Yes, they were. The pulsating White was used as a starting signal when going from a signalled system to a token system. A MLI was indicated by a diamond plate with a letter (originally only X, Y or Z). If you feel inclined, a check of ANSG 606, pg 9 (found on ARTC website) will show a Pusating White light as a proceed indication.
Edit: reference added.
Dave, as a former Train Control Supervisor for Staterail I went to Orange in 1997 to train train controllers, drivers and infrastructure staff in Train Order Working. after 2000 I worked on the safeworking rules rewrite as a subject matter expert in Safeworking. and from 2008 until late last year returned to safeworking, also serving as the RailCorp representative on the Australian National Rules Project, believe me I speak with experience and authority on these matters.
whilst the reference you quoted is correct, it is only a part of the knowledge required in the different aspects of safeworking.
the introduction of the pulsating light was an attempt to permit an increase in the sighting distance than that possible with Mechanical Point Indicators.
Whilst Train Order Working (TOW) was designed to allow trains to not stop at former staff stations, there was still the limitation that a driver was unable to proceed at track speed until he had sighted the points indicator and be prepared to stop if the points were against him, remembering that there was no guarantee to the driver that the points had been correctly set.
this philosophy was expanded to give the driver an indication that active control level crossing equipment was also operating correctly, and where there were multiple level crossings at a location (think Wellington ) there was a repeater function.
however back to then being treated as a starting signal, drivers were vehemently opposed (and quite rightly so in my opinion) to the entrance to a section having no interlocking as such. Think Orange on the down to Dubbo. A driver who had been responding to colour light signals and was not to enter a token section, albeit a train order, there was no prompt to a driver that the signal was no longer the authority for the section, but he needed a train order.
this concept was supported by human factors studies and risk assessments, and was the genesis of the pulsating white light.
However after that trip down memory lane, let us return to the rules.
ANSY 502 Train Order working - states :In Train Order territory, Train Orders are the only
normal authorities for:
- a through-movement only, or
- shunting at a location (Shunt Order), or
- a through-movement with shunt access at a
Authority to enter a block is given by a valid Train
Train Orders must specify:
- departure and fulfilment locations, and
- if necessary, reporting, crossing and shunting
Rail traffic must pass indicators at STOP only in
accordance with Rule ANSG 610 Passing indicators
if we look at Electric staff as representative of a token system, the ANSG 504 Electric Staff states:
The authority to enter and occupy a section in the Electric Staff
• possession of the correct staff for the section, as authorised by
the Train Controller, and
• where provided, clearing of relevant signals, or the display of
a U indicator.
here there is a clear corollary to clearing a signal, note this is not evidenced in TOW.
You claim they are a starting signal, however ANSG 600 Running Signals states that a Starting Signal is an Absolute, (Table Page 6) then if we go to the glossary the authority to pass an absolute signal is a signallers or a SPA, SPA are generally not issued in TOW areas, the system utilises a mishap order for out of course working.
if they were a single light colour light signal as you postulate, then they would have a marker light below the main light (ANSG 600 Page 8 )
if we go to ANSG 604 Indicators and Signs page 4 talks about main line indicators
Main line indicators:
- advise rail traffic crews about the condition of
the points and level crossings, and
- are identified by a black letter on a white
reflective diamond attached to the indicator
Main line indicators do not indicate that the line
ahead is clear.
if we go to ANSG 606 responding to signals and signs, then
The clearing of a signal gives authority to enter the
block for which the signal has been cleared,
provided that, in token systems, the Driver or track
vehicle operator has the token for the movement or
in Train Order systems, the Driver or track vehicle
operator has the Authority for the movement.
A running signal authorises a through-movement
between that signal and the next running signal.
therefore if you look at the table on page 9 of 606, there is a clear distinction between a single light GREEN signal indication that authorises
as opposed to a single light WHITE that only has CLEAR
there is no authority statement associated with this indication.
think of it, by your hypothesis, a single flashing light at Parkes on the Down would in your mind be the authority for a movement to Broken Hill.
you have taken me back to possibly the most enjoyable work with a real sense of achievement, when i left RailCorp last year after 41 1/2 years, this was one of the activities that i was proud to be associated with.