Re: Train Order working in NSW

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

Dave Proctor wrote:

> 
> What is to stop the points from moving underneath a train entering the loop?

No more and no less than what there is in any other system where the
points are manually operated from an adjacent lever frame - i.e. mainly
the vigilance of the personnel.

Almost any ground frame, once it has been released initially, has little
protection against operator errors. For instance if the frame is
released by the train staff or loose key in a staff-and-ticket
situation, and the FPL is released, the lever actually controlling the
points is entirely free to move until the FPL is again restored.

There have been incidents when the person operating the frame has moved
the points under a train, but they are rare, especially when viewed
relative to the number of times when frames have been in a released
state without any adverse incidents.

Eddie