Re: Safeworking!

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

Krel wrote:

 
> Normal operation is full electronic but when, for some reason,
> authorities cannot be transmitted electronically we revert to
> 'electronic manual' authorities. Under this system the computer
> generates the authority which is then verbally transmitted to the
> train crew by radio (or phone). The train controller dictates the
> authority (including codes) which the driver writes onto a pre-printed
> form. Once the driver has 'repeated back OK' the display on the train
> controllers workstation will show the authority but not the codes. It
> is a hanging offence for the train controller to write down the codes
> while dictating this information to the driver. When the train has
> exited the section the driver dictates the codes back to the train
> controller so he can 'unlock' the section.

It is interesting that this backup system from Victoria is the full
system in NSW (i.e. the Orange-based train order system), i.e. NSW has
not gone to the electronic units within locomotives but does have the
code system.

Train order systems elsewhere have not in general found it necessary to
have the codes, relying on verbal declarations from drivers when they
clear sections, perhaps being matched with the train controller
observing as far as possible from other evidence that the train is
indeed in the right place. (There is always a fear that a driver will
declare that he is has cleared the section A-B when he is actually at
some different point C). In the NSW system the codes are even backed up
by GPS-style units on the locomotives, which transmit an independent
verification to the train controller as to the train's location.

It is of course consistent with general NSW safeworking conservatism
that there should be more protections provided than other railways have
typically found necessary.

Eddie Oliver