Re: Train Accident in Blue Mountains

[G.Lambert@unsw.edu.au (Geoff Lambert)]

Rob McDonald <robert.mcdonald@nepean.uws.edu.au> wrote:

>This morning the same commuter train service involved in the Glenbrook
>disaster was yet again running close behind the yet again late-running
>Indian Pacific. On leaving Hazelbrook it was travelling less than 5 minutes
>behind the IP. Many of us commuters who were on the train that crashed were
>understandably concerned.

>One of the newspapers which reported the Glenbrook disaster claimed there
>should be a 7-minute interval between trains. I've heard elsewhere that the
>interval should be 9 minutes.

>Can anyone in this group inform me whether there is a regulation
>stipulating a time interval between the trains on the Blue Mountains Line?
>Or is there just a regulation stipulating distance?

Since the mid to late 19th century, the principle has been that
separation of trains on a line is by space, not by time.  In certain
circumstances time interval working might still be used for freight
trains (e.g. on a sparsely-trafficked country line worked under the
"staff and ticket" system)  It is not used on a line like the Blue
Mountains line.  There, and elsewhere, the signalling system, or
safeworking system, is operated on the basis of ensuring a certain
mimim block of empty track exists behind each train.

Geoff Lambert