Re: [NSW] Tangara Derailment , Hornsby

[signal_spotter@my-deja.com]

Firstly, I didn't put the catchpoints in the main line. Now let me
explain the process here. The scheme layouts in each state (and each
country) are usually designed by the relevant authority's own
signalling design section. That includes Hornsby. The layout is
determined by a number of factors such as traffic patterns, number of
trains per hour etc etc. There is usually meetings between signalling
design staff, operators and drivers (or at least the bosses) to work
out the scheme layout. We mere mortals get involved later down the
process. Having said that, from the history of what I know of Hornsby,
I think the layout hasn't changed that much from the previous. I think
the only major change was the down refuge and 520 points at the
northern end of Platform 4 and some new points near Bridge St. The
catchpoints have been there for a long time. Now the reason for putting
catchpoints (and I'm only speculating here because I wasn't part of the
Hornsby decision making process) is to allow trains to come up to the
signals and still provide a valid overlap, even though it's in the dirt
it's better than an overlap into an oncoming train. Now if you only had
2 trains a day into Hornsby then you wouldn't require the catchpoints.
But you don't. And the alternative would mean that you wouldn't be able
to get anywhere near Hornsby if another is approaching (and has the
road) and this would affect on time running. So your gripe is not with
me. I can only design a signalling system based on the relevant
authority's rules and regulations. I design systems in other states and
countries too and I have to abide by their layouts, their rules and
their regulations.

regards

In article <397bb0f5@news.rivernet.com.au>,
  "K.Andronicus" <kda4203@telpacific.com.au> wrote:
> If you designed Hornsby WHY DID YOU PUT A CATCH POINT ON THE
> BLOODY MAIN LINE?????. Somebody is only looking for trouble I'll give
> it six months before somebody goes thru them.
> Kim Andronicus
> Countrylink Driver Sydney
> <signal_spotter@my-deja.com> wrote in message
> 8lfocg$epi$1@nnrp1.deja.com">news:8lfocg$epi$1@nnrp1.deja.com...
> >
> > > Regarding what happened at Hornsby the other evening I've been
> > informed by a
> > > source that I consider most reliable that the T-set came from
Berowra
> > into
> > > platform 3 (up main).  It then reversed and proceeded northwards
past
> > HY55
> > > over 522 points which were reverse for a move set from no. 2
> > platform - so
> > > the lead bogie trailed through the points.
> > >
> > > In an attempt to try to retrieve the situation, the train was then
> > driven
> > > back towards the platform. The lead car's second bogie was on the
> > station
> > > side of 522 (on the up main) and the first bogie was on the
northern
> > side
> > > with the points still reverse, i.e. set for number 2 platform. The
> > result -
> > > Sydney end bogie to platform 3, country end bogie to platform 2.
> > >
> > This explanation is the most plausible and sort of what I thought
> > happened. Having designed Hornsby, I know it pretty well. Although I
> > don't like to speculate on such matters, I wouldn't rely on what the
> > media puts in the papers explaining the reasons either. So although
> > aus.rail may have some rumour mongering, it does have experts in the
> > various diciplines of the railways. And that's something the media
> > doesn't have.
> >
> > regards Ian
> > Signal Design Engineer
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>
>


Sent via Deja.com http://www.deja.com/
Before you buy.