ELECTRICAL RAILWAY SIGNALLING
Year: 1884

page_text: I, JAMES ENRIGHT, Electrician of 202 Holland Road, Kensington do hereby
declare the nature of my invention for ELECTRICAL RAILWAY SIGNALLING to be as
follows:-
The object of my invention is to signal to or from a train without making
electrical contacts. The principle of my invention is that any change in the field
in the neighbourhood of a closed coil with or without an iron core produces a
current in the coil.
There are fixed along the permanent way in any convenient place coils of insulated
wire with iron cores. These are joined up in series with a battery by means of
a line wire which is also insulated and continued to the station or signal box. On
the train is fixed a coil or permanent magnet so that as it passes along the coil or
magnet shall come into close proximity with a line coil. This causes an induced
current to flow in the coil on the permanent way which opens to any convenient
indicator at the station. Thus the train signals itself at various points along
the line.
When the coil on the train is joined up with any convenient indicator such as a
galvanometer a signal may be sent to the driver by the signalman. For this
purpose all that is necessary on the part of the signalman is by means of a key to
complete the circuit of the coils on the permanent way. On the trains first
reaching a coil a signal is then received.
If the train stop so that a line coil is near the coil on the train making or
breaking contact gives signals.

page_text: "
I JAMES ENRIGHT Electrician of 202 Holland Road Kensington do hereby
declare the nature of my invention for "ELECTRICAL RAILWAY SIGNALLING and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :—
The object of my invention is to signal to or from a train without making
electrical contacts. The principle of my invention is that any change in the field
in the neighbourhood of a closed coil with or without an iron core produces
a current in the coil.
There are fixed along the permanent way in any convenient place coils of wire
preferably with iron cores. These are joined up in series with a battery by means
of a line wire which is also insulated and continued to the station or signal box.
On the train is fixed a coil or permanent magnet so that as it passes along the coil
or magnet comes into close proximity with the line coil. This causes an induced
current to flow in the coil of the permanent way which operates any convenient
indicator at the station. Thus the train signals itself at various points along
the line.
When the coil on the train is joined up with any convenient indicator such as
a galvanometer a signal may be sent to the driver by the signalman. For this
purpose all that is necessary on the part of the signalman is by means of a key to
complete the circuit of the coils on the permanent way. On the train first
reaching a coil a signal is then received.
If the train stop so that a line coil is near the coil on the train making or
breaking contact gives signals.
I will proceed to describe more fully the arrangements which I prefer.
Along the railway a telegraph wire is fixed in the usual way but with great
attention to the insulation. It is put to earth at both ends.
At certain points where it is desirable that the train should report itself to the
signalman there is inserted in circuit in this telegraph wire a coil of wire with or
without an iron core-preferably the former. This coil may be circular and flat.
The strands of the coil must be well insulated from one another. It is fixed at a
convenient place as near as may be to passing trains that it may be inductively
affected by a similar coil placed on the train. The wire forming the core is of
copper and rather stout. The core consists of a bundle of iron wires. The coil or
certain parts of it is enclosed in a suitable casing to protect it from the weather.
This coil is fixed so that its plane preferably makes an angle of about 45° with the
direction of the railway, so that a coil similarly placed on the train will for a
short time as it passes along almost directly approach it and almost directly recede
from the coil on the line.
These coils enable passing trains to report themselves at the signal station. At
a convenient distance beyond in the direction which the trains travel the line
wire is brought down carefully insulated so that it may be in close proximity
to the passing trains for a distance of say forty feet more or less; this is to enable
the signalman to communicate with the trains and send a stop signal when it may
be necessary.

page_text: To obtain an increased effect a coil of several convolutions of like length may
be substituted for the single line wire, one side of the coil throughout the length
being in proximity to the trains and the other at a distance therefrom.
Again at a further convenient distance along the line I provide another arrange-
ment similar to the last by which when the train has pulled up in answer to signal
the signalman may be able to transmit any further signal which may be required.
Here also the train may communicate with the signal station.
This line wire is led into the signal station and put to earth at one end and at
the other end it is permanently connected to earth.
Figure 1 of the drawings annexed shews diagrammatrically the arrangements
upon the line of railway.
a is the line wire. b is the reporting coil. c. is the place where the line wire is
approximated to the rails for the purpose of transmitting stop signals to the trains.
d is the place where the train pulls up to receive further signals and to transmit
signals if necessary. e. e. are the rails of the line of railway. f are the instru-
ments in the signal cabin and.g.g. are the earth connections at the two ends of the
line wire.
Upon the train two coils are provided one the reporting coil similar to the coil b,
on the line and the other the signal coil for receiving and transmitting signals
when the train is in the positions c and d upon the line.
The reporting coil on the train is similar to that on the line-it is so set as to be
parallel to the stationary coil and as the train passes the moving coil should come
as closely as may be to the coil on the line. The coil on the train may be replaced
by a magnet but the use of a coil is preferable.
The other coil on the train is of great length, preferably it is coiled on an iron
frame, around one of the carriages. This coil may be in a vertical plane parallel
with the rails it is carefully insulated and its ends are connected with instruments
on the train herein after described. The under side of this coil is so placed that
as the trains run on the line it passes in close proximity to the line wire arranged
as already described at the places c and d, ou the line. I provide a galvanic
battery upon the train in circuit with the reporting coil. When this coil approaches
one of the reporting coils on the line an induced current flows in the line wire and
as it recedes another current flows in the reverse direction.
These currents in the receiving cabin are caused to operate a delicate indicator
preferably a relay. I utilize both currents by causing the first to press back the
relay arm indicator or contact maker against a very light spring which reacts on
the reversal of the current and aids the reversed current in moving the relay arm
or contact maker to close a local circuit in which a recorder is included. The
recorder then registers the passage of the train upon a travelling sheet of paper in
the manner described in the specification of a former patent granted to me and
now well understood.
Or the current from the line may be made to circulate in two coils so placed
that when thus excited they repel or attract each other, the change of sign of the
current causing no change in the direction impulse upon the receiving instrument.
I also provide in the signal cabin a battery and a make and break apparatus
by means of which the signalman at the station can as soon as a train reports
itself transmit alternating currents into the line wire.
When the train arrives at the space c these currents will affect the signalling coil
upon the train and intermittent currents will pass in the circuit of which this coil
forms a part.
In this circuit I provide a relay such as already described and so ring a bell or
obtain a signal of any convenient sort. If the train be required to stop it draws
up at the space d. and then the signalman in the signal cabin by opening and
losing the line circuit by means of an appropriate key can order the train to stop
r move on as may be required. I provide also a make and break apparatus and a
key on the train and the operator can put these into circuit with his signalling coil.
Intermittent currents are then produced in the line wire which by opening and

page_text: closing the circuit with the key may be broken as may be required for the
transmission of signals. The signals are read at the signal cabin by means of
a receiving instrument or relay such as already described. A telephonic receiver
is convenient.
Figure 2 is a diagram of the apparatus upon the train. k is the reporting coil.
Z is the signalling coil. m is a commutator which in one position will place the
battery n into circuit with reporting coil. In this position of the commutator the
train reports itself. If now as the train passes the space c the signalman at
the cabin causes an intermittent current to pass in the line wire, a like current will
pass in the signalling coil . This coil is connected with the contact posts o¹ o' and
these by the commutator are at this time coupled with the contact posts p'p'
which are connected through the receiving instrument or relay or telephone q. The
indication or absence of indication on this instrument is the signal to stop and the
train is brought to rest in the space d Figure 1. The train whilst standing at d
receives its orders as already described. If the operator on the train desire to
speak with the signal cabin he turns his commutator m so as to couple the
battery with the contact posts 7 and 8 and the circuit is then complete from the
battery through the key t, the make and break apparatus u the signalling coil &
and so back to the battery.
"
vis the battery
Figure 3 is a diagram of the apparatus in the signal cabin.
with one pole to earth wis the signalling key x is the make and break apparatus
and y is the switch by which the foregoing apparatus is connected with the line
wire or by which the line wire is connected with the receiving relay z which
operates the recorder and notes all reports and signals from the trains.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
(1.) The method of railway signalling by electricity without contact but with
coils acting inductively substantially as described.
(2.) The arrangement of apparatus on a railway line train by which the train
whilst in motion may report itself electrically but without contact substantially as
described.
(3.) The arrangement of apparatus on a railway line and train by which the
train may receive signals from a signal station on the line and also if necessary
transmit signals thereto by electrical induction without contact substantially as
described.