Australian National Common General Operating Rules
(extracts only)
Only information relative to 3-colour searchlight signals is given on this page Retyped by the webmaster of this site from a photocopy of an undated original
permission is given to copy for non-commercial purposes
2b. Unless otherwise specified, the following definitions shall apply:
absolute block working: A system whereby only one train at a time is authorised to enter a section
absolute permissive block working: A system whereby one or more trains travelling in the same direction and spaced apart a block distance, may consecutively enter a section of single line on signal indication.
automatic signal territory: Territory over which train movements are governed by automatic signals. Automatic signal territory may include one or more unattended or attended block stations, the latter being locally or remotely controlled.
block: A length of line of defined limits. On automatic signal territory or centralised traffic control territory, the length of line between signals.
centralised traffic control A system by which train movements are controlled by the train controller at and between remotely controlled stations on single line, where the train controller operates signals and switches within the territory.
centralised traffic control territory A length of railway which may include one or more block stations and single line sections, on which the movement of trains is governed by the regulations of the centralised traffic control system.
Three-position Block Signals
25. The indications of absolute colour light signals are displayed to the front by day and at night as under:
25a. "Stop Signal"
Indication - Stop Occasion for use - Block is not clear
25b. "Caution (normal speed) Signal"
Indication - proceed prepared to stop at next signal Occasion for use - Block is clear, next signal is at 'stop'
25c. "Clear (normal speed) Signal"
Indication - Proceed Occasion for use - Block is clear, next signal is at 'caution' or 'clear' for normal speed
25d. "Reduce to medium speed Signal"
Indication - Proceed prepared to pass next signal at medium speed Occasion for use - Block is clear, next signal is at 'caution' or 'clear' for medium speed
25e. "Caution (medium speed) Signal"
Indication - Proceed at medium speed prepared to stop at next signal Occasion for use - Block is clear for medium speed only, next signal is at 'stop'.
25f. "Clear (medium speed) Signal"
Indication - Proceed at medium speed Occasion for use - Block is clear for medium speed only, next signal is at 'caution' or 'clear' for medium or normal speed.
25g. "Caution (low speed) Signal"
Indication - Proceed at slow speed prepared to stop.
27. The indications of permissive colour light signals are displayed to the front by day and at night as under:
27a. "Stop Signal"
Indication - Stop Occasion for use - Block is not clear
27b. "Caution (normal speed) Signal"
Indication - proceed prepared to stop at next signal Occasion for use - Block is clear, next signal is at 'stop'
27c. "Clear (normal speed) Signal"
Indication - Proceed Occasion for use - Block is clear, next signal is at 'caution' or 'clear' for normal speed
27d. "Reduce to medium speed Signal"
Indication - Proceed prepared to pass next signal at medium speed Occasion for use - Block is clear, next signal is at 'caution' or 'clear' for medium speed
27e. "Caution (medium speed) Signal"
Indication - Proceed at medium speed prepared to stop at next signal Occasion for use - Block is clear for medium speed only, next signal is at 'stop'.
27f. "Clear (medium speed) Signal"
Indication - Proceed at medium speed Occasion for use - Block is clear for medium speed only, next signal is at 'caution' or 'clear' for medium or normal speed.
28. Signal indication speeds
Normal Speed The normal speed signal, when displaying a 'caution' or 'clear' indication, must not be passed at a speed exceeding that specified for the locality and class of train in the Working Time Table, train notice or other instructions.
Medium Speed The medium speed signal, when displaying a 'caution' or 'clear' indication, must not be passed at a speed exceeding that specified for the locality and class of train in the Working Time Table, train notice or other instructions, or at a greater speed than 35km/hr.
Low Speed The low speed signal, when displaying a 'caution' of 'clear' indication, must not be passed at a greater speed than 25km/hr. A driver receiving a 'caution' indication from a low speed signal may proceed prepared to stop within half the distance the track is seen to be clear ahead, expecting to find the track in advance occupied or the next signal at 'stop'.
The images used in this page have been derived from the Word document about three aspect signals associated with the RailSim train driving simulator produced by its author, Jens Schubert, to whom all credit is due.
