IMPROVEMENTS IN SIGNALLING BY VOLTAIC ELECTRICITY, FOR THE PURPOSE OF INCREASING THE SAFETY OF RAILWAYS
Year: 1854

page_text: LETTERS PATENT to Robert Walker, of Glasgow, in the County of
Lanark, North Britain, Merchant, for the Invention of "IMPROVEMENTS IN
SIGNALLING BY VOLTAIC ELECTRICITY, FOR THE PURPOSE OF INCREASING THE
SAFETY OF RAILWAYS."
Sealed the 28th April 1854, and dated the 21st February 1854.
PROVISIONAL SPECIFICATION left by the said Robert Walker at the
Office of the Commissioners of Patents, with his Petition, on the 21st
February 1854.
I, ROBERT WALKER, of Glasgow, in the County of Lanark, North Britain,
Merchant, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN SIGNALLING BY VOLTAIC ELECTRICITY, FOR THE PURPOSE OF INCREASING THE
SAFETY OF RAILWAYS," to be as follows:-
My Invention consists in establishing along the line of railway at the
ordinary stations galvanic indicators of the kind commonly employed for
telegraphic purposes, and connecting them with a double line of conducting
wires extending from one station to the other, or over the entire length of the
line for the purpose of enabling the guard or conductor of a train in case of
accident to intimate the stoppage and consequent interruption of the line to
the stations before and behin, and by a pre-arranged set of signals to intimate

page_text: "
at what point the stoppage has taken place. The wires or conducting cords
in their ordinary or normal condition, when the apparatus is not in action, are
so arranged that no electricity passes through them, although in constant
communication with the galvanic indicators at the respective stations. The
arrangement is as follows:-One wire is connected at its extremities with
positive elements or poles of a pair of voltaic generators, and the other with
negative elements; and these wires are disposed parallelly along the line, and
insulated in the ordinary way; or they may proceed respectively from the
positive and negative elements of separate batteries placed one at each of the
two connected stations, that is to say, one wire is attached to the positive
element of the battery in one station, and the other wire to the negative
element of the battery at the other station; and the two wires thus attached
are carried along the line in opposite directions from station to station, or from
one end of the line to the other, separately but contiguously. When a signal
is to be communicated from any intermediate point in case of accident or
stoppage, a metallic connection of the two wires is effected by means of an
apparatus carried on the train for that purpose, and which apparatus may
consist simply of a spring clamp. of any convenient form, fixed to the end of
a rod of wood. sufficiently long to enable the operator thereby. to reach to the
height of the wires and apply the clamp. When this has been done, the
galvanic current passes through the spring from one wire to the other, thereby
completing the galvanic circuit, and affects the indicators simultaneously at
the stations, and thereby gives_notice of the interruption of the line. Or this
connecting apparatus may besides be provided with a galvanic needle or bell
apparatus, whereby signals may be returned to the operator from the con-
tiguous stations, intimating that the alarm signal transmitted by him has been
received. Or apparatus for completing the galvanic circuit may be permenently
attached to the posts erected along the line of railway for supporting the wires
and by having the posts numbered, the exact point of stoppage may be signalled
to the stations. As the batteries do not act except when the connection o
the wires as above intimated is formed, two of the wires in use for transmitting
signals by the ordinary telegraph may be used instead of laying other wires, as
herein described:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Walker in the Great Seal Patent Office on the 19th
August 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I; ROBERT
5 WALKER, of Glasgow, in the County of Lanark, North Britain, Merchant,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of February, in the year of our
Lord One thousand eight hundred and fifty-four, in the seventeenth .year -of
o Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Robert Walker, Her special licence that I, the said Robert Walker,
my executors, administrators, and assigns, or such others as I, the said Robert
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. SIGNALLING BY
VOLTAIC ELECTRICITY, FOR THE PURPOSE OF INCREASING THE SAFETY OF RAILWAYS,"
upon the condition (amongst others) that I, the said Robert Walker, by an
O instrument in writing under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
**NOW KNOW YE, that I, the said Robert Walker, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following state-
ment thereof (that is to say):-
My Invention consists in establishing along the line of railway at the
ordinary stations galvanic indicators, of the kind commonly employed for
telegraphic purposes, and connecting them with a double line of conducting
wires extending from one station to the other, or over the entire length of the
line for the purpose of enabling the guard or conductor of a train in case of
accident to intimate the stoppage and consequent interruption of the line to
the stations before and behind, and by a pre-arranged set of signals to intimate
at what point the stoppage has taken place. The wires or conducting cords
in their ordinary or normal condition, when the apparatus is not in action, are

page_text: so arranged that electricity passes through them, although in constant com-
munication with the galvanic indicators at the respective stations. The
arrangement is as follows:-One wire is connected at its extremities with
positive elements or poles of a pair of voltaic generators, and the other with
negative elements; and these wires are disposed parallelly along the line and
insulated in the ordinary way, or they may proceed respectively from the
positive and negative elements of separate batterics placed one at each of the
two connected stations; that is to say, one wire is attached to the positive
element of the battery in one station, and the other wire. to the negative
element of the battery at the other station; and the two wires thus attached
are carried along the line in opposite directions from station to station, or from
one end of the line to the other, separately but contiguously. When a signal
is to be communicated from any intermediate point in case of accident or
stoppage, a metallic connection of the two wires is effected by means of an
apparatus carried on the train for that purpose, and which apparatus may
consist simply of a spring clamp of any convenient form, fixed to the end of a
rod of wood sufficiently long to enable the operator thereby to reach to the
height of the wires and apply the clamp. When this has been done, the
galvanic current passes through the spring from one wire to the other, thereby
completing the galvanic circuit, and affects the indicators simultaneously at the
stations, and thereby gives notice of the interruption of the line. Or this
connecting apparatus may besides be provided with a galvanic needle or bell
apparatus, whereby signals may be returned to the operator from the continuous
stations intimating that the alarm signal transmitted by him has been received.
Or apparatus for completing the galvanic circuit may be permanently attached
to the posts erected along the line of railway for supporting the wires, and by
having the posts numbered, the exact point of stoppage may be signalled to
the stations. As the batteries do not act except when the connection of the
wires as above intimated is formed, two of the wires in use for transmitting
signals by the ordinary telegraph may be used instead of laying other wires, as
herein described.
Having thus stated the nature of my Invention, I will proceed to describe
the best means I am acquainted with for performing the same.
DESCRIPTION OF THE DRAWING.
Figure 1 shows two wires, A and B, extending between two stations on a
railway, or it may be between the two other parts of a length of railway. The
wires are insulated from each other and from the earth by being suspended on

page_text: posts or otherwise above the earth at intervals, as is well understood. The
wire A is at one end connected with one element, say zinc, of a galvanic
battery situated at the station or place Y, and the other end of the wire A is
connected with the like element, say zinc, of another galvanic battery, situated
at Z. The wire B is also at its two ends in connection with the two galvanic
batteries situated at Y, Z, but the ends of the wire B are connected to the
other element of each battery, say copper. By such arrangement it will be
evident that, in case of accident to a train, by simply connecting the wires
A and B by any suitable piece of wire or metal the needles at each station
Y or Z, or any intermediate places between Y and Z will be deflected, and
thus indicate that an accident has happened to a train on the line, and that
the line is stopped. And by the aid of an instrument hereafter described
telegraphic signals may be given from and to the stopping trains. By this
arrangement it will be evident that any number of indicating instruments,
each consisting of a coil and needle, may be introduced in the circuit, and
they will remain in a quiescent state; and if upright, they will remain vertical
till the wires A and B are connected, when the needles will all be simul-
taneously deflected.
Figure 2 shows another arrangement of wires and batteries which differs
somewhat from the preceding one. In this arrangement only one end of each
wire is in connection with a battery at the two points Y, Z. Thus the wire A
is in connection with one element, say zinc, of the galvanic battery at the
station or place Y, whilst the wire B is in connection at one end only, and
with the other element, say copper, of the galvanic battery at Z, and the two
batteries are by the other poles connected with the earth in the ordinary
manner. By this arrangement no circuit will be formed, and no current
of electricity passed till the wires A and B are connected by a piece of
wire, or other suitable connection of metal, when the circuit will be formed
in the two wires A and B, and the needles of any indicating instruments
will be caused to be deflected, and thus intimate that the line of railway is
stopped; and by using an instrument, such as herein-after described, by
making and breaking the circuit, telegraphic signals may be given so as to
communicate where the stoppage is, and the extent of such stoppage com-
municated; and thus may the drivers of other trains on coming to stations be
informed of the stoppage, and by having instruments at lesser intervals the
drivers of trains may know by observation or by information from signal-men
on the station whether the line is clear. The arrangement of apparatus
according to my Invention may be varied; and the peculiarity of my improve-

page_text: ments consists of combining the use of two wires and two distant batteries in
such manner-that no electric circuit is formed in either or both the wires till
they are connected at an intermediate position by a suitable connection of
metal. I do not, however, confine myself to the use of two wires only, as
advantages may be derived by the adding of a third wire to my combination.
Thus Figure 3 shows an arrangement or combination similar to Figure 2, but
with an additional wire C, which is connected with the different elements of
the two batteries at Y, Z, by which arrangement a person accompanying a
train which may be stopped at an intermediate position may communicate in
either direction according as he connects the wires A, C, and B, C; or, as in
Figure 2, he may connect the wires A, and B, and then he will communicate in
both directions. It will thus be seen that the arrangement shown at Figure 3
is identical with that shown at Figure 2; with the addition of the wire C, by
which at an increased cost the power of communicating in either direction, as
well as in both directions, may be obtained..
Figure 4 shows another variation, wherein an additional wire B' is in con-
nection only at one end with one element of one end of the galvanic batteries
at Y or Z. The wire A in this case is in connection with the like element of
both the galvanic batteries, as in Figure 1.
The wire B, as in Figure 2, is only in connection at one end, therefore the
wires B and B in this arrangement answer for the single wire B, of Figure 1.
But by having the wires B in two parts, and overlapping each other, com-
munication can be made in either direction without, for the tinie being,
communicating in the other direction, for it will be seen that a circuit may be
completed in either direction by coupling two of the wires A, B, or A, B', and
by. connecting all the wires simultaneously communications will take place in
both directions, as in Figure 1. The description of instrument which I prefer
for coupling the wires when a train is stopped, is shewn at Figures 5 and 6.
It consists of a handle a which carries a coil of wire, and a magnetic needle b;
the upper end of the handle by the metal c is put in communication with the
wire A; and by the metal d it is put in connection with the wire B. The
metal c is in connection with the one end of the coil, and the key e is in con-
nection with the other end of the coil. Hence when the key comes in contact
with d, a circuit will be made up; hence by making and breaking contacts,
signals will be given according to an understood arrangement.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would wish it to be understood that I make no claim
to the parts separately; nor do I confine myself to the use of any particular

page_text: form of indicating instrument, as bells may be sounded, or other forms of
pointing or sound-giving instruments may be used as a means of notifying
when a connection has been made by reason of a train being stopped. But
what I claim is, the combination of two suspended insulated wires, A and B,
with two distant batteries, as herein described, for signalling, for the purpose of
increasing the safety of railway trains.
In witness whereof, I, the said Robert Walker, have hereunto set my
hand and seal, this Eleventh day of August, in the year of our Lord
One thousand eight hundred and fifty-four.
Witness,
FRED HARRIS.
ROBT WALKER. (L.S.)