Re: Crossing loop design (r.e. Southern Aurora crash)

[Gavin Potter <gavpot@ozemail.com.au>]

Krel wrote:

> >>This raises an question of interest, namely what signaling schemes are used
> >in Aus.
> >
> >NSW is simple - the top aspect tells oyu if you can pass THAT signal - the
> >bottom one gives you warning of the next one.
>
> It is like having a Home above a Distant on the same post.
>
> >Basically - NSW has two aspect signalling in MOST heavily trafficked areas -
> >providing Green (G), Yellow (Y) and Red (R) in both aspects.
> >
> In Victoria this is called three aspect signalling. There are two
> lights that can show up to seven combinations:-
> G/R - clear normal speed                "Top Green" in driver speak.
> Y/R - normal speed warning              "Top Yellow"
> R/R - stop                      "On the red"
> R/Y - medium speed warning      "Bottom Yellow"
> R/G - clear medium speed                "Bottom Green"
> Y/G - reduce to medium speed    "Reduce"
> G/Y - clear on a repeating signal (a repeater in Vic is like a
> distant).

A Repeater signal indicated that you where going from a three position signaled
area into a two position signaled area.

>
> At some locations only one light is used. This is called two position
> signalling. The aspects are
> G - clear
> R - stop
> In 2 pos areas signal that have no stop indications are called
> distants (cf repeaters in 3 pos). These show only:-
> G - clear
> Y - caution
> Only distants can show caution, all other yellow lights indicate
> 'warning' (no one seems to know why)

If a Distant signal was on the green while you where running on the miniature
electric staff system, it also indicated that you where on the auto staff
exchange.
The reason Distant signals might have shown a caution aspect is (thinks back to
old rules and regs days), When you were running on time interval (the one, five
rule), I forget which reg it was, but you could have another train infront of you
and if you approached the distant at caution you had to be prepared to stop at
the distant if the section ahead was occupied. Upon passing the distant you had
to proceed cautiously to the next signal, once again being prepared to stop if
the section was occupied. From memory, if you stooped at the starting or advanced
starting signal in a two position signaled area, you had to assume that you were
running on the one, five rule.

>
> .
> In NSW this is called double light colour light signalling. There are
> two lights that can show six combinations:-
> G/G - clear             "Two" in driver speak
> G/Y - medium            "one and a half"
> G/R - caution           "one"
> Y/Y - medium turnout
> Y/R - caution turnout
> R/R - stop
> At some locations only one light is used. Each signal has a small red
> marker light that only illuminates when the main light is red (or
> out).  This is called single light colour light. they can show:-
> G - clear
> Y - caution
> Y(pulsating) - medium
> R/r - stop
> slcl signals that do not have a stop indication are called distants
> (and are not numbered). They have a yellow light that only illuminates
> if the main light fails.They show:-
> G - clear
> Y - caution
> Y (pulsating) - medium
>
> Of course there are many subsidiary lights as well.
>
> Hope this illuminates.
>
> Cheers
>
> Krel
>
> Just another eccentric crank.

--

--------------------------------------------------------
Gavin Potter.

e.mail: (home) gavpot@ozemail.com.au
 (work) gavin.potter@agric.nsw.gov.au
--------------------------------------------------------