|
Post by taylor on May 22, 2021 12:06:12 GMT
Sunday 23 May 2021::No service will operate on the whole line due to power and signalling commissioning, Saturday 22 May : No service between Charing Cross and Kennington for Northern Line Extension Power Testing at Kennington. Charing Cross to Kennington (-Battersea) complete closure could be understandable, but everything from Barnet etc. to Morden, seems a bit extreme, or am I missing something? It seems increasingly that closures these days extend far beyond the affected sections. In this case there's a cross-over at Charing Cross (reverse on platform 6 at CX) and the power sections N15 and N16 terminate at Embankment -- so possible to run a skeleton service and isolate south of there. Is it possible to run a partially operator driven public service on the Northern ATO infrastructure? I do have a note that at least until 2013 owing to defective switching equipment that the N12 (Lambeth to Kennington SB) and N11 (Kennington to Lambeth NB) current sections were coupled until further notice. Maybe that's part of what is being rectified. Any info. Thanks.
|
|
DWS
every second count's
Posts: 2,419
|
Post by DWS on May 22, 2021 13:34:40 GMT
I don’t have any more information but the Sunday closing may be that the whole line ATO signalling system needs all areas to upgrade at the same time .
|
|
|
Post by MoreToJack on May 22, 2021 13:40:07 GMT
Commissioning the NLE requires software modifications to the entirety of the Northern line’s Seltrac signalling system.
Closure areas are always as small an area as possible, and where it is practicable to operate reduced services this is done so.
PM driving is possible on any and all of the Northern line, even under normal operations.
|
|
|
Post by taylor on May 22, 2021 14:27:55 GMT
Commissioning the NLE requires software modifications to the entirety of the Northern line’s Seltrac signalling system. Closure areas are always as small an area as possible, and where it is practicable to operate reduced services this is done so. PM driving is possible on any and all of the Northern line, even under normal operations. Thank you for the update, which in fact begs another question - extended contingency operations when there is a derailment blocking say the entrance to Morden. Are there subsidiary versions (for want of a better word) or editions of the Seltrac software for the line which enable subsets of it to be operated to reverse at Tooting Broadway for example, or is it planned to revert to PM driving in such circumstances. Incidentally, I can well imagine that the NLE software modifications have been written and tested but need time to be proven under operational conditions...but a whole day!?
|
|
|
Post by Chris L on May 22, 2021 15:05:51 GMT
Commissioning the NLE requires software modifications to the entirety of the Northern line’s Seltrac signalling system. Closure areas are always as small an area as possible, and where it is practicable to operate reduced services this is done so. PM driving is possible on any and all of the Northern line, even under normal operations. Thank you for the update, which in fact begs another question - extended contingency operations when there is a derailment blocking say the entrance to Morden. Are there subsidiary versions (for want of a better word) or editions of the Seltrac software for the line which enable subsets of it to be operated to reverse at Tooting Broadway for example, or is it planned to revert to PM driving in such circumstances. Incidentally, I can well imagine that the NLE software modifications have been written and tested but need time to be proven under operational conditions...but a whole day!? Recent introduction of new systems on the District line was achieved earlier than had been allowed and passengers were being carried in the afternoon. However, a whole line closure requires replacement buses which needs forward planning. Better to plan for a whole day than say half a day and then struggle to move passengers if it doesn't work.
|
|
Tom
Administrator
Signalfel?
Posts: 4,098
|
Post by Tom on May 22, 2021 21:14:51 GMT
. Are there subsidiary versions (for want of a better word) or editions of the Seltrac software for the line which enable subsets of it to be operated to reverse at Tooting Broadway for example, or is it planned to revert to PM driving in such circumstances. There's no need for a different version of software to run a service in such a scenario, unless the circumstances require the relevant VCC to be taken offline. As MoreToJack said, PM driving is possible at all times on the Northern line (assuming the TBTC system is functioning). If you mean manual driving without TBTC, it's possible, but only at a maximum of 10mph (16km/h). It isn't like New York where CBTC has been overlaid on top of the existing signalling; it's the only signalling system available on the Northern line.
|
|
Tom
Administrator
Signalfel?
Posts: 4,098
|
Post by Tom on May 22, 2021 21:17:57 GMT
Recent introduction of new systems on the District line was achieved earlier than had been allowed and passengers were being carried in the afternoon. Actually the work was finished later than planned; first (empty) trains ran some 20 minutes later than planned EB and a bit more than that WB. The fact that it was a very straightforward piece of railway meant that the Operational proving period could be significantly reduced and the operators were happy for the system to be used to carry passengers much earlier than might have otherwise been the case on a more complicated section.
|
|
North End
Beneath Newington Causeway
Posts: 1,769
|
Post by North End on May 22, 2021 21:36:27 GMT
. Are there subsidiary versions (for want of a better word) or editions of the Seltrac software for the line which enable subsets of it to be operated to reverse at Tooting Broadway for example, or is it planned to revert to PM driving in such circumstances. There's no need for a different version of software to run a service in such a scenario, unless the circumstances require the relevant VCC to be taken offline. As MoreToJack said, PM driving is possible at all times on the Northern line (assuming the TBTC system is functioning). If you mean manual driving without TBTC, it's possible, but only at a maximum of 10mph (16km/h). It isn't like New York where CBTC has been overlaid on top of the existing signalling; it's the only signalling system available on the Northern line. Yes there’s a bit of a misconception (including among some operational staff) that PM is some kind of backup facility. It isn’t - all PM does is give the driver an opportunity to do what the computer would otherwise do in driving the train, albeit perhaps to a more refined driving style if it’s someone reasonably proficient. PM is only really there for specific scenarios when ATO working isn’t permissible, for example if there’s people working on the track, or if someone needs dropping off at a trackside location. I’m given to believe there is going to be a slight tightening up of PM driving on the Northern, perhaps changing the current rule book wording (back in the early 2010s when all this was being done the union reps who had some input into all this were in many cases members of the “PM club”, as well as in many cases instructor operators, which allowed IOs to be able to drive in PM at any time they wanted). I’m sure in reality there won’t be much of a change, those handful who drive in PM regularly generally are very good at it, so get left alone by service control. Unlike the Jubilee where the radio will be pinging within seconds. I’ve also heard from a reliable source that the Northern may be getting the adhesion prediction software used on SSR, which might just allow some more spirited braking in the open sections. We’ll see if the ATO manages to be able to hit Brent Cross platform ramp at 40 mph like used to happen in the old days with bad old manual driving. So a good many millions and the greater part of a decade, and after all that things are almost as good as they were before!
|
|
|
Post by taylor on May 23, 2021 9:51:05 GMT
Thank you Tom for pointing out the difference in application of CBTC on LUL and the Flushing Line (7) [CBTC overlay] on the New York Subway. I’m much more familiar with the signaling on that network than the NL [TBTC – sole signaling system].
My wife and I travel regularly from Stoclwell to Moden. On some units we have noticed (sorry about this, can’t think of a better way of phrasing it) repeated, almost hesitant very slight accelerations and decelerations between successive stations between Clapham Common and South Wimbledon. It’s less marked than say the sudden brief acceleration of Victoria Line trains when they enter Green Park only to markedly brake some way along the platform. Am I correct in assuming that on the NL those slight bursts of acceleration and retardation are Seltrac’s attempt to maintain line speed? Other units don’t exhibit this erratic behaviour. Are they perhaps been driven by IOs or other “PM Club!” members driving to “keep their hand in”? It will be interesting to see if there are any noticeable changes after this weekend.
|
|
North End
Beneath Newington Causeway
Posts: 1,769
|
Post by North End on May 23, 2021 20:15:25 GMT
Thank you Tom for pointing out the difference in application of CBTC on LUL and the Flushing Line (7) [CBTC overlay] on the New York Subway. I’m much more familiar with the signaling on that network than the NL [TBTC – sole signaling system]. My wife and I travel regularly from Stoclwell to Moden. On some units we have noticed (sorry about this, can’t think of a better way of phrasing it) repeated, almost hesitant very slight accelerations and decelerations between successive stations between Clapham Common and South Wimbledon. It’s less marked than say the sudden brief acceleration of Victoria Line trains when they enter Green Park only to markedly brake some way along the platform. Am I correct in assuming that on the NL those slight bursts of acceleration and retardation are Seltrac’s attempt to maintain line speed? Other units don’t exhibit this erratic behaviour. Are they perhaps been driven by IOs or other “PM Club!” members driving to “keep their hand in”? It will be interesting to see if there are any noticeable changes after this weekend. The way TBTC drives the trains is dire, though it’s slightly less dire than when it first came in. As far as I know the system is simply set up to use motoring, braking or coasting to match the target speed - there is no anticipation or taking into account gradients. In PM the driver does have to drive to a large extent like this in order to keep time, though if the train is on time then there is scope to smooth things out slightly with only a fractional loss of time. The biggest clue to a PM train is the final stop may well be a lot smoother - most of the regular PM drivers tend to be the more thoughtful ones so you are more likely to get niceties like off & release stops (rare on LU nowadays, sadly, when it should be standard practice). 95 stock has also become a bit rougher over the years. No one seems to quite know if this is simply an age thing, a maintenance issue, or the result of modifications done over the years, but the result is some trains are very considerably more jerky when motoring and/or braking then others. I rode on one up to Barnet yesterday which was stopping with a really nasty jolt at virtually every station (and it was in ATO so not a driver issue), as well as no rheo in my car for some but not all stops. Overall though they’re still pretty fine trains, certainly miles better than 92 and 96 stocks.
|
|
Colin
Advisor
My preserved fire engine!
Posts: 11,310
|
Post by Colin on May 23, 2021 21:56:50 GMT
My wife and I travel regularly from Stoclwell to Moden. On some units we have noticed (sorry about this, can’t think of a better way of phrasing it) repeated, almost hesitant very slight accelerations and decelerations between successive stations between Clapham Common and South Wimbledon. It’s less marked than say the sudden brief acceleration of Victoria Line trains when they enter Green Park only to markedly brake some way along the platform. Am I correct in assuming that on the NL those slight bursts of acceleration and retardation are Seltrac’s attempt to maintain line speed? Other units don’t exhibit this erratic behaviour. Are they perhaps been driven by IOs or other “PM Club!” members driving to “keep their hand in”? It will be interesting to see if there are any noticeable changes after this weekend. Don't forget that Seltrac is moving block so it won't necessarily perform the same way on two separate trips over the same bit of railway. If you're train is following another train ahead of it, the target in front of your train is moving so your train will move accordingly. Obviously things like platforms and permanent speed restrictions are fixed and never move but the moving block element of the signalling might explain why you've experienced differences. most of the regular PM drivers tend to be the more thoughtful ones so you are more likely to get niceties like off & release stops (rare on LU nowadays, sadly, when it should be standard practice). It's not possible use the stopping in off & release technique on S stock - as soon as you release the brakes they immediately dump all the air (much like when you use the remote brake release switch on older stocks). Interestingly though, our CBTC system does achieve a relatively smooth stop compared to the TBTC equipped lines.
|
|
jimbo
Posts: 1,660
Member is Online
|
Post by jimbo on May 24, 2021 2:20:05 GMT
It's not possible use the stopping in off & release technique on S stock - as soon as you release the brakes they immediately dump all the air (much like when you use the remote brake release switch on older stocks). Interestingly though, our CBTC system does achieve a relatively smooth stop compared to the TBTC equipped lines. Sounds like the pure Westinghouse braked trains of near a century back, e.g. T stock on the Met. No partial release possible, and no further brake application with the reservoir empty! So that is progress!
|
|
|
Post by t697 on May 24, 2021 5:30:40 GMT
It's not possible use the stopping in off & release technique on S stock - as soon as you release the brakes they immediately dump all the air (much like when you use the remote brake release switch on older stocks). Interestingly though, our CBTC system does achieve a relatively smooth stop compared to the TBTC equipped lines. Sounds like the pure Westinghouse braked trains of near a century back, e.g. T stock on the Met. No partial release possible, and no further brake application with the reservoir empty! So that is progress! That's not really the case. The S stock brake is fully graduable in both application and release. That's not the same as saying the release is quite fast.
|
|
|
Post by superteacher on May 24, 2021 6:09:08 GMT
Can we get back to discussing the extension rather than the finer points of rolling stock braking - thanks.
|
|
|
Post by taylor on May 24, 2021 8:25:58 GMT
Can we get back to discussing the extension rather than the finer points of rolling stock braking - thanks. Did yesterday's closure (in anticipation of integrating Battersea X into the remainder of the NL) produce any noticeable / anticipated results on the line's operations?
|
|
|
Post by superteacher on May 24, 2021 8:40:49 GMT
Can we get back to discussing the extension rather than the finer points of rolling stock braking - thanks. Did yesterday's closure (in anticipation of integrating Battersea X into the remainder of the NL) produce any noticeable / anticipated results on the line's operations? No idea personally - hopefully somebody “in the know” may know something.
|
|
|
Post by t697 on May 24, 2021 11:47:36 GMT
Did yesterday's closure (in anticipation of integrating Battersea X into the remainder of the NL) produce any noticeable / anticipated results on the line's operations? No idea personally - hopefully somebody “in the know” may know something. Nothing the average passenger will notice at the moment. However a big list of detailed engineering/infrastructure control progress it's probably not appropriate to describe in a public forum. And I'm told a big start was made briefing Train Operators on rules, processes and procedures relevant to NLE.
|
|
roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
Posts: 1,255
|
Post by roythebus on May 24, 2021 19:18:52 GMT
To hark back a couple of comments, I'll start a separate thread in the historical section about the Westinghouse brake and it use if that's any help.
|
|
|
Post by superteacher on May 24, 2021 20:33:50 GMT
To hark back a couple of comments, I'll start a separate thread in the historical section about the Westinghouse brake and it use if that's any help. 👍 That’s great. We can move posts to it.
|
|
|
Post by grumpycat on May 25, 2021 21:54:52 GMT
When is trial running due to start then?
|
|
Tom
Administrator
Signalfel?
Posts: 4,098
|
Post by Tom on May 25, 2021 22:07:50 GMT
I'm not sure what the current date is other than 'later this summer'.
|
|
|
Post by goldenarrow on Jul 8, 2021 17:08:09 GMT
With trial operations now underway, various details have now made their way into the public domain with the conformation of a 6 tph peak and 5 tph off-peak service on the NLE when it first opens rising to a 12 tph peak and 10 tph off-peak service after in 2022 (presumably after the Bank Branch blockade). Mill Hill East is also confirmed as getting the remainder of it's direct service restored. TFL Press Release here
|
|
rincew1nd
Administrator
Junior Under-wizzard of quiz
Posts: 10,225
|
Post by rincew1nd on Jul 8, 2021 20:41:29 GMT
ianvisits reports that trial operations have started:
|
|
|
Post by burkitt on Jul 9, 2021 9:52:20 GMT
Included in the Ian Visits article is this video which is one of several I took while participating in the train operations on Sunday. A highly successful weekend with several more planned before operations begin.
|
|
|
Post by grumpycat on Jul 9, 2021 19:17:54 GMT
What's the exact date that the NLE will be opening hopefully
|
|
|
Post by goldenarrow on Jul 9, 2021 19:19:32 GMT
What's the exact date that the NLE will be opening hopefully 12 September 2021 has been mooted as a potential date from a few sources.
|
|
|
Post by spsmiler on Jul 10, 2021 10:27:54 GMT
With trial operations now underway, various details have now made their way into the public domain with the conformation of a 6 tph peak and 5 tph off-peak service on the NLE when it first opens rising to a 12 tph peak and 10 tph off-peak service after in 2022 (presumably after the Bank Branch blockade). Mill Hill East is also confirmed as getting the remainder of it's direct service restored. TFL Press Release hereDoes this mean that Battersea trains will go to Mill Hill East? Sort of a self-contained service?
|
|
|
Post by scheduler on Jul 14, 2021 18:48:58 GMT
With trial operations now underway, various details have now made their way into the public domain with the conformation of a 6 tph peak and 5 tph off-peak service on the NLE when it first opens rising to a 12 tph peak and 10 tph off-peak service after in 2022 (presumably after the Bank Branch blockade). Mill Hill East is also confirmed as getting the remainder of it's direct service restored. TFL Press Release hereDoes this mean that Battersea trains will go to Mill Hill East? Sort of a self-contained service? That is not outside the realms of possibility, the problem would be the speedy reversal required at Mill Hill East on 6tph. Since Finch C to MHE is 2.5 mins run time - that's 5 mins gone on a return trip. Train operator needs minimum 5 mins to change ends, so that makes 10 mins for a through train to be off the branch and the next one to run in. That is 6tph, but as you see there's no slack -so it's risky. 5tph would have some margin in it, and so very possible that Battersea - MHE is a self-contained service.
|
|
|
Post by xplaistow on Jul 15, 2021 17:05:57 GMT
I can think of 2 reasons why Mill Hill East is regaining it’s off-peak through service. First is all the new housing that’s been built on the former barracks nearby increasing the potential demand at the station. Second is that by diverting some trains that would otherwise go all the way to High Barnet to replace the shuttle would free up a couple of sets to balance out the extra sets needed to run the extension, thus keeping the total number of trains in service roughly the same. Does this mean that Battersea trains will go to Mill Hill East? Sort of a self-contained service? That is not outside the realms of possibility, the problem would be the speedy reversal required at Mill Hill East on 6tph. Since Finch C to MHE is 2.5 mins run time - that's 5 mins gone on a return trip. Train operator needs minimum 5 mins to change ends, so that makes 10 mins for a through train to be off the branch and the next one to run in. That is 6tph, but as you see there's no slack -so it's risky. 5tph would have some margin in it, and so very possible that Battersea - MHE is a self-contained service. Although the idea of running MHE to Battersea as a self-contained service is an interesting idea that would help to keep service patterns as simple as they could be, I’m not convinced that is the plan. 5tph is the current maximum frequency of the branch (so it is possible that all off-peak Battersea trains will run to MHE) but 6tph on the branch is a bit too tight. The typical turnaround time at MHE is 6 mins so while 6tph there is plausible*, it would probably need something like stepping back in order to reduce that turnaround time. (*One thing that could help to make 6tph more plausible is the fact that the last 300m or so of the branch at the Finchley end is double track, meaning that a train could depart for MHE shortly before the previous train off the branch arrives. This would probably save less than a minute but, in the words of a well known supermarket chain, every little helps.)
|
|
|
Post by A60stock on Jul 16, 2021 20:36:23 GMT
Not sure if it's been discussed already but was an answer given as to why PEDs have not been installed on the extension?
|
|