IMPROVEMENTS IN THE MEANS FOR WORKING AND INTER- LOCKING RAILWAY SIGNALS BY ELECTRICITY"
Year: 1883

page_text: LETTERS PATENT to Stanley Charles Cuthbert Currie of 21 Clarges Street
Piccadilly Gentleman and Illius Augustus Timmis of 17 Great George Street
Westminster Civil Engineer both in the County of Middlesex, for an
Invention of "IMPROVEMENTS IN THE MEANS FOR WORKING AND INTER-
LOCKING RAILWAY SIGNALS BY ELECTRICITY"
PROVISIONAL SPECIFICATION left by the said Stanley Charles Cuthbert
Currie and Illius Augustus Timmis at the Office of the Commissioners of
Patents on the 12th December 1883.
STANLEY CHARLES CUTHBERT CURRIE of 21 Clarges Street Piccadilly Gentleman
and ILLIUS AUGUSTUS TIMMIS of 17 Great George Street, Westminster Civil
Engineer both in the County of Middlesex, "IMPROVEMENTS IN THE MEANS FOR
WORKING AND INterlocking RailLWAY SIGNALS," [BY ELECTRICITY]
The objects of this Invention are to provide safe and economical means, for
working Railway signals, by Electricity, so that, First, all the switches and levers
in a signal Box, working given signals and points, as far as necessary, interlock,
one with another, and also with any other switches and levers, working signals or
points. Secondly:-This working and interlocking is done electrically, or by
combination of electrical and mechanical means, and the arrangement of parts is so
simple and strong, that it is perfectly reliable
Thirdly The Electric current is so arranged that a maximum amount of power
is used, to actuate the magnets, but after the armature and bobbin of any magnet
are brought together, a minimum expenditure of electrical energy takes place, by.
the reduction of the Electric current
Fourthly: Any signals and points, worked on this system, can be under the
combined control of two or more signalmen at separate stations, any distance apart,
and also under the automatic action of a passing train; thus forming a complete
Block system, between any given places or points
In order to effect these objects we put an electro-magnet, to work each signal
arm, and so arranged that the magnet pulls the arm down or Free" by a direct
"

page_text: $
action (of course it may work in conjunction with a mechanically applied means).
The magnet is actuated by a current of Electricity, so arranged, that when the
magnet is in work (ie when the armature and Bobbin are coming together) the
current is at its maximum, but when a practical contact is made (ie when the
Armature and Bobbin are together, whether in absolute contact or not) the current
is reduced, so as to minimize and of course economize, the expenditure and production
of the Electric current.
"
Because we find that a very small electric current is sufficient to hold the
armature and Bobbin together (or in other words to resist the leverage of signal
arms, or weights, or other pulls) and we must here point out that one main feature
in this Invention is having a continuous current of electricity, running through the
magnets, while the signals are held "free" or (Line clear) so that on disarrange-
ment of the electric, or mechanical means, the signal arms at once go to their
normal position, "Danger," as described in Curries' patent, N° 83282 It will thus
be seen that the signal arms only come down "free," and are only held "free," or
"Line clear," under the direct influence, as above described, of a continuous electric
current; which we regulate in strength to meet, and suit, all contingences, and we
further place Switches, or small levers (these may be single or commutator) in the
Signal box, corresponding to the Signals to be worked; each switch or lever
representing one or more Signals, and according to its position, either making, or
partially making, or breaking, a circuit, or more than one circuit-These switches
are used instead of the ordinary mechanical levers, as now used for working signals,
and the movements of our switches can be precisely similar to those of the present
levers, ie when back the signal arm is at danger, its normal position, and when
forward, the signal arm is down, "free;" and, whereas, in the ordinary mechanical
arrangements, certain levers cannot be pulled forward (signal lowered) unless
certain other levers are set," in proper position, so, with our switches, the
completion of the circuit, from battery to Signal Magnet, depends upon certain
other switches, being in certain positions, ie "set"-We do this by making as
many breaks, and contact pieces, in the said circuit as there are switches upon the
setting." These contact pieces and breaks are attached, also, to the ordinary
point levers, so that in order that any circuit may be complete, and any Signal
lowered, the said point levers must be in their proper positions-These positions of
course depending upon the arrangement of the lines of Signals, in Station―These
switches may be connected, mechanically, with one another, as
the- present
mechanical levers are. In which case, each Switch would have one contact piece,
and each circuit but one break, or the two methods, that is Electrical and
Mechanical, can be combined. The one point being observed, that no current can
be allowed to pass through Signal magnet, until all other necessary Signals are
blocked, and points locked-It will readily be seen that by this Electrical method
we dispense with all complicated catches and locks, and in place of such we use
simple contacts, and thus, if any one contact is broken, the whole circuit is broken
aud, moreover, during the whole time any signal is down, each of the contacts, in
that signal circuit, must remain in position, as the current is running continuously;
and the breaking of any one circuit current causes the signal, or signals, to assume
a position of danger. We use magnets, of sufficient size, and current, of sufficient
strength, to allow for all contingences, arising from frost, snow, or other causes,
sticking the signal arms; And also for actuating the magnets, and thus pulling the
signal arms down, and as this is considerably greater than the current required to
hold the arms down, we use a sinaller current, when the signals are down (armature
home). If however the ordinary electrical power, used, is insufficient, owing to
extraordinary causes, such as herein before mentioned, to work the magnets, there
is a heavy reserve, at the disposal of the signalman, which he can switch on at a
moments notice. We may state, here, that in case the Signalman is careless of the
expenditure, or production, of the Electric current, there is a check provided, in the
Signal Box. We do this by any of the following, or other methods. In order to
lower a Signal, the Signalman pulls over his switch and allows a current,.

page_text: sufficiently strong, to pull signal arm down, to pass; but as soon as it is down, he
allows his switch to assume a position, regulated by a strong spring, or any other
suitable means, and when it is in that position, the current passes through a wire,
or any other suitable substance, of higher resistance, than the one which conveyed
the current, to lower the signal arm; or the armature, itself, can have a suitable
switch attached, which causes a resistance to be inserted in the circuit; or a less
number of cells can be switched on, when Armature is home; than when bringing
it home; or any other means may be used, so long as during the time the current
is running, and holding the Armature home, the strength of that current may be
less than the current which caused the armature to be attracted to the bobbin. The
object, of course, being that we greatly economise the expenditure, or production, of
Electrical energy.
The mechanical means used, to switch on a powerful current, as hereinbefore
described, when the switch lever is pulled right over; and then to go back, through
part of its travel (actuated by a spring, or weight, or other similar means) and
switch in reduced current, may be varied in very many ways. In order that
certain Signals, worked upon the above principle, may be under the combined
control of two or more Signalmen, at different stations, so as to be worked upon
the Block system-We have transmitting, and receiving instruments, in each
Signal Box, the working of which is as follows-we have a main circuit, or
circuits, which actuate the Signal or Signals, and their relative points, and
repeaters, from each Signal Box, as already described, and, in addition, we have
an auxiliary circuit, from Box to Box, for the purpose of moving contact pieces,
and thereby completing the main circuits, above mentioned-It is then evident
that a complete check is provided, whereby any particular signal (such for instance
as a departure signal) is placed under the combined control of two or more
signalmen.
Thus the train cannot pass a given signal, without the joint consent, of two or
more signalmen, and an additional check is provided, by the breaking or making of
the Electrical circuits, by the automatic action of a passing train.
It must again be pointed out that the main electrical currents, and auxiliary
electrical currents, are running, continuously, during the whole time that their
relative signals are down, "Line Clear"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Stanley Charles Cuthbert Currie and Illius Augustus Timmis in
the Patent Office on the 9th June 1884.
STANLEY CHARLES CUTHBERT CURRIE of 21 Clarges Street Piccadilly Gentleman
and ILLIUS AUGUSTUS TIMMIS of 17 Great George Street Westminster Civil
Engineer both in the County of Middlesex "IMPROVEMENTS IN THE MEANS FOR
WORKING AND INTERLOCKING RAILWAY SIGNALS" [BY ELECTRICITY]
The objects of our Invention are to provide safe and economical means for
working Railway Signals by Electricity so that First:-All the switches and
levers in a Signal Box working given signals and points and as far as necessary
interlock one with another and also with any other switches and levers working
Signals or Points.
Secondly: This working and interlocking is done electrically or by the
combination of Electrical and mechanical means and the arrangement of parts is so
simple and strong that it is perfectly reliable.
Thirdly The Electric current is so arranged that a maximum amount of
power is used to actuate the magnets but after the armature and bobbin of any
magnet are brought together a minimum expenditure of Electrical energy takes
place by the reduction of the Electric current
FourthlyAny Signals and points worked on this system can be under the
combined control of two or more Signalmen at separate Stations any distance
apart and also under the automatic action of a passing train thus forming a
complete Block system between any given places or points.
In order to effect these objects I put an electro magnet to work each signal arm
and so arranged that the magnet pulls the arm down or "Free" by a direct action
(of course it may work in conjunction with a mechanically applied means). The
magnet is actuated by a current of Electricity so arranged that when the magnet
is in work (ie when the armature and bobbin are coming together) the current is
at its maximum but when a practical contact is made (ie when the armature and
Bobbin are together whether in absolute contact or not) the current is reduced so
as to minimize and of course economize the expenditure and production of Electrical
energy
"
Because I find that a very small electric current is sufficient to hold the
Armature and bobbin together (or in other words to resist the leverage of Signal
arms or weights or other pulls) and we must here point out one main feature in
our Invention is having a continuous current of Electricity running through the
magnets while the Signals are held free or Line Clear so that on disarrangement of
the electrical or mechanical means the signal arms at once go to their normal
position "DANGER as described in Currie's Patent N° 632/82.. It will thus be seen
that the Signal arms only come down "Free" and are only held down "Free" or
"Line Clear" under the direct action as above described of a continuous current of
Electricity which we regulate in strength to meet and suit all contingences and we
further place switches or Small levers (these may be single or commutator) in the
signal box corresponding to the Signals to be worked; each switch or lever
representing one or more Signals and according to its position either making or
partially making or breaking a circuit or more than one circuit. These switches
are used instead of the ordinary mechanical levers as now used for working Signals
and the movements of our switches can be so arranged as to be precisely similar to
those of the present levers i,e. When back the signal arm is at "DANGER" its
normal position and when forward the signal arm is down "Free" and whereas in the

page_text: ordinary mechanical arrangements certain levers cannot be pulled forward (signal
lowered) unless certain other levers are set in proper position so with our switches
the completion of the circuit from Battery to Signal Magnet depends upon certain
other switches being in certain positions i,e set. We do this by making as many
breaks and contact pieces in the said circuit as there are switches upon the setting.
These contact pieces and breaks are attached also to the ordinary point levers so that
in order that any circuit may be complete and any Signal lowered the said point
levers must be in their proper positions. These positions of course depending upon
the arrangement of the lines of Signals in Station. These switches may be connected
mechanically with one another as the present mechanical levers are. In which case
each switch would have one contact piece and each circuit but one break or the two
methods that is Electrical and mechanical can be combined The one point being
observed that no current can be allowed to pass through Signal magnet, until all
other necessary Signals are blocked and points locked. It will readily be seen that
by this Electrical method we dispense with all complicated catches and locks and in
place of such we use simple contact pieces and thus if any one coutact is broken the
whole circuit is broken and moreover during the whole time any signal is down,
each of the contacts in that signal circuit must remain in position as the current is
running continuously and the breaking of any one circuit current causes the signal
or signals to assume a position of danger. We use magnets of sufficient size and
current of sufficient strength to allow for all contingences arising from frost, snow
or other causes sticking the signal arms and also for actuating the magnets and
thus pulling the signal arms down and as this is considerably greater than the
current required to hold the arms down we use a smaller current when the signals
are down (armature home). If however the ordinary electrical power used is
insufficient owing to extraordinary causes such as hereinbefore mentioned to work
the magnets there is a heavy reserve at the disposal of the signalman which he can
switch on at a moments notice. We may state here that in case the Signalman is
careless of the expenditure or production of the Electric current there is a check
provided in the Signal Box. We do this by any of the following or other methods.
In order to lower a Signal the Signalman pulls over his switch and allows a
current sufficiently strong to pull signal arm down to pass but as soon as it is down
he allows his switch to assume a position regulated by a strong spring or any other
suitable means and when it is in that position the current passes through a wire or
any other suitable substance of higher resistance than the one which conveyed the
current to lower the signal arm, or the armature itself can have a suitable switch
attached which causes a resistance to be inserted in the circuit; or a less number
of cells can be switched on when Armature is home than when bringing it home or
any other means may be used so long as during the time the current is running
and holding the armature home the strength of that current may be less than the
current which caused the armature to be attracted to the bobbin. The object of
course being that we greatly economise the expenditure or production of Electrical
energy.
The mechanical means used to switch on a powerful current as hereinbefore
described when the switch lever is pulled right over and then to go back through
part of its travel (actuated by a spring or weight or other similar means) and
switch in reduced current may be varied in very many ways. In order that
certain Signals worked upon the above principle may be under the combined
control of two or more signalmen at different stations so as to be worked upon the
block system. We have transmitting and receiving instruments in each Signal
Box the working of which is as follows. We have a main circuit or circuits which
actuate the Signal or Signals and their relative points and repeaters from each
Signal Box as already described and in addition we have an auxiliary circuit from
Box to Box for the purpose of moving contact pieces and thereby completing the
main circuits above mentioned. It is then evident that a complete check is
provided whereby any particular Signal (such for instance as a departure Signal)
is placed under the combined control of two or more signalmen

page_text: Thus the train cannot pass a given signal without the joint consent of two or
more signalmen and an additional check is provided by the breaking or making of
the Electrical circuits by the automatic action of a passing train.
It must again be pointed out that the main Electrical currents, and auxiliary
electrical currents are running continuously during the whole time that their
relative signals are down "Line Clear"
DESCRIPTION OF DRAWINGS
Figure 1 represents the method of working and interlocking Railway Signals
and points of a double junction Station A in which X is a plan of switchboard the
numbers on which from 1 up to 13 correspond with similar numbers which
represent the signals and points and lock. The contact pieces on switchboard are
marked EHL and B B and S S M M are the incandescent lamps through which
the current passes when the armature and Bobbin of the Magnet are in contact
and the Signal arm indicating Line clear. Of course as herein before mentioned
any other substance may be used instead of the lamp for instance an ordinary wire
can be used so long as it is of a higher resistance than the one which conveyed the
current which is used to lower the signal
P is the platform and W the main up line and V the down main line U and T
being the branch up and Down lines. The pieces C C representing the strip C
which makes contact between E H and L as shown at C Figures 5 and 6. D is
the wire leading to Battery.
Let it be supposed that an up Main Line train is required to be sent on to the
Branch. It is necessary to work the locking bar 6 the points 7 the Signals 1, 3
and 5 The normal position of points being as shown on plan it is necessary to
pull the Locking bar 6 and point lever 7 forward making connection between P P 6
and P P 7. The points are thus set right for Branch line. Then in coming
to S S 8 (Down Branch Point Lever) which must be back, or in its normal position.
Then from S 8 to E 3. By putting switch 3 forward the connection is made
between E H L 3. On the switch touching E HL the current runs through B B 2 to
Signal 3 which is lowered. Also the current runs from H. 3. to E. 1. and on the
switch 1 being put forward EH L. 1 are connected and Signal 1 is lowered.
Similarly the current runs through P P 6. P P. 7. S. S. 8. E H L 5. B B 4.
BB 10 to Signal 5.
It can easily be seen that the down home main Signal 10 must not be lowered
and on reference to the Drawing it will be seen that if the signal 10 were lowered
(i,e The switch 10 put forward to make connection E H L 10) then B B 10. would
not be connected and therefore Signal 5 (up Branch Departure) could not be
lowered and all the other Signals are similarly interlocked so as to secure absolute
safety. The points and Locking Bar 6. 7. 8 may be worked by Electrical power
or by ordinary Levers, the latter being furnished with contact pieces similar to the
Electrical Levers.
On the plan X Figure 1. the Signals are worked Electrically but the points 7.8
and lock 6 are worked by mechanical means the levers being furnished with
contact pieces similar to the Electrical Signal levers 1 to 5; 9 to 13 but I prefer to
work the points Electrically as well as Signals and then the lock 6 and the lock
lever 6 and its contact piece are dispensed with and the current runs direct to
lever 7 and thence onward as hereinbefore described.
Figure 2 represents the arrangement of Signalling between Station A and B on
the said Figure 2 in which P. P¹. are the platforms R R1 the Signal Boxes.
W and V The up and down main lines. U and T the up and down branch lines.
The numbers 1. 2. 3. 4. 5. 9. 10. 11. 12. 13. are signals at Station A and 14. 15. 16.
17. 18. 19. Signals at Station B. EE are the Treadles H. G are trains on down
main and up main lines. The enlarged plan of switchboard showing contact
pieces and connections is shown at X Figure 1.
Figure 3 shows transmitting and receiving instruments and signal levers and
-

page_text: the resistances in the shape of an incandescent lamp in cabin R¹ Station A in
which B. B are the transmitting and receiving instruments C. C the repeaters
D the resistance lamp 1 to 13 are the Signal and point levers and F the current
meter.
Figure 4 represents the transmitting and receiving instruments and resistance
lamp and signal levers at Cabin R Station B.
Let it be supposed that a train is about to leave Station A for Station B on
down line, before Signalman at A can lower Signal 9 he must ask permission
from B by three beats on Receiver button which give three rings on. Transmitter
bell in cabin B
The Signalman at B thereupon (if the Transmitter disc shows Line clear) presses
the plunger and
1 Disc at B is altered from Line clear
2
"
ور
A
"
"
»
to Permission
Line Blocked Line clear
"
3 A is allowed to lower Signal 9 which he was unable to do before
The train now leaves A and in passing treadle E
1 Signal 9 goes automatically to " Danger"
2 Disc at A is altered from "Line clear" to Line blocked
3
B
"
"
»
"
"
Permission to Train on line and is locked there
Thus Signal 9 is sent to Danger automatically and both Signalinen at A and B are
apprised of it. The plunger of Transmitter in cabin when pressed in locks itself
and remains locked till the train passes treadle E¹ when
1 Signals 5 and 6 go to danger automatically.
2 Transmitter Plunger P¹ is unlocked in cabin R
3 Bell rings in Cabin R¹
Figure 5 is an elevation of a Signal Post A represents the arm B the connecting
rod M the magnet Bobbin and N the armature of same P the Post and the Disc D.
SS the Signal levers in Figures 5 and 6 are placed in Signal cabins R and R',
B B, EHL are contact pieces shown fully in the plan of switchboard X Figure 1.
T the lever and C the connecting strip. The contact E is connected to
Battery G on the lever T being back into position Z¹ the strip C makes contact
between E H and L the result being that the current passes from Battery
through E along C to L and from L away to Signal through the wire O to
the bobbin M of the magnet then the armature N is then attracted to bobbin M
by the Electric current and the arm A is thrown into the position Figure 6 by the
mechanical means shown on the Drawing or by any other suitable mechanical
means. The arm A being down the lever T is released by the Signalman and the
Spring W causes it to assume the position Z the current now passes from G
through E C to H through the resistance lamp to contact piece L from L to Signal
Post through wire O as herein before mentioned. The current in passing through
resistance lamp is reduced to the retaining current. The Signal arın A will thus
remain in position Figure 6 so long as the lever remains in position Z but if the
lever be placed in the position X the current through E H L is broken and the
Signal arm goes to "DANGER" At the same time the strip C if required can
make contact between B B and allow the current to pass if necessary to some
other signal as hereinbefore described Figure 1 but if lever and contact C remain
in a vertical position no current is running and all Signals are at " DANGER."
Having now described the nature of the said Invention and the manner in
which the same is or may be carried into effect I claim
First The use of a continuous maximum working current to free or lower any
Signal and a reduced or minimum continuous working current to hold them down
substantially as and for the purposes hereinbefore described.
Secondly-The interlocking of Railway Signals and Points one with another
and also with any other switches and levers working Signals or points by Electrical
ineans or by the combination of Electrical and Mechanical means in conjunction
with a continuous working current substantially as and for the purposes herein-
before described.

page_text: Thirdly-The arrangement of Signals and Points and treadles in Station to
Station Signalling and the working of them so that all. Signals and points are
under the joint control of two or more signalmen and the automatic action of
passing trains substantially as and for the purposes hereinbefore described.
Fourthly-The arrangement of any or all of the above claimed systems at any
number of Stations or junctions substantially as and for the purposes hereinbefore
described
In witness whereof I the said Illius Augustus Timmis on behalf of myself
and the said Stanley Charles Cuthbert Currie have hereunto set my hand and
seal this thirty-first-day of May in the year of our Lord one thousand eight
hundred and eighty-four.