Re: Simple Question.....

[John MacCallum <johnmac@lisp.com.au>]

David Bradshaw wrote:
> 
> Just a simple question from an inquisitive commuter:
> 
> Often I see two sets of lights one atop the other (ie on the same post).
> I gather (correct me if I'm wrong here) that red = stop; amber=proceed
> with caution; green = proceed, though I am a bit lost as to the role of
> the dual signals!!
> 
> David Bradshaw
Double Light Colour light Signalling allows many combinations of 
Indication . In NSW these Signals take a number of forms but the basics
are as follows :-

Green over green 	=	Full Clear
Green over Yellow	=	Medium Caution (Next signal not at Stop)
Green over Red		=	Caution (Next Signal at Stop)
Yellow over Yellow	=	Turnout	(Next Signal not at Stop)
Yellow over Red		=	Turnout (Next Signal at Stop)

There are some Subsidiary signals that work in conjunction with signals.
They can be either Low Speed Indicators , Calling On , Close Up and
Shunt ahead . These subsidiary Signals are provided by either a small
light included with the lower set of main lights or they are a small
light on a separate bracket on the Signal post .

John Maccallum