TfL’s Rail and London Underground Panel reports tomorrow on the Jubilee Line Upgrades and their status.
Their summary report is now online and makes for interesting reading both with regards to current timescales and some of the issues facing the commissioning of the new signalling system. Obviously the upcoming takeover of Tube Lines may mean a rethink of this report, but as things stand it remains a valid assessment of the current situation, and gives an interesting insight into the Commissioning process that Tube Lines felt needed to be utilised, and which may yet end up being put into practice.
Timescales and Extensions
The report makes stark reading in terms of delivery date slippage, with Tube Lines requesting additional closures in order to finish putting the Transmission Based Control Train Control (TBCT) system (which is intended to replace the current Tripcock based system) in place several times. Each time, assurances were given that this would mean the system would be delivered on time, and each time this did not prove to be the case.
Ultimately, as the report reveals (bolding ours):
Despite some furhter additional closures being provided, it soon became clear that there was no prospect of the upgrade being delivered by 31 December 2009. Finally, as the deadline approached, TLL offered a more realistic programme; in addition to the 113 weekend of closures already granted, TLL asked for a further 19 weekend closures and a further 14 “contingency” closures up to the start of October 2010.
Based on this new, more credible, programme, LU issued a Corrective Action Notice to TLL on 5 January 2010 requiring it to deliver the upgrade by 11 October 2010, more than nine months late, in line with its revised programme.
The indication is – assuming that the date is still valid (as is most likely the case) – therefore, that it is likely not until October that we will likely see the upgrade project finally finished at the earliest.
Milestone Creep and Ever-Increasing Risk
Arguably more interesting than the honest reporting that October is likely the earliest date for completion is the commentary the report provides on some of the issues facing the testing of the new signalling system and the disruption this may yet cause.
Originally, Tube Lines had proposed to test and commission the new system in four stages running east to west. This would reduce the risk a failure during rollout causing major disruption – not entirely unlikely given that at project commencement the Jubliee Line Upgrade represented the largest TBCT system attempted.
Between each of the stages, “system boundaries” would be created. These would allow trains to switch between using the existing Tripcock system on sections yet to be tested and commissioned to the new TBCT system where needed – effectively this would allow both signalling system to be used concurrently along the line, with units switching to the relevant system depending on which particular section they inhabited.
As time (and rollout delays) accrued, however, Tube Lines modified their approach. As milestones were missed, sections were combined in an attempt to ensure that the original December 2009 could still be met. Originally the plan had been to run J2 (east of Greenwich North) in a limited TBCT mode as a first step but by April 2009, Tube Lines had indicated that they were now looking to commission sections J23 together. By July, further amalgamation had taken place and the plan had become to commission J234 (everything up to Dollis Hill) in one go.
Obviously, as sections were combined, the inherent risk the rollout carried grew. Not a problem if the new system could be brought online with minimal issues, but a major issue should any problems manifest.
Unfortunately, the report indicates, it appears that they did indeed manifest. Despite limited success in trial runs over the J23 sections during the Christmas closure, issues emerged during a more extensive test covering J234 over Easter. Although the report doesn’t go into detail, a number of problems apparently manifested – including new issues at Stratford Market Depot and Neasden Control Centre.
These issues, combined with the fact that J5 – the most complex of the sections (it contains Stanmore’s third platform, Neasden Depot, and the “multi-mode” requirement with the Metropolitan Line) – has yet to be properly tested at all, have left the risk of continuing with the current massive multi-section rollout (with the full weekend closures it entails) too high – at least in Tube Lines’ current estimation.
As a result, the report indicates, Tube Lines have suggested that the best approach may be to return as much as possible to the original plan – commissioning in smaller stages.
As my colleague Mwmbwls might say, this would appear to be a return (if belated) to common sense. As seems to be the perpetual case with the Jubilee Upgrades, however, there is a bit of a hitch.
Breaking the Line
The simple fact is that, as Tube Lines fell behind in works and the plan was modified, one of the activities that was deemed surplus to requirements was the creation of the “system boundaries” mentioned towards the head of this article. At the time this arguably made sense – after all, if the plan was no longer to commission J2 and J3 seperately, why spend time and resource building a system boundary to allow differing signals operation between the two?
As a result, only one system boundary actually exists – that between J234 and J5. This means that whilst a return to the original commissioning plan may well be the correct decision, it now presents some serious practical issues – notably that it is not possible to run units across segments with differing active signal systems. To commission segments seperately (i.e. to avoid full weekend closures), a physical barrier needs to be created.
In effect, the line has to be split.
This, therefore, means that whilst things may have come almost full circle, and arguably returned to a commissioning approach that makes the most sense, it is not without cost.
Tube Lines recommend commissioning J23 (still a fair chunk of the line) and J45 seperately. If this comes to pass it will, therefore, likely mean no service either to or through Westminster at weekends. TBTC would then be implemented east of Waterloo (with services likely dropping from roughly 18 to 10 trains an hour on that section) and regular services run above Green Park. This situation would then be reversed once commissioning had been deemed successful.
Overall, therefore, the report is well worth a read – whilst it may need to be reworked and re-evaluated after Tube Lines impending takeover, it nonetheless still contains an interesting perspective on the current situation, and it throws an interesting light on the problems those upgrading the Jubilee Line will likely still face – be they Tube Lines or London Underground.
Whether we see a reduction in full weekend closures as a result of TfL’s impending buyout of the company remains to be seen. If we do though, it seems likely that this will not be without cost – the temporary splitting of the line. Whilst that may be an improvement, it will still not be a pain-free experience.
Comments are closed.