Re: Signalling queries

["Bradley Torr" <truenorth@one.net.au.SPAMTRAP>]

Eddie Oliver <eoliver@efs.mq.edu.au> wrote in article
<3B248B62.8AC73EF1@efs.mq.edu.au>...

Hi Eddie, thanks for your reply... I'd just like to clarify some of your
answers though...

> More or less. Electric staffs are placed into "machines". There are a
> number of identical staffs (e.g. 36 or 50) for a given section, but only
> one of these can be released for use at any one time. 

Okay, I've seen this at Albion Park and Kiama. I think this is being
replaced with CTC along with the electrification project now though....

> In ordinary train staff and ticket working, there is only one staff for
> a section; when not in use, it lives in a box at either end of the
> section, but also in the boxes are bits of paper called "tickets". If
> more than one train is to pass through the section in one direction
> before one goes the opposite way, the first train(s) carries a duly
> written-out ticket after the driver has seen that the staff is at the
> correct end of the section; the final train in that direction physically
> carries the staff through the section.

OK, under staff-and-ticket working, what is to stop a driver using a ticket
instead of the staff when entering a particular section, when the next
train scheduled to enter the section is coming from the opposite direction?
In this scenario, if the driver of the first train uses a ticket instead of
a staff, when the second train arrives at the other end of the section,
there will be no staff there for the second train to pick up!

> Between Sutherland and Waterfall; Campbelltown; between Penrith and Emu
> Plains; Berowra. However there are a few double light areas on the south
> outside the suburban area, mainly in areas where upper quadrant signals
> still exist in substantial numbers.

So that sign I saw near Picton signified the end of one of those isolated
double-light sections on the Main South?

Regards
BT