Why do Jubilee line trains often stop just outside Stratford?

[brookzy]

Perhaps I've just been unlucky, but it seems common to pause for a couple of minutes on the approach to Stratford. We move again when a train passes by westbound, so I assume we're waiting for a platform?

But when we do arrive, it turns out there was a spare platform regardless.

Why does this happen? I care because it usually means I miss my desired GA connection by seconds...

And while I'm on it, is the Jubilee line getting slower in general these days? Citymapper always seems very optimistic on journey times, but of course may well be a data issue on their end.

 

[Via Bank]

There’s a staff halt outside the station throat which I believe serves the depot.

 

[MCR247]

Perhaps I've just been unlucky, but it seems common to pause for a couple of minutes on the approach to Stratford. We move again when a train passes by westbound, so I assume we're waiting for a platform?

But when we do arrive, it turns out there was a spare platform regardless.

Why does this happen? I care because it usually means I miss my desired GA connection by seconds...

And while I'm on it, is the Jubilee line getting slower in general these days? Citymapper always seems very optimistic on journey times, but of course may well be a data issue on their end.

They prefer to use the island platforms off peak as I assume it’s more efficient for drivers of the return runs

 

[Flying Snail]

Just because there is a spare platform doesn't mean there is an available path to it. If the outgoing train is a conflicting move your train will have to wait for it to pass or it will have to wait for yours to clear the points.

 

[Dstock7080]

They prefer to use the island platforms off peak as I assume it’s more efficient for drivers of the return runs

There are no scheduled trains into platform 13, M-F 0725-2255. Has been closed since May 2018.

 

[notverydeep]

Stratford Jubilee mostly operates like a two track terminus, with Train Operators 'stepping back'. Stepping back is where arriving Train Operator alights and a new Train Operator boards, with the arriving operator changing ends to board a subsequent departure (usually on the same platform). The two platforms (14 and 15) normally used form an island, so mostly passengers to go to the same place and be assured of catching the indicated next train. Platform 13 is normally only used by trains from Stratford Market Depot going into service at the start of the day or trains stabling there at the end of the day.

The reoccupation sequence has two moves conflicting for the first pair of trains followed by two parallel moves for the second pair of trains. The time required for the conflicting moves is only just less than the headway at 30 trains per hour (tph), so there is little recovery available during the layover (which will be roughly the same amount of time as the arriving and departing headway). In consequence, to preserve some recovery, some additional time is normally scheduled on the approach and the reoccupation time from rest is usually a little shorter than reoccupation from line speed as the latter starts at the point the arriving train would have to commence braking for the 'home' signal - in Jubilee line signalling with Automatic Train Operation (ATO) the last point it can stop before the confliction point. What this means is that you can expect to be (and are timetabled to be) held outside briefly on most approaches to Stratford, especially at peak times.

 

[Taunton]

The 30 trains per hour is the core frequency, but about one in four at peaks turns short at North Greenwich. I know these short workings seem to come and go over time, but at the moment they are certainly happening. So maybe 24 trains per hour at Stratford.

Inbound trains crossing over to platform 15 can come right up to the crossover point without needing an overlap, as the track straight ahead to the now unused platform 13 provides them with flank protection for an overrun.

Two platforms in use instead of three, just one island, is a bit of an upside for passengers, as particularly poor signing of which is the next train regularly saw passengers not understanding which train was next to depart. It shouldn't be difficult to provide an intuitive sign there, but seems to have defeated the station operator for the last 23 years since the Jubilee opened.

 

[MCR247]

Another advantage of using the island platform is that it makes it much easier for passengers when trains are swapped.

There are times you’ll walk on to the platform with a train waiting but the next train to depart will actually be on that is yet to arrive. People will board the one waiting in the platform and assuming it has a driver onboard he’ll announce that the train on the other side will be departing first

 

[notverydeep]

The 30 trains per hour is the core frequency, but about one in four at peaks turns short at North Greenwich. I know these short workings seem to come and go over time, but at the moment they are certainly happening. So maybe 24 trains per hour at Stratford.

With passenger numbers reaching numbers equivalent to Central London, the 30 tph peak service was extended to Stratford with Working Timetable (WTT) 16 in March 2020. Since then North Greenwich reversing has been limited to the service start and end plus ramp up and ramp down to / from the peak 30 tph level.

WTT18 on Mondays to Fridays has four North Greenwich starters between 0656 and 0733, with 30 tph to Stratford until ten further reversers between 0936 and 1126. In the afternoon there are 11 between 1453 and 1651 with 30 tph to Stratford until the six reversers between 1910 and 2012. The standard off peak 24 tph patterns have no North Greenwich reversers. Those North Greenwich reversers that remain free up paths between Stratford Market Depot (SMD) and Stratford, or allow a detrainment stand at West Ham for a train stabling at SMD via the 'west' (actually south) entrance.

 

[Mojo]

WTT18 on Mondays to Fridays has four North Greenwich starters between 0656 and 0733, with 30 tph to Stratford until ten further reversers between 0936 and 1126. In the afternoon there are 11 between 1453 and 1651 with 30 tph to Stratford until the six reversers between 1910 and 2012. The standard off peak 24 tph patterns have no North Greenwich reversers. Those North Greenwich reversers that remain free up paths between Stratford Market Depot (SMD) and Stratford, or allow a detrainment stand at West Ham for a train stabling at SMD via the 'west' (actually south) entrance.

It’s worth pointing out that the WTT you have linked to is not the current service operating on the Jubilee line. Since May, the service has been subject to Timetable Notice (TTN) 82/13 which has a number of trains withdrawn and other slight service alterations to take account of the long term stock unavailability.

This means that there are only three North Greenwich starters in the morning period, and similarly means Stratford has lost a couple of services.

 

[notverydeep]

It’s worth pointing out that the WTT you have linked to is not the current service operating on the Jubilee line. Since May, the service has been subject to Timetable Notice (TTN) 82/13 which has a number of trains withdrawn and other slight service alterations to take account of the long term stock unavailability.

This means that there are only three North Greenwich starters in the morning period, and similarly means Stratford has lost a couple of services.

Yes, these planned cancellations are to account for various projects impacting the Jubilee fleet including long term works related to the coupler issues discovered in 2019 and also Heavy Overhauls plus some other projects / issues. This TTN doesn't appear to be on the TfL website, hence my referring to WTT18 (which remains accessible). Journey Planner will give times associated with TTN87/23 though. The impact on frequencies is a bit varied, but it does still reach a scheduled 28 trains in an hour at Stratford in both the morning peak and evening peak.

 

[2192]

Another advantage of using the island platform is that it makes it much easier for passengers when trains are swapped.

There are times you’ll walk on to the platform with a train waiting but the next train to depart will actually be on that is yet to arrive. People will board the one waiting in the platform and assuming it has a driver onboard he’ll announce that the train on the other side will be departing first

Can't the driver lock the doors and turn the lights out on the train that is not the first to depart?

 

[rebmcr]

Can't the driver lock the doors and turn the lights out on the train that is not the first to depart?

People begin boarding while there are still a few stragglers yet to alight.

 

[Peter Mugridge]

People begin boarding while there are still a few stragglers yet to alight.

...and if it's busy and I'm going more than a few stops, I'll often get the second train while the first is still in the station simply so I can sit down.

 

[Benjwri]

Can't the driver lock the doors and turn the lights out on the train that is not the first to depart?

Not without staff clearing the train of passengers first, which on a non walkthrough train takes a fair while and a fair few staff members when an announcement will suffice.

 

[Taunton]

I must be just unlucky then in finding these odd reversers in the early afternoon peak (including this week) coincide with my travels, including finding we stop in the tunnel halfway to NG because the reverser ahead is waiting for the previous reverser to clear the platform. Possibly they increase on days the service has been disrupted. I presume North Greenwich is only used for Neasden drivers.

 

[Dstock7080]

I presume North Greenwich is only used for Neasden drivers.

All depots work trains into North Greenwich platform 2.
The Jubilee only has Wembley Park, North Greenwich and Stratford as train staff depots.

 

[Taunton]

I'm sure all can/do. But for logistics, especially recovering from disruption, it doubtless suits trains crewed from the west end of the line.

 

[notverydeep]

I must be just unlucky then in finding these odd reversers in the early afternoon peak (including this week) coincide with my travels, including finding we stop in the tunnel halfway to NG because the reverser ahead is waiting for the previous reverser to clear the platform. Possibly they increase on days the service has been disrupted. I presume North Greenwich is only used for Neasden drivers.

The shortest platform 2 Westbound Departure to Eastbound (terminating) arrival is two minutes (0949 to 0951), the rest are at least 2 mins 45 seconds (four more trains) or more. Excluding widely separated reversals, the average is slightly more than 4 minutes. I would be interested to know what time this is regularly occurring, so I can identify which reversers are encountering this or whether it is because there are unscheduled reversals occuring, perhaps to recover from disruption.

Most of the reversers will see the Train Operator change ends. There is a train crew depot at North Greenwich itself, but in truth the reversers there could be Stratford or Wembley Park crews also. By the way, it is Metropolitan train crews that have a depot at Neasden, whereas Jubilee are Wembley Park (the building adjacent to the North end of platform 1). There are also (though not many) changes of crew on the through platforms at North Greenwich, though none are scheduled at peak times. Many changeovers for North Greenwich crews now occur at Stratford.

 

[brookzy]

Thank you all for your knowledge and informative responses.