Re: Indian Pacific Accident

[Eddie Oliver <eoliver@efs.mq.edu.au>]

John MacCallum wrote:
> 
> Eddie Oliver wrote:

> > This topic has been done to death on another thread about the same
> > incident.
> >
> > Eddie Oliver
> 
> Oh come on Eddie, your the safe working expert!

My intended point was that we had well established in previous threads
that there was no track circuiting (or if there was it was extremely
localised) and therefore there was no way of generating approach locking
other than by unconditional time releases. 

It is really a question of how much you want to protect against human
"error" when there is basically full information available to the human
at the site. This was certainly not the first time that a human has
moved a set of points in front of a train at a crossing loop - there was
at least one quite major American accident of that kind, and I think
several - but it is a very "extreme" form of error which has
traditionally not been seen to justify a high level of protection in
train order systems - probably because there are so many other
more-obviously-dangerous types of "error" possible in such systems
anyway!!

Eddie