Improvements in Electric Locking and Block Apparatus on Railways.
Year: 1896

page_text: Date of Application, 14th Oct., 1896
Complete Specification Left, 12th July, 1897-Accepted. 2nd Oct. 1897
PROVISIONAL SPECIFICATION.
Improvements in Electric Locking and Block Apparatus on Railways.
I FREDERICK THOMAS HOLLINS of Saltley House, Forest Drive, Leytonstone,
in the County of Essex, Telegraph Engineer to the Great Eastern Railway Com-
pany do hereby declare the nature of this invention to be as follows:-
The object of this invention is to improve present Systems of Block Telegraph
and Electric Interlocking on Railways so as to make them more reliable and
secure as regards releasing certain portions by the operation of a Rail Contact,
and to provide an improved means for cancelling Trains and resetting either the
electrical or mechanical apparatus or both after a Train has been offered to the
box in advance, and accepted, and which for various reasons may not require to
go on; and where the section signal may have been taken off for the Train but
which requires to be again put to danger without the Train entering the section.
Such resetting or restoring of the apparatus or signals to the normal condition
may also be desirable owing to failures of one kind or another and this invention
has for its object the provision of means for more safely doing this than any
at present in use. At present the key or switch or other means to be used for
cancelling Trains and the indications of the apparatus and for resetting and
restoring the apparatus or signals is solely in the hands of the Signalman at any
one box and there is no doubt that this unchecked and uncontrolled possession
of this key, whatever form it may take, is a distinct danger and a menace to the
security of any system of Electric Interlocking.
In Sykes' well known system of Electric Interlocking a key is provided which
by insertion in the Instrument and giving a half turn resets his plunger and
enables him to plunge again to accept another Train and releases the signal
controlling the entrance to the section in the rear. Aud for cases where the
section signal has been lowered for a Train to enter a section and the Train
does not enter so as to operate the Rail Contact to release the back lock or
where the Train does enter but for some reason or other the Rail Contact fails
to release the lock the same key is utilized to operate an electrical switch to
transmit a current from a local battery through the coils of the locking Instrument
equivalent to the current from the Rail Contact.
In other systems of Electric Interlocking a key or switch or switches is or are
provided and placed in a lock up box with a paper or glass front which has to be
broken to get at the switch to transmit a current to reset the apparatus the object
being to induce the Signalman to report the fact that he has used the resetting
apparatus. In other cases no attempt is made to cover up the switch but it is left
open in the shape of a small press button. In no case is there any effectual
check upon it as confining its use to the particular time, Instrument, and purpose
for which it may legitimately and safely be used.
I propose to improve this by making it incumbent upon the Signalman at
any box to obtain the sanction or concurrence of the Signalman at the box
in advance or the box in the rear, or both, before he can release or reset the apparatus

page_text: on cancellation of a Train, or in case of failure of the usual means of releasing
or resetting the apparatus into its normal condition. In Sykes' or similar
systems of Electric Interlocking I propose that the Signalman requiring to reset
any portion of his apparatus shall by means of an Acoustic or Visual signal or
both or by Telegraph or Telephone ask the Signalman at the box in advance
or in the rear as may be desired, to give him the necessary permission by trans-
mitting a certain current or by interrupting a current already upon the line wire
to enable him to by its means reset the apparatus by means of a key which he
already possesses or by a switch which he may operate to do so; and in somve
cases a Signalman shall have to obtain the permission and concurrence of both
the man in advance and the man in the rear in order to entirely reset his apparatus
on cancellation of a Train. And I propose that in some cases the resetting of
one portion of the Instrument, that is for replunging to accept another Train,
permission shall be given or the act concurred in by the Signalman at the box
at the rear whilst the resetting of the other portion of the apparatus to put the
signal to danger and relock the same shall be given or concurred in by the
Signalman at the box in advance who would best know that the Train for which
he had freed the signal had not arrived.
In other systems of Electric Interlocking after the plunger has heen once
plunged to unlock the controlling signal for the entrance into the section in the
rear and to accept a Train therefrom such plunger or key or commutator becomes
locked and cannot be used again until the Train arrives and passes into the
section in advance. In some cases the releasing of this plunger key or commutator
shall I propose only be unlocked by the concurrence of the Signalman in advance
and in rear, whilst in other cases it may be only necessary for the man in advance
to release the plunger or key or commutator the same as the Rail Contact would
have done had the Train entered his section and this permission or concurrence
of both men or by one shall be by the transmission of a current from one or both
boxes in advance and rear
rear through the Signalman asking permission;
or it may be by the transmission of a current from the box in
advance the completion of the circuit for which shall be done by the
Signalman concurrently depressing or otherwise a key or press button at the box
in the rear; or it may He done by the transmission of such current from the
box in advance alone concurrent with the Signalman at the box asking for it
depressing or otherwise a key or press button to conduct a current to the particular
Instrument which requires resetting into its normal position. And in order to
ensure such permission given or current forwarded from either the box in advance
the box in the rear only affecting the one particular Instrument such current
shall he transmitted either on the present locking wire or wires or upon the
bell wire for the particular road to which the Electric Locking Instrument
refers; or of course a special wire may be provided between the points for the
purpose of giving this permission to reset the apparatus. In utilizing the current
iransmitted from the Signalman in advance or the Signalman in the rear I may
utilize the coils already in use in the locking Instrument or the plunger
Instrument or both for giving the necessary releasing or permission to reset; or
I may use à special electro magnet or electro magnets for the purpose either
polarized or otherwise as may be required. And where a key is utilized by the
Signalman requiring to reset his apparatus I may cause the current (giving
permission to reset) to unlock a shutter or other means preventing in combination
with the electro magnet the key from being put into the key hole to reset the
annaratus or the electro magnet in question may by its armature prevent the
insertion of such key or otherwise prevent the key from resetting the Instrument
whether it can be inserted into the Instrument to do so or not. And so that
the key or other means may only he used for the particular Instrument and at
the particular. time and for the particular Train for which permission is given
I may by the use of the key or obtaining the permission to reset the Instrument
break down the locking circuit or bell circuit or some portion of it for the section

page_text: of the line so as to prevent the acceptance of another Train from the rear until
the Instrument has been restored the key taken away or switch closed and
locked and the Instrument placed in its normal position; and the permission
for restoring signal or current having been stopped (or the permission otherwise
withdrawn) the object being to prevent the use of the means for unlocking except
for the one occasion and purpo for which permission has been obtained. I
may in some instances make either this signal or permission to reset the
Instrument or the act of resetting it, record the fact that it has been so used
upon any suitable index or recording apparatus or successive number indicator.
In some cases I may make it necessary for the Signalman seeking the
permission to reset his Instrument manipulate a small lever or key which in
doing so shall itself lock such portion of his apparatus as may prevent him
using his Instrument again until he has withdrawn his key or otherwise reset
a switch or press button by which he has utilized the means transmitted to him
by either the Signalman in advance or the Signalman in the rear.
regards the improvement in the Rail Contact and to ensure that it is the actual
Train and the Train only that operates it I propose to insulate the two ends of
one rail from the adjoining rails at the point where the Rail Contact is fixed to
be operated by the deflection of the rail and the battery being also fixed near
the same spot shall have its usual earth terminal whichever pole that may be,
attached to the said insulated rail and the earth connection only completed just
at the moment when the wheels of the Engine or Train or part of a train is
passing over this rail and thus through the axles connecting the insulated rail
to the other rails which are making good earth connection at the same moment
that the weight of the Engine or Vehicles is depressing the rail and actuating
the Rail Contact. I may in some cases find it advisable to insulate a rail on
both sides and have one connected to the earth by any well known means or I
may in some cases wish to supplement the earth obtained by the ordinary rails
by a better earth connection attached to such rails.
Dated this 14th day of October 1896.
Improvements in Electric Locking and Block Apparatus on Railways.
1, FREDERICK THOMAS HOLLINS of Saltley House, Forest Drive, Leytonstone,
in the County of Essex, Telegraph Engineer to the Great Eastern Railway Com-
pany, do hereby declare the nature of this invention and in what manner the same
is to be performed, to be particularly described aud ascertained in and by the
following statement:-
The object of this invention is to improve present Systems of Block Telegraph
and Electric Interlocking on Railways so as to make them more reliable and
secure as regards releasing certain portions by the operation of a Rail Contact,
and to provide an improved means for cancelling Trains and resetting either the
electrical or mechanical apparatus or both after a Train has been offered to the
box in advance, and accepted, and which for various reason may not require to
go on, and where the section sigual may have been taken off for the Train but
which requires to be again put to danger without the Train entering the section.
Such resetting or restoring of the apparatus or signals to the normal condition
may also be desirable owing to failures of one kind or another and this invention
has for its object the provision of mean tor more safely doing this than any
at present in use. At present the key or switch or other means to be used for

page_text: cancelling Trains and the indications of the apparatus and for resetting and
restoring the apparatus or signals is solely in the hands of the Signalman at any
one box and there is no doubt that this unchecked and uncontrolled possession
of this key, whatever form it may take, is a distinct danger and a menace to the
security of any system of Electric Interlocking.
In Sykes' well known system of Electric Interlocking a key is provided which
by insertion in the Instrument and giving a half turn resets his plunger and
enables him to plunge again to accept another Train and releases the signal
controlling the entrance to the section in the rear. And for cases where the
section signal has been lowered for a Train to enter a section and the Train
does not enter so as to operate the Rail Contact to release the back lock or
where the Train does enter but for some reason or other the Rail Contact fails
to release the lock the same key is utilized to operate an electrical switch to
transmit a current from a local battery through the coils of the locking Instrument
equivalent to the current from the Itail Contact.
In other systems of Electric Interlocking a key or switch or switches is or are
provided and placed in a lock up box with a paper or glass front which has to be
broken to get at the switch to transmit a current to reset the apparatus the object
being to induce the Signalman to report the fact that he has used the resetting
apparatus.
In other cases no attempt is made to cover up the switch but it is left
open in the shape of a small press button. In no case is there any effectual
check upon it as confining its use to the particular time, Instrument and purpose
for which it may legitimately and safely be used.
I propose to improve this by making it incumbent upon the Signalman at
any one box to obtain the sanction or concurrence of the Signalman at the box
in advance or the box in the rear, or both, before he can release or reset the apparatus
on cancellation of a Train, or in case of failure of the usual means of releasing
or resetting the apparatus into its normal condition. In Sykes or similar
systems of Electric Interlocking I propose that the Signalman requiring to reset
any portion of his apparatus shall by means of an Acoustic or Visual signal or
both or by Telegraph or Telephone ask the Signalman at the box in advance
or in the rear as may be desired to give him the necessary permission by trans-
mitting a certain current or by interrupting a current already upon the line wire
to enable him to by its means reset the apparatus by means of a key which he
already possesses or by a switch which he may operate to do so; and in some
cases a Signalman shall have to obtain the permission and concurrence of both
the man in advance and the man in the rear in order to entirely reset his apparatus
on cancellation of a Train. And I propose that in some cases the resetting of
one portion of the Instrument, that is for replunging to accept another Truin,
permission shall be given or the act concurred in by the Signalman at the box
at the rear whilst the resetting of the other portion of the apparatus to put the
signal to danger and relock the same shall be given or concurred
in by the Signalman at
at the box in advance who would best know
that the Train for which he had freed the signal had
had not arrived.
In other systems of Electric Interlocking after the plunger has been onde
plunged to unlock the controlling signal for the entrance to the section in the
rear and to accept a Train therefrom such plunger or key or commutator becomes
locked and cannot be used again until the Train arrives and passes into the
section in advance. In some cases this plunger key
key or commutator;
shall I propose only be unlocked by the concurrence of the Signalman in advance
and in rear, whilst in other cases it may be only necessary for the man in advance
to release the plunger or key or commutator the same as the Rail Contact would
have done. had the Train entered his section and this permission or concurrence
of both men or by one shall be by the transmission of a current from one or both
boxes in advance and rear through the Signalman asking permission;
or it may be by the transmission of a current from the box in

page_text: advance the completion of the circuit for which shall be done by the
Signalman concurrently depressing or otherwise a key or press button at the box
in the rear or it may be done by the transmission of such current from the
box in advance alone concurrent with the Signalman at the box asking for it
depressing or otherwise a key or press button to conduct a current to the particular
Instrument which requires resetting into its normal position. And in order to
ensure such permission given or current forwarded either from the box in advance
or the box in the rear only affecting the one particular Instrument such current
shall be transmitted either on the present locking wire or wires or upon the
bell wire for the particular road to which the Electric Locking Instrument
refers; or of course a special wire may be provided between the points for the
purpose of giving this permission to reset the apparatus. In utilizing the current
transmitted from the Signalman in advance or the Signalman in the rear I may
utaze the coils already in use in the locking Instrument or the plunger
lustrument or both for giving the necessary releasing or permission to reset; or
I may use a special electro magnet or electro magnets for the purpose either
polarized or otherwise as may be required. And where a key is utilized by the
Signalman requiring to reset his apparatus I may cause the current (giving
permission to reset) to unlock a shutter or other means preventing in combination
with the electro magnet the key from being put into the key hole to reset the
annaratus or the electro magnet in question may by its armature prevent the
insertion of such key or otherwise prevent the key from resetting the Instrument
whether it can be inserted into the Instrument to do so or not. And so that
the key or other means may only be used for the particular Instrument and at
the particular time and for the particular Train for which permission is given
I may by the use of the key or obtaining the permission to reset the Instrument
break down the locking circuit or bell circuit or some portion of it for the section
of line so as to prevent the acceptance of another Train from the rear until
the Instrument has been restored the key taken away or switch closed and
locked and the lostrument placed in its normal position; and the permission
for restoring signal or curient having been stopped (or the permission otherwise
withdrawn) the object being to prevent the use of the means for unlocking except
for the one occasion and purpose for which permission has been obtained. I
may in some instances make either this signal or permission to reset the
lustrument or the act of resetting it record the tact that it has been so used
upon any suitable index or recording apparatus or successive number indicator.
cases I may make it necessary for the Signalman seeking the
permission to re-et his Instrument manipulate a small lever or key which in
doing so shall itself lock such portion of his apparatus as may prevent him
using his Instrument again until he has withdrawn his key or otherwise reset
a switch or press button by which he has utilized the means transmitted to him
by either the Signalman in advance or the Signalman in the rear. And as
regards the improvement in the Rail Contact and to ensure that it is the actual
Train and the Train only that operates it I propose to insulate the two ends of
one rail from the adjoining rails at the point where the Rail Contact is fixed to
be operated by the deflection of the rail and the battery being also fixed near
the same spot shall have its usual earth terminal whichever pole that may be
attached to the said insulated rail and the carth connection only completed just
at the moment when the wheels of the Engine or Train or part of a Train is
passing over this rail and thus through the axles connecting the insulated rail
to the other rails which are making good earth connection at the same moment
that the weight of the Engine or Vehicles is depressing the rail and actuating
the Rail Contact. I may in some cases find it advi-able to insulate a rail on
both sides and have one connected to the earth by any well known means or I
may in some cases wish to supplement the earth obtained by the ordinary rails
by a better earth connection attached to such rails. And in order that my

page_text: invention may be more fully understood I will now proceed to describe the
accompanying drawings in reference thereto.
Fig: Sheet 1 shows the complete electrical connections of Sykes system
of Electric Interlocking and Block with one method of applying this invention
thereto clearly shown and explained-A. B. and C. represent tiree Signal Boxes
with the complete electrical connections for two Block sections as between
A. and B. and B. and C. In every case where the additional apparatus to effect
the purpose of this invention is inserted or made use of the keys number 2 are
the cancelling back lock buttons the keys 3 are the cancelling back lock switches
those marked 4 are the cancelling plunger buttons and the coils 5 are the can-
celling plunger switches and 6 the cancelling plunger coils for unlocking the
shutter over the key hole. The actual mechanical locking is not shown because
it is not essential to a clear understanding of the object and application of this
invention. In the position the locking apparatus is shown all is right to admit of
the ordinary plunging to accept a Train and unlock the section signals at the
rear box. The levers which have actually to be depressed for this purpose are
inarked, 1), and their operation has the effect of joining the plunging battery, F,
to the line and so transmitting a current which when the locking switches are
in the position shown it operates the electric lock of the signal lever by means
of the locking coils 8. When the signal lever is pulled into the "off" position
the locking switch rod 9 is lowered and the switch connections are altered. The
Rail Contact circuit 10 is then joined up to the locking coils and the line spring
is put into electric connection with the earth through the lever contact 11.
In diagram Fig. 1 the Bell wire coils 12 and keys 13 are also shown in order
to make more clear the application of this invention to the cancellation of Trains
or Signals given therefor. It will be seen that this cancellation arrangement
has reference only to the release of the plunger when locked and the release
of the back locks their equivalent in other systems of Electric Interlocking.
Now in Sykes' system when the plunger has been used to accept a Train
and release the section signal in the rear a locking piece drops in front of the
said plunger and su prevents its being used again (as everyone knowing Sykes'
Instrument will clearly understand) until either in ordinary working of the
signal lever in passing the Train through the section or by the use of a key
similar to an ordinary door key this locking piece is again raised from the front
of the plunger. Now it is the indiscriminate use of this key that part of this
invention is intended to prevent. It is obvious that by using this key a Signal-
man might plunge and accept as many Trains into one section as he pleased.
Now it will be seen (see diagram Fig. 1) that at Station A. in the down locking
wire 14 there is a cancelling plunger button or key 4 capable by depression of-
joining battery, H, to the down locking line wire 14; and at Station B. on the
same wire there is another cancelling plunger button or key 5 which on being
depressed would divert any current on the line from Station A. through the can-
celling plunger coil t shown below. There is a similar arrangement between B.
and C. also on the Down locking wire 14; and between both points in the
reverse direction on the Up line locking wire 15. This provides for both roads
and for both sections.
On B. requiring to use his key to unlock his plunger working to A. he would
by a prearranged Bell signal or by Telephone ask A. to give him permission to
unlock or release his plunger (a locked shutter covering up the keyhole prevents
him without) B. then depresses his cancelling plunger button 5 and A. if he
concurs with 13. having his plunger released also depresses his cancelling plunger
button 4 and so transmits a current which passing through the cancelling
plunger coil 6 at B. releases the shutter 1 Figs. 2 and 3 over the keyhole 2 Fig. 3.
How this is effected is shown in Figs. 2 and 3. In Figs. 2 and 3. the cancelling
plunger coils are marked 3. The shutter referred to normally covering up
keyhole 2 (see Fig. 3) also carries on its axis 4 Fig 2 and 3 a cam piece 5 which
engages with locking piece 6 carried by armature with its axis at 11 and

page_text: pulled over by spring 12. When there is no current passing through the coils 3
the arrangement is as shown the locking piece 6 holding by means of eam piece 5
the shutter over the keyhole 2. When however a current is transmitted as
described armature 7 is attracted to the cores of coils 3 and cam 5 and the shutter 1
is released. The shutter 1 may now be turned by hand from over the keyhole 2
and the key inserted and the plunger released as required. It is obvious if the
key were left in and the apparatus could still he worked that the object of this
invention would be frustrated. The key could be used any number of times. Th
prevent this the armature 7 Fig 2 also carries an insulated projection 8 which
when the armature is attracted presses against spring 9 and breaks it from
electric contact with stud 10 and as these two parts are inserted in the locking
wires at the point marked X, in diagram Fig. 1 the locking wire to which this.
key refers is disconnected and as cam 5 is interlocking with locking piece 6 the
armature cannot go back to the position shown in the drawings until the key.
has been taken out and the shutter 1 by means of spring 13 pressing on stud 14
restored over the key hole 2. When it is so restored and locked then the locking
wire is again joined up. This absolutely limits the use of the key to the particular
Instrument upon which its use is authorised and to the one occasion for which
permission is given. The diagram shows the connections complete for A. to give
this permission to B. and B. to C. for the Down road 14; and for C. to give the
permission to B. and B. to A. for the Up road 15 as will be seen and understood.
Having effectually dealt with the plunger it now only remains to explain
the application of this invention to the back lock of the Signal lever as used.
in Srkes' Instrument which should in ordinary working be released uy the action
of a Rail Contact or Treadle actuated by the Train itself on passing into the
advance section to which the Signal lever refers. In some cases although the
Signal has been taken off the Train for which it has been lowered does not
require to go forward into the section and over the said Rail Contact; or the
Rail Contact may have failed from some cause to electrically release the back
lock of the Signal lever so that it may be put to danger again. In other systems
the Rail Contact is used to release the plunger directly but in einer or any case
it is the same a key or some other means must be provided to release the hack
lock or plunger. In Sykes' system a
In Sykes' system a key is used by the Signalman himself to
operate a switch to release the hack lock by transmitting a local current through
the locking coils. In other systems a mere press button is used to transmit a
current through the coils to release whatever it may be controlling or locking.
Now under this invention I propose by one method to use the Bell wire 16 for
giving permission to release the back lock or its equivalent both for the Up and
the Down roads. The different buttons and switches and circuits are clearly shown
and indicated on the diagram itself. For the purpose of making its application
however more clear still we will again deal with the down road between A. and B.
it being understood that the other sections are precisely the same. In this case
it is A. who wishes to release his back lock and (as B. is best able to know whether
the Train has really arrived or if it is safe for A. to cancel his back lock) the
latter asks B. by Bell or Telephone to give him a current for the purpose. A. at
the same time depresses his cancelling hack lock switch 3 for the Down road
and as his locking switch 7 (with his signal of) has placed the loeking enils 8
in connection with his Rail Contact eirenit 10 when B. depresses his cancelling
back loek button 2 for the Down Road Be. plunging battery, F, for the Down
mad is electrically connected through the Bell coils 12 at, A, to the leeking
coils 8 at, A, and so releasing the back lock which the Rail Contact had failed
to do. The reverse arrangement and use of button and switch as shown between A.
and B. serves for the Up road as explained. This anangement revent the
Signalman therefore from releasing his lorks for either plunging or resetting
his signals or apparatus without the concurrence of the Signalman in advance
or in the rear and limits his ability to release anything to the patienlar occasion
and the particular Instrument for which he has sought and obtained permission.

page_text: It is obvious that the arrangement might be used with separate wire or wires
and is applicable to any system of Electric Interlocking or Signalling where it is
necessary to cancel Trains or reset the apparatus used in the Signalling or safely
controlling the traffic on Railways and where it is desirable that the concurrence
of a second party shall be needed to alter or amend or cancel a portion of the
prescribed indications or precautions utilized in such method or methods of Train
Signalling.
I am aware that it has been proposed to lock up the switch or key or equivalent
releasing device in a box to be electrically unlocked by the Signalmen at the
adjoining boxes on being asked to do so but this in no way controlled the number
of times the key could be used when it was got nor did it limit its use to any
one Instrument or anyone road or Signal nor did it prevent its being entirely
useless if two keys got by any means into the possession of the Signalman or
to a dummy key being put into the box instead of the actual one. In other words
it did not limit its use to the one occasion; the particular time asked for; and
the particular Instrument or Signal intended and therefore-
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be carried out, I declare that what I
claim is :-
Firstly. In any arrangement of Electrical Interlocking of the Block and
Mechanical Signals the method of controlling the use of the releasing key or
switch or equivalent device for releasing or resetting any portion of the apparatus
substantially in the manner and for the purpose as set forth and described.
Secondly. The combination of the method of controlling the use of the said
releasing or resetting device with the arrangement or insertion of the same upon
the existing Block or Locking or Bell wires substantially in the manner and for
the purpose set forth and described.
Thirdly. In any arrangement of Electrical Interlocking the electric control by
the Signalman at an adjacent box or boxes of the use of the releasing or resetting
key or switch or other device for releasing or resetting the apparatus or lever
or levers at an adjoining Signal box whereby its use is limited to the particular
Instrument or lever, the time and the one occasion for which permission is asked
and given substantially in the manner and for the purpose set forth and described.
Fourthly. The combination of parts and circuit arrangements whereby the use
of the said key or equivalent device is controlled by others than the person who
wishes to make use of it substantially in the manner and for the purpose set
forth.