at
the ends of the tunnel, and to allow but one train on each track in either direction to
pass through the tunnel at the same time. Thus the danger signal at the entrance
of the tunnel has been maintained until the train which has passed into the tunnel
has reached the other side, and through automatic or other means a signal is received
at the entrance of the tunnel, showing that the train has passed clear through the
tunnel, and it is safe to go ahead.
Of course this is a safe system, but in roads where there are a great many trains
which necessarily follow each other at short intervals, and thus travel at a rapid
rate, it causes a great loss of time, and it is impracticable to follow this system.
It is the object of this invention to provide means which shall be automatic and
simple in its construction and mode of operation, and at the same time shall allow
a number of trains to follow each other within comparatively short distances and
at rapid rates through a tunnel with safety.
In carrying out this invention, the track of the tunnel is divided into a series of
sections of greater or less extent according to the rapidity of travel and number of
trains passing over the track in a given time, and means are provided for lighting
the track by electric lamps which are automatically controlled, and which are all
of one color so that dependence is not placed upon signals of various colors to
indicate safety or danger, but upon any colors or light signal to indicate "safety,"

page_text: and the absence of any signal or darkness to indicate "danger" under all and every
condition.
Thus arranged adjacent to every section of track, are a series of lamps, which
when lighted indicate that the track is clear throughout the section lighted, but
which when extinguished, and the section is in darkness, indicates to the engineer
or any other official that there is danger, and the train must come to an immediate
stand still and that no train under any circumstances must run into a section not
fully lighted.
These signals are arranged to be automatically controlled, and as a further safe-
guard, all of them are arranged to be under the control of a single signalman, who
shall have charge of all the sections in the tunnel, and whose business it is to see
that the signals are operated and properly displayed under all conditions. In other
words, it is proposed to provide a system of signals, whereby long tunnels may be
safely operated to allow the passage of trains in rapid succession and at high
speed.
Referring to the drawings Figure 1 shows the general features of the invention
and in this figure the track A is shown as divided into a series of blocks 1, 2, 3, 4,
representing the sections of a single track through a tunnel, and arranged along
each section are a series of lamps B', B2, B3, B4, which may be supplied from any
suitable source in this diagram one generator Z, being shown for all sections for the
purposes of explanation W being one of the main conductors, and V, being the
other main conductor, and at each station a series of lamps are shown as connected
to the line W, and to a short line w, w¹, w², &c. Each of these lines is provided
with a terminal r, while the lines v, vl, are connected to the main line V, and to the
lever forming a corresponding terminal ¹.
Each light circuit is shown as controlled by a local circuit including a magnet or
circuit breaker D', D2 D3 &c. which controls the corresponding armature d¹, d², d³,
&c. to which the terminals of the lamp circuits are connected. Each circuit
breaker is shown as controlled by a relay E¹, E2, E³, which is connected by suitable
conductors e, to the rails of each corresponding section, preferably at the beginning
of said section or block, and located between the rails or connected to the rails of
each section, preferably at the opposite end, is a generator G, G¹, G² G³ &c. there
preferably being an independent generator in each block.
As before indicated, the signal lamps are arranged so that in the normal con-
dition, and no train in the tunnel, all the various sections of track are illuminated.
Thus referring to the section marked 3, it will be seen that the generator G
energises the rails, which through the medium of the conductors e energises the
magnet E, causing its armature e to be attracted, closing the local circuit of
the magnet or circuit breaker D³, and this draws the armature d' up, closing the
contacts x, x and causing the lamps fed by the loop vw to be illuminated, and
this is the normal condition of all the sections, although they are not shown in the
drawing in this condition for the sake of clearness.
When however, a train is on any section, it operates to cause the lamps in the
section next preceding to be extinguished, and this will be clearly understood by
referring to section 2, where T may represent a train just entering section 2, and it
will be seen that the generator G¹ will be short circuited and the armature e¹², of
the relay magnet E' is on its back stop, breaking the local circuit of the circuit
breaker D' and its armature d¹ is on its back stop breaking the circuit at the
contacts a, a, causing the lamps in the loop vw, to be extinguished. These are
arranged along section 1, and this section is therefore in darkness, and so remains
until the train passes completely out of section 2, when the generator G¹ again
closes the circuit of the relay E' attracting its armature, and closing the local
circuit of the circuit breaker D' again closing the circuit of the lamps corresponding
to section 1 of the road.
If, for instance, a preceding train is on section 4, the lamps corresponding to
section 3, will be extinguished and the train on section 2, must not enter section 3
until they are again illuminated.

page_text: Thus it will be seen that when the track is clear it is illuminated, and when any
section is occupied by a train the next preceding section at least is in darkness, and
furnishes a complete and definite signal to the trainman, which cannot possibly be
misunderstood. In this way it is possible to run trains a comparatively close
intervals and at relatively high speeds through the tunnels without danger of
accident.
So far there has been shown simply the main idea of the invention, in which
the train automatically controls the signals of the block or section in rear thereof.
through the instruments indicated. It is preferable however, to have a signal
operator controlling all of the sections of the tunnel as a safeguard against a failure.
of the automatic mechanism to operate, and to act in case of emergencies, and in
Figure 2, there is shown such an arrangement of circuits. In this view the lamp is
shown for two sections only, and the signal devices connected to the automatic
operating devices in the other sections for the sake of clearness.
In this figure the road as before is shown as divided into four blocks 1, 2, 3, 4,
and opposite each are signal lamps B1, B2, but for purposes of additional safety, it
is preferred to have these signal lamps in duplicate supplied from separate sources,
and there is shown an additional series of lamps at each section or block, which
is lettered H1, H2, different series of each block being shown as connected to a
separate source, as the generators X, X, which are preferably located at the signal
station S and are under control of the signal operator.
Thus there is shown the generator X, as connected by the conductors b b¹ to the
lamps B, and the generator X', connected by conductors h², to the lamps H¹
branch circuits as h2, h3, leading to the other series of lamps H2 &c., so that in case
of failure of one generator or any of the connections therewith, the other generator
and lamps supplied thereby will be operative.
As before stated it is understood that all the lamps are in operative condition,
and in order that the signalmen may be sure that they are burning properly, there
is provided a test, which is located at the signal station, for which purpose various
well known tests may be used, but in the present instance there is shown a lamp L,
located in each circuit, which is preferably of higher resistance than the lamps in
the tunnel, so that it will not be fully illuminated when the lamps in the tunnel
connected to the circuit are fully burning and the signalman by a glance at this
lamp can readily determine the condition of the circuit.
In this view there is shown a little different arrangement of the electric currents.
Thus each section or block of track is provided with a magnet I, having a local
circuit including the rails of the track, and closed by the wheels of the train. The
armature 1, is provided with a double contact c, c', insulated from each other,
while the stop or fixed contact is also made double as at c², c³. These contacts are
respectively connected with the lamps circuits B', H', in such a manner that when.
the armature I, is drawn forward the contacts c and c² short circuit the lamp
circuit H', and the contacts c¹, c³ short circuit the lamp circuit B', and consequently
extinguishes the lamps in the respective circuits. It is obvious that the circuits can
be arranged to open the lamp circuits as in Figure 1.
In order to insure absolute safety there is preferably provided for each section
another magnet J, also having its local circuit, the armature J', of which is
provided with contacts similar to the contacts I', which control loops from the short
circuits of the respective lamps circuits B₁ H', so that if, perchance, the magnet I,
did not properly operate, and the train was upon the section 2, the magnet J, would
accomplish the result of extinguishing the lamps corresponding to section 1, of the
track.
In order to signal to the signalman each armature I¹ J¹ is further provided with
an extension 12, J2 having a contact ct arranged to co-operate with a fixed bearing
contact c. These last contacts are connected by conductors k with the respective
hells K or other indicating devices at the signalman's station, and it will be seen
that when the train enters any block, and closes the circuits of the magnet 1 or J
or both, the contracts c', c, will be closed, sending an alarm to the signalman which

page_text: will indicate the position of the train and it will be his duty to immediately observe
the test lamp L or other device to see if the lamps have been extinguished in the
section preceding the one on which the train is entering and if these lamps have not
been extinguished, he is to take proper steps to do so, by means of switches or
other well known appliances in connection with the generator circuits.
Moreover, the signalman can in case of any question as to the condition of the
track operate the lamps of any section to stop the train, and hold it until the track
is clear. By this arrangement, it will be seen that not only are the signals operated
automatically by the passing train, but that the signalman is notified by a separate
circuit of the movements of the train in the tunnel, and can be sure that the signals
are properly displayed.
While there is shown in this figure a single magnet operating to short circuit the
lamp, it is evident that the relay and circuit controller shown in Figure 1, can as
well be made use of for controlling the lamps, but in all cases, the lamps are
supposed to be constantly illuminated, except in cases of danger, and if the lamps
are extinguished for any cause the train must stop.
In this way in properly dividing up the track in the tunnels, it is possible to
control the passage of trains through the tunnel, even when they are running at
comparatively high rates of speed, and following closely after each other, being
necessary of course to provide sufficient distance between the trains to allow them
to be safely stopped after the signal is given.
While it is preferred to use bells in the signal station which will ring continuously
as long as the train is on the corresponding section of track, of course other
indicating devices may be used, and while circuits automatically controlled have
been shown they can be manually controlled from signal towers or otherwise and
while one form of cut-out well adapted for the purpose, has been shown others have
been used and so with regard to any other features of the invention, while there has
been described and indicated the preferred construction of the devises, it will be
understood that other equivalent and well known devises may be substituted without
departing from the spirit of the invention. And while there has been shown circuits
adapted and arranged for a single track it is evident the same general principles
may be carried out and applied to any arrangement of tracks.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondents and in what manner the
same is to be performed I declare that what I claim is :-
1. In a system of railway signals for tunnels the combination with the various
sections or blocks, of a series of lights extending throughout each section, and
normally lighted, and electric circuits controlling each series of lights and con-
nected with the respective blocks so that the passage of a train upon any block
will automatically extinguish the lights of the preceding block, substantially as
described.
2. In an automatic system of signals for railway tunnels the combination with the
various sections or blocks of series of lights arranged along the blocks and normally
lighted, a controlling magnet for each series of lights having a local circuit, and a
relay connected to each section of track, and controlling the local circuit, whereby
the passage of a train on any section or block will automatically extinguish the
lights on the next preceding section, substantially as described.
3. In an automatic system of signals for railway tunnels the combination with the
various sections or blocks, of a series of lights arranged along blocks, and normally
lighted, a controlling magnet for each series of lights connected to the rails of the
respective blocks and arranged to control the lights in the preceding block and a
signalling circuit connected to said controlling magnet and arranged to operate a
signal in the signal station, substantially as described.
4. In an automatic system of signals for railway tunnels the combination with
the various sections of blocks, of two series of lights arranged adjacent to each
block and supplied by a separate generator, electro magnetic controlling devices

page_text: connected to each block and arranged to control the lights of the preceding block,
a signal circuit connected to the electric magnet controlling device--and operating
a signal in the signal station, substantially as described.
5. In an automatic system of signals for railway tunnels the combination with
the various sections of blocks, of a series of lights arranged adjacent to each block
and normally illuminated, an electro magnet controlling the device connected to each
block, and arranged to control the circuit of the lights of the preceding block, &
signal circuit from each electric magnetic controlling device controlling a signal in
the signal station, and a test device at the station in the circuit of each series of
lamps substantially as described.
6. In an automatic signalling system the combination with two separate series of
lamps corresponding to each section or block, of an electro magnetic controlling
device connected to the rails of each block, said device being provided with an
armature, carrying double contacts controlling both series of lights in the preceding
circuit, the armature also carrying a contact controlling a signal circuit connected
to the signal station substantially as described.
Dated this 12th day of June 1893.
PHILIP M. JUSTICE.