Arnos Grove station congestion

[Peregrine 4903]

As someone who has used Arnos Grove station my whole life, congestion and getting stuck at red signals when arriving into Arnos Grove into the eastbound direction has always been common. However since I started commuting again in October, every evening I get stuck at multiple red signals on the approach to Arnos Grove station and crawl into the station.

It seems to me the problem is a combination of terminating trains, and crew changeovers, blocking both of the eastbound platforms at Arnos Grove causing congestion. A particularly big issue I've seen recently is both platforms 1 and 2/3 being occupied by terminating eastbound services about to head westbound, meaning cockfosters trains have no platform they can use at Arnos Grove until one of those services has departed. Also terminating services using platform 1 causes a lot of delays as they have to cross the station throat.

Its no big deal, but I'm just wondering why its got worse recently, it may be that its timetable that way but I'm doubtful.

One thing I do wonder if that if London Underground has its own version of the Timetable Planning Rules perhaps a larger junction margin is needed there, but that's probably not the case.

 

[Surreytraveller]

Perhaps the train you're on is running early, due to fewer passengers, and is just waiting its booked slot into a platform

 

[bramling]

As someone who has used Arnos Grove station my whole life, congestion and getting stuck at red signals when arriving into Arnos Grove into the eastbound direction has always been common. However since I started commuting again in October, every evening I get stuck at multiple red signals on the approach to Arnos Grove station and crawl into the station.

It seems to me the problem is a combination of terminating trains, and crew changeovers, blocking both of the eastbound platforms at Arnos Grove causing congestion. A particularly big issue I've seen recently is both platforms 1 and 2/3 being occupied by terminating eastbound services about to head westbound, meaning cockfosters trains have no platform they can use at Arnos Grove until one of those services has departed. Also terminating services using platform 1 causes a lot of delays as they have to cross the station throat.

Its no big deal, but I'm just wondering why its got worse recently, it may be that its timetable that way but I'm doubtful.

One thing I do wonder if that if London Underground has its own version of the Timetable Planning Rules perhaps a larger junction margin is needed there, but that's probably not the case.

Multiple different issues coming together, unfortunately. Arnos is a crew relief point, and the Piccadilly Line was particularly heavily bitten by a concept in the 1990s called "superdepots", where there was a school of thought that each line would be best served by a small number of very large train crew depots. Whilst this brings in some level of efficiencies, the problem is that by definition you end up with massive numbers of crew reliefs, which makes things difficult to manage when there's problems. An associated problem is that a "superdepot" by definition is one which has a lot of drivers based there, and in order to house lots of drivers the depot needs to be physically large, space on that scale not being something typically found on the average station, so both Piccadilly Line depots ended up being sited some way from the platforms, which doesn't help when things go wrong as any sit down will be amplified by the time it takes for a fresh driver to walk from the depot to platform. Lessons have been learned from this, and new depots have opened in recent years at Northfields and Cockfosters, however Arnos is still a fairly large depot, and still has the legacy of being remote from the platforms. Add in the typical 1980s signalling designed for a time when passenger numbers were falling and it adds up to a sub-optimal setup.

 

[FOH]

Worst station for this on the network in my experience. The only time I've seen open revolt by passengers with feet jammed in the doors forcing train destination changes.

 

[Peregrine 4903]

Multiple different issues coming together, unfortunately. Arnos is a crew relief point, and the Piccadilly Line was particularly heavily bitten by a concept in the 1990s called "superdepots", where there was a school of thought that each line would be best served by a small number of very large train crew depots. Whilst this brings in some level of efficiencies, the problem is that by definition you end up with massive numbers of crew reliefs, which makes things difficult to manage when there's problems. An associated problem is that a "superdepot" by definition is one which has a lot of drivers based there, and in order to house lots of drivers the depot needs to be physically large, space on that scale not being something typically found on the average station, so both Piccadilly Line depots ended up being sited some way from the platforms, which doesn't help when things go wrong as any sit down will be amplified by the time it takes for a fresh driver to walk from the depot to platform. Lessons have been learned from this, and new depots have opened in recent years at Northfields and Cockfosters, however Arnos is still a fairly large depot, and still has the legacy of being remote from the platforms. Add in the typical 1980s signalling designed for a time when passenger numbers were falling and it adds up to a sub-optimal setup.

Thankyou for your response. Crew changes have always caused delays from what I can remember, but its really interesting to hear the background behind why the crew changes cause delays.

I do think the timetabling could be better, today I had delays again because Platform 1 and 2/2 were occupied by westbound services, meaning there is no available platform for eastbound services to arrive at Arnos Grove until one of those trains has departed.

 

[philthetube]

This would not be timetabling, this would be a stuck train either for a defect or lack of driver, or possibly something to do with a passenger, illness perhaps.

 

[Mojo]

Lessons have been learned from this, and new depots have opened in recent years at Northfields and Cockfosters, however Arnos is still a fairly large depot, and still has the legacy of being remote from the platforms.

Even though the depots at Northfields and Cockfosters have (re)opened it still suffers from the problem that the majority of pick ups are still at Acton and Arnos.

I'm sure you are well aware but for the benefit of others, a particular problem is with second half pick ups after meal relief, the majority of these for the line are at Acton or Arnos but pose the biggest risks in the event of late running whereby the first train is running late meaning the Train Operator doesn't have time to have their meal relief and be in position for their second pick up.

 

[Peregrine 4903]

This would not be timetabling, this would be a stuck train either for a defect or lack of driver, or possibly something to do with a passenger, illness perhaps.

I don't think it is, but as someone who uses the station everyday, delays are happening everyday at the minute, and at least twice a week two terminating trains are blocking both of the eastbound platforms at Arnos Grove.

 

[LU_timetabler]

Definitely not timetabling, reversing trains at Arnos Grove are, I believe at about 10 mins apart in the timetable. In the morning and evening peaks the Arnos reversals are even "stepped-back"; in other words the driver arriving reverses onto the train 1 behind the one they arrived in. Of course with absent train crew due to the pandemic, it maybe that the driver has to take the reversing train, or indeed to start the stepping back process is not there, meaning the driver has to take their own train back, this slows the reverse, possibly making it late, and then you get a hold-up. Also driver shortages may also be causing trains to reverse short of their timetabled destination in order to maintain a good service in the central section. Also a favourite crew change is to take over a Arnos reversing train. If the crew to do this are either absent due to COVID or late arriving for their meal break, then you would get a blockage. Often times the fact there is no driver to take over the train is a problem, because what you really then want is the driver going off shift to shunt the train to Arnos Grove sidings. If you don't request this before they arrive, chances are the driver will have gone, probably via the station main entrance, rather than via the depot, so no way to catch them for the shunt. These are all possible scenarios, but certainly nothing to do with the timetables themselves.

 

[bluegoblin7]

In the morning and evening peaks the Arnos reversals are even "stepped-back"; in other words the driver arriving reverses onto the train 1 behind the one he arrived in.

Do female or non-binary drivers never step-back then?

Extremely disappointing to see such exclusionary language from someone who clearly identifies themselves as an LUL employee.

 

[bramling]

Definitely not timetabling, reversing trains at Arnos Grove are, I believe at about 10 mins apart in the timetable. In the morning and evening peaks the Arnos reversals are even "stepped-back"; in other words the driver arriving reverses onto the train 1 behind the one he arrived in. Of course with absent train crew due to the pandemic, it maybe that the driver to take the reversing train, or indeed to start the stepping back process is not there, meaning the driver has to take his own train back, this slows the reverse, possibly making it late, and then you get a hold-up. Also driver shortages may also be causing trains to reverse short of their timetabled destination in order to maintain a good service in the central section. Also a favourite crew change is to take over a Arnos reversing train. If the crew to do this are either absent due to COVID or late arriving for their meal break, then you would get a blockage. Often times the fact there is no driver to take over the train is a problem, because what you really then want is the driver going off shift to shunt the train to Arnos Grove sidings. If you don't request this before they arrive, chances are the driver will have gone, probably via the station main entrance, rather than via the depot, so no way to catch them for the shunt. These are all possible scenarios, but certainly nothing to do with the timetables themselves.

Yes I would imagine it’s the case the Arnos would function with no issues if everything managed to keep to the timetable.

The difficulty seems to be that it doesn’t take it to go very far “off book” before the issues with the local setup and layout start to amplify and multiply issues. By contrast most other locations have enough in reserve that disruption can be contained or even recovered.

Blocking back can happen through any crew relief point in the right circumstances, however at Arnos it’s certainly the case that it happens much more readily, especially on the eastbound. It happened even more readily with some of the more ambitious off-peak services attempted in the past - the 1996 (?) timetable was a particular example, I think this came at roughly the same time as the larger depots?

 

[LU_timetabler]

Do female or non-binary drivers never step-back then?

Extremely disappointing to see such exclusionary language from someone who clearly identifies themselves as an LUL employee.

Fixed! My apologies, it was very late.

 

[Val3ntine]

Do female or non-binary drivers never step-back then?

Extremely disappointing to see such exclusionary language from someone who clearly identifies themselves as an LUL employee.

Clearly wasn’t intentional to be fair, no need for such an attack. A simple note or correction was all that was needed.

 

[hermit]

I’m surprised there’s been little mention of the consequences of all this for the poor passengers simply wanting to know which is the next train into town. My use of the station goes back to the 50s, and there has always been a problem with platform indicators showing nothing or getting it wrong. Mad last-minute dashes across the bridge to another platform are often necessary, and there have been dozens of occasions when trains have departed empty leaving frustrated would-be passengers fuming on the wrong platform.
Having read the above comments, I now have more understanding of why this happens!

 

[Mojo]

I’m surprised there’s been little mention of the consequences of all this for the poor passengers simply wanting to know which is the next train into town. My use of the station goes back to the 50s, and there has always been a problem with platform indicators showing nothing or getting it wrong. Mad last-minute dashes across the bridge to another platform are often necessary, and there have been dozens of occasions when trains have departed empty leaving frustrated would-be passengers fuming on the wrong platform.
Having read the above comments, I now have more understanding of why this happens!

Hopefully this should have gotten better since 2017-18 as the signalling control system was upgraded so the boards should be more accurate; this still however won’t be fully accurate if the signaller has manually cleared a train to depart however.

 

[bramling]

I’m surprised there’s been little mention of the consequences of all this for the poor passengers simply wanting to know which is the next train into town. My use of the station goes back to the 50s, and there has always been a problem with platform indicators showing nothing or getting it wrong. Mad last-minute dashes across the bridge to another platform are often necessary, and there have been dozens of occasions when trains have departed empty leaving frustrated would-be passengers fuming on the wrong platform.
Having read the above comments, I now have more understanding of why this happens!

To be fair this happens at many crew relief locations, as this introduces an element of volatility to train movements.

In older times there would have been a dedicated signalman in a local cabin looking after each location, making dissemination of information easier, however on LU nowadays it’s typical for one person to oversee multiple sites, so information suffers accordingly especially during disruption. I’m not sure this is something which will ever change - an informed passenger will always have a better journey experience.