Improvements in Telegraph Block Systems of Railway Traffic Control.
Year: 1891

page_text: Date of Application, 10th June, 1891-Accepted, 29th Aug., 1891
COMPLETE SPECIFICATION.
Improvements in Telegraph Block Systems of Railway Traffic
Control.
We, DAVID COLIN COOMBES, of Lewisham near Sydney in the Colony of New
South Wales Railway Signalman, and WILLIAM ROWE of Marrickville near
Sydney in the said Colony Railway Interlocking Gear Mechanician do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:—
This invention relates to the control of railway traffic by means of telegraph
block systems or those systems of control in which the railway line being divided
into sections the entry of a train or engine into a section is "blocked" by means of
signals until a telegraphic message is received by the signal man from the other
end of such section intimating that the previously entered train or engine has
passed out of such section and that the line is clear. This invention has been
devised with the special objects, first to provide an automatic alarum in the signal
boxes at either end of the block section should a train or engine in error advance
"against the block" and to provide an additional or error signal which may be
manipulated by either signal man at the ends of the section to warn the driver of
such a train or engine of the fault or error; secondly to provide means by which the
telegraph signal transmitter or "block instrument" is locked in position so that
after the train having been taken on to the section and the signal man having given
his telegraphic message to such effect said signal man cannot give the telegraphic
message "line clear" until the said train leaves his said section; thirdly to provide
means whereby upon movement of a points lever so that the train will be shunted
into a siding the lock of the block instrument may be released by the advance of
the train a pre-determined distance into such siding and fourthly where it is.
necessary for a train to cross over to the other line of rails to enable a following
or through train to pass it to provide means in such sections whereby alarums will
be given in the signal boxes. Should a train enter said section before the waiting
train has returned to its own line and resumed its journey and this notwithstanding
the following or through train has in passing out of the section released the electro
mechanical lock hereinbefore mentioned and made it possible to transmit the tele-
graphic signal "line clear" in error. By this invention railway traffic may be
controlled almost automatically and the liability to err on the part of signal men
pointsmen and drivers is reduced to a minimum.
:
These improvements in telegraph block systems of railway traffic control consist
first in a novel method of combining and operating known mechanisms so that the
entry of a train into a blocked section will cause an alarum to be sounded in the
signal boxes at both ends of such section and so that an error sigual may be caused
to be exhibited by either signal man. They consist secondly in the combination
and arrangement with the telegraph signal transmitter or block instrument of
electro mechanical devices in communication with an insulated rail at the forward
end of the section such device being adapted to lock the "block instrument" lever
handle knob or "switch" in a normal position denoting line blocked and to release
the lock upon the passage of a train over the said forward insulated rail. They
consist thirdly in the combination and arrangement with an electro mechanical
device (such as that just before described) in connection with the "switch" of the
block instrument and insulated rail at the forward end of the section an insulated
rail in a siding and a points lever of an electrical switch adapted to cut out from
the circuit the main line insulated rail and to join up in such circuit the siding
insulated rail and vice versu. They further consist in the particular combinations

page_text: and arrangements of electrical and mechanical parts hereinafter described and
claimed.
But in order, that this invention may be clearly understood reference will now
be made to the drawings herewith in which
Figure 1 is a diagram of part of a railway line worked on the telegraph block
system according to these improvements.
Figure 2 is a diagrammatic plan of the same but in order to save confusion these
figures show the details only of the "down" line of rails the "up" line section or a
single line section having parts arranged identically the same.
Figures 3 and 4 are elevation and plan respectively of the electro mechanical
lock (combined with a switch or contact maker and breaker) for the operating
device or switch of the "block instrument."
Figures 5 and 6 are plan and elevation respectively of an electric switch
attached to or connected with a points lever.
66
"
"
. According to this invention each "section" of a railway controlled by a tele-
graph block system has between stations or platforms A and B or between signal
boxes A and B (and as in Figure 1 between signal boxes B¹ and C¹) the usual
"home" signal A2 "distant" signal A³ "start" signal B (and if necessary an
"advance "
start signal as B) on their respective semaphores as well understood.
It also has a joint control additional signal hereinafter called an "error" signal
cither upon an independent semaphore in a convenient position or say in the form
of an additional arm of arbitrary form or for night time a light of arbitrary color
or configuration half mast high upon the distant semaphore A³. The "section on
the rails terminates in insulated rails A and B connected up by insulated electric
wires to apparatus in the respective signal boxes A and B. Each signal box has
the usual signal levers and the usual telegraph block instruments for each section
controlled therefrom consisting of the interlocking signal levers and an electric bell
a transmitter or switch a miniature semaphore X₁ a battery and line wire con-
nections all as well understood and in addition each box has for each section con-
trolled therefrom an electrically controlled alarum or error bell C or C³ a
battery D and an electrical cut out or contact maker and breaker or switch E
attached to or operated by the "switch". or other operating device of the trans-.
mitter or block instrument say (as shown in the drawing) a lever F. One pole of
the battery D is connected to earth while the other is joined up by wire a to
binding post E¹ of the switch E whose other post E' is connected by wire a¹ to the
electric controlled alarum or error bell C. Insulated rail A is connected by
wire a² to bell C2 in box A¹ while wire a³ connects bell C³ in box A¹ to bell C' in
box B and insulated rail B is connected by wire 62 to bell C' in box B¹. The
sliding piece E³ is adapted to electrically connect binding posts E¹ and E³ by.
taking on to insulated bases E and E' of posts or terminals E¹ and E. This
piece (as shown in Figures 3 and 4) is carried by sliding bar E (forming part of
the electro mechanical device for locking the switch or block instrument although
it might be a separate and distinct movable connecting piece). The bar E is con-
nected to lever G which has links G¹ (adjustably fastened in slot G³) connecting to
the operating device of a telegraph transmitter say to the lever F of a block
instrument such as those usually employed. The electro mechanical locking
device consists of the sliding bar E with connections to the switch lever F such as
those before described carrying a stop piece g under a catch g' hinged at g³ said
catch g' forming the armature of an electro magnet g³ in electrical connection with
a battery H and with additional insulated rails A' and B' just within the sections.
The bar E also carries a permanent magnet g' adapted to be unable to lift the
armature g above which it is set but on the cessation of an electrical current:
through the clectro magnet 93 to hold the armature g¹ (which such electro
magnet g has lifted) free of the stop piece ġ until the sliding bar E has been
moved to give a telegraphic signal and so has drawn the magnet g away from
above the armature g'. The wire his led from one pole of the battery H to one
end of the coil of electro magnet g and from the other end of said coil the wire h¹
1

page_text: is led to insulated rail B' or to pivot pin of switch M. This switch has hinged
bar j¹ with arm j against which the points lever K' is always pressing when in its
normal position and thus keeps said bar j' against contact piece on binding post /.
When said points lever K' is moved the spring pulls said bar j' over insulated
piece and holds it against contact piece on binding post ³ and thus alters the
electric circuit from 1 to 2 to ¹ to h³. From post h² a wire /* connects to
rail A' and from post ³ a wire ³ connects to insulated rail K in the siding of
which the lever K' controls the points where the section contains a."cross over
and has no siding as an absolute check against error. An additional switch such as
that before described and marked h² h³ jjj³ and 3 is placed behind the cross over
points lever and further connection marked by dotted lines he made by wire from
one post h or h³ to one post E' or E2 of the switch E which post is already
connected to the electric alarum bell C³.
message
وو
"
"
In operation with the trains travelling "down" or from B to A when signal man
in box B¹ receives the message "line clear" on his miniature semaphore X' he
allows the next train to pass his "start" signal B* or his advance start signal B
and thereupon transmits "train on " by means of the lever F of his "switch instru-
ment" to miniature semaphore X' in box A¹ and in doing so moves lever G and
sliding bar E so that connecting piece E³ takes upon the bases E and E³ of
terminals E and E. Signal man A¹ makes a like connection by the same means
in giving the answering message "train on." Now should a train advancing in
error pass on to insulated rail Be an earth connection is at once made through
the first vehicle and. the non-insulated rails to earth and an electric circuit from the
earth connection of battery D through that battery by wire a terminal E¹ base E
connecting piece E³ base E' bell C³ bell C' wire 62 and rail Be to earth causing both
error bells C and C2 in respective boxes A' and B' to ring and thus warn the
signal men of the error or fault from whatever cause arising. On hearing the sound
of the error bell which is made destructive either signal man may throw up the
joint control error signal (which is of known construction) and the train is stopped
in time to prevent accident. Should either signal man neglect to transmit his
"train on
in giving or taking a train "on" the connecting of the piece E³
with bases E and E5 in but one of the signal boxes will allow of the completion of
the electric circuit when a train passes on to rail B and will cause the ringing of
the error bells C and C³ in both boxes A¹ and B¹. The electro mechanical lock
gives a further security against error for signal man in box B₁ having given the
train "on" and signal man in A¹ having taken it on it is impossible for the latter
to give a further message until in passing out of the section the train joins up
insulated rail A' with earth. In taking the train " on the transmission of the
message to miniature semaphore X' in box B' necessitates the placing of the
"switch" lever F and the attached device in the position shewn in Figures 3 and 4
and the armature catch g' taking over stop piece g prevents a further movement of
lever F until the electro.magnet 93 lifts the armature catch g'. On the train
leaving the section it must pass over rail A' and in doing so the circuit is
completed from earth of battery H through that battery wire h electro magnet g³
wire insulated rail A' the vehicle to the other rails to earth. This current
exciting the electro magnet g³ it lifts the armature catch g¹ on to the field of the
permanent magnet 9' which attracts and holds said armature to itself after the
circuit is broken when the train leaves rail A'. The lever F can now be moved to
transmit the message "line clear" to box B' and in being so moved it slides bar E
and draws permanent magnet g₁ away from armature catch g' thus causing said
catch g¹ to fall above the stop piece 9 ready to again take over said stop g when
the lever F is again restored in the transmission of "train on to the position
shown in Figures 3 and 4. Where a siding is in use the signal man would be
prevented from giving "line clear" when required to take a train following the one
which travelled into the siding unless. provision were made for the completion of an
electric circuit through electro magnet g³ so as to release his stop piece g. This is
effected by placing an insulated rail at a pre-determined distance within the siding
"
""

page_text: 26
and attaching to the points lever of such siding a switch such as that shown in
Figures 5 and 6. When the points lever is in its normal position (pressing against
bar j and keeping bar j¹ on base of terminal 2) with the points closed so that the
train will travel right through the electric circuit (when earth connection is made
through rail A') will be from earth to battery H electro magnet g³ wire ' bar j'
terminal wire rail A' to earth and when the points lever is pulled over to open
the points so that the train will enter the siding the spring causes barj¹ to leave
base of terminal 2 and take upon base of terminal 3 so that the electric circuit will be
(when the train reaches rail K which is placed at such a distance within the siding
as may be required to allow of a train standing on such siding clear of the through
line) as before from earth to battery H electro magnet 93 wire and bar j¹ but thence
to terminal and by wire ho rail K and through the train to earth. The current
passing through the electro magnet g³ as before described releases the stop piece
until a further message is transmitted by lever F. Where a cross over is used
the cross over points lever has in connection with it a similar switch to that just
described and illustrated in Figures 5 and 6 and in the opposite line of rails
similarly to that in the siding an insulated rail is placed having similar connections
to the electro magnet g³ so that when a train crosses over on to the other line it
advances as far as the insulated rail and thus joins up circuit and releases the stop
piece so that "line clear" may be transmitted to allow of the taking on on his
section by the signal man of a following train. It is possible but hardly likely that
after the release of the stop piece by the earth connection through the following
through train the signal man A' might give line clear before the waiting train has
recrossed to its own line to signal man B but in this case connection being made
through similar connections to those shown by dotted lines but through a distinct
switch M in connection with the cross over points lever the error bells would ring
on another train reaching rail B. Of course in the opposite line upon which the
train must wait provision is made by means of the insulated rails and alarums &c.
as before described for the sounding of the alarums should an oppositely travelling
train seek to enter the section upon which the train is waiting.
"
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
First. In telegraph systems of railway control the combination with the operating
device of the telegraph transmitter or block instrument with insulated rails at either
end of a block section and with an additional or error signal of make and break
connections electric alarums electric batteries or generators in the signal boxes and
line wire connections between the parts all arranged and adapted to complete an
electric circuit and give alarums on the entry of a train into a blocked section
substantially as herein described and explained.
Second. In a railway section for the purposes set forth the combination and
arrangement with the signals the telegraphic block instruments and connections and
with an additional or error signal of insulated rails such as A and B electric bells
such as C3 and C2 batteries such as D connections such as a E¹ E2 a¹ a³ 2 and a
connecting piece adapted to connect the terminal such as E¹ and E on movement
of the operating device of the transmitter or switch of the block instrument
substantially as herein described and explained and as illustrated in the drawings.
Third. In telegraph block systems of railway control the combination with the
operating device of the telegraph transmitter or block instrument and with an
insulated rail at the forward end of the block section of an electro mechanical
locking device arranged and adapted to lock and hold said operating device in a
normal "section blocked" position after the acknowledgement of the "train on
message until the train passes out of the block section and automatically releases
said lock substantially as herein described and explained.
"
Fourth. In a railway section for the purposes set forth the combination and
arrangement with the telegraph block instrument operating device say such as

page_text: lever F and with an insulated rail such as A' of a sliding bar such as E carrying
stop piece such as g and permanent magnet such as 9 an electro magnet such as g³
a hinged armature catch such as g₁ a battery such as H and connections such
as hand h substantially as herein described and explained and as illustrated in
the drawings.
Fifth. In telegraph block systems of railway traffic control the combination with
the block instrument having an electro mechanical lock such as that set out in the
preceding claim and with points levers of electric switches adapted to cut out con-
nection with the insulated rail at the forward end of the section and to substitute
a connection with an insulated rail in a siding or (in cross over sections) with
an insulated rail in the opposite line of rails substantially as herein described and
explained.
Sixth. In a railway section for the purposes set forth the combination and
arrangement with a line wire such as 'making connection between an electro
mechanical lock and a forward insulated rail in the main line with an additional
insulated rail in a siding or a cross over and with a points lever such as K of the
electric switch marked jjjj³ ³ h³ h and the wire h substantially as herein described
and explained and as illustrated in the drawings.
Seventh. In a railway section for the purposes set forth the combination and
arrangement with error bells and battery and connections such as those set out in
preceding (first and second) claims and with an electric switch such as that set out
in the preceding (sixth) claim of additional line wire connections such as those
dotted and marked hª substantially as herein described and explained and as illus-
trated in the drawings.
Dated this Twenty-seventh day of April One thousand eight hundred and
DAVID C. COOMBES.
WM. ROWE.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicants.