The Jubilee Line

Those travelling on the Jubilee Line since Christmas will have noticed that its trains have developed a strange habit of repeating themselves.

The new habit of doubly announcing stations is one of the subtle signs that the new signals system has entered passenger service – one announcement is triggered by the new TBTC system, the other by the standard Train Management System, the software for which has yet to be updated.

For those whose knowledge of the Jubilee’s signalling extends little beyond the fact that its replacement has caused a significant percentage of the closures on the London Underground in recent years, it is probably worth a short recap.

The Jubilee Line is currently being switched to an Automatic Train Operation (ATO) system. Contrary, perhaps, to the perception perpetrated by certain Mansion House speakers in recent weeks, this does not mean that the Jubilee Line can become “driverless.” Although the SelTrac system being installed is an evolution of that found on the DLR, true driverless trains are simply not possible on the current London Underground at present for a number of reasons. Instead, the goal on the Jubilee is to replicate the situation found on the Central Line and Victoria, where Train Operators are present but the train’s systems effectively carry the responsibility for the majority of driving tasks. This allows trains to be run faster and closer together, increasing the frequency of services – something which is the ultimate goal on the Jubilee (where journey time decreases of up to 20% and increased frequency of up to 30% are the goal).

Signalling has had a checkered history on the Jubilee Line, and thus to a certain extent it is no surprise that the current project has been fraught with difficulty. Political and financial pressures during the line’s construction and early years resulted in a patchwork of traditional LU signalling and proto-ATO Westinghouse modifications that needed to be addressed, as well as some complex depot integrations and the need to maintain a link with both the Metropolitan and Bakerloo lines. An already complex problem was made worse by the presence of Platform Edge Doors (PEDs) on the (somewhat rushed) Jubilee Line extension and repeated management upheaval both within LU throughout the nineties and with the arrival of the Public Private Partnership.

This left Tube Lines responsible for the upgrade along with their new signalling contractor Thales, an exercise that it is fair to say largely ended in disaster. The project has massively overrun (it was originally due to be delivered in 2009), has caused significantly more closures than intended, and has ultimately resulted in a system with frustratingly little options for testing and implementation that does not carry the risk of disrupting vast swathes of the Line if anything goes wrong. It has been, to steal a truly groan-worthy pun from a messageboard an “Epic Thale.”

Given all the above, it is perhaps unsurprising that it was the Jubilee Line that was a major contributor to Tube Lines’ ultimate failure as a private company, it now having been bought out by TfL who have once again taken over ultimate responsibility for the project.

Broadly speaking, the rollout now appears to be going well (or at least apparently well enough for TfL to feel brave enough to put a press release out). The new signals system has been running in passenger service since the end of last year, and currently all trains running between Stratford and Dollis Hill use it (with the exception of the occasional defective train).

There have been failures, but so far these have rarely been major and at no point has the “plan b” option of reverting to the original signalling system (which is obviously still in place on all trains) been close to being implemented. Indeed, it seems likely that this is not really even a realistic option now, given the length of time for which the new system has been running.

We’ve talked before about the idea of the bath tub curve – the concept that all systems have a high failure rate at the beginning of their lifespan as problems are ironed out, and so far the Jubilee’s performance has been broadly speaking in line with that. This is obviously of little comfort to those caught in those disruptions, but so far it appears that the system is reasonably robust. One of the few persisting major issues appears to be occasional failures south of Canary Wharf, which are currently being investigated.

In terms of actual train performance, one other side effect of the new system appears to be an increased stop/start nature to train traction (as the train repeatedly accelerates/coasts to try and keep to a target speed). This often isn’t hugely noticeable, but it is an issue nonetheless (although one that may disappear once full conversation and new timetables come into force), and one wonders what long term effects this might cause in wear-and-tear terms.

Ultimately, of course, the new signalling means nothing until passengers can see the improvements, and that is still some way off as timetable changes (to make use of the increased frequency possibilities) cannot be implemented until the system is fully implemented everywhere and bedded in. Interestingly, there have been some hidden benefits already though – although somewhat ironically these only manifest when problems occur. These are in the amount of time it takes to recover the service, which do seem to generally be improved since the rollout (the ability to soft-reset the whole system in five minutes also probably helps with this).

TfL’s press release now talks of a spring completion date for the rollout, but doesn’t get more specific  than that. It also fails to dwell on the fact that the remaining implementation north of Dollis Hill is arguably the most complex part of all.

Luckily more, less PR-heavy, detail – including a pessimistic option – can be found in the words of London Underground MD Mike Brown, who was up before the London Assembly Transport Committee yesterday. A transcript of his exchange with Val Shawcross, the Committee Chair is below.

Val: Mike, When do you think the Jubilee Line upgrades will be completed?

We’ve been told Spring. So…

Mike: Well the remaining part of the Jubilee Line is scheduled for the spring.

Val: What does spring mean? Give us a month.

Mike: Well the reason I say spring, Chair, is because the complexity of the final bit, which is the bit between Dollis Hill and Neasden is, as I think I have said before to this committee and certainly in public, is the complexity of the interface with the metropolitan line.

Val: Well what’s your most pessimistic projection at the moment?

Mike: I am absolutely convinced it’ll be the first half of this year, but I am determined it will be the spring. But, you know, let me put this into context this programme was nowhere – nowhere – when we inherited it so I am absolutely confident that we’ve turned it around, that we’ve got a good relationship with the supplier, and that we will deliver the benefits of this upgrade.

[…]

Val: Are we talking April? May?

Mike: Well yes that’s the Spring to my reckoning so April/May, could be as late as June but I am confident we will get it delivered.

The Sub-Surface Lines

Mike Brown also talked to the committee about progress on various London Underground projects elsewhere, which yielded some useful information.

Firstly, although no precise date was given, he confirmed that the Metropolitan Line will shortly begin running S-Stock services beyond Baker Street to Aldgate on the North Circle.

He also confirmed that following on from the successful Hammersmith and City blockade last summer, this is now an option that LU will consider where it’s appropriate for civil engineering work (the SSL signalling contract, which is currently being tendered, actually has a “no closures” clause included in it) and where other transport connections can pick up the majority of the slack. He confirmed that this summer will see a block closure between Edgware Road and High Street Kensington along the same lines as the Hammersmith and City Blockade.

Although not exactly “news,” he also once again touched on some of the difficulties in both maintaining and upgrading a line where some of the infrastructure has, genuinely, been in place since the end of the nineteenth century:

One of the great challenges we have at the moment, and I don’t want to over dramatise this because they are safe and they are a credit to our forebears, but there are some parts of this equipment that are not really maintainable at the moment – you have to wait for a failure to occur.

The reason for that is not only is every replacement component bespoke to its manufacturer, but also some of the condition of the wires and the wiring around these complex signal cabins – Edgware Road being a good example – is so fragile that maintaining it in itself is likely to cause a failure. Now these things fail safe, and failing safe in signalling terms means a red signal. Not good, but we are continuing to drive all our effort on those critical junctions – Edgware Road being a very critical one obviously for the Circle and Hammersmith and City lines so absolutely we’ll keep on top of that.

Victoria Line

As is public knowledge, the Victoria Line upgrades performed less-than-stellarly in the lead up to Christmas. This was something Brown acknowledged and whilst again that won’t bring comfort to passengers affected by disruption, he did confirm that performance was now up to the levels they expected with the new stock outperforming the old for the very first time last month.

Interestingly, Brown provided confirmation that one of the major issues causing train failures has been in relation to the sensitive edge doors on the new stock. He confirmed that analysis had shown that the majority of the problems were being caused by the doors being overly sensitive to pressure inside rather than out, and that the software had now been altered in relation to this. As it stands, a full switch over to new stock and the beginning of the process of removing the old signalling is now on course for May. Following on from that, it seems likely that the first noticeable improvements in times and frequency will therefore manifest at the end of the year when timetable changes can be made.

Unsurprisingly, Brown’s overall perspective on the Victoria’s issues seemed to mirror that of Peter Hendy in recent months – that the new stock simply wasn’t tested extensively enough by Metronet and were rushed into service. It’ll be interesting to see whether those lessons stay learned when TfL itself has to tender for new stock on the Bakerloo and Piccadilly Lines.

Northern Line

Finally, Mike Brown also made several comments on the progress of the Northern Line Upgrades. These have now officially begun, although they are at an early stage. He confirmed that a significant amount of preparatory work had taken place at Kennington over Christmas and that the basis for a commercial and delivery plan for signalling was in place with prospective suppliers. He is likely to make his own recommendations on this in the coming weeks, with a decision then reached on delivery.

Importantly, he confirmed that, as with the SSL, the plan is to have a “no non-civils closures” policy in place for the Northern Line as well:

There is absolutely no question that you’re not going to get anything like the closure regime we saw on the Jubilee Line. That is something that is unacceptable.

He also confirmed that block closures may be considered on the Northern as well (which makes sense as the nature of the line does seem to lend itself to sequential closures), but again these would be limited to places where other options were practical. Hopefully, therefore, that residents of Kennington are unlikely to find themselves suddenly Tube-less for three weeks at a time.

And Finally…

Whilst it is not strictly related to the upgrades, it seems worth mentioning that the Mayor’s recent, slightly misleading, comments at Mansion House have had the unfortunate effect of renewing the Conservative Assembly Members’ zeal for a fully automated transport future, and unfortunately Brown found himself (eventually) on the end of a question from Richard Tracey on the subject.

A full transcript of the exchange is provided below for the sake of completeness, but those who would prefer a short version can skip straight to the summary below it.

Richard: The Mayor himself spoke at Mansion House – what two or three weeks ago? – about the potential for driverless trains, so tell us, Mike, can I ask you to say, from your position – what is the scope for the driverless train and indeed TfL obviously must be supportive of the research of this for the Mayor, as the Mayor has said it as the Chairman of TfL. Can you give us your view on the scope for driverless trains?

Mike: I think, Chair, if I may, that the reality is that all the new trains we’re currently procuring and which are arriving in London for the Victoria Line and on the Subsurface Lines do have train cabs where a driver would live. So my absolute focus is to ensure delivery and operability of those trains in the best way possible and aligned with the new signalling systems.

Clearly if you look in the wider part of my domain now and look at DLR and other parts of the system there are examples where different solutions have been proposed and indeed have operated…

Richard: In Many parts of the world.

Mike: …And in many parts of the world. I think where I come from in this is put very simply – I think that the role and confidence that comes in having a properly trained and fully fledged member of staff on our trains throughout the underground network – the confidence it brings to passengers, the ability to keep things moving if things might get delayed, dealing with passenger issues and safety issues – is really important. So I think any debate on this going forward as to what we might do, hypothetically, and in a future train procurement process has to have that very much in the centre of our thinking and I will do so.

Or to summarise:

Richard: Is it possible to have driverless trains on the Underground?

Mike: No.

Written by John Bull