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Post by superteacher on Jun 4, 2018 17:48:45 GMT
What I find annoying are the Twitter updates on the TFL feeds showing pictures of the trains being tested using the new signalling. The way the tweets are worded is vary misleading since they imply that after the weekend closures, the new signalling will be in operation! This was shown on the District line feed, even though no areas if the District line will be going live for quite some time.
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Deleted
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Post by Deleted on Jun 4, 2018 20:22:35 GMT
Stepney Green to Tower Hill will be the first for the District Line
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Post by andypurk on Jun 5, 2018 1:01:10 GMT
Stepney Green to Tower Hill will be the first for the District Line Won't Paddington to Edgware Road be the first for the District Line?
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Post by t697 on Jun 5, 2018 17:46:10 GMT
Stepney Green to Tower Hill will be the first for the District Line Won't Paddington to Edgware Road be the first for the District Line? Yes! But Stepney Green - Monument is the first on the District main route.
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Post by malcolmffc on Jun 10, 2018 6:35:26 GMT
Is SMA0.5 still likely to go live on 24th June?
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Post by Dstock7080 on Jun 10, 2018 8:32:51 GMT
Is SMA0.5 still likely to go live on 24th June? At present yes but remember the previous ‘Go Live’ date was only officially postponed 3 days before. Officially there is engineering work that weekend and the advice to passengers remains:
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Post by d7666 on Jun 11, 2018 19:48:11 GMT
What is the maximum speed that CBTC for 4LM will be able to run trains at? In outer areas I’m expecting 100kph, eg. beyond Barking. Are the S7's still limited to 47.5 mph to mitigate against the compromise to signal braking distances due to the spacing of signals? In weak-field areas they are at present, in non- weak-field areas around 42mph. Err ummm could expand a bit please. I know what weak field is, and I know what weak field areas are. But weak field is what DC motor units have. AC motors do not have field weakening they work in an entirely different way. So S stock does not have weak fields. Or, me not being a T/Op, have they done something like mark S stock with equivalent to A/C/D stock terminology, in which case it's misleading , and certainly not weak fielding. -- Nick
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rincew1nd
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Post by rincew1nd on Jun 11, 2018 19:53:17 GMT
AIUI there are two performance modes which are automatically switched, similar to weak field.
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Post by d7666 on Jun 11, 2018 19:54:29 GMT
A small but significant milestone this morning as Hammersmith Service Control Centre entered operational, revenue usage for the first time. Line control functions for the Circle, Hammersmith & City and Metropolitan and District lines have moved into the building from Baker Street (Service Managers, Service Controllers and Line Information Specialists) however at this time there is no signalling functionality, which remains at the legacy cabins and control centres. . Just like to point out some of us systems engineers moved in too, to support the systems the SM SC LIS etc use. -- Nick
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Post by Dstock7080 on Jun 11, 2018 20:42:34 GMT
In outer areas I’m expecting 100kph, eg. beyond Barking. In weak-field areas they are at present, in non- weak-field areas around 42mph. Err ummm could expand a bit please. I know what weak field is, and I know what weak field areas are. But weak field is what DC motor units have. AC motors do not have field weakening they work in an entirely different way. So S stock does not have weak fields. Or, me not being a T/Op, have they done something like mark S stock with equivalent to A/C/D stock terminology, in which case it's misleading , and certainly not weak fielding. -- Nick AIUI there are two performance modes which are automatically switched, similar to weak field. Indeed 'weak-field areas' is an over generalisation by myself, old habits die hard!; officially called APS Automatic Performance Switching is operative in exactly the same areas as weak-field and the in-cab APS indicator is exactly the same as a weak-field indicator (yellow & black stripes).
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Post by d7666 on Jun 11, 2018 20:56:58 GMT
Err ummm could expand a bit please. I know what weak field is, and I know what weak field areas are. But weak field is what DC motor units have. AC motors do not have field weakening they work in an entirely different way. So S stock does not have weak fields. Or, me not being a T/Op, have they done something like mark S stock with equivalent to A/C/D stock terminology, in which case it's misleading , and certainly not weak fielding. -- Nick AIUI there are two performance modes which are automatically switched, similar to weak field. Indeed 'weak-field areas' is an over generalisation by myself, old haebits die hard!; officially called APS Automatic Performance Switching is operative in exactly the same areas as weak-field and the in-cab APS indicator is exactly the same as a weak-field indicator (yellow & black stripes). thanks it had to be something like that....... or 40 years of knowledge of AC motors had just gone down the pan -- Nick
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rincew1nd
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Post by rincew1nd on Jun 11, 2018 21:52:12 GMT
...the in-cab APS indicator is exactly the same as a weak-field indicator (yellow & black stripes). Is this just displayed to the train op', or is it visible externally?
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Post by goldenarrow on Jun 11, 2018 22:14:41 GMT
...the in-cab APS indicator is exactly the same as a weak-field indicator (yellow & black stripes). Is this just displayed to the train op', or is it visible externally? Just for the train op now days. The photo shows the indication nestled at the bottom of the SID (Signal Interface Display), since the SSR fleet has had ATO mods this layout has changed somewhat. Photo below has been cropped from the original for ease of viewing. flic.kr/p/FyqPUR
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Post by spsmiler on Jun 11, 2018 23:35:56 GMT
oooh 60mph! Nice. But will it ever be achieved?
My question excludes the Met Line north of Finchley Road... but there are some stations which are a distance apart with relatively straight track where maybe higher speeds could be possible.
Simon - who believes that 'rapid transit' should travel rapidly.
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Post by MoreToJack on Jun 12, 2018 5:30:38 GMT
oooh 60mph! Nice. But will it ever be achieved? My question excludes the Met Line north of Finchley Road... but there are some stations which are a distance apart with relatively straight track where maybe higher speeds could be possible. Simon - who believes that 'rapid transit' should travel rapidly. Not the place for discussion, but there is more to rapid transit than top speed. Indeed, on many 'straight' sections such a high speed could reduce capacity, not increase it.
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Post by MoreToJack on Jun 19, 2018 0:35:04 GMT
Is SMA0.5 still likely to go live on 24th June? At present yes but remember the previous ‘Go Live’ date was only officially postponed 3 days before. Officially there is engineering work that weekend and the advice to passengers remains: The intention remains for SMA 0.5 (only) to 'go live' in revenue service on Monday morning (although don't be surprised if trains end up running in passenger service from some time on Sunday!). There is a final Go/No-Go meeting planned for later this week, so things could change yet. Note to self: don't route any non-fitted trains to Hammersmith on Saturday morning. 🙈
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Post by Dstock7080 on Jun 19, 2018 5:37:48 GMT
Line speed Hammersmith-Latimer Road is to be increased in CBTC to 50mph from the current 35-40mph, obviously restrictions apply over certain infrastructure and pointwork.
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Post by superteacher on Jun 19, 2018 6:07:37 GMT
Line speed Hammersmith-Latimer Road is to be increased in CBTC to 50mph from the current 35-40mph, obviously restrictions apply over certain infrastructure and pointwork. Will trains run at the higher speed straight away, or will they be capped in order to keep them to the current timetable?
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Post by Dstock7080 on Jun 19, 2018 6:17:28 GMT
Will trains run at the higher speed straight away, or will they be capped in order to keep them to the current timetable? No capping, Timetable uplift not due until December 2020 at earliest. CBTC lineside infrastructure and hardware installation now visible from station platforms in SMA areas 2, 3, 4, 5 and 6 to Plaistow. New signal equipment rooms being built alongside Barking sidings; East Putney; approaches to Wimbledon. West Kensington and Ealing Bdwy recently completed.
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rincew1nd
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Post by rincew1nd on Jun 19, 2018 6:58:01 GMT
Note to self: don't route any non-fitted trains to Hammersmith on Saturday morning. 🙈 How would you know? Other than looking out the window?
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Post by superteacher on Jun 19, 2018 7:49:15 GMT
Will trains run at the higher speed straight away, or will they be capped in order to keep them to the current timetable? No capping, Timetable uplift not due until December 2020 at earliest. CBTC lineside infrastructure and hardware installation now visible from station platforms in SMA areas 2, 3, 4, 5 and 6 to Plaistow. New signal equipment rooms being built alongside Barking sidings; East Putney; approaches to Wimbledon. West Kensington and Ealing Bdwy recently completed. So as the signalling gradually migrates, will there not be an issue with trains running early? This was a big issue when the Central line went over to ATO in phases.
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Post by MoreToJack on Jun 19, 2018 8:23:52 GMT
No capping, Timetable uplift not due until December 2020 at earliest. CBTC lineside infrastructure and hardware installation now visible from station platforms in SMA areas 2, 3, 4, 5 and 6 to Plaistow. New signal equipment rooms being built alongside Barking sidings; East Putney; approaches to Wimbledon. West Kensington and Ealing Bdwy recently completed. So as the signalling gradually migrates, will there not be an issue with trains running early? This was a big issue when the Central line went over to ATO in phases. The Central line system works differently in terms of how things like target points work. If a train does arrive at a station early it will be given a longer dwell time to keep to booked departure. I believe there's been discussions previously on how this is handled with TBTC - it will effectively be the same. @north End may be able to assist.
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Post by MoreToJack on Jun 19, 2018 8:26:16 GMT
Note to self: don't route any non-fitted trains to Hammersmith on Saturday morning. 🙈 How would you know? Other than looking out the window? Yeah, exactly. In theory it isn't the signaller's problem - everything should be formed of appropriate stock, and the train operator should alert us if they are on a train with no VOBC. The issue would come if we were to accidentally lower the wrong signal, or if reforms were made up without checking the stock formation (in theory still down to the controller but nonetheless worthwhile checking if ex-District.)
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cso
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Post by cso on Jun 19, 2018 12:51:23 GMT
Presumably though, it would be easily rectified if it did happen... it's not like sending an electric train down a bit of line with no electricity for example?
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Post by superteacher on Jun 19, 2018 13:14:36 GMT
Presumably though, it would be easily rectified if it did happen... it's not like sending an electric train down a bit of line with no electricity for example? Similar result though - both will stop!
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North End
Beneath Newington Causeway
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Post by North End on Jun 19, 2018 15:06:39 GMT
So as the signalling gradually migrates, will there not be an issue with trains running early? This was a big issue when the Central line went over to ATO in phases. The Central line system works differently in terms of how things like target points work. If a train does arrive at a station early it will be given a longer dwell time to keep to booked departure. I believe there's been discussions previously on how this is handled with TBTC - it will effectively be the same. @north End may be able to assist. If the train runs early it will simply be held to time at each platform, unless the signalman intervenes for any reason. The system will also impose a velocity ceiling between stations to prevent a train arriving too early. I wouldn’t bank on the trains running too early though. If anything like the Northern it is likely the system will be set to low brake rates to mitigate against trains going non-communicating, so what is gained in speed uplift may well be lost with earlier braking. Certainly on the Northern the run from West Finchley to Barnet and back took longer under TBTC. I’m not too sure what enhancements there are on the SSR system, however I believe whilst the non-communicating issue still exists the recovery process is a little quicker. As for what happens if a non-CBTC train turns up, it’s just the same as if one turns up where the CBTC equipment is defective - Restricted Manual either until the nearest siding or off the CBTC railway whatever is the quicker option, with the move being done on sight and authorised by the signalman with points remotely secured. In practice this will be a substantial delay.
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Post by domh245 on Jun 19, 2018 18:08:08 GMT
The system will also impose a velocity ceiling between stations to prevent a train arriving too early. Does that not basically constitute a cap as superteacher was asking about? Should the need arise to do 50mph they'll do 50, but by and large they'll still be going at the same speeds as before? I can't imagine that the braking rates will be that low (nor the gaps between stations be long enough) to necessitate hitting 50mph in service?
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Post by roman80 on Jun 19, 2018 19:12:18 GMT
What percentage of trains have been modified for CBTC to date?
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Post by Dstock7080 on Jun 19, 2018 20:28:59 GMT
What percentage of trains have been modified for CBTC to date? On the last figures reported (more would certainly have now been done): S8 38 competed, 20 still to go S7 60 completed, 73 still to go
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North End
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Post by North End on Jun 19, 2018 20:34:15 GMT
The system will also impose a velocity ceiling between stations to prevent a train arriving too early. Does that not basically constitute a cap as superteacher was asking about? Should the need arise to do 50mph they'll do 50, but by and large they'll still be going at the same speeds as before? I can't imagine that the braking rates will be that low (nor the gaps between stations be long enough) to necessitate hitting 50mph in service? Regarding the velocity ceiling, this is only imposed if the system identifies the train is running sufficiently early, in which case it will calculate a set speed and this will be imposed all the way to the following station. It’s only calculated in a station-to-station basis, so it tends to occur in particular sections, certainly not for the whole journey. On the Northern Line it’s way more common than not to be running at full speed as most of the time the trains are running late - personally I prefer to run a minute or so late precisely so there’s no need to mess about adhering to silly velocity ceilings (and forever catching up to ATO trains which Thales told us was impossible!). It’s not really a cap as such, as it’s something which will continue to be part of the system into the future. LU did look at changing it to a more superior coasting point system as used successfully on the Vic, however the expense wasn’t deemed worthwhile according to papers I have seen. As regards speeds generally, I can’t specifically speak for SSR, however I can speak for the Northern, and it seems SSR is copying the Northern format as far as possible - and in many cases being delivered by the same people. Initially the railway was recalculated to modern standards, which on the Northern resulted in a lot of lower speeds cropping up in many places. To be fair I suspect the geometry on the Northern is probably about as bad as it gets, so we may see less of this in the SSR (only my guess however). The full traction capability of the 95 stock was uncapped from the start, however it wasn’t until subsequent software drops that we started to see speed uplifts in places, which was done primarily to meet the needs of new timetables. Note the Northern is still unable to meet the timetable on certain open sections - this is due to a combination of the infamous brake rate issues, plus partly that 60mph running has not yet been achieved for various reasons - mainly to do with safety assurances. The line speed on the Northern is actually 60, however a velocity ceiling of 50 mph has been imposed in the whole line and will remain for the foreseeable future. So as far as SSR goes, if they have a line speed of 50 then it will probably be achieved more often than not. You might be surprised how fast modern trains can achieve on relatively short sections - we reach 47mph on the short hop from Warren Street to Goodge Street southbound, albeit assisted by gradient. The brake rate on the Northern in the open is painful - as an example Brent Cross southbound platform ramp could quite happily be hit at 40 mph, even in the wet- under TBTC it’s a pitiful 22mph. This level of slow running is certainly enough to cause trains to struggle to meet the timetable, hence why we’ve always been late into Barnet and Edgware pretty much ever since TBTC came in, and hence why you’ll hear Northern drivers forever moaning about short turnarounds at those places!
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