Re: Train Accident in Blue Mountains

["Bill McNiven" <wmcniven@gunzel.ozemail.com.au>]

Derick Wuen wrote in message <3854e49b.0@iridium.webone.com.au>...
>-0.52 m/s/s seems slow. I understand old red rattlers were designed for -2
>mph/s braking ~ -0.89 m/s/s.
>What effect would downhill on a 1 in 60 do to braking rate? Decrease rate
by
>1-2 %, stopping distances increased 1-2%?


Hi all!

I know that 0.52 m/s/s looks slow.  Especially because the very old books of
rules I have refer to protecting the train 1400 ft (427m) in the rear.

I don't know what the nominal stopping rate for a 'V' set is. Stop from 110
Km/h in 900m was the only suggestion in this NG.

The adjustment for a falling 1 in 60 grade would, as a first-order
approximation, be +g/60, i.e. +9.8m/s/s /60, i.e. +0.163 m/s/s.

I'm quite happy to discuss facts (other than those sourced form press
reports) about this tragic accident.  Other posters have suggested the
stopping distances of 'V' sets and I've only analysed their information.

Given that there is to be a joint inquest/judicial inquiry, I'm not
otherwise speculating on how this senseless loss of seven lives occurred.

My only line of *SPECULATION*, based largely on previous postings to this
NG, goes like this ...
1    If the train ahead was hit, the second train was going too fast, or it
had a calamitous brake problem
2    If the train was going too fast after discussions with a signal box or
with station staff at the station, then possibly
3    the driver was given incomplete, misleading or mischievous
information/disinformation about the state of signal 41.6 at Glenbrook
Station and the line ahead to signal 40.8, possibly over the telephone and
possibly face-to-face at Glenbrook.

I'm not surprised that professional railway persons have largely refrained
from providing numerical input to the speculations of amateurs in this NG.
Nor do I complain about this.

I expect that the inquest/judicial enquiry may well provide a more thorough
investigation than past (more than a decade ago) internal NSW public sector
"inquiries".

Not for Derek, but for other readers, I must emphasise that, while some of
us "get out kicks" out of watching the trains go by, the principal issues
after this sad event are preventing further deaths on a major urban rail
system and meeting the needs of the families, friends and co-commuters of
the deceased.

Rgds

Bill

Disclaimer:  the writer was one of the organisers of a steam-hauled
excursion from Sydney to Maitland (which did not return) in May 1990.