Slade Lane Junction lack of flashing aspects

[323235]

Hi,
I don't believe this has changed recently but feel free to interject if it has, I was curious as to why Slade Lane Junction Up Fast-Up Slow (Stockport) has always lacked flashing aspects. It has always seemed an ideal candidate for such a move.

I can only thing (not being an expert in how these decisions are made) that some level of risk assessment have deemed it inappropriate.

 

[Tomnick]

Hi,
I don't believe this has changed recently but feel free to interject if it has, I was curious as to why Slade Lane Junction Up Fast-Up Slow (Stockport) has always lacked flashing aspects. It has always seemed an ideal candidate for such a move.

I can only thing (not being an expert in how these decisions are made) that some level of risk assessment have deemed it inappropriate.

Possibly the standards didn’t allow it at the time that the signalling was commissioned (they used to be a lot more restrictive), and a change since then has never been justified - it’d involve a fair bit of design work. It’d certainly be helpful, but it doesn’t really cost you a great deal of time, especially given that most trains using it are fairly nippy multiple units and that the signal comes off in good time. The same goes for the crossovers both ways in the Down direction - if anything, they’d benefit from it more, I’d say, but that’s subject to getting a decent run through there which is a rarity in normal times at least!

 

[MadMac]

The whole idea was to give advance notice of a junction being set and let drivers take maximum advantage of whatever the permitted speed was. There was one instance on, I think, ECML where it was an equal speed junction with one electrified and the other not to avoid misrouting of an electric service.

I think they, to some extent, fell out of favour post-Colwich, although that looked to be a trap waiting for someone to fall into it.

 

[Aictos]

The whole idea was to give advance notice of a junction being set and let drivers take maximum advantage of whatever the permitted speed was. There was one instance on, I think, ECML where it was an equal speed junction with one electrified and the other not to avoid misrouting of an electric service.

I think they, to some extent, fell out of favour post-Colwich, although that looked to be a trap waiting for someone to fall into it.

Indeed Huntingdon North Junction has that for southbound services with flashing yellows indicating you're being routed onto the Up Slow and I believe the same applies at Fletton for northbound services approaching Peterborough to indicate you're being routed onto the Down Slow.

 

[The Planner]

I think they, to some extent, fell out of favour post-Colwich, although that looked to be a trap waiting for someone to fall into it.

Plenty of them get put in on resignalling schemes.

 

[Bald Rick]

It’s a non-trivial exercise changing the interlocking for this, particularly if it is a relay interlocking (I’m not sure what Slade Lane interlocking is).

How many trains make the move - 2 an hour?

 

[323235]

It’s a non-trivial exercise changing the interlocking for this, particularly if it is a relay interlocking (I’m not sure what Slade Lane interlocking is).

How many trains make the move - 2 an hour?

Just looking on RTT I've counted 7 trains per hour during the day on a typical weekday between 11am-12pm.

 

[Bald Rick]

Just looking on RTT I've counted 7 trains per hour during the day on a typical weekday between 11am-12pm.

Going fast to slow? It should only be those starting at Piccadilly, everything else will be slow - slow.

 

[323235]

Now revised to 5 as interestingly the Blackpool - Hazel Grove is booked for FL from Piccadilly to Slade Lane although that doesn't sound like normal practice - certainly pre-May 2018 (I don't use the service frequently). I can't recall what happened a few months ago when I did a 331 on that service.

 

[edwin_m]

Anything going from Piccadilly platform 13 via Hazel Grove has to get across somewhere, but where that happens will depend on conflicting moves taking place at the time. It's also likely to be adjusted by the signaler if the train is running late (as is usually the case!).

 

[Llama]

Now revised to 5 as interestingly the Blackpool - Hazel Grove is booked for FL from Piccadilly to Slade Lane although that doesn't sound like normal practice - certainly pre-May 2018 (I don't use the service frequently). I can't recall what happened a few months ago when I did a 331 on that service.

More often than not I find I tend to get put fast line before Slade Lane on a BPN-Hazel Grove.

 

[323235]

More often than not I find I tend to get put fast line before Slade Lane on a BPN-Hazel Grove.

Interesting so it is the routing they usually take!

Is that to avoid clogging up Slade Lane, as just thinking about it some service groups have a bit of slack between Piccadilly and Levenshume so perhaps it makes sense for them to stay on the fast out of the way?

 

[Ianno87]

Interesting so it is the routing they usually take!

Is that to avoid clogging up Slade Lane, as just thinking about it some service groups have a bit of slack between Piccadilly and Levenshume so perhaps it makes sense for them to stay on the fast out of the way?

It'll be the case that there just happens to be somethimg coming the other way at the same time at Slade Lane, but not at Piccadilly throat.

 

[Tomnick]

It'll be the case that there just happens to be somethimg coming the other way at the same time at Slade Lane, but not at Piccadilly throat.

Exactly. The Norwich service is invariably booked slow line to Slade Lane, where there’s a gap in Down trains. If it’s a few minutes late, there’s a good chance that it’ll be put out fast line straight from P13 instead, or cross over at Ardwick, utilising the same gap on the Down Fast. For the most part, Picc signalmen do a cracking job of making the most of the layout there.