Approach control discussion (ex Chester FAQ)

beast66606 in post 133474 said:

Minor Bug :

For trains approaching Hooton which are to take the Ellesmere Port line, the sim holds the junction signal (209) to red whereas it's a free signal and will clear (provided the line is clear obviously) to either yellow or green as appropriate. I thought this may have been changed on the prototype when Hooton box was abolished and Chester took control (I moved out of the area 10 years ago now) but I've just had my son check it out (as he was in the area anyway) and sure enough 209 signal cleared to green with the feather, even though the Ellesmere Port train was still back at Bromborough Rake.

Thanks. looking at the line speed through the station throat area, it makes sense that approach control would be redundant here. Mantis 31920 for attention.

Speed is not the only factor in approach control. It is also used to give advance warning of a path to be taken at a junction, as in if the driver sees a green at the signal before the junction signal, and knows it's approach controlled for his/her expected route, then s/he can call it in before taking the route at line speed.

GeoffM in post 133490 said:

Speed is not the only factor in approach control. It is also used to give advance warning of a path to be taken at a junction, as in if the driver sees a green at the signal before the junction signal, and knows it's approach controlled for his/her expected route, then s/he can call it in before taking the route at line speed.

Is it? I know that drivers make use of that property (and I know at least one driver who used the flashing greens approaching Peterborough for the same purpose). But has approach control ever been designed in just for this purpose when not needed to slow the train down for the junction? That would seem to me to train drivers to not brake for the yellows because they "know" it's just a reminder; c.f. Colwich. Wasn't that why PRIs were invented?

<snip>

PRIs didn't come about until... late 1990s?

I thought the first one was on the Down Fast, sorry, "Main", approaching Airport Junction.

clive in post 133518 said:

I thought the first one was on the Down Fast, sorry, "Main", approaching Airport Junction.

Clive your first line description is perfectly correct, any decent naming convention will use fast and slow :p

Now time to grab coat and taxi before the Western clan lynch me ;-)

Paul

Now time to grab coat and taxi before the Western clan lynch me ;-)

No slow trains on the Western.

Stephen Fulcher in post 133529 said:

No slow trains on the Western.

You've clearly never ridden Looe to Liskeard.

Stephen Fulcher in post 133529 said:

No slow trains on the Western.

You've clearly never ridden Looe to Liskeard.

A key one was Colton Junction on the ECML, where a misrouted 91+Mk4s could find itself running out of wire at 125 mph, because there was no speed limit on either arm of the junction and the junction signal was hidden round a curve until it was far too late to stop at it.

A key one was Colton Junction on the ECML, where a misrouted 91+Mk4s could find itself running out of wire at 125 mph, because there was no speed limit on either arm of the junction and the junction signal was hidden round a curve until it was far too late to stop at it.

clive in post 133527 said:

A key one was Colton Junction on the ECML, where a misrouted 91+Mk4s could find itself running out of wire at 125 mph, because there was no speed limit on either arm of the junction and the junction signal was hidden round a curve until it was far too late to stop at it.

I suppose it wasn't an issue when the panel and junction was commissioned as there were no wires, although its a missed opportunity where the IECC was commissioned.

Stephen Fulcher in post 133529 said:

No slow trains on the Western.

You've clearly never ridden Looe to Liskeard.

Stephen Fulcher in post 133529 said:

No slow trains on the Western.

You've clearly never ridden Looe to Liskeard.

It was doing a signal sighting cab ride to Gunnislake that cost me the will to live