SSR resignalling

[JustPassingBy]

Thanks for the reply. Wouldn't want anyone to break rules/put their jobs at risk. Was just asking as I thought there might be some dates that are public knowledge that I just didn't know.

 

[Mag_seven]

The first section of the long awaited SSR resignalling, Thales CBTC Signal Migration Area 0.5 from Hammersmith-Latimer Road goes live with the first trains tomorrow morning.
Hammersmith signal cabin (OZ) will close after the last train tonight. >insert tears from bluegoblin7<

A normal weekend timetable will operate but trains will initially run empty from Paddington-Hammersmith until passenger approval is gained, hopefully sometime on Sunday.

The contract was signed on 3 August 2015:
http://www.railwaygazette.com/news/...-sub-surface-lines-resignalling-contract.html

Maximum line speed will be increased to 50mph in this section, from the previous 35-40mph. Restrictions obviously remain on certain infrastructure and pointwork.

Thread reopened to allow @Dstock7080 to update.

 

[Dstock7080]

This weekend a software update for the forthcoming SMA 8 Finchley Road-Preston Road commissioning has addressed the tag-reading issue restricting maximum speed in CBTC to 56mph.
From today District/H&C trains operating to the planned 62mph in the appropriate sections.

 

[A60stock]

Apologies if I have missed this but what is the go live date for SMA8? I recall seeing July 2025?

 

[Dstock7080]

Hopefully 31 May/1 June weekend

 

[Kay_M]

Hopefully 31 May/1 June weekend

Hoping so. Thank you for the update.

This weekend a software update for the forthcoming SMA 8 Finchley Road-Preston Road commissioning has addressed the tag-reading issue restricting maximum speed in CBTC to 56mph.
From today District/H&C trains operating to the planned 62mph in the appropriate sections.

Quick question. (If this has been asked before then apologies) with regards to the fast lines (tracks) on the met line from Wembley Park to Harrow. Will that part remain conventional signalling until the next update.

 

[Mojo]

Hoping so. Thank you for the update.


Quick question. (If this has been asked before then apologies) with regards to the fast lines (tracks) on the met line from Wembley Park to Harrow. Will that part remain conventional signalling until the next update.

No, the signalling applies to all roads. Meaning that even Fast / Semi-fast trains will have to stop and change over

 

[Kay_M]

No, the signalling applies to all roads. Meaning that even Fast / Semi-fast trains will have to stop and change over

Oh I see. Fair enough

 

[A60stock]

Sorry, are Northbound fast trains also stopping outside Preston Road? Or do these switch over at Wembley?

 

[Dstock7080]

Fast trains will stop alongside Preston Road station.

 

[notverydeep]

Fast trains will stop alongside Preston Road station.

To add, they will still be on the fast lines, so it wouldn't be possible for these to form additional services at Preston Road.

 

[A60stock]

SM9 is also expected in 2025 right? So we won't have this situation for too long?

Also what happens if a driver forgets and runs past the boundary at normal line speed?

 

[Bald Rick]

Out of interest, why do they have to stop to switch systems? Thameslink trains dont when switching to ATo over ETCS, and I’m fairly sure Elizabeth line trains don’t on approachto the Crossrail core (although I’m happy to be stood corrected on that).

 

[Nym]

Not to be too critical with it, but it might have something to do with it being the 3rd company that has been selected to deliver the system, and not exactly being 'optimised' for the purpose?

 

[bramling]

Out of interest, why do they have to stop to switch systems? Thameslink trains dont when switching to ATo over ETCS, and I’m fairly sure Elizabeth line trains don’t on approachto the Crossrail core (although I’m happy to be stood corrected on that).

I suspect the answer is that this is how the off-the-shelf product works, and to attempt to change this would have been extremely expensive (as well as introducing risk), likely not worth it when virtually all the boundaries are at a station in any case.

Seltrac seems to work on the basis of providing a movement authority from A to B, so going in you have to have a start point, and coming out you have to have an end point. It’s also the case that when entering the system a series of checks have to be made, and I’m not sure to what extent the system would allow for these being done on the move.

There’s also the issue that the the train has to be changed in and out of tripcock mode. I believe the tripcock remains operative (it certainly did on the Jubilee), but there’s a risk of having a train able to proceed at full speed with no protection if the changeover into ATC doesn’t occur correctly. I suspect this would be regarded as being risky.

There was an issue recently on the District Line where it was found that trains could enter a platform under ATC at the exit point into conventional signalling, with the preceding train potentially stopped within the overlap of the first colour-light signal.

The other issue that springs to mind is that, on the Jubilee and Northern, drivers had to operate a switch, which meant standing up and theoretically turning away from the driving position. Also if operating under ATO then you’d have to cross the cab to change the train to manual operation, or vice versa. This couldn’t be done on the go without leaving the driving position. Also the traction/brake controllers aren’t designed for this, as to go from motoring to stow, which would involve passing through the emergency brake positions. I daresay design changes could be made, but presumably massive cost all for a couple of locations.

So, in essence, cost/complexity/risk versus benefit doesn’t stack up. And Thales don’t exactly have a great record of coming up with solutions to very LU-specific problems - “send us your problem over to Canada and we’ll see if we can find a workaround, meanwhile if you could please give your attention to the invoice we’ve just sent you it would be much appreciated”…

 

[Bald Rick]

Thanks @bramling