Alphabetical - SignallingWA

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Block Working in WA




These Block Telegraph Instruments were described and published in the Departmental Book:



Guidance of Officers and Servants,





It is interesting to note that this Book of Rules pre-dated the official opening of the 'Eastern Railway' by 2 years, and in so being gained the honour of being the first electrical means of controlling trains along single line sections in Western Australia.

1856 Siemens and Halske Alphabet Telegraph - in the Siemens collection of the Munich museum Germany

1856 Siemens and Halske Alphabet Telegraph - in the Siemens collection of the Munich Museum, Germany

These instruments were described in the technical journals of the day as being:
"...a convenient and trustworhy apparatus" that had been constructed for use on the Bavarian Telegraph Lines.

They later found use on the railway lines of Russia and Europe, and of course Western Australia.

How the instrument worked:

The operator of the instrument was provided with a
large handle above a notched circle, each notch represented by an alphabetic character. Inside the instrument, and worked by way of the handle, a coil of insulated wire was wound around a soft metal core, all of which rotated between the poles of a set of twelve permanent magnets. The rotating motion of the coil between the permanent magnets produced alternating positive and negative currents, which when transmitted down the telegraph line to the distant station, passed through the coils of an electro-magnet which caused the armature of the receiving instrument's smaller indicator dial to vibrate, which turned an escape wheel that drove the indicator dial pointer to rotate to the matching character of the sending instrument. Apart from the large handle, each instrument was provided with a Indicator Dial re-set facility in the form of an Ivory knob to the left of the Indicator Dial (and therefore out of view in the above photo) and a switch above the Indicator Dial that connected the line current to either the Indicator Dial or the Alarm (the two 'Call Bells' mounted at the top of the instrument).

The instrument as described in the 1879 Rule Book:






351. For transmitting Signals from Station to Station the handle of the large dial should be turned from left to right at a speed of about 120 revolutions per minute, allowing the handles to fall into the notches of the of the metal ring at the letters to be communicated.
 The Station required must be called by stopping the handle for an instant at the letter representing the Station to be communicated with, and then continue the revolution to zero (marked * ). This is repeated three or four times, stopping at letter of your own Station, and then resting for a moment to give the Stations called an opportunity to reply. If the Signal in answer to the call be given while a Station is calling, the needles of the small dials throughout the line are thrown into a state of confusion, so care should be used in calling, and time given at intervals for the reply Signal.
 It is necessary to start the motion of the handle of the transmitter with a sudden jerk to insure the needle following from the zero point, and it should be dropped into the notches in a firm manner.
 The operator should allow his eye to travel to the letter required before moving the handle, he will then with greater certainty hit the notch in the metal rim.

 352. When the instruments are at rest, the handle and needles should all point to the zero, or blank spaces on the dials.
 The little ivory knob at the side of the small dial, when pressed in, will stop the needle of the indicator at zero; when the handle of the large dial is turned round by this means the instruments can be corrected if thrown out of adjustment.

 353. After each word has been telegraphed, the handle of the transmitting instrument is to be brought to the blank space, to give the receiving Station an opportunity to transmit the sign "understood" which is once around from zero to zero. If the word is not understood, the needle must be stopped at R, and then continued to zero - the sending Station then repeats the word.

 354. At the end of a message the transmitter should turn the handle twice round, to signify that the message is completed.

 355. If the sender wishes to transmit figures, &c., on the inner circle, he must give the letter N between two complete revolutions from zero; if he desires to return to letters, he must give the letter L between two revolutions from zero.

 356. The letter K between two revolutions indicates a
                              do.  comma   ,
                         S   do.  semicolon  ;
                         C   do.  colon   :
                         F   do.  full stop   .
                         I   do.  interrogation  ?
                         E   do.  exclamation  !
                         A   do.  apostrophe  ’
                         H   do.  hyphen   -
                         Q   do.  quotation  " "
                          P   do.  parenthesis  ( )

 The two last-named letters are given before and after the word or words quoted in parenthesis.


Pages 101 to 103, Rules and Regulations, 1879.

Regulations for Single Line working by Telegraph System.

1879 Rule Book - Regulations for Single Line working by Telegraph System.








Regulations for Single Line working by Telegraph System.

239. One those portions of the Railways where a Single Line only is provided, care must be taken, before any Train leaves a Station, that there is no Train due in an opposite direction.

240. Before allowing any Train to leave his Station, the Station-master must ascertain by Telegraph from the next Station in advance, that the Line is clear. If the Station-master is unable to obtain telegraphic communication, all Trains (except those specified in Rule No. 242) are to be started and run strictly in their turn or order as laid down in the Working Time-tables.

“Line Clear Inquiry” and “Line Clear Report” Messages.

241. The greatest attention must be paid to the wording of “Line Clear Inquiry” and “Line Clear Report” messages, so as to render it impossible for confusion or misunderstanding to take place. An ambiguous or vaguely worded telegram must not be acted upon. If any such be received, the sender must be required to repeat the message in a perfectly clear form. Such replies as merely “Yes” or “O.K.” cannot safely be accepted as an assurance that Line is clear, and to start a Train on so doubtful an authority is prohibited.

The directions and explanations which follow (a, b, c, d, e) will illustrate the working of this Regulation.

(a) A Line Clear Inquiry must state the number and description of the Train to which it refers, and also the number and description of the Train which last arrived in the opposite direction to that for which the “Line Clear Report” is sought — for example the following is given :—

(Line Clear Inquiry)

(b) A Line Clear Report authorising a Train to come on, must state the number and. description of the Train for which it is intended, and the point to which such Train may safely run. No “Line Clear Report” must be given in reply to a “Line Clear Inquiry” by any Station-master, or Officer in charge, until he has satisfied himself that the Train specified in the Inquiry Message as having arrived is the last Train which left his Station in that direction.

(c) Referring to the foregoing illustration, the Station-master, Perth, having first satisfied himself that no Up Train has left his Station since the departure of No. 1 Up Passenger, will reply as follows :—
(Line Clear Report)

(d) If the “Line Clear Inquiry” refers to a Train which is required to follow another, as, for example, should there be a Down Special Goods Train at Fremantle waiting to follow the No. 2 Down Passenger Train, Perth will be telegraphed thus :—

(Line Clear Inquiry)

Then, if the Down Special Goods is the next in turn, and there is no reason why it should not follow, Perth's answer will be :—

(Line Clear Report.)

Upon receipt of this answer, Fremantle may allow the Down Special to proceed, after the necessary interval, first informing Driver and Guard that previous Train has not arrived at Perth, and instructing them to proceed cautiously. The same information and caution order must always be given to a Train following another before its arrival at the Station in advance has been telegraphed.

(e) The foregoing are illustrations of ordinary “Line Clear Inquiry” and “Line Clear Report” messages ; but when arranging for Trains to cross at other than the usual crossing places, some alteration and addition will be necessary. The messages should be made as clear as possible, and Stationmasters must endeavour to adhere to one uniform style.

As it may occasionally take a little longer time than usual to ascertain whether Line is clear, care should be taken to prevent detention by obtaining the “Line Clear Report” in advance — that is, before the arrival of the Train for which it is required.

242. All Trains which — per Working Time-tables — “will run only when required,” and all Untimed, Pick-up, Mineral, and. Ballast Trains, or Engines, are only to be worked by telegraph; and no such Train or Engine is to leave any Telegraph Station unless the Guard has in his possession a Line Clear Report from the next Telegraph Station in advance, stating how far the Train is to proceed, and countersigned by the Officer of the Station his Train is then at.

If telegraphic communication be interrupted, such Trains or Engines as are enumerated above are not to run until the road can be secured for them by “Line Clear Report” being otherwise obtained.

243. When Trains, either Passenger or Goods, are shown on a Working Time Table, or are otherwise appointed to meet or cross at a particular Station or Siding, the Train first arriving there must not leave (except in cases provided for in the following Rule) until the Train or Trains from the opposite direction shall have arrived.

244. When circumstances render it necessary, or highly expedient, that Trains should cross at other than the appointed crossing place, and one Train has to proceed beyond the usual crossing point — special precautions must be taken to preclude the possibility of misunderstanding or accident. On no account must any Train depart from an appointed Crossing Station prior to the arrival of the Train or Trains which it has to cross there, unless the Guard has in his possession a Line Clear Report from the Telegraph Station in advance, stating how far the Train is to proceed, and countersigned by the Officer in charge of such appointed crossing place. The same rule must be observed at every Telegraph Station which may intervene between the appointed Crossing Station and the Station or Siding at which a late Train is to be crossed. No such Station must be left until the Guard has a Line clear Report from the Station in advance, countersigned by the Officer of the Station his Train is then at. As therefore in such circumstances no Train can proceed beyond an appointed crossing place without the authority of the Stations in advance, the Officers in charge of these will have it under their control, and the responsibility of crossing the Trains safely will devolve upon them.

245. No Station-master or Officer in charge of a Station shall Telegraph Line clear for a Train to advance beyond its appointed crossing place and come on to his Station out of order, until he has taken the necessary steps to block the line on the other side, so as to prevent the late Train by any chance running through his Station. The Signals commanding the road in the opposite direction must therefore be kept at Danger, and in the event of the late Train arriving first, the Guard must be at once informed that the crossing will take place there instead of at the appointed crossing place, and that the other Train is approaching.

246. When the appointed crossing place is a Siding at which there is no telegraph communication, the Officers in charge of the adjacent Telegraph Stations will be responsible for altering the crossing place, when circumstances render it necessary, in accordance with Rule 244. When Trains running out of order are meant to cross at such a Siding, being other than the appointed crossing place, the Officers in charge of the Telegraph Station on each side must come to a clear understanding, and will be responsible for giving the Guards distinct crossing orders in writing, and obtaining their signature for same.

247. When two Trains running in opposite directions are to cross each other at a Station, the Signals must not to be lowered for the admission of both at the one time. Where the crossing point is a Siding where there are no Signals, the Siding must be approached with great caution, and no Train must reach the points leading into such Siding until it is perfectly safe to do so.

248. No Train waiting at a Station or Siding, for the purpose of crossing another to arrive from the opposite direction, is to be started until the rear vehicle of the Train in motion has passed the rear vehicle of the waiting Train and the Guards of the respective Trains have communicated with each other.

249. When an Officer in charge of a Station, in advance of which there is any Platform or Siding unprovided with Signals, has despatched a Train or Engine, which may be required to call or work at such Siding or Platform, he shall not allow any other Train or Engine to follow—unless the road be absolutely clear—without handing to the Guard of the latter a written notice of such first Train or Engine being on the road : and it shall further be his duty, as well as that of the Guard receiving such written notice, to instruct the Driver of the following Train to approach each Siding or Platform with extreme caution, lest the Line should be obstructed by the preceding Train or Engine.

Source: Pages 63 to 70, Rules and Regulations. 21/05/1879

NOTE: This page is under development - please check back later, however, if you have any additional information on this type of train working, it would be most welcome.

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