ATO on the Met

It may well be the District & Met lines by then ;D ;D ;D

They are going to have to unless both lines use the same system, otherwise the two lines will not be able to run along the same piece of track.

I don't think anyone should underestimate the importance of MA's statement.
To interlock two different ATO/ATC systems in a totally fail-safe manner is so far completely untried, and a logistical nightmare.
For example if (say) a Picc fails, then the Met system would not only have to recognise that fact, but act on it and reset its own codes to stop its train running into the back of the failed one.
Even under non-failure conditions a (cab or track-based) signalling system would have to recognise every train in the same way regardless of the control system.
It would be a brave engineer indeed to even attempt to implement differing control systems on the same line, let alone priority control at junctions (RL in this case) etc.

Imagine the early problems with ATO on the Central, then mix it with either non-ATO, or with a second system for a second 'line', and the ************(adjective deleted) effects of a failure can start to be imagined.

No. The PPP companies must be allowed commercial choice as part of the deal, hence LU is not permitted to specify what system is to be used, merely that the two systems must be interoperable.

If a particular system were to be specified the rules of the PPP in allowing commercial choice and competition with suppliers would be broken.

It may be stupid, but that was the decision LU reached. For once it can't be blamed on the private sector.

As for the systems not working together, how do SNCF, SNCB, NS, DB, CP, ÖBB, SBB and FS cope? While none of these railway administrations run ATO trains, they do use different ATP/ATC systems on the same tracks regularly. There must be literally thousands of system changes for the TGV and Thalys networks every day. And not to forget the Japanese
either, with intense commuter and tube services sharing the same tracks.

We can also look at the problem on a smaller scale than the Picc/Met dual running: The Victoria line during resignalling will have trains that can work on two different ATP inputs and Stockholm already has trains that work on both old style HS Cab Signalling and Siemens ATP.

WRT one system not detecting a stalled train using the other, what about track circuits? The SSL systems will all be track circuit based and just because a Piccadilly line train uses a different set of ATP codes and ATO data, it still has wheels and axles to shunt a track circuit. All it needs is for the inputs and to be fed to both ATP systems as the ATO route and run data is uploaded to the train in one hit during the station stop.

This could be solved if the piccadilly was to run a Acton Town to Rayner's Lane only shuttle service, this would mean a better Cockfosters to Heathrow service and the district would not have to over the branch.

Allright then Acton Town to South Harrow.

hey, why not go the whole hog and make it acton town to ealing common ;D ;D ;D ;D ;D ;D