Re: Three Position Signalling

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

David Guymer <davidmg@optusnet.com.au> wrote in message
37F9AD7B.CD073581@optusnet.com.au">news:37F9AD7B.CD073581@optusnet.com.au...
>
>
> Exnarc wrote:
>
> > snip
> >
> > There are (at least) 3 locations where 2 Position Dwarfs show a Yellow
> > Light.
> >
> > 1: Portland.
> >
> > 2: Showgrounds. From Platform to Up Refuge Siding.
> >
> > 3 Newport. Dual Gauge to Anzac Siding.
> >
> > They are mounted on the same post as a Home Signal and only light up
when
> > the signal is pulled off. Unlike a Calling On signal they do not read to
the
> > same road as the Home signal, but other than that they look the same,
> > except, they have the word "Siding" painted on or attached to the
target..
> >
> > The purpose of these signals resulted from the need to find a
replacement
> > for the mechanical Disc signal, so the Siding Dwarf was developed.
> >
>
> Not quite the Dwarf at Epsom Rd (Showgrounds) existed well before it was
written
> into the rule book. I don't know why the powers that were decided to
finally
> include this anomaly in the rule book but it was certainly after the fact.
> David G.
>
Not quite David, the Portland Dwarf was the first, Alan Hales introduced it
when he was Supt Safeworking. It came out as a Special instruction first,
then the Show Grounds was added.

The first instance was at Murtoa during the CTC construction when the Up
home at Murtoa was replaced by a colour light signal, as an intrim the "A"
light was used for the mainline departure and the "C" light was used to
access Marmalake Siding from the mainlaine , this came out as a Special
Instruction also.

The first use of the light dwarf (on same post as a home) with the lettering
"SIDING" was the Portland one. (After Murtoa), then the Show Grounds, with
the lettering "SIDING". What ever existed at the Show Grounds before I can't
remember (may have been a mechanical Disc)? but it certainly was not the
current "SIDING" signal.

Bob.