ATO on the Met

[lindsay]

ATO is planned to be installed on the SSL lines by 2014. Will the Met from Rayners Lane to Uxbridge have Seltrac and Westinghouse Distance-to-Go installed due to the Piccadilly running on the Met?

[Colin]

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

[Deleted]

There is a possibility that both ATO systems may be able to work together, as they both use different train position detection, and wayside to train communication. Good project management would be needed for that! Also, it may be possible that the trains driver boxes may be able to switch between ATO systems. Or it may be the case that the District may run to Uxbridge, and thus both lines may use the same ATO.

[Deleted]

stephenk said:

There is a possibility that both ATO systems may be able to work together,

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.

[Deleted]

well it would coincide with the district taking back over the rayners lane branch but again only a rumour but it would make sense with the re-signalling in mind
the met line from rayners lane to uxbridge i believe will be the first area to be re-signalled on ssl first to make sure it works before installing it system wide

[Phil]

metapprentice said:

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.

[Tomcakes]

One imagines that the companies working together on a standardised system would be too sensible an idea?

[Tom]

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.

[Phil]

I started by being neutral about PPP, but the more I've seen the more stupid it becomes. Not to be able to specify a system is sheer madness and is bound to lead to increased risk. Even assuming the computers talk to each other unfailingly (and that's by no means certain), how do you actually TEST compatibility in practice? Shut down the line for several weeks whilst ALL scenarios are tested? Run test trains running on both control systems out of traffic hours (but that would still need a full peak service to prove it)?

I'm not scaremongering coz the systems will Have to be proved first to satisfy Rail Acceptance board (whatever it's called nowadays), but just seeing the problems NR have linking up supposedly compatible new signalling systems from different manufacturers doesn't fill me with confidence - as usual it will be the longsuffering passenger that suffers.

[Tom]

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.

[Phil]

tom said:

The SSL systems will all be track circuit based .

Ah.. That's what was not clear before. Failsafe indeed! Confidence restored!

[mowat]

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.

[setttt]

mowat said:

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.

Sorry, what would be solved? The picc would still have to share tracks with the met at Rayners even if the former was operated as a shuttle from Acton.

[mowat]

setttt said:

mowat said:

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.

Sorry, what would be solved? The picc would still have to share tracks with the met at Rayners even if the former was operated as a shuttle from Acton.

Allright then Acton Town to South Harrow.

[Deleted]

What about Acton Town - Hangar Lane Jnc?!

[Deleted]

tubechallenger said:

What about Acton Town - Hangar Lane Jnc?!

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

[Deleted]

rbruce1314 said:

To interlock two different ATO/ATC systems in a totally fail-safe manner is so far completely untried, and a logistical nightmare.

Actually it has recently been done in Hong Kong. Part of the Tung Chung Line is signalled with both Alcatel Seltrac and Alstom SACEM.