Re: Three Position Signalling

["Notagunzel" <notagunzel@bigfoot.com>]

Christopher_Martin GORDON <cmgord@ecr.mu.oz.au> wrote in message
7ss441$jfi$1@mulga.cs.mu.OZ.AU">news:7ss441$jfi$1@mulga.cs.mu.OZ.AU...

> Just a little about three psotion signalling.

The only way Signal your Railway. (None of this 2 position rubbish).

> I noticed with an AUTOMATIC signal that there is Clear Medium Speed
> (red/green), I am not talking about a home signal here, there are
> plenty that show red/green, but an Automatic I only know of two and
> they are on the Goods lines between North Melbourne and Spencer Street
> for an up train, next to docklands.  Are there any other automatic
> signals that show red/green?

Certainly C.8/15 didn't envisiage Clear Medium Autos, as they don't get
mentioned anywhere.  The are few applications where it would be needed.

1. If you needed a 5 aspect sequence, G/R -> Y/G -> R/G -> R/Y -> R/R, because
of high speed & tight signal spacing.  AKAIK there are aspects like this through
Werribee.

2. If line speed is low, and you are leading up to a diverge.  Why bother with
working 'a' lights?  This is methinks the application you mention on the Up
Through Goods - Autos 724 & 822.

> C.8/15 was good reading but what about some others like C.18/15
> (single line Upperferntree Gully - Belgrave) and C.14/26 (single
> line and unattended junction)
> C.21/27 (ATC)
> C.15/31 (ATC and remote control of pts and signals)

Alas C.8/15 is the only one I have.  If anyone out there has a photocopy of
C.14/26, C.21/27 or C.15/31 that is surplus to requirements, I'm more than
willing to give it a good home. |-)

> Are there any home signals that show normal speed only and have
> a red marker light?  (not one with a big target behind), I think
> Elsterwick is the only one I know of.  And all the semaphore
> home signals now have two arms (ie none left with a red market)?

Very few Homes have a marker light as the 'b' arm/'b' light.  Elsternwick, as
you mentioned, Maldon Jct had 2 in the days of the ATC, I don't know of any
others.

SAR/AN/ARTC however do have Absolute signals with only a marker light for a 'b'
light.

On a different tangent, how many Homes have a full target for all 3 arms?  The
Up Home at Rockbank is the only one I know of.

--
Mr Notagunzel.
Rail Transportation Connoisseur.
notagunzel@bigfoot.com
(Waiting for the next move at http://www.bigfoot.com/~notagunzel)