New Timetable - 19/05/14

That first 24tph should be a 20tph, right? That is, a 20tph service from 0830 to ~2300, increasing to 24tph between 1000 and 2000. (At least according to WTT 13 for the Jubilee line from www.tfl.gov.uk/corporate/publications-and-reports/working-timetables).

It could simply be that the Jubilee Line does not have enough trains to run a more intensive service on a regular basis. This timetable requires 58 trains in the peaks out of a total fleet of 63 trains. That is pretty close to, if not actually at, the limit of reliable availability for a fleet of that size.

I too am a little underwhelmed. Surely this level could be achieved with "legacy signalling."

Of course, that might in itself be a slightly silly thing to say because it might be that the Jubilee would have needed resignalling to manage that and that the signalling which was in place could not reliably achieve 33 or even 30 tph without extensive work and would be the point of putting in loads of old-fashioned signals, at least from the point of view of TfL. But I can't help but wonder whether all the pain was worth it and now, of course, we have a relatively isolated Jubilee line which means the Met can't really run on it anymore. Not that that was done very often but all the same, I would've wanted more for my money if I were TfL and it makes me wonder whether it was all necessary.

According to documentation I have seen, the main constraints are insufficient trains, and also the whole detrainment issue at the various reversing sidings which since the Liverpool Street incident has still never quite been fully resolved. A more frequent service through the central section could be achieved if more trains terminated short, but in practice it's unrealistic for Wembley Park and Willesden Green to reliably handle more than 6 tph each, which for a 30 tph service still means 18 tph through to Stanmore. There is the option to regularly use West Hampstead, however it is preferred to leave this unused in order to facilitiate use for service recovery when required.

One longer term plan under consideration is to run to Harrow-on-the-Hill, but this doesn't resolve the immediate issue of insufficient trains. It has crossed my mind whether a cheaper solution could end up being remodelling Wembley Park so the Jubilee takes over platforms 2 & 5 in order to provide a reversing facility. With the current service patterns on the Met this could be achieved, although at a cost of losing flexibility on the Met side.

Having said all this, whether the TBTC system could reliably cope with over 30 tph is another issue. Based on experience on the Northern Line, throughput of trains through more complex layouts is not always particularly impressive. It will be interesting to see how the Northern Line performs with its two upcoming new timetables.

Thank you.

Well, WTT 54 on the northern has introduced a 6 minute time saving, 1hr9 minutes mon-fri HBT to MOR via bank which is kinda pathetic as that's what WTT53 had as the runtime on a sat / sun anyway