Re: Beresfield Accident Findings

[David Johnson <trainman@ozemail.com.au>]

Chris Grace wrote:

> It has consistently been stated that the trainstops as used on LUL and parts of
> NSW railways are not considered usable at high speeds (In this case so far as I
> know 'high speed' means over around 35mph).

Brake tests conducted at Holsworthy are done using a fixed trip-stop.  I have been on
tangaras and double-deck intercities which have hit the trip at over 140 km/h without
any problem.

>  Not only that, but the train which had tripped (and
> potentially destroyed its tripcock) would then have to run with it isolated, and
> consequently with no protection at all. which defeats the purpose of having it in
> the first place.

All CityRail trains have a control governer which is connected to the Safety apparatus
air-line.  This means that if you isolate the trip gear, the train will not power
without the Emergency Pushbutton being depressed.  This means that the person pressing
the pushbutton is the protection for the train, and that is why they must be safeworking
certified.

>  I don't know if the
> City Underground in Sydney is all electropneumatic or not, but even if it isn't
> we're talking about a pretty restricted geographical area, and in any case
> traction current could presumably be used to drive compressors. I
> could imagine problems getting compressed air to every signal in
> non-electrified or country areas.

The underground is, but in suburbia, they are fully electric.

> And, of course, trainstops are another maintenance problem. I have no idea how
> they would fare in the open air in the country - they would obviously be subject
> to vandalism, and unlike a signal, this wouldn't be immediately obvious to
> drivers, so they'd have to be inspected frequently.

Vandalism would be immediately obvious, because if the train-stop fails, the signal will
not clear.

--
David Johnson
CityRail Guard
trainman@ozemail.com.au
http://www.ozemail.com.au/~trainman/