Re: Three Position Signalling

["Exnarc" <gwrly@netspace.net.au>]

Christopher_Martin GORDON <cmgord@ecr.mu.oz.au> wrote in message
7tjme0$fua$1@mulga.cs.mu.OZ.AU">news:7tjme0$fua$1@mulga.cs.mu.OZ.AU...
> Newmarket:
> Last year I went out to Newmarket to get a couple of photos of the down
> home (junction to Flemington Racecourse) This signal will show normal
speed
> of a movement to Broadmeadows and a medium speed aspect of a movement to
> Flemington Racecourse.  During the time the Upfield trains were running to
> Newmarket and last year this signal showed red/green (clean medium speed)
> of the move to the Flemington racecourse line.  But for the exam trains
> in July and show trains in September this signal only showed red/yellow
> (medium speed warning) but the next 3 (2 position) autos were at proceed.
>
> Why did the signal only show red/yellow, when it should have been
red/green
> or is it that these times the showgrounds boxes were switched in, were as
> when the Upfield and empty car trains ran/run the Showgrounds boxes are
switched
> out?
>
>
> Flinders Street:
> Was there any reason that the home signal for a movement for the through
> suburban viduct to no.10 platform can only show red/red, red/yellow?
> why can't this signal show red/green (for a movement along platform 10 to
> platform 12)
>
>
> Umm, the wonders of signalling.
>
Thats a good question, empty car movements to the Racecourse during the day
usually get a Bottom Green on that signal, but like you say the Show and
Exam Specials only received a Medium Speed Warning, whilst I can't see why,
it must have some bearing on whether the Showgrounds Signal Boxes are
switched in or out. The actual Newmarket panel is situated in Kensington
Signalbox and can be switched in or out by the Kensington Signalman, of
cause if it were switched out trains would not be able to access the
Racecourse line anyway, so I assume the aspect is tied in with the
Showgrounds frames???

How about one of the signalling expert filling us in on this one.

Bob.