IMPROVEMENTS IN ELECTRIC INTERCOMMUNICATION IN RAILWAY TRAINS
Year: 1866

page_text: LETTERS PATENT to Charles Vincent Walker, of Fernside, Redhill, in
the County of Surrey, Telegraphic Engineer, for the Invention of
"IMPROVEMENTS IN ELECTRIC INTERCOMMUNICATION IN RAILWAY TRAINS."
Sealed the 31st July 1866, and dated the 5th February 1866.
PROVISIONAL SPECIFICATION left by the said Charles Vincent Walker
at the Office of the Commissioners of Patents, with his Petition,
on the 5th February 1866.
I, CHARLES VINCENT WALKER, of Fernside, Redhill, in the County of
Surrey, Telegraphic Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ELECTRIC INTERCOMMUNICATION IN RAILWAY
TRAINS," to be as follows:-
1st. I require and use only one wire from end to end in a railway train,
and only one connection or coupling between vehicle and vehicle, and the
wire and couplings are not necessarily insulated from the carriages or
covered with any insulating coating.
2ndly. I connect permanently a voltaic battery at each end or as near
as may be to each end of this wire and between these ends respectively
and the earth, the batteries being equal or nearly so in power, and the
similar battery poles being connected with the wire.
3rdly. I provide every battery carriage, one or both or each of which
must be the guard's van, with a switch or turnplate, so constructed that
whether the van or carriage be toward the front, the..rear, or the centre of

page_text: the train, or its direction be reversed, a simple action of the switch will
make the electrical connections correct for the position in which the van
may be placed.
4thly. I provide each guard's van and each engine with a direct-action sig-
nal bell having two armatures, one for producing signals in the usual way, as
in my South-eastern signal bells, and the other for locking this the ordinary
armature so as to prevent its making signals by the shaking of the train.
By this combination of conducting wire, batteries, and switches pas-
sengers are enabled to make signals in all the guards' vans; guards may
intercommunicate with each other, and may send signals to the engine
driver; also carriages that break away may make signals to the guards;
for which purposes an earth wire and an ordinary contact maker or ringing
key is fitted in each guard's van, and one or more in each compartment of
each passenger carriage; and this combination may be made with any
form of battery that will withstand the motion of a train, and any form of
telegraph instrument that will produce satisfactory signals under the
proposed conditions may be used in connection with this combination.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Vincent Walker in the Great Seal Patent
Office on the 4th August 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
VINCENT WALKER, of Fernside, Redhill, in the County of Surrey, Tele-
graphic Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of February, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Charles Vincent Walker, Her special licence that I, the said
Charles Vincent Walker, my executors, administrators, and assigns, or such
others as I, the said Charles Vincent Walker, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter 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 ELECTRIC INTERCOMMUNICATION IN
BAILWAY TRAINя," upon the condition (amongst others) that I, the said
Charles Vincent Walker, my executors or administrators, by an instrument

page_text: object improvements in electric intercommunicating and signalling media
for establishing perfect communication, 1st, between guard and guard;
2ndly, between passenger and guards, and also driver if desired; 3rdly,
between guard and engine driver; and, 4thly, in case a portion of the
train should break away, between the several parts and the guards,
which improvements I propose to effect as follows:-I fix a conducting
wire, which I call the "train wire," by preference entirely round
each passenger carriage, and where practicable immediately under the
eaves of the carriage roof. The wire may be bare or coated with any
suitable insulating material. In guards' vans, horse boxes, and the like
I lead the wire direct from end to end by the most convenient route.
For engines and tenders I prefer the wire to be insulated and protected with
an outside cover of spiral wire, or by enclosing it in a tube. At each end
of every vehicle, and as high up as convenient, I fix a hook of stout
brass wire, which may be tinned; one or two turns are given to the wire
hook to prevent the ring of the coupling (to be presently described) from
being shaken off by the motion of the train. This hook, which I call
"twisted hook," is permanently connected with the "train wire "by a short
piece of conducting wire. Another form of hook (to be described hereafter)
is substituted for the " twisted hook" when carriages that break away are re-
quired to make automatic signals to the guard. The simplest form of coupling
from carriage to carriage is a wire of hard brass wound into a spiral spring
and having a stout brass ring which may be tinned at each end. To assist
the elasticity and to protect the spiral it is enclosed in a tube of vulcanized
india-rubber. I place a stout cord or wire within the tube to prevent it
from being overstrained; the rings are placed over the "twisted hooks,"
and the tension of the spring produces good electric contact; when not in

page_text: use, and if still left on the "twisted hook," I prefer to secure the free end
of the coupling on a plain hook placed below or where convenient. Every
guard's van is permanently fitted with a voltaic battery, the batteries being
all of equal strength, or nearly so. I prefer to use platinized graphite
(or gas carbon) and amalgamated zinc excited with diluted sulphuric acid;
and in order that battery elements of this kind may not suffer from the
motion of the train I place on the surface of the liquid a disc of ebonite,
wood, or other convenient material with slits properly cut to admit of the
passage of the zinc and graphite plates, and I fill up the cell above the disc
with sawdust. I so connect up the batteries in the guards' vans that
homonomous poles (the zinc, for instance,) are in electrical connexion with
the "train wire," and homonomous poles (the graphite, for instance,) with
the "earth wire. Under the frame of all the carriages and vans I connect
together electrically, with wire or strips of copper, the draw rods, axles,
and tyres of the wheels and other ironwork; and from this metallic mass I
lead up wires, which I call "earth wires," into the vans, and also into the
compartments of carriages and wherever else an earth wire" may be
required.
"
I will now proceed to describe the several improvements in detail,
reference being made to the accompanying Drawings marked A and B
respectively, and to which Drawings the following explanation refers:-
EXPLANATION OF THE DRAWINGS.
Fig. 1 is a diagram representing the general arrangement of the system
with vans as at V and V₁, one at each end of the train; G and G' are
the graphite poles of the batteries connected with the rails by the "earth
wires" E, E; Z, Z', are the zinc poles connected with the "train wire."
The batteries being of equal strength the voltaic currents are thus in a
state of equilibrium, but if any part of the "train wire" situated between
Z and Z is brought into electric communication with the rails by the
"earth wires" e¹, e", e, the current from both batteries is set in motion
and will act upon any apparatus, as B, B1, in its course. The methods of
making this communication are described further on. Every van is per-
manently fitted with a "switch" or commutator, by means of which the
guard adjusts his van or apparatus therein in accordance with the con-
ditions given in Figure 1, whether for the front or for the rear of a train or
for running either end first, as well as for occupying an intermediate place,
and for other purposes, as the case may be; the switch should be fixed
against the side of the van. Fig. 2 is an outside view of the switch, Fig. 3

page_text: an inside view thereof. The switch box A is of wood about 8 inches
square and 3 inches deep; B is a brass index pointer moving on a centre ;
C is the knob of a bolt sliding under the index and made to fit tightly into
the grooves a, b, c, d, e, f, where it makes good electrical contact assisted
by a pressure spring; D is a segment of a circle in brass insulated; E is a
similar segment connected with an "earth wire"; g, Fig. 3, is a camm on
the axis h of the index pointer B (Fig. 2). The axis h, the index pointer
B, the bolt C, and the camm g are in permanent connection with one
end of the wire of the electro-magnet of the guards' "signal bells" (also
described further on (see Fig. 6); the other end of the said bell wire being
in connection with the graphite pole G (Fig. 1) of the battery by means of
a spring not shewn in the Drawing pressing on the end of the axis at h;
S, S', in Fig. 1, and the feathered arrows in Figs. 1, 5, 7, and 8, shew the
relative position of the switch pointer; i is a strong brass pillar (with two
projecting studs and ) in permanent connection with the zinc pole
Z (Fig. 1) of the battery; j and I are strong springs in permanent con-
nection with the "train wires" that lead respectively to either end of the
van; he springs are in strong contact with the studs i¹ and i", except
when either of them is held off by the camm g in the position shewn by
the dotted lines. For a rear van the index hand when set is pointed
downwards and fixed in groove e of the earth segment E (see Fig. 2), in
which position the graphite end of the battery is connected with the earth,
as shewn at F, Fig. 4. For a front van the index hand is pointed
horizontally towards the engine in grooves d or f, as the case may be, of
the earth segment E, in which position the graphite end is connected with
the earth in the van and also (by the contact then made between the
camm g and one of the springs jor k with the wire leading to the
engine), as shewn at G, Fig. 4. For an intermediate van the index hand
is pointed vertically upwards and fixed in groove b; in this position the
graphite end of the battery is insulated so that the balanced currents of
the batteries in the extreme vans are not disturbed (shewn at H, Fig. 4)..
When signals are required to pass onward to the engine the index hand of
the front van (still pointing toward the engine) is elevated a little, so as to
be fixed in the groove a or c of the upper brass segment. In this position
the graphite end of the battery is connected by the camm g with one of
the springs or k connected the "train wire" with the engine; this
arrangement is shewn in Fig. 5. Where there is only one guard and van,
and this at the rear of the train, and communication with the driver is
required, but not otherwise, a battery and switch must be placed on the

page_text: Each
engine or tender as well as in this rear van, or else as far forward in the
train as possible, and the index bolt must be fixed in the groove a or c;
in this case the switch should be under cover on the battery box. Where
there is only one guard and van, and this at the front of the train, no
switch or battery is required at the rear; the guard in the front van will
set his switch in position as at G, Fig. 4, and when he desires to open
communication with the driver in the position shewn in Fig. 5.
guard's van and engine is furnished with a single-stroke direct-action
signal bell. The guard's bell, as already shewn in Fig. 1, B, B', and also
in Figures 4 and 5, is interposed between the graphite end G of the battery
and the index of the switch S. Fig. 6 is a side view of the bell; " is
one of the two coils of the electro-magnet; is the soft iron armature
pivoted at a in front of the pole x, and carrying the hammer A, which
strikes the bell k every time a current of electricity passes through the coil
wire and attracts the armature. To prevent the bell being rung by the
motion of the train I introduce a second or locking armature m, as shewn
at Fig. 6. The principal armature 7, which carries the hammer, is pierced
so that the poles of the electro-magnet produced pass through it and
project as at ; m, the second armature in front of the poles, which
projects through the holes in the principal armature, is pivoted at y and
moves by magnetic attraction when the principal armature is moving;
n is a clutch or lock arm which forms part of the second armature, and is
raised thereby as it is attracted to the poles x produced, and thus releases
the principal armature and sets it free to be attracted by the electro-magnet
and ring the bell. When the current ceases the second armature returns
and the clutch drops into the position here shewn, and the bell hammer is
held in its normal position. o is a screw for adjusting the locking
armature; p is a metal rest to receive the hammer; r is a light spring
which assists the return of the hammer; s is also a light spring which
assists the return of the locking armature n. The engine bell is in all
respects the same as the guard's bell with the addition of an axis carrying
externally and visible an index or red left-hand semaphore arm, and
within a magnetized needle suspended between the poles of the electro-
magnet and between the two armatures above described. These additions
are shewn in Fig. 6; n', s¹, is the needle; t, the axis; u, the dial plate; w, the
semaphore arm seen edgewise; and z, the semaphore pole. The ordinary
position of the semaphore arm is down, and the bell semaphore is so to be
connected that the ordinary currents from the graphite end of the battery
when the switch is set, as in Fig. 5, ring the bell but do not raise the

page_text: arm. In order to raise the arm the guard in the front van sets the index
hand of his switch pointing upward in groove b, which removes his battery
from circuit and allows a constant current from the zinc end of the rear
guard's battery to pass through the electro-magnet and ring the bell
continuously, and also to hold the semaphore arm up; this arrangement is
shewn in Fig. 7. When there is only a front van and one guard and he
wishes to raise the semaphore arm he turns his index pointer towards the
train, setting it in groove dorfas the case may be, thus sending a constant
current from the zinc end of his battery to the engine and holding the
semaphore arm up; the mode in which this is done is shewn in Fig. 8.
Other combinations or positions of the switch may be made to meet other
conditions that may arise. The engine bell semaphore is to be fixed, if
practicable, in front of the driver on the boiler or weather board; one end
of the wire of the electro-magnet is to be in permanent connexion with an
"earth wire," the other end is to be in connexion with the "engine
wire" a, b, Figs. 4, 5, and 7. This wire runs from end to end of the
engine and tender when provision is required to be made for running a
tender first, as shewn at x, Fig. 5. Any of the well-known simple methods
of making contact between the zinc end of the battery or "train wire"
and the "earth wire," as at e¹, e", ell, Figs. 1, 4, 5, 7, or 8, will produce
bell signals, but I prefer that the guard's signal, the break-away signal,
and the passengers' signal shall each be made by a different method and
so that each shall be readily distinguishable from the other. The guard's
ringing key is mounted with the switch, Figs. 2 and 3, and consists of a
spring connected with the earth segment E, a stud m connected with
the zinc, and a knob F. Every pressure of the knob moves the spring into
the position shewn by the dotted lines and produces one stroke on the
bell; the guards can thus communicate by code signals. The self-acting
key for producing signals when carriages break away from a train in
motion consists of the "break-away hook," which is substituted for the
"twisted hook," and is shewn in section in Fig. 9; A is the outer case,
which may be made of wood or iron; B is a fixed brass hook for receiving
and taking the strain of the coupling; and C, a vertical spring with a
heavy weight D at top; A, B, and C are in metallic connexion, and are
connected with the "train wire" by a short wire; E is a brass cock
connected with the "earth wire" and carrying à platinum point which
faces a platinum plate in the spring C, neither of which are visible in the
Drawing; F is a hook turning on pivot at a, and having a camm 6 on
the inner arm; when the coupling is on and over both the hooks it draws
a

page_text: the hook F into the position shewn by the dotted lines, and the camm b
locks the spring C back from an earth stud. When the strain of the
coupling is withdrawn the hook F is drawn into the position shewn by the
full lines by the spiral spring c... The spring C is released from the camm,
and as long as the train moves it oscillates, making successive contacts
with the earth stud and producing a succession of bell signals. It is well
to have a permanent coupling for the break-away hooks, the other end to
be strained on a plain hook to lock the spring C when required in making
or breaking up trains. Fig. 10 gives a front view of the passenger key;
A is a knob at the end of a stout wire which the passengers can pull out
but not return; B is a brass disc; C, the plan of a wooden box in which
the whole is mounted; D, a stud which the guard can shift with a fork
key in order to replace the knob and wire. Fig. 11 is the same in section,
the letters having the same reference; E is the wire attached to the knob;
F, ratchet grooves in E, into which the plate G is pressed by a spring H to
prevent the passenger returning the knob and wire. Fig. 12 is a back
view of the passengers' key, shewing how its acts. When the wire E is
withdrawn the spring H, which is connected with the earth wire, takes the
position shewn by the dotted lines (being assisted by the spiral spring H¹),
and comes into contact with the point I insulated and connected with the
"train wire;" this connects the zinc of the batteries permanently with the
earth and causes the armatures 1 of the bell, Fig. 6; to be permanently
attracted to the poll of the electro-magnet and the hammer to be held
up against the bells, but the motion of the train causes a reaction, and
then is produced a continuous shaking of the hammer and striking of the
bell quite distinct in character from that produced by the "break-away"
key. The spring H, by moving into contact with I, presses upon a pin a,
and forces the brass plate G into the position shewn by the dotted lines
and closes the hole against the return of the wire E until it is removed by
the guard's key fork fitting into the stud D, Figs. 10, 11, and 12. Should
the driver be required to make signals an extra wire is led to the engine
from the zinc end of the battery in the front van, and the engine is pro-
vided with a ringing key like that of the guards, as shewn at F, l, m,
Fig. 3. Fig. 13 is a bissel or ring of metal A, with disc of glass C, and a
metal cross B; it is well to paint the disc and the cross red; it is fixed
flat against the outside of the carriage when an external indicator is
wanted; it turns on a hinge at D, and when released is forced by a spring
behind a, a, into a position at right angles to the carriage so as to be
visible along the train. The wire E of Figs. 11 and 12 projects into the

page_text: short tube E, Fig. 13, and retains the disc flat on the carriage. It is
released when the wire is withdrawn.
Having now described the nature of my said Invention, and in what
manner the same is to be performed, I wish it to be understood that I do
not claim the separate and several parts of the apparatus represented and
referred to above, nor the exclusive use of such several or separate parts
except when the same are combined and employed for the purpose of my
said Invention, that is to say, for enabling passengers in railway trains to
make signals audible and visible to the guards, guards to make signals
audible each to the other, and to make audible and visible signals to the
engine driver; and for this I claim,-
1st, to seal up a platinized graphite or silver battery with a disc as
described, and with sawdust or other like material.
2ndly, to use in combination with battery currents, balanced or not, a
switch by means of which the guard can adjust the apparatus in his van
to suit any position or relative position it may occupy in the train, and for
the other purposes described.
3rdly, to use a locking armature in the manner and on the principle
described, so that the bell shall only ring by the action of electric currents,
and also to impart motion to an external index by a magnetized needle
suspended between the two armatures.
4thly, to use the different kinds of ringing key described for the
guards, the "break-away," and the passengers respectively, so as to pro-
duce three different kinds of ringing, each of which may be readily
distinguished from the others.
And, 5thly, for an outside indicator to use a disc in immediate combination
with the passenger ringing key, to be locked or released in the manner
described.
In witness whereof, I, the said Charles Vincent Walker, have here-
unto set my hand and seal, this Twenty-seventh day of July, in the
year of our Lord One thousand eight hundred and sixty-six.
Witness,
WILLIAM BULL.
CHARLES VINCENT WALKER. (L.S.)