Re: Oakleigh

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

Eddie Oliver <eoliver@efs.mq.edu.au> wrote in message
37C1335F.58834940@efs.mq.edu.au">news:37C1335F.58834940@efs.mq.edu.au...
> David Langley wrote:
> >
> > Christopher_Martin GORDON wrote:
> >
> > > I have updated up Oakleigh Signalling page to include the pull chart.
> > >
> > > I have no idea why they have a stupid pull chart which is totally
> > > different from normal pull charts.  But it is there any way.
> >
> > It may be stupid to you (reason please) but to the engineer who put it
> > there, probably perfectly normal. Have you seen the pull chart from
> > Flinders Street D, West Tower or Camberwell all similar panels i.e.
route
> > setting panels.
>
> OK, I'll bite. It seems stupid to me too. Reason: a pulling list
> involving points is essentially meaningless for a route setting panel
> where the buttons set the complete routes, because the signaller does
> not have to do anything with the points individually. In other words,
> the pulling list is telling him to do things which he does not have to
> do.
>
> It seems silly enough for an OCS panel; it would be one stage sillier
> for NX.

For an NX panel, I really think pulling lists are not necessary for NX
panels, especially where the buttons/icons are physically located adjacent
to the relevent signals.  P.S. Oakleigh is a OCS, not NX, am I right?

> So back in your court, David. What purpose DOES it serve? The only
> constructive thing I can think of is that it would define the required
> positions for each individual set of points if they were to be set
> individually rather than via the route setting, perhaps because the
> route setting was not responding for some reason???????? Is it a sort of
> diagnostic tool along the lines of "if the route won't set, check that
> the points are in the required positions?" That could surely be done by
> commonsense without requiring a pulling list format.

Hmmm....haven't got the documentation on hand, but I think Oakleigh, (&
Flinders St E) have a peculiar type of solid state/transistorised route sett
ing equipment.  i.e., the pressing of the OCS button is read by the
non-vital route setting equipment, and the equipment drives the vital relay
interlocking to request the points, then the signal in turn.  Now, if this
equipment fails, it may be that there might be some sort of 'graceful
degredation' involved, where the points can be manually called, then the OCS
button calls the Route Proving Relay (or whatever) directly.  The Panel at
Spencer St 2 Box was a true NX panel, where the buttons were read in by a
PLC, and the PLC then drove the geographic relay interlocking.  Of course,
all the Metrol area interlockings are driven directly by the JZA, the route
setting logic being performed by the Metrol computer.

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