Re: [WA] Zanthus collision 18 Aug

[semi.retired.banana@xtra.co.SPAM.egggs.nz]

On Sun, 31 Oct 1999 04:01:03 GMT, mauried@commslab.gov.au (Maurie
Daly) wrote:

>Any half decent system simply woudnt have let the points be reversed whilst a 
>train was sitting in the loop.
>Common sense really.

A little while ago there was an incident in which the Otira (NZ)
tunnel door started closing as a passenger train was leaving the
tunnel. The door edge hit a carriage but fortunately there was only
minor damage.

The report of the Transport Accident Investigation Commission stated
that the closing of the door was *not* interlocked with the track
circuit. This suprised me as I thought it would have been standard
practice to do so. 

Closing of the door was supposed to be prevented by the interruption
of a light beam similar to those used in shop entrances. It was
configured to fail to danger and that is just what it did!

It occurred to me that with all of the restructuring and redundancies
of the past few years maybe Tranz Rail has lost most of its signalling
expertise. My apologies to the signal engineers if this is not the
case.