Re: Signalling in Victoria

[Eddie Oliver <eoliver@efs.mq.edu.au>]

MarkBau1 wrote, referring to a comment by David:

> I'm sorry, I can't make any sense out of this question/comment at all. You may
> be getting confused with VR where there is a "medium speed" Under GCOR there is
> no such thing as "medium speed" a bottom light simply tells you that you are
> diverging and you are to proceed at the speed for that location.

But there IS medium speed in NORAC and CROR. And the third head is then
effectively a slow speed head - i.e.

top = normal
middle = medium (or limited if flashing or supplemented by an
appropriate plate)
bottom = slow (also gives the restricting indication on some roads)

Note that in the latest versions of CROR, even the NAMES of the aspects
are expressed in terms of what you do speed-wise at THIS signal and then
what you do speed-wise at the NEXT signal = e.g. "medium to stop",
"limited to slow".

This whole discussion is getting very convoluted because Mark's
experience is with GCOR, and he doesn't seem to appreciate that NORAC
and CROR are so conspicuous throughout all the rest of North America -
after all, CROR covers the WHOLE of Canada!

NORAC and CROR rules are available on the web somewhere - if anyone is
interested, I'll dig out the URLs but tell me if you are interested so I
don't waste time searching!


> Not a coincidence because if there is more than one diverging route the signal
> gets another light, this is why 3 head masts are common in the US, the top
> light is for the straight road, the middle light is for the left most diverging
> road, the bottom light would be for the right most diverging road. The key
> point is that there is a separate light for each route, hence, route signaling.

You are claiming that to be true for GCOR, but it is plainly untrue for
NORAC and CROR - see above.

The NORAC and CROR heads are ENTIRELY speed-indicative, and the top to
bottom layout bears NO relationship whatever to left, right etc.

Moreover the UP - one of the GCOR roads you claim to be route-signalled
- has (amongst others) the following aspects:

DIVERGING CLEAR SLOW: red over red over green, proceed on diverging
route, speed through turnout must not exceed 15 mph.

DIVERGING CLEAR LIMITED: red over flashing green, or red over flashing
green over red: proceed on diverging route, speed through turnout must
not exceed 40 mph.

DIVERGING APPROACH SLOW: red over red over yellow: proceed on diverging
route prepared to stop at the next signal, speed through turnout must
not exceed 15 mph, speed to next signal must not exceed 30 mph.

Need I go on?

Note how these are immediate counterexamples to your own assertions re
the meaning of the multiple heads, and how they contain SPEED rather
than ROUTE information (other than the simple diverging information).

> I've never seen a installation that had 3 or more diverging routes but I would
> assume they would keep adding lights.

You may assume it; until you find an example, I shall be totally
unconvinced. It would, for a start, require some sort of very special
instructions.