Re: Train Order working in NSW

["Dave Proctor" <thadocta@spambait.dingoblue.net.au>]

Eddie Oliver wrote in message <3898234A.57C9F544@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.

What about FPL's, they same way they work in the metropolitan area, i.e. the
FPL is unlocked, the points move, the FPL is relocked. When the points are
to be restored, the FPL unlocks, the points move, the FPL relocks.

>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.

See above.

>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.

See above. If the FPL had to be locked (whether set for the loop or the
main) then accidents would be less likely to happen, as two levers would
have to be swung instead of one.

Dave