Service pattern during Bank Branch closure in 2021

I vaguely remember there was a similar closure of the southbound between Moorgate and Kennington when similar works were done at London Bridge.

I can’t recall the service pattern then, but that would be a useful starting point.

Moorgate reversing has to be done in one platform. Required layover for a stepping-back reversal is 2.5 minutes. I doubt the platform re-occupation after departure of a northbound train over the crossover will be as good as 1.25 minutes, so I doubt 16tph is achievable.

Will this be before opening of the Battersea extension? If not, that would limit he number of trains available to go to Morden from the CX branch.

And I see the original consultation (linked to above) suggests Crossrail was expected to take some of the extra traffic. Given the revised timescales for both projects, will that still be possible?

If the extra train terminates at Finchley Road that could make for an interesting pattern/route!

I assume you mean Finchley Central as reversing a train at East Finchley would delay the through service.

As we’ve established though, it would be a struggle to run 16tph off one platform even with stepping back multiple trains. That’s a train every 3 3/4 minutes and, as mentioned, that’s going to be unlikely due to platform re-occupation times.

LR are quite good at waffling on with thousands of words yet nothing of substance, or dressing up their glorified crayoning as somehow being fact. I think the only place that rivals their accuracy is Londonist.

I wonder what the minimum 'safe' level is. At 12tph or 10tph so many people are going to try and squeeze on to so few trains it might lead to dangerous overcrowding. Better then to close the branch entirely, surely.

My first thought is to wonder whether it's linked to the changes to the signalling system that would be required - technically, economically or contract-related?

The Bank project is agreed for £563 million, and I think it should have included adjustments to minimise passenger inconvenience during construction, especially during the major disruption for implementation. Doubling emergency reversing capacity on the City branch would also provide a long-term improvement, so not wasted.

On any railway there is balance between flexibility for times of disruption to the usual service (whether planned or otherwise) or other out of course events on one hand and the costs (time and financial) of maintenance of those assets and reduced reliability they cause* on the other. Flexibility vs simplicity is how I've described it in the past, but I have no idea if that's a term used by anyone other than me.

LU's current philosophy is very heavily weighted towards simplicity - significantly too far in my opinion, especially when compared to the DLR which has flexibility baked into it's design and can (and does) institute passenger-benefiting workarounds at the (relative) drop of a hat, but it's not my job to balance the books**.


*In broad terms, anything with a moving part is less reliable than something without one.
**Thankfully.

Well this will never work in practice, since drivers from a depot at a branch at the north end, have to return to the same depot. So unless you are going to waste driver resources by having the drivers step-back 2 trains at Moorgate, or have the trains themselves switch branches - which would go against keeping the service robust. I strongly suspect that the Moorgate service will have to be supplied from one branch exclusively.

Stepping back two trains might not be so bad, given this service will require considerably fewer trains and drivers than a normal day.

Apparently Moorgate has a further difficulty for stepping back, which is that both driver cabs are in tunnel when the train is berthed in the platform, meaning the drivers have to enter/exit through the passenger doors. It is possible they might have to have the drivers board and alight at Old Street, in which case a very fast reversal maybe possible, so they might be able to hit 15tph, I think 16tph is really pushing it. Also the number of trains to/from Moorgate has to divide exactly into the number of trains running via CHX, otherwise the service won't mesh at Camden Town. So if it has to be 15tph Moorgate, it will have to be 30tph via CHX.

Driver changes most likely at Old Street for a very fast Moorgate reversal. The current verbiage I am hearing is that "they" would like 16tph to Moorgate and 32tph via CHX, but it is not considered achievable by some quarters and a 15tph to Moorgate and 30tph via CHX is the preferred, more reliable, more robust option, which whilst challenging is at least more likely to work.
The thing is ironically 16tph might just be possible with light passengers loads, but is probably too difficult in peak.