Re: Oakleigh

[Eddie Oliver <eoliver@efs.mq.edu.au>]

Notagunzel wrote:


> 
> People often complain about how 'slow' the recent resignallings (SSI &
> Westrace) are, it's actually IMHO a symptom of Unit Lever Panels.

Isn't it a combination of the two types of factors?

If you compare a unit-lever-controlled relay interlocking with a
unit-lever-controlled CBI, the latter is still typically slower.

>  If a
> conflicting move is to be made, the Signaller has to wait for the track circ
> uit to pick up, (plus 'hidden' anti-bobbing protection time) then operate
> the point lever(s), then operate the signal.  If a halfway modern
> processor/VDU/mouse/trackball/NX workstation was used, (surely the costs
> would have to be comparable to all the MUXing for a Panel & Diagram) the
> route can be stored in advance, and excecuted as soon as possible, instead
> of factoring in human reaction time to point free lights etc... and
> operation of multiple levers...

It just requires more logic, which does cost more money??? The costs for
the human interfaces are probably perceived separately from the costs of
the logic elements, even though the latter are predominantly entries in
control tables or other software-based things and should logically (no
pun intended) be quite cheap.

There are said to be few cost-savings in CBIs versus relay systems,
whereas with the current state of computer technology, one would expect
the CBIs to be much cheaper. It may be another case of the prices in a
not-very-competitive market being set at what the consumers will pay.

> P.S., re my TMF post, I forgot to mention it apparently doesn't store routes
> for later excecution, how strange?

Not really so strange, for the same cost reasons. Moreover NSW used to
be ultra-conservative about possible dangers of pre-setting (because
routes might cancel prematurely with bobbing tracks, trains that didn't
shunt the track circuits properly, etc) but seems to have grown out of
the phobia; perhaps Victoria hasn't.

And there have, I believe, been incidents overseas where pre-setting
produced unintended consequences wherein if several routes were preset,
they didn't set in the proper sequences. That just sounds like bad
software and/or hardware design, but it was enough to generate another
cause for paranoia.

Eddie