Re: Three Position Signalling

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

Maurie Daly <mauried@commslab.gov.au> wrote in message
mauried.343.37FDC300@commslab.gov.au">news:mauried.343.37FDC300@commslab.gov.au...

> In reading the articles about the situation at Tottyhan and signal
TOT/U8 ,
> could someone explain exactly what auto guage detection is.

I don't know the exact technical construction details, but it detects
the gauge of the train.

> Also is there a potential dangerous situation here.
> Lets assume that an SG train has left Brooklyn and is heading for
Tottenham.
> Signaller in TottyB Box mistakes oncoming SG train for BG train and
attempts
> to clear signal TOT/U8 by causing it to display R/R/Y with a V
indication.
> A/ Is the above possible.

No, the automatic Gauge Detection will prevent the Stick being cleared
for the wrong gauge.  Also, this would require gross incometance on
behalf of both Mile End & the Signaller @ Totty B, as a Signaller
*should* know what train is approaching.

> If so what are the rules about not passing homes showing proceed if
the wrong
> indication is shown , ie are there any other circumstances where a
train may
> not pass a home displaying R/R/Y.

There is no Automatic Gauge Detection AFAIK at:
West Footscray Post 186,
Sims St Jct Post 162,
The Dwarf next to it,
Moonee Ponds Jct Dwarf 214 & Home 206,
West Tower Post 218,
Spencer St Posts 62 & 183.

> Obviously if the SG train does pass the signal at R/R/Y a prang is
quite
> possible at the SG junction.

Only if it's for a BG route.

> Can this happen ?

As I said, it shouldn't.

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