please empty your brain below

The Bombardier contract was the 2nd attempt. The original contract was with Invensys (Nee Westinghouse,now Siemens Automation) for a system very similar to that on the Victoria line. This contract was part of the Metronet PPP. LU chose to let the contract "die" when bringing Metronet out of administration.
A more successful signalling trial than they had in Hong Kong today.
What happens when there is a failure of the new automatic system? Is there a manual backup, or does everything grind to a complete halt?

I wonder if this new system will still be in place, 50 years hence...
Tortuous progress!
A few comments:

The fact that the existing system lasted 50 years illustrates its fundamental soundness

The new software based system "is estimated to cost" £800m MORE than originally expected. So what is the real cost-benefit of the seconds of time / extra capacity that is due to be gained?

The drivers (humans) are becoming even more de-skilled. That (apart from being demeaning) leads to higher boredom, and less attentiveness for when things start to go wrong. Is this really progress?

There is an illusion that IT systems can deliver big solutions in mega-projects. The evidence is (see innumerable government / NHS projects) that very many end in extremely costly failures. (Private business just keeps it private)
1, Can vintage trains run on the new signalling?
2, Does it work in the rain? Unlike the Central Line where the trains have to be coaxed into stations.

dg writes: 1) No. 2) Yes.
Will this signalling system allow for the Circle line to be restored to an actual circle? I know that many locals still struggle with the Circle-Hammersmith branch, let alone tourists.

I suspect the counter argument is that there will be too few trains running to Hammersmith, but would it be feasible to have a Hammersmith-Edgware Road service? I suspect this may need an update to how trains terminate at Edgware Road.
If anyone has details of the rationale as to why the branch was added to the Circle line, it would be much appreciated if you could please share.

dg writes: The Circle line's much more reliable now it's not a circle. Benefits to passengers along the line outweigh the inconvenience at Edgware Road. Some background here and here.
The branch was added to the Circle Line to double the frequency to Hammersmith. There wasn't, and isn't, any spare capacity between Baker Street and Aldgate so more trains had to terminate at Edgware Road. They could have run the extra Hammersmith trains as a shuttle, and kept the Circle, but a circular service is always inconvenient operationally (no termini where some slack can be added to the timetable to allow for late running, or where a train with a problem, or with no crew available, can be parked out of the way). And passengers from the western side of the (original) Circle not wanting to change at Edgware Road have alternatives to go east, notably the Central Line from Queensway (very close to Bayswater) or Notting Hill Gate.
An overspend of how much???

That said, having my main station in section 9 I shall enjoy looking out for the lights, even if they're not in operation on my section for some time to come!
Re: DG's reply to Tony:
Does that mean the end of steam/heritage runs then?

Also, if/when they ever get around to area 6, will the NTIs at Bow Road get better? Or have they already gotten better, and I missed it?

dg writes: Yes, yes and yes.
They'll have to fit some old trains to cover the common section with Chilton up to Amersham - this also has limited freight (the refuse trains?), plus the LU battery locomotives for p.w. work and don't they also have a measurement train?

Also the southern end of the Wimbledon branch is cleared for occasional National Rail use - do they just stop using it?
Software failure worries me too. How frequently do banking systems fail? They must have huge fail safe elements but, occasionally, this bank or that suffers a minor outage. No great loss if you cannot use the Faster Payments system for a few minutes or even an hour, but stuck in a hot sweaty tube train? Also will not the tube system software be a prime target for a rogue hacker? As regards the end of heritage trains, would it not be possible for such a train to be manually signalled to follow immediately behind a 'pilot' tube train equipped with all the latest gizmos?
A precursor to one day having driverless trains?
That's the 20th question someone has asked today. In just 13 comments.
Interesting that the current signalling is roughly the same age as the Victoria Line, which had ATO from the start

Signalling replacement schemes do seem to be really complicated, the Jubilee line seemed to be closed at weekends for an eternity. The massive cost overruns with this one has made a massive hole in the TfL budget too
Re Hong Kong: While that's certainly shocking (the affected section has to close for at least two days), I still have to assert that it's exactly why all those gruelling tests are essential.
There was a faulty train at Latimer Road during rush hour this morning - I wonder if it was related to the new signalling.

dg writes: TCP mismatch.
@Still Anon: Each section of shared track (Harrow-Amersham, Rayners Lane-Uxbridge, Acton Town-Hanger Lane Junction, Gunnersbury-Richmond & East Putney-Wimbledon) will feature both new and classic signalling so that both manual and automatic trains can use the line.
I will probably be long retired before this is finally completed.
...which is why those will be the last five sections to be converted. It is even possible that the Piccadilly Line will have its new trains by then, which could simplify sections 11 and 14 if the trains are compatible with the new system.
Thanks X-Plaistow, having had a look around there is this article from 2015, apparently each shared section will have different arrangements.
It strikes me as odd that Amersham is several years away - they are doing the works to build a new signal box already!
For info.....

Some elements of the existing system are over 90 years old ...e.g. Edward Road signal cabin and interlocking.

To Still Anon. The Wimbledon branch has AWS/TPWS for the occasional SWR train. This will be retained. For the shared section between Harrow on the Hill and Amersham, train stops will be retained for Chiltern trains.

LU is fitting the CBTC system to some battery locomotives and other key engineers trains.
Not advertising the preview service went to the extreme of announcing at Kings Cross yesterday evening that there were no trains to Hammersmith, which seems a bit overcautious unless it had actually gone belly-up by then.
I would question the assertion that drivers are being de-skilled, as they still have to know how to drive and they still have responsibility for the passengers.

The Northern Line service has been much more solid and consistent since automation. I have also noticed that they have up-skilled the automation. For many years the software made annoying micro-adjustments to to the speed with short bursts of power alternating with short bursts of engine breaking on downhill sections, when a driver would have just let it coast. They seem to have fixed that now.

All they need to do now is ban the ridiculous rail grinding and get rid of the 107dB shriek, and it'll be happy days.
i went to have a look this evening !

as the train pulled into Wood Lane, the driver had his hands in his pockets !!

the journey wasn't quite as smooth as i had expected - it nearly stopped too early at Shep Bush, and had to do an extra shimmy, hopefully they will fix that soon.

there seemed to be a notetaker in the cab of both my train, and in the one i saw going in the other direction.
I can only imagine the complexities regarding changing these lines. Overnight, weekdays only. Outdated wiring and configurations. Aging switches and damaged transistors. Not to mention the bureaucracy from TFL! I hope they get it sorted asap but I won't hold my breath!
I wonder if some frequency improvements will be possible after SMA5 is implemented and not after the entire process is over. SMA5 will cover all the remaining complex junction around the inner circle.










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