SSR Resignalling

The problem is once you need new software there is a lead time to develop it, test it in the lab and potentially field test it. That's made worse by the fact that once you lose a commissioning date, you have to find a new one which has the available staff and isn't already one where there's a closure. This has a habit of forcing the closures around other project teams, events etc. It's not as simple as naming any date and hoping for the best.

I'm with you on that one !


If only for non technical reasons; before software testing, Earls Court complexity, lack of other dates, etc, we've got a winter of covid presence to get through, and potential re-introduction of covid working a minimum, or even increased restrictions if things deteriorate. I'm not attempting to start a new covid debate, just stating that any plans for anything over this winter may be subject to its effect - - - and we do not yet know what that effect may be.

You've been a member here for 10 days. I would politely suggest you think before hitting the post button in future as those you are doubting are the very people delivering the CBTC signalling system.

No the system won’t know about driver changes but this should be inbuilt into the timetable and the system does have the full timetable loaded

There are also many reasons for a driver change that aren't timetabled - for example a reform, an Instructor Operator taking over the train with a trainee, a spare doing part of a duty to name a few.

Driver change overs should only occur at a few particular "crew relief" locations on a given line though and more often than not stand time is built in to the timetable at those locations so it doesn't really matter whether a driver changeover occurs or not as every train has the delay built into the timetable regardless.

As for CBTC, or any other ATO system for that matter, it allows a period of dwell time before it offers the driver a target point ahead (essentially a green signal). More often than not the cab will be shut down well before the dwell time completes (particularly when you consider the vast majority of trains at crew relief locations have additional stand time added on) and so the system can't then offer a target point till the next driver opens up the cab and logs in. In other words it can't "hurry up the driver" as it has to wait for them to changeover first.

On the point of the system making up lost time, I have to say I'm still waiting to actually see this happen. Today, typically on my last trip east there's a problem and I leave Earls Court five minutes late. A train left Earls Court just before me so I'm still five minutes late when I enter the CBTC area at Sloane Square. Guess how I was doing when I left the CBTC area at Stepney Green? Yep, five minutes late.

This isn't the first time. I've been running late on about five or six occasions now and every single time I exit the system as late as I entered it.

Thank you for the detail Colin. The part on shutting down and restarting the cab is very interesting and explains everything.

Target speeds can indeed exceed 50 mph between King’s Cross and Farringdon conditions permitting. Whilst the northern half of the SSR combine had journey time reductions introduced in September, present factors including cancellations and out of sequence running might influence the degree to which this is being felt.

I thought so, I was going to say 50mph but thought I was being optimistic. I am not sure where I read it, that the zone 1 part of the SSR had a maximum speed of 30mph, I guess this may have been wrong then.

That makes a big change from the old days of standing outside the old supervisor's office at Farringdon and seeing a short section of the outer rail track bounce up and down every time a train came in.

Been on a C stock plenty of times with the motors screaming between Kings Cross and Farringdon it was way above 30mph

As a schoolboy I sometimes got to travel in the cab and distinctly recall the speedometer exceeding 40mph whilst travelling westbound through the disused platforms of the original Kings Cross station.

The pdf is not up to date, 26-27 March is the target.

Indeed it has, I've been reviewing documents for it this week.

Supporting that date, it is now at least appearing to be an internal target for some of the migration related non-CBTC assets.

The passenger travel info on public web site :
tfl.gov.uk/tube-dlr-overground/status/?Input=&lineIds=&dateTypeSelect=Future%20date&direction=&startDate=2022-03-26T00%3a00%3a00&endDate=2022-03-26T23%3a59%3a59#line-lul-district
seems not caught up yet as that info does not contain all of SMA 5 area or the whole area necessary (which obviously extedns to outside SMA 5 area itself).