Re: NRC <> Brisbane to Sydney safeworking.

[mauried@tpg.com.au (Maurie Daly)]

In article <72m6n5$q79$1@reader1.reader.news.ozemail.net> "David Proctor" <daproc.spambait@umpires.com> writes:
>From: "David Proctor" <daproc.spambait@umpires.com>
>Subject: Re: NRC <> Brisbane to Sydney safeworking.
>Date: Sun, 15 Nov 1998 20:23:00 +1100

>Richard Wardle wrote in message ...

>>I can see that you were never an engineman ( I was for over 14 years). From
>>my experience I personally would prefer the crew to have some electrical
>>means of safety, I.e. C.T.C signalling or a physical staff then a piece of
>>paper issued to you hoping that everything goes according to the plan and
>>that the train controller or enginemen don't make a fatal error.


>So how about a computerised system of train orders, so that the computer
>will not allow an invalid order to be issued? I can see some problems with
>this (in other peoples minds, anyway):


One of the fundamental problems with Train Orders , and with any electronic 
equivalent of them , like ASW , is that it simply isnt anywhere near what one 
would call a fail safe system of train working.
Train orders rely 100% for safety on trains being where the controller thinks 
they are.
Train order systems , certainly in Australia dont provide any form of 
independant verification of where a train is, at any time , as they are 
generally used to save money and the lines over which they are used 
have no track circuits , or any other forms of train detection.
With train orders , all that is needed is just one mistake by a driver 
and the first thing that the train controller will know about it , is when the 
police and ambulance ring him up to tell him about the head on thats just 
happened.
This is not to say that train orders have no place in railway operations.
Where train densities are low , and opposing movements are rare, ie the 
possibility of a head on is minimised , then can be a useful tool, but there 
is no place for them on an intercapital main line like Brisbane to Perth.

CTC should be introduced all the way from Brisbane to Perth right now , even 
across the TAR.
Whilst there are many variants of CTC in differant states , and differant 
variants of it in the same state ,(contrast the Ne SG line with the Western SG 
line.),I beleive that with minor variations to the aspects displayed on some 
signals it would be possible to come up with uniform aspects and rules.
These aspects and rules may differant to what we currently have now in any 
state, but at least they would be the same.

All that is required to be done , is to answer a few really basic questions.
What information does a driver need to know when he is approaching a crossing 
loop on a CTC operated single track.

1/ He needs to know if he has a through run thru the loop via the main.
2/ If not 1/ then he needs to know if he is to take the main.
3/ If not 1/ He needs to know if he is to take the loop.(both these 
conditions require the train to slow down.)
4/ He needs to know if he should stop at the arrival signal.
5/ Anything other than 1 or 2 or 3 and we have an unusual condition that the 
driver would have to be informed about .

Personally , I am not in favor of speed signalling , where speeds are 
dictated by signals, as you require too many differant indications , speed 
boards are much better and cheaper.

TO indicate the above conditions we only need 
1/ A single green light to indicate condition 1/
2/ A single red light to indicate condition 4/
3/ A single yellow light to indicate condition 2/ 

Condition 3 is the more difficult one as it currently varies from State to 
State, and withing states, and requires for simplicity some minimum changes in 
the physical infrastructure which currently exist .

The above indications could currently be displayed on the CTC systems in WA.SA 
and VIC , although the NE std guage arrivals would need the yellow lenses 
re-installed.
NSW CTC arrivals cant display a single yellow and would have to modified.

To accomodate the indication that the loop road is set , without having to 
dream up another aspect which would require existing signal modification,
the obvious answer is the NSW system of a flashing yellow.
This is used in some places currently to indicate a turnout where the more 
common indication of the row of yellow lights is missing.

For loop departures , all that is needed is a single red or a single green, a 
la NSW.

Note that in the above , there is no such thing as the concept of a home 
signal , ie red over red, simply because all signals are defined as home 
signals, ie a single red means red over red.
The concept of an automatic, ie a red that you can pass at stop after a short 
dely would be abolished.
 
It wouldnt cost a heap of dough to do this , and at least we would end up with 
one system of safeworking on most of the interstate track.

cheers
MD