Re: Beresfield Accident Findings

[mauried@commslab.gov.au (Maurie Daly)]

>Thank you for putting a balanced perspective on this.

>The original point was that emergency applications USUALLY don't have any very
>adverse consequences; nevertheless they can have such consequences, ranging
>from skidded wheels through damaged drawgear through (in a worst-case
>scenario) derailments. Thus granted that they CAN have adverse or very adverse
>consequences, they are to be avoided wherever possible.

>What some of us were trying to point out was that installing mechanical trips
>on freight trains would (amongst other adverse outcomes) generate unnecessary
>emergency applications which COULD have consequences comparable with the
>problems which were sought to be solved in the first place. which is one of
>several reasons why the rest of the world has generally not used mechanical
>trips on freight trains.

>Now that we have thrashed that subject to death, can we return to being more
>constructive about what viable options - i.e. other than mechanical trips -
>are available for automatic train control? The commonest systems around the
>world seem to be either single-location type devices like British AWS, or
>continuous transmission devices like most forms of cab-signalling where the
>information is continuously contained in coded track circuits and the like
>(with an immediate fail-safe provision that zero coding is interpreted as the
>most restrictive indication).

>These things are expensive but effective. They do however depend on fairly
>traditional signalling principles (although some have progressive rather than
>fixed blocks). Presumably the alleged advantage of GPS-based systems is mainly
>that they will work without so much fixed hardware such as track circuits.
>Unfortunately at the moment I am not aware of any such systems which are
>actually operational in the railway signalling context.

>I would be interested in appraisals of such alternatives, and especially as to
>what advantages will accrue from GPS-type systems relative to more traditional
>ones.

>Eddie Oliver

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As Eddie has pointed out , there are many alternatives that could be used 
other than trips.
Unfortunately here we will see one of the major problems that beset Railways 
in this country compared to anywhere else , in that whatever system is chosen 
it will be a NSW unique system that wont be used anywhere else.
Whilst modifying locos owned by Freightcorp that will run over the modified 
track will be an expense it will be nothing like the expense that will have to 
be met by any other operator that wants to or needs to run over the same 
tracks.
We can see already the sorts or problems that arise when State specific forms 
of safeworking or communication are used.
A good example is Victorias ASW which requires modifications to every 
locomotive that needs to run across it.
Whilst NR have 120 locos which are approved to run everywhere in Australia in 
reality they only have about 22,as only 22 are fitted with the Victorian 
specific hardware.
It is absolutely imperative that before we go any further down the road of 
installing more and more State specific infrastructure, especially on lines 
that carry interstate traffic , that the whole issue of uniform standards for 
communications / safeworking and driver accreditation be solved,otherwise the 
trucking industry , which doesnt carry any of these State specific impediments 
will be the only winners.

cheers
Maurie Daly