Jubilee Line suspension and DLR service disruption Friday 4 February 2011

Jubilee Line

Signalling system problems in the North Greenwich area resulted in three trains becoming stalled (held between stations) between Canada Water and Canary Wharf stations on the Jubilee Line. Each train held approximately 900 customers. All trains were moved into platforms within 63 minutes.

London Underground staff, BTP and London Ambulance Service were all on site at both Canada Water and Canary Wharf stations to assist customers. Water was also despatched to site. 5 people received medical attention, 3 for heat and 1 for anxiety and a pregnant customer experiencing abdominal pains. 2 customers went to hospital, one of which was the pregnant customer who was taken as a precaution.

Also as a consequence of this incident overcrowding and some other station closures were experienced on adjacent parts of the network. A more detailed timeline for the incident is shown as appendix 1.

DLR

The DLR had a points failure near Bank at 06.20 and also had a train that was unable to communicate with its signalling system at All Saints at 08.10. It also had a further signal failure at 09.30 at Canary Wharf. These issues were unrelated to the Jubilee line failure but clearly meant that Canary Wharf was very isolated from a public transport perspective.

The causes of these three failures are under investigation by Serco and are not yet fully concluded. Although the DLR is generally reliable there have been a few more incidents recently and we have become more concerned about how Serco are performing. They have changed some of their management team at senior level – even in the last few days they have appointed a new very experienced Engineering Director. In addition all possible contractual measures and pressures are being applied to them.

Cause of Jubilee line incident

From approximately 0700 a number of Jubilee line trains came to a halt when they lost contact with the new signalling system (the trains did not pass their unique identification to the main signal computer).

The new signalling system relies on very accurate train position information. It would seem that some trains experienced momentary wheel spin in the area. This signalling system is much more sensitive to such an issue than other more conventional systems would be. Indeed on a conventional system a failure would probably not have occurred. It is not yet clear as to why the wheel spin occurred. However there could have been some traces of grease on the tracks. Regardless of the final conclusion immediate processes are in place to provide further checks of rails for any grease deposits.

With the new signalling system (moving block) the location of each train is pinpointed by a computer on the train that matches up with the main computer at the control centre. Once these could not be reconciled the system went into “fail safe” mode as it should do, to avoid any collision risk.

The movement of the trains to the platforms could have been quicker had there been bi- directional signalling on the line. This capability was, however, removed from the signal system specification several years ago by the PPP contractor, despite huge protest by London Underground.

Actions Arising from Jubilee line failure

There are a number of actions underway to prevent or mitigate this type of incident and to improve operational response. These include:

• Software implementation to reduce incidence of non-communicating trains; • Exploration of and early warning alarm system for this type of incident; • A better means of preventing and detecting wheel slip incidents to be developed; • Additional technical resources to be positioned at Canada Water and London Bridge to improve response times; • Further training to LU control staff dealing with such problems in the context of the new signalling system; • A desk-top exercise to be commissioned to further test and improve cross-functional operational response; • Review of operational rules requiring securing of points; • Further exploration of how other railway operators deal with similar situations; • Review of operational arrangements at Bank to improve response to Jubilee line incidents; • A weekly call to be set up with the supply chain involving the MD.

Recent Performance

A summary of recent Jubilee line runtime performance showing post transmission based signalling control (TBTC) implementation against the average pre TBTC performance is shown as appendix 2. This shows that over recent weeks there has been a steady improvement in run times although recent days’ performance has not been good Appendix 1

Jubilee line Incident Timeline

07.08 First sign of a problem when train eastbound train 322 overran the platform at North Greenwich. Train 310 immediately behind it become non-communicating (stops sending information to the signalling system regarding its location and status) on approach to the platform.

07.20 Line goes to severe delays as more trains go to non-communicating status.

07.30 Reports that rail adhesion/wheel spin problem in vicinity of North Greenwich may be the cause of the problem (as this can cause trains to become non-communicative due to being out of synch with signalling system)

07.38 Service now suspended between Stratford and London Bridge owing to non- communicating trains.

07.48 Confirmation of 3 stalled trains on eastbound between Canary Wharf and Canada Water;

o 1st stalled Train 355 came to halt at 07.35

o 2nd stalled Train 306 at 07.38

o 3rd stalled Train 312 at 07.40

Each train had approximately 900 customers on board.

08.01 Confirmation received that the first stalled train is sitting over the points outside of Canary Wharf. As a result, and in order to eliminate the derailment risk or point damage, the points must be manually secured on site to ensure that they are in the correct position. The plan at this stage is to wrong direction move two of the stalled trains back to Canada Water and move the first train forward into the platform at Canary Wharf.

08.12 Traction current discharged to allow Station Supervisor to go onto the track to manually secure the points.

08.24 Points secured and current recharged

08.29 First stalled train is moved into the platform at Canary Wharf and detrained. Total stalled time 54 mins

08.41 Decision taken to only wrong direction move the last train and now move up the 2nd train to Canary Wharf. The third stalled train completes a wrong directional move back to Canada Water station total stalled time 61 minutes. The third stalled train completes move into the platform at Canary Wharf, total stalled time 63 minutes. Appendix 2

A summary of recent Jubilee line runtime performance showing post transmission based signalling control (TBTC) system performance against the average pre TBTC system performance is shown below. This shows that over recent weeks there has been a steady improvement in run times although recent days performance has not been good.