Re: Indian Pacific Crash

["Notagunzel" <notagunzel@bigfoot.com>]

Exnarc <gwrly@netspace.net.au> wrote in message
7qfofl$2m84$1@otis.netspace.net.au">news:7qfofl$2m84$1@otis.netspace.net.au...

> Maurie Daly <mauried@commslab.gov.au> wrote in message
> mauried.417.37CB50BC@commslab.gov.au">news:mauried.417.37CB50BC@commslab.gov.au...

> > In article <7qfcbv$2ktn$1@otis.netspace.net.au> "Exnarc"
> <gwrly@netspace.net.au> writes:

> > >Source has reported that IP prang was caused by crew member on ground
> > >opening switch in path of IP, diverting it onto the goods.

> > >Route was set correctly but he was standing alongside the switch stand
> and
> > >read the wrong face, in a panic without looking at the blades he
though
> the
> > >points.

> > This tends to suggest that the loop points are still manually
controlled ,
> ie
> > a manual switch and not power operated as previously indicated.
> > Dual control point machines are normally approach locked by an
approaching
> > train and cant be moved , usually until the timeout period has expired,
at
> > least thats how it normally works.
> > Odd though that the crew member was anywhere near the points as they
would
> > have been set correctly in the first place ,and would only have needed
> > changing to allow the goods out of the loop.

> Don't have anymore info Maurie,

> Just got that from a normally reliable source over there.

> Don't know the location personally, or if the remote control points were
> working, but if they weren't, there would have to be a way of manual
> operation. ie: DCPM.

> Switch Stands, aren't all mainline points on the TAR fitted with them?

>  As for the crew member being at the points, the old rules for CR T.O.
> working required that a member of the other crew admit the second train
to
> the cross by showing a green flag or light from the points, not sure how
> they do it, now that radio has become the main form of safeworking in TO
> Territory.

Hmmmm... Very interesting...

I have got a small piece (including pictures) on the TAR loops on my site:
http://www.geocities.com/CapeCanaveral/Cockpit/9412/tar_loop.html

Just to summarise, the points between the main & loop are power operated by
dual control point machines, the points also are fitted with switchstand
indicators, and the position of the points are also repeated by
searchlights mounted on the roof of the equipment hut.

The points are self restoring, and to provide the logic to state when the
train has passed over the points, there is a crude system resembling an
axle counter.  This uses commercial proximity detectors & a PLC to count
the axles.  BUT...  this 'section' is only between the fouling point of the
loop, and the toe of the turnout, so if the poor soul pushed the reverse
button just as the train approached, the points would have motored across
in front of the IP, admitting it into the loop, and on to the goods.  There
is therefore, AFAIK, no approach locking.

Doesn't seem very safe, does it?  ARTC must be thinking along similar
lines, as Westinghouse has got a contract for the resignalling of all the
loops, AFAIK the latest edition of Track & Signal has details.  However, at
this point, I'm only aware of Tent Hill, the first loop out of Port Augusta
having being completed.  (They may have done more now, but I haven't heard
anything.)

--
Mr Notagunzel.
Rail Transportation Connoisseur.
notagunzel@bigfoot.com
(Waiting for the next move at http://www.bigfoot.com/~notagunzel)