IMPROVEMENTS IN AND CONNECTED WITH THE WORKING OF RAILWAY SIGNALLING PAPPARATUS
Year: 1880

page_text: LETTERS PATENT to George Kift Winter, Telegraph Engineer of the Madras
Railway Company, at present residing at Chiswick, in the County of
Middlesex, for an Invention of "IMPROVEMENTS IN AND CONNECTED WITH
THE WORKING OF RAILWAY SIGNALLING PAPPARATUS." Partly a communi-
cation from abroad by James Craik, Assistant Traffic Manager of the Madras
Railway Company, Madras.
PROVISIONAL SPECIFICATION left by the said George Kift Winter at the
Office of the Commissioners of Patents on the 12th June 1880.
GEORGE KIFT WINTER, Telegraph Engineer of the Madras Railway Company, at
"IMPROVEMENTS IN
present residing at Chiswick, in the County of Middlesex.
AND CONNECTED WITH THE WORKING OF RAILWAY SIGNALLING APPARATUS."
(Partly a communication from abroad by James Craik, Assistant Traffic Manager of
the Madras Railway Company, Madras.)
This Invention, which relates to improvements in and connected with the
working of railway signalling apparatus, has especial reference to improvements in
block telegraph instruments which require the combined action of the signalmen
at the ends of a section in order that the indications of the instruments may
be varied, so that no signal is complete until it has been acknowledged, the
combined action of the signal itself and its acknowledgment being required to
cause the instrument to indicate the signal that has passed, and in which the state
of the line is clearly indicated, not only as to whether there is a train on the section
or not, but also the direction in which a train is travelling over the section, and a
modification of which allows of either signalman causing both instruments to indicate
"train on line," i.e., the "danger" signal, but requires the combined action of both
signalmen to remove the "danger" signal and cause the instruments to indicate
"line clear." The Invention also has reference to the connection of a starting-
semaphore with the block instruments and with an attachment to the permanent-
way in such a manner as that it is put to "danger" by the passage of a train into
the block section between such instruments, and can only be lowered by the combined
action of the signalmen at the ends of that section.

page_text: In the block-instruments to which our improvements relate there are two
indicators on each instrument, one, which is painted black, and is marked "train
going to," and is termed the "train going" indicator, referring to trains leaving the
station; and the other, which is painted red, and is marked "train coming from,"
and is termed the "train coming" indicator, referring to trains approaching the
same; the name of the station with which the instrument is connected, and which
consequently forms the last word of each of the above phrases, being immediately
underneath and common to both dials. Each indicator has two positions, viz., " clear,"
and "on line," from one to the other of which the indicators are actuated by coils
which are not in the line circuit, so that no accidental current either from lightning
or contact with another wire is able to affect them. In order to move either of
the indicators from one position to the other, it is necessary that the tongue of a
polarized relay should be moved from one position to another with the object of
reversing the direction in which a local current when it flows will circulate the
wire of the indicator coils, and that the circuit of the local battery should be then
completed.
The relay may accomplish the reversal above alluded to, either by reversing the
poles of the battery or by reversing the wire connections of the coils. In order to
reverse the poles of the battery the simplest way is to divide the battery into two
parts, and connect up the apparatus as illustrated in Figure 1 of the accompanying
diagrams, and in order to reverse the connections of the coils the simplest way is to
wind the coil differentially or in an equivalent manner, and connect it up as illustrated
in Figure 2. In either arrangement the circuit is broken at some point, such as A, in
the undivided portion, and the second necessary operation above referred to is to
close this break.
It should be borne in mind that the fundamental object of the arrangement now
being described, and of which I was the inventor, is the placing of the apparatus
for controlling the direction of the local current under the power of the signalman
at one end of the section, and the apparatus for completing the circuit in the
power of the signalman at the other end of the section, so as (as above referred to)
to render necessary the combined action of the signalmen at the ends of a section in
order to make any alteration in the indications of the instruments.
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Suppose a key of the ordinary form (let reference now be had to Figure 3) is
used for giving signals, then it is evident that any apparatus, such as B, that may
be placed between the contact point A and the battery, or between the battery
and "earth," is affected only by the out-going signals, and is therefore entirely
under the control of the signalman at the instrument; and that any apparatus,
such as D, that may be placed between the back contact point C and "earth is
acted on only by signals from the distant end, and is therefore under the control of
the signalman at the distant end of the section. If therefore the relay for reversing
the direction of the local current acting on the "train going" indicator be placed
at D, and the apparatus for completing the circuit be placed at B, it is evident
that though the signalman at the distant station can control the relay D, and
consequently the direction of the local current, he cannot cause the local current to
act on the indicator, as the local circuit is not completed until the key at C, at the
near end, is depressed. In like manner if the relay for controlling the direction of
the "train coming" indicator battery be placed at B, and the relay for closing the
circuit be placed at D, the combined action of the signalmen at the ends of the
section is required to move the "train coming" indicator.
The reversal of the direction of the current for the "train-coming" indicator
may also be accomplished by using the line battery, as modified by the "train
coming switch" hereinafter referred to, for the local battery acting on the coils of
this indicator; and the completion of the break in the circuit of the battery acting
on the "train going" needle may be made by causing the key when pressed to
bring two additional contact points together. The switch or commutator is used
for reversing the poles of the line battery, but the current, as modified by the
switch, is inactive until the key is pressed. Each time the key is pressed a current

page_text: passes and a bell is rung at the distant station; the bell may either be rung by
the direct action of the current or by using a relay and a local current. In practice
it is found convenient to work the "train coming" indicator and the bell by means
of the line battery, which is made to act for the time being as a local battery, the
circuit of which is completed by a neutral or unpolarized relay placed at D,
Figure 3.
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When using these block instruments, according to our Invention, in connection
with the starting semaphore which is described hereinafter, the following additions
are made to them-An extra tongue is put into the relay at D so arranged as to
close a circuit only when the "line-clear" signal is sent. A relay tongue is placed
between the poles of the electro-magnet which controls the "train-going" indicator
so arranged as to break the same circuit when the indicator is moved to "on line,"
and the switch-handle may be caused to mechanically break this same circuit when
it is placed at on. In this circuit, which is acted upon as above described, are
placed a battery, and the coils of the unlocking apparatus of the semaphore-arm or
of the signalling-lever. Thus the current is only allowed to pass through these
coils and unlock the semaphore-arm or the signalling-lever when the "line-clear"
signal is being received from the distant station, and it is so arranged that the
semaphore circuit cannot be completed even by this signal, if the " train-going
indicator represents train "on line," or if the switch handle is at "on," thus showing
that permission has been given for a train to come from the distant station. This
latter provision is unnecessary, and can be removed when the instrument is used
on double lines.
"
The semaphore-arm when put to "danger" is held in that position by an electric
lock, which can only be liberated by the signalman at the distant station, and
by a counterpoise which has to be removed by the signalman in charge of the
signal.
The electrical locking arrangement is constructed with an arm which is attached
rigidly to the axle of the semaphore-arm, and is held when the semaphore-arm is
at "danger" by a cranked-clutch. It is also provided with an electro-magnet, the
armature of which is provided with a detent which engages with a weighted lever
overhanging the cranked arm of the clutch. When a current passes through the
coils of the magnet the armature is attracted, liberating the weighted lever, which
falling upon the extension or arm of the clutch releases the arm on the semaphore
axle, and allows the semaphore-arm to be lowered to "caution" by the signalman
in charge at the near station; and this ho effects by raising the counterpoise or
weighted arm which passes through a slot in a rod connected to the tail of the
semaphore-arm, and this he conveniently does by means of a cam which is turned
by pulling a wire-rope by means of his signalling-lever, and thus turning an axlo
to which both the can and a bent weighted lever are rigidly attached; this being
done a weighted piece falls under the counterpoise-arm and keeps it up, and at the
same timo by means of a connecting-rod raises a cranked cam attached to a jaw of
a chair carrying one of the rails of the permanent way, so that the flange of one of
the advanced wheels of the next passing train can bear on and lower it, until which
time the semaphore arm keeps at "caution." Upon a train passing the supporting
piece is pulled back, and the counterpoise-arm falls, raising the semaphore-arm to
danger," and holding the [cranked cum down out of the way of the following
wheels of the train. Upon the semaphore-arm falling to "caution" the electrical
locking contrivance is automatically set into locking position again, and on the
semaphore being raised to "danger" by a passing train, as just described, it is again
held in position by the clutch and by the counterpoise, and it cannot be again
lowered until the arrival signals of that train have been exchanged, and a signal
meaning "line clear" for another train has been received from the distant station.
On double lines when the positive system is used the semaphore-arm may be
unlocked by the arrival signals instead of the line-clear" signal by a simple
"
modification of the contacts in the instruments.
In addition to the above described arrangement in connection with the permanent-

page_text: "
way for liberating the weighted-piece by which the counterpoise-arm or lever is
supported when the semaphore-arm is at "caution," so that the latter may go to
danger," the semaphore-arm may be caused to indicate " danger" by thrusting
the signalling lever in the cabin so as by slackening the wire to allow the bent
weighted lever to turn, and by means of a spur or projection, with which it is
provided, cause it to tilt the weighted piece out of its supporting position, whereupon
the counterpoise immediately causes the semaphore-arm to indicate danger."
This spur or projection is moreover of advantage in causing the semaphore-arm to
be automatically raised to "danger" should the wire from the signalling-lever
break, the bent weighted lever being then released and causing its spur to act upon
the weighted piece as just described.
"
In lieu of the above described arrangement for interlocking the semaphore-arm
with the block-instruments, the signalling lever in the cabin may be interlocked
therewith, an equivalent electrical locking device to that described in connection
with the semaphore-arm being used in connection with the signalling lever, the
arrangement for raising the semaphore-arm to "danger" by the passage of a
train, or by the signalling lever, or upon the wire breaking, remaining as hercinbefore
described.
The starting semaphore and its attachments, as hereinbefore described, may also
be worked in connection with other block instruments than of the nature
herein before referred to, or they may be used without the electric locking
arrangement.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Kift Winter in the Great Seal Patent Office on the 11th
December 1880.
"
GEORGE KIFT WINTER, Telegraph Engineer of the Madras Railway Company, at
present residing at Chiswick, in tho County of Middlesex. "IMPROVEMENTS IN
AND CONNECTED WITH THE WORKING OF RAILWAY SIGNALLING APPARATUS.'
(Partly a communication from abroad by James Craik, Assistant Traffic Manager of
the Madras Railway Company, Madras.)
This Invention, which relates to various improvements in and connected with the
working of railway signalling apparatus, has reference to improvements specially
applicable to block. telegraph instruments which require the combined action of the
signalmen at the ends of a section in order that the indications of the instruments
may be varied, so that no signal is complete or indicated by the instruments until
it has been acknowledged, the combined action of the signal itself and its
acknowledgement being required to cause the instruments to indicate the signal
that has passed, and in which the state of the line is clearly indicated, not only as
to whether there is a train on the section or not, but also the direction in which a
train is travelling over the section, so that neither signalman alone can in any way
alter the indications of either instrument, and there is a record at each instrument
unalterable by either signalman alone of the last signal which has passed between
the instruments, the signalmen being thus supplied at a glance with the exact
condition of the block section, and having no need to trust to memory or to entries
in the signal book; the objects of the present improvements being rendered
apparent in the following description. The Invention also has reference to the
connection of a starting semaphore outside the signal box and in view of the driver
of the train with the block instruments, in such a manner as that it cannot be
lowered to allow a train to leave until "line clear" has been received from the
other end of the section, and with an attachment to the permanent way in such a
manner as that it is automatically put to "danger" by the passage of a train
when entering the section, and can only be lowered by the combined action of the
signalmen at the ends of that section, as and at the times hereinafter described.
"
In the block instruments to which our present improvements have especial
reference (though they or equivalent modifications thereof are also applicable to
other forms of block instruments in present use to enable them to control the
semaphore hereinafter described), there are two "indicators on each instrument,
one, which is painted "black" and is marked "train going to," and is termed the
"train going" indicator, referring to trains leaving the station, and the other, which
is painted red and is marked "train coming from," and is termed the
" train
coming" indicator, referring to trains approaching the same, the name of the
station with which the instrument is connected, as the other terminal of the block
section, and which consequently forms the last word of each of the above phrases,
being immediately underneath and common to both dials. The needle of each
indicator has two positions, videlicet, "clear" or "cleared" and "on line," from one
to the other of which the needles are actuated by coils which are not in the line
circuit, so that no alterations in the indications of the instruments can be caused by
lightning or by contact between the block or line wire and any other. In order to
move either of the indicator needles from one position to the other, it is necessary
that the tongue of a polarized relay should be moved from one position to another
with the object of reversing the direction in which a local current when it flows
will circulate the wire of the indicator coils, and that the circuit of the local
battery should be then completed. The relay may accomplish the reversal above
alluded to either by reversing the poles of the battery, the simplest way of doing

page_text: which is to divide the battery into two parts and connect up the apparatus, as
illustrated in Figure 1 of the accompanying Drawings, or by reversing the wire
connections of the coils, the simplest way of doing which is to wind the coils
differentially and connect up, as illustrated in Figure 2. In either arrangement
the circuit is broken at some point, such as A, in the undivided portion, and the
second necessary operation above referred to is to close this break.
It should be borne in mind that the fundamental object of the arrangement now
being described, and of which I was the inventor, is the placing of the apparatus for
controlling the direction of the local current which actuates the indicators under
the power of the signalman at one end of the section, and the apparatus for
completing the circuit in the power of the signalman at the other end of the section,
so as (as above referred to) to render necessary the combined action of the signalmen
at the ends of a section in order to make any alterations in the indications of the
instruments.
Suppose a key of the ordinary form (let reference now be had to Figure 3) is
used for giving signals, then it is evident that any apparatus, such as B, that may
be placed between the contact point A and the battery or between the latter and
"earth" is affected only by the outgoing signals, and is therefore entirely under
the control of the signalman at the instrument, and that any apparatus, such as D,
that may be placed between the back contact point C and "earth" is acted on only
by signals from the "distant" station, and is therefore under the control of the
signalman there. If, therefore, the relay for controlling the direction of the local
current acting on the "train going" indicator be placed at D, and the apparatus for
completing the circuit be placed at B, it is evident that though the signalman at
the distant station can control the relay D, and consequently the direction of the
local current, he cannot cause the local current to act on the indicator, as the local
circuit is not completed until the key at C at the near end is depressed. In like
manner, if the relay for controlling the direction of the local current acting of the
"train coming" indicator be placed at B, and the relay for closing the circuit
be placed at D, the combined action of the signalmen at the ends of the section is
required to move the "train coming" indicator.
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The reversal of the direction of the current for the "train coming "indicator may
also be accomplished by using the line battery, as modified by the "train coming'
switch (to which further reference is hereinafter made) for the local battery acting
on the coils of this indicator; and the completion of the break in the circuit of the
battery acting on the "train going" needle may be made by causing the key when
pressed to bring two additional contact points together. The switch or commutator
(any of the ordinary forms of which are or may be used) is used for reversing the
poles of the line battery, but the current as modified by the switch is inactive
until the key is pressed. Each time the key is pressed a current passes and a bell
is rung at the distant station; the bell may either be rung by the direct action of
the current or by using a relay and a local current. In practice it has been found
convenient to work the "train-coming" indicator and the bell by means of the line
battery, which is made to act for the time being as a local battery, the circuit of
which is completed by a neutral or unpolarized relay placed at D, Figure 3.
When using these block instruments, according to our Invention, in connection
with the starting semaphore which is described hereinafter we make the following
additions to them:-We put an extra contact on the tongue of the relay at D, so
arranged as to close a circuit only when the "line clear" signal is sent. We also
place a relay tongue between the poles of the electro magnet which controls the
"train going" indicator, so arranged as to break the same circuit when the indicator
is moved to "on line." And we cause the switch handle to mechanically break the
same circuit when it is placed at "on." In this circuit, which is acted upon as above
described, we place a battery, which is not shewn on the annexed Drawings, and the
coils of the unlocking apparatus of the semaphore arm or of the signalling lever.
Thus the current is only allowed to pass through these coils and unlock the semaphore
arm or the signalling lever when the "line clear" signal is being received from the

page_text: distant station, and it is so arranged that the semaphore circuit cannot be
completed even by this signal if the "train going" indicator represents train "on
line," or if the switch handle is at "on," shewing that permission has been given
for a train to come from the distant station. This latter provision is, however,
unnecessary when the instrument is used on double lines.
Figure 4 represents a general plan view of one modification of our improved
block telegraph instruments as adapted according to our Invention for use with the
starting semaphore hereinafter described, and the following description is more
in detail than the foregoing, both as regards the arrangement and working of
the apparatus as previously constructed and the combination of our present
improvements therewith.
A and B represent two polarized relays, and C is an unpolarized relay;
D is the plunger or key to give signals to the distant station; E, the com-
mutator or switch which, provided an acknowledgment be obtained from the
distant signalman, controls the "train coming indicator of the near station
and the train going" indicator of the distant one, and F is an ordinary
single stroke bell on which the signals from the distant station may be received.
The coils of the relays A and C are connected between the back contact of the
key and "earth," and are consequently only acted upon by received signals. The
two contact points and m of the relay A are joined to the two outer ends of the
coils of the electro magnet H of the "train going" indicator, and serve to determine
through which of these coils the local current shall flow when it is completed by
the closing of the contacts a and b during the prossing of the plunger. If the relay
tongue is in contact with when the plunger is pressed the current will flow
through the coil i of the electro magnet h, and will not move the indicator from
"cleared," but if the relay tongue is in contact with m when the plunger is pressed
the local current will flow through the coil i of the electro magnet, and, drawing
the soft iron tongue to the left, will turn the indicator to "on line."
One of the terininals leading to the semaphore is, according to our above referred
to present improvements, connected with another contact point n, and contact
between the relay tongue and this point is only made during the passage of the
current through the relay, the small spring o, or prolongation of the tongue, carrying
the other contact of the tongue being sufficient to prevent prolonged contact
between the tongue and n. The other terminal leading to the semaphore is
connected through the spring contact p to a relay tongue working simultaneously
with the "train going "indicator needle, which, while the indicator is at "cleared,"
is in contact with the point g, which is connected with the tongue of the relay A.
So that, in order that the semaphore circuit should be completed, it is necessary
that the spring p should be in contact with its point as shewn; that the "train
going" indicator should be at "cleared," so that the relay tongue working with it
should make contact with q, and that a current should be coming from the distant
station in such a direction as to cause the tongue of the relay A to make contact
with n.
This current is that given by the distant signalman when he gives the
"line clear" signal. This signal is therefore unable to unlock the semaphore; if
the spring p is pushed away from its contact point, which is done by turning the
switch handle to "on," which is the case when "line clear" has been given to the
distant station, and when the "train going" indicator points to " on line," shewing
that the arrival of the last train has not been announced at the next station.
hereinbefore referred to, the spring p is not required when the instrument is used
on double lines.
As
The coils of the relay B are, as they have hitherto been, connected between the
commutator and the battery contact of the key, so that this relay is only acted on
by outgoing signals, and the tongue is placed against one or other of its contact
points according to the direction of the issuing current as controlled by the switch.
The contact points of this relay are joined to the outer ends of the coils i, i', of the
electro-magnet G of the "train coming" indicator, and the position of the tongue
determines through which coil the local current shall flow when it is completed by

page_text: the unpolarized relay C. The inner ends of the coils of the electro magnets
G and H are joined to the cores, so that the wires attached to the screws r, 1', are
connected with the inner ends of the wires of the electro magnets in each case.
The soft iron needles g, g, which are deflected from one position to the other by the
coils of the magnets G and H, as hereinbefore described, are rendered magnetic by
the inducing action of the magnets h, h, and the cores of the said coils are made of
steel or cast iron so as to retain the magnetism last impressed on them, and thus
hold the needle in the position to which it has last been deflected.
The commutator is similar in its action to the commutator formerly used with
needle instruments; it consists of an axle c with a projecting T-piece d, two springs
e and e¹, and a bridge piece f. As shown in the drawing the T-piece has pressed the
spring e' away from the bridge piece, and has left the spring e in contact with the
other side of the bridge. Thus e is connected with f, and e' with d and c; by simply
turning the axle (by means of a handle which is not shown in the Drawings) the
connections are reversed. The T piece d will leave e¹ in contact with f, and at the
same time raise the spring e away from f; thus, in the reversed position, e will be
in contact with c and d, and e' will be in contact with f
A simplification may be made by doing away with the relay B, and causing the
"train coming" indicator to be actuated by means of the line battery as modified
by the commutator, and the instrument may be still further simplified by combining
the relays A and C, that is, working them by means of the same electro magnet.
This modification is shewn in Figure 5.
Plain needle indicators are shown in the arrangements herein before described,
being preferred in consequence of the clearness with which they indicate the state
of the line; but indicators of any other form, such as counterbalanced miniature
semaphores, may be used if desired. A sounder may be substituted for the bell
herein before described, or may be added thereto; so that ordinary messages, as well
as block signals, may be exchanged. In this case a key of an ordinary form, but
provided with a double contact, may be used in lieu of the plunger; messages so
sent will not interfere with the indicators so long as the switches remain unaltered.
The words on the indicator dials may be varied as required.
The external appearance of the complete improved block instrument is shewn in
Figures 6 to 8.
The starting semaphore herein before referred to, and now about to be described, is
placed in any convenient position outside the signal cabin, so that it shall be in
front of the driver prior to his leaving the station. The details of the apparatus are
shown in Figures 9 to 16, of which Figures 9, 10, 11, and 12 show the arrangement
with the semaphore arm at "danger," and Figures 13, 14, 15, and 16 show the
arrangement when the arm is at "caution or "clear." The same letters indicate
the same parts in all these Figures of the Drawings.
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The semaphore arm when put to "danger" is held in that position by an electric
lock, which can only be liberated by the "line-clear" sigual received from the distant
station, and by a counterpoise which is under the control of the signal man in
charge of the semaphore, and must be raised by him to give the "all right" signal.
Figures 12 and 16 represent the electrical locking arrangements in positions corre-
sponding respectively to the positions of "danger" and "clear" of the semaphore arm.
The semaphore arm A is held at "danger," see Figure 9, by a cranked clutch b
see Figure 12, locking an arm c, which is attached rigidly to the same axle & to
which the semaphore arm is attached. It is also held at "danger" by a weight W,
which, acting through a rod B connected to the tail of the semaphore arm,
counterpoises and overbalances the weight of the arm. The weight W is attached
to the end of a rod C pivotted at D, and passing through a slot in the rod B rests
on a cross pin Ex at the bottom of the slot. Thus, in order to lower the semaphore arm,
firstly, the arm c must be liberated from the clutch b, and, secondly, the weighted
arm c must be raised off the cross pin E*.
The electrical locking arrangement is also constructed with an electro magnet E,
the armature of which is provided with a detent x, as shewn, which engages with

page_text: a weighted lever g, the weight w of which overhangs the horizontal arm h of the
cranked clutch b.
When a current passes through the coils of the magnet E the armature fis
attracted, liberating the arm g of the weighted lever, the weighted end w of which
then falling upon the horizontal extension or arm ½, causes the clutch b to liberate
the arm c, this being done by the signal received from the distant station. The
semaphore arm can then be lowered to "caution" by the signalman in charge at
the near station, and this he effects by raising its counterpoise or weighted arin C,
which is conveniently done by means of a cam F, which is turned by pulling a wire
rope G by means of the signalling lever, thus turning an axle H, to which both
the cam and a bent weighted lever L are rigidly attached. This being done, a
piece M falls underneath the arm C and keeps it up, and at the same time by
means of a connecting rod y, raises a cranked cam N attached to one jaw of a
chair, carrying one of the rails of the permanent way from the position shewn in
Figure 9 to the position shewn in Figure 13. So long as the piece M is allowed to
remain in this position the weighted arm C is supported on it, and the semaphore
arm is allowed to remain at "caution." When, however, the flange of one of the
advanced wheels of the next passing train presses down the cam N, the supporting
piece M is pulled back and the arm C falls, raising the semaphore arm to "danger,"
and keeping the piece M back, and therefore holding the cam N in the position
shewn in Figure 9 out of the way of the following wheels of the train.
»
As the semaphore arm falls to "caution" the electrical locking contrivance is
automatically set into locking position again as follows:-A pin or projection
on the axle d, to which the arm A is attached, comes in contact with a projection m
on the axle carrying the small weighted lever, and thus turns the lever into its
original position, shewn in Figure 12, and when the semaphore arm is raised to
"danger
by the action of the passing train, as just described, in entering the
block section it is again held in that position by the clutch and by the counterpoise,
and the connections in the block instruments are so arranged that when the
semaphore arm has been locked in this way it cannot be again unlocked, nor be
again lowered until the arrival signal for the train concerned has been received
from the distant station, and has been acknowledged, and a fresh "line-clear'
signal for a succeeding train has been asked for and obtained. On double lines, if
the positive system of working be in use, a simple modification of the connections
in the block instruments allows the arrival signal to liberate the semaphore arm
so that it may be set at "clear" directly the train running over the section has
passed the next station. This may be done by putting the extra contact point n
in the relay A, Figure 4, on the other side of the relay tongue, but leaving the
point q in the same position as already described.
""
In addition to the above described arrangement in connection with the permanent
way for liberating the weighted piece M, by which the counterpoise arm or lever C
is supported when the semaphore arm is at "caution," so that the latter may go
to "danger," the semaphore arm may be caused to indicate "danger" by allowing
the signalling lever in the cabin to fall back so as by slackening the wire to allow
the bent weighted lever L to turn, and by means of a spur or projection p with
which it is provided cause it to tilt the weighted piece M out of its supporting
position, whereupon the counterpoise immediately causes the semaphore arm to
indicate "danger." This spur or projection is moreover of advantage in causing
the semaphore arm to be automatically raised to "danger" should the wire from
the signalling lever break, the bent weighted lever being then. released, and causing
its spur to act upon the weighted piece as just described.
When the semaphore arm is at "caution" the signalling lever is vertical, and it
is prevented from going back by a spring catch, which has to be released in order
to give the "danger" signal from the cabin.
In order to avoid trouble from the expansion and contraction of the wire the
weighted lever L has to turn through a considerable angle before it causes the
counterpoise to rise, and thus lower the arm to "caution on the one hand, and
"

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before it liberates the counterpoise by means of its spur, and thus raises the arm to
danger" on the other hand.
In lieu of interlocking the semaphore arm with the block instruments, as herein-
before described, the signalling lever in the cabin may, as hereinbefore referred to,
be interlocked with and controlled by the block instruments, a similar or equivalent
electrical locking device to that hereinbefore described in connection with the
semaphore arm being used in connection with the signalling lever. The arrange-
ments for raising the semaphore arm to "danger" by the passage into the blocked
section of a train, and for giving the signalman the power to set the arm at
danger" from the cabin, and for its being automatically raised to "danger” upon
the wire breaking, remaining as hereinbefore described.
"
The starting semaphore and its attachments, as herein before described, may also
be worked in connection with other block instruments than that hereinbefore
described, and they may be used without the electric locking arrangement.
Having now described the nature and object of the said Invention, together
with the manner in which the same is to be or may be performed or carried into
practical effect, I would remark in conclusion that what I claim as the Invention
secured by the hereinbefore in part recited Letters Patent is,-
"
First. The use of the starting semaphore, herein before described and illustrated
in the accompanying Drawings, which is so constructed that it is put to "danger
and locked in that position automatically by the entrance of a train into the block
section, and which can be so connected electrically with block telegraph apparatus,
as hereinbefore described, that the semaphore arm when put to "danger can only
be unlocked by the signalman at the other end of the section so as to allow it to be
lowered to "clear" by the near signalman.
دو
Second. The hereinbefore described improvements in and additions to the block
instruments, of the nature hereinbefore referred to, whereby the instruments are so
arranged that the arm of the semaphore or the signalling lever connected with the
arm cannot be unlocked until the arrival signals have been exchanged, and in single
lines until moreover a fresh "line clear" signal for a succeeding train has been
asked for and obtained.
Third. The combination of the block instruments, hereinbefore described,
together with the before mentioned improvements and additions thereto, with the
hereinbefore described starting semaphore, substantially as and for the purposes
described.
«
Fourth. The method, hereinbefore described, of putting a semaphore arm to
danger" by means of a passing train.
Fifth. The method, hereinbefore described, of locking a semaphore arm at
"danger," and unlocking it by means of an electric current, and the application
of similar or equivalent mechanism to the locking and unlocking of signalling
levers.
Sixth. The use of the starting semaphore and its attachments, as hereinbefore
described, in connection with block instruments other than those described, and
which may be fitted with arrangements analogous to those described to enable
them to control electrically the semaphore arm or signalling lever in the manner
hereinbefore described.
In witness whereof, I, the said George Kift Winter, have hereunto set my
hand and seal, this Fourth day of December, in the year of our Lord One
thousand eight hundred and eighty.
G. K. WINTER. (L.S.)