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Post by imran on Mar 28, 2024 11:41:35 GMT
<<Thread split from 92TS refurb/replacement - goldenarrow >>
To be honest, I think it’s time a new Signalling System is installed on the Central Line. Maybe that will help the refurbished trains work better. Maybe upgrade the power on the Line as well so that it can benefit the AC Motors?
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Post by xtmw on Mar 28, 2024 12:05:41 GMT
To be honest, I think it’s time a new Signalling System is installed on the Central Line. Maybe that will help the refurbished trains work better. The signalling on the Central line does the job - indeed there are some issues with it but with any system you do. From my understanding the CLIP train communicates with the signalling just fine - it's just running into traction motor and connect radio problems (Connect radio is what used on the LU network) If there was a new signalling system installed this would involve modifying not just the CLIP train, but all trains! (engineering as well) This would create more hassle as once again, you'd be mixing 90s technology with modern spec technology which would create further problems. If the Central were to receive new stock (not refurbished), yes, it would make sense to put new signalling in. The plan is to fit the Central with CBTC, like all other lines, once the line receives new stock, but this won't be for a long time. When it does get new stock, they'll be optimised to work on the existing signalling. From there, the line will be upgraded, pending funding and resources available. And of course we come to money. Where would the money come from? Funding isn't allocated for the Picc resignalling so I doubt there is money available for the Central resignalling when the current signalling system can provide an intense service when it's put under stress and gets the job done! Currently, there is a life extension scheme for the current signalling (hence the closure last weekend between WOO and EPP). This should keep the signalling running for a while until new signalling comes. In short, if you want to resignal the big red artery through London, you're going to have to take into account how much it'll cost and if it actually makes sense. Right now, it dosen't, but we could revisit this question when the line has new stock and the cash available. You'd also need to take into account how many closures would be needed for resignalling work! |
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Post by imran on Mar 28, 2024 13:07:30 GMT
To be honest, I think it’s time a new Signalling System is installed on the Central Line. Maybe that will help the refurbished trains work better. You'd also need to take into account how many closures would be needed for resignalling work! Oh god! I didn’t think of that! I remember the nightmare the Jubilee went through in the late 2000s/early 2010s with constant weekend closures for resignalling works! Imagine that with the Central! But as long the current signalling system works fine, then it’s all good! But what I wonder how much the CLIP trains will benefit from a power upgrade? Not much probably. |
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gefw
Gone - but still interested
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Post by gefw on Mar 28, 2024 16:22:12 GMT
To be honest, I think it’s time a new Signalling System is installed on the Central Line. Maybe that will help the refurbished trains work better. If there was a new signalling system installed this would involve modifying not just the CLIP train, but all trains! (engineering as well) This would create more hassle as once again, you'd be mixing 90s technology with modern spec technology which would create further problems. If the Central were to receive new stock (not refurbished), yes, it would make sense to put new signalling in. The plan is to fit the Central with CBTC, like all other lines, once the line receives new stock, but this won't be for a long time. When it does get new stock, they'll be optimised to work on the existing signalling. From there, the line will be upgraded, pending funding and resources available. And of course we come to money. Where would the money come from? Funding isn't allocated for the Picc resignalling so I doubt there is money available for the Central resignalling when the current signalling system can provide an intense service when it's put under stress and gets the job done! Currently, there is a life extension scheme for the current signalling (hence the closure last weekend between WOO and EPP). This should keep the signalling running for a while until new signalling comes. In short, if you want to resignal the big red artery through London, you're going to have to take into account how much it'll cost and if it actually makes sense. Right now, it dosen't, but we could revisit this question when the line has new stock and the cash available. You'd also need to take into account how many closures would be needed for resignalling work! We are rather drifting of the subject on this thread - perhaps the moderators will create a new heading. There are some papers in the public domain about the strategy/method for signalling modernisation/upgrade schemes (googling "incremental upgrade" will show some - for example board.tfl.gov.uk/documents/s16685/pic-20211013-Item12a-Part1-lu-signalling-controls.pdf.)The strategy for the central line is no longer going to be a big bang - it is going to be a gradual process, and a project team is already on the case with a lot of things to be upgraded before the new trains arrive. So future testing and changeovers (like the one last weekend) are planned some of which probably can't be efficiently done during standard Engineering Hrs. The last I heard they were completing the procurement processes to enter into a longer term relationship/commitment with a supplier for this work (Siemens included). Hopefully this will mean that new computerised interlockings will be able to simultaneously support/control both the 92 stock (with ATP speed codes & ATO PACs) as will as new stock just running under CBTC. (in the same sort of vein as the SSL/Thales system is intended to do on the Met with both CBTC equipped trains and colour light signal/trainstop controlled trains) |
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Post by spsmiler on Mar 31, 2024 12:49:40 GMT
To be honest, I think it’s time a new Signalling System is installed on the Central Line. Maybe that will help the refurbished trains work better. Maybe upgrade the power on the Line as well so that it can benefit the AC Motors? Please, PLEASE... no (and NO!) What is there works - and some people might say that it actually works better (fewer foibles) than some other automated train control systems. It does not matter that this does not use the latest in 'all singing, all dancing' moving block tech. |
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Post by xtmw on Mar 31, 2024 14:09:50 GMT
Exactly my point ! The ongoing signalling life extension works prove that a replacement for it is not needed... Yet... We can revisit this topic in maybe 10-15 years !
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gefw
Gone - but still interested
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Post by gefw on Mar 31, 2024 17:49:12 GMT
I agree that central line Signalling system for fills its functional purpose well and reasonably reliably and there is not a business case for changing the concepts or equipment for better runtime or trains per hour.
The key issue to point out is rather like that of the Central Line Train; the technology used in the system is now well out of date, obsolete and believe now only used by LUL.
LUL can't keep relying on 8 bit microprocessors, RS232/422 serial comms and MS DOS based operating systems/languages (for in service equipment or critical support systems ) - Siemens are trying hard but the parts to repair failed electronic modules or build replacement modules are increasingly expensive or in some cases unobtainable so we are in danger of running out of spares and signalling be inoperable.
This now means that LUL are having to invest 10's of Millions £ (via the life extension project) for Siemens to support the system by redesigning/replacing the obsolescence critical elements on a "Like for like" functional basis - This includes the whole central control system.
There is also the problem that when new stock eventually arrives, the Trainborne signalling "boxes" are not available off he shelf to enable the new trains to operate on the current signalling (eg ATP codes and PAC's).
So the review of the above (under the incremental upgrade project) has noted it does make sense to take opportunities to upgrade to more mainstream/current hardware products/architecture/operating systems. I am not sure whether this could also mean the Trackside systems would reach a status whereby they could simultaneously support introduction of new trains equipped only with CBTC boxes.
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Post by superteacher on Mar 31, 2024 20:58:43 GMT
Back in the 90’s, the signalling was state-of-the- art and the first time that a traditionally signalled line was upgraded to electronic based systems. I think few people could have foreseen how quickly technology was going to become obsolete.
Without wishing to drift off topic, will the systems on the northern, jubilee and SSL have similar issues, or not because there are fewer solid-state components?
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Post by tut on Mar 31, 2024 21:18:17 GMT
It was rightly said at the time "The Central Line now works almost as well as it did in the days before they spent £800,000,000 on it".
But of course that was an investment, it was money well spent, because once you'd spent all that money ironing out all the flaws and making it work and suffering the teething problems, you were away weren't you? The growing pains were over and now you've got a stable base from which to equip your other lines and now you've got the know-how and you can roll it out elsewhere much more easily and it'll last for years.
Ah except before you've even finished installing it it's already out of date and the whizz kids who designed it are already bored of it. So every single time you have to buy a new product that's entirely incompatible with everything else and try and make that work. And by the time you get to the next line TBTC just isn't the thing nowadays, you need CBTC, which is incompatible, so even though you have the Jubilee Line, which traditionally could interwork with the Met and shares a depot using TBTC, no no no you can't put that on the Met as well, to give you back that interoperability, you need to buy our new rubbish which'll be sooooo last year before we've even finished it, much less keeping it going for long enough to justify the outrageous expense of the growing pains.
There was an FPL failed at Tunnel Junction a few months ago which was found to have dated from the 1940s. Now it would be reasonable enough for that to be unsupported by the original manufacturer, 70-80 years of life is quite good value for money, but all that was required was to weld a metal plate on and it was restored to service that very evening.
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Post by xtmw on Mar 31, 2024 22:33:27 GMT
Back in the 90’s, the signalling was state-of-the- art Are we forgetting the amount of overruns and wheelflats that happened when it was first introduced!  To this day it's still no good in the rain, not when it's heavy raining, but that 'fine' drizzle. DTS will fill itself up with 'LOW ADHESION' or 'ATO OVERSPEED' For those who don't know how the Central Line ATO 'calculates' how to get to the next stop, I would explain it but I really can't be bothered. It's almost midnight on a Sunday. aslefshrugged has explained how it works perfectly. Click here |
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Post by jimbo on Apr 1, 2024 8:04:23 GMT
I wonder what the signal upgrade is aiming to achieve. Is it intended to extend the equipment life indefinitely by a rolling program over the years? Is it intended to extend the current system to match the CLIP project on trains, so that new trains and signalling may be ordered maybe ten years later than originally intended? Is there any upgrade featured in the project so that current trains might travel faster, or closer together, in time? Picc signalling to match the new trains is the next priority followed by the Bakerloo, especially if the Lewisham extension is to get started. So Central line signalling replacement is unlikely to be affordable until new trains are ordered, which will probably be after the current Siemens contract has expired.
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Post by spsmiler on Apr 1, 2024 10:31:18 GMT
its a money pit, and at a time when the cupboard is bare that is unaffordable
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Post by xtmw on Apr 1, 2024 12:02:56 GMT
Is it intended to extend the equipment life indefinitely by a rolling program over the years? That is my understanding, yes No need for a service increase as the signalling can deliver around 32-34tph between White City and Leytonstone, before the disruption it wasn't uncommon to see a train every minute or two during the peak The CLIP trains operate just fine on the existing signalling. They've done test runs on the entire line and it's coped fine. No doubt gefw can explain the in's and out's of what is going on |
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Tom
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Post by Tom on Apr 1, 2024 13:05:17 GMT
I wonder what the signal upgrade is aiming to achieve. Is it intended to extend the equipment life indefinitely by a rolling program over the years? Yes. The idea is to move away from 'big bang' full line upgrades and back to a rolling programme of upgrades and renewals - with the aim that when a rolling stock renewal programme begins that the signalling doesn't have to be upgraded or replaced to support them. |
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towerman
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Post by towerman on Apr 1, 2024 17:23:07 GMT
Sounds like common sense.
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gefw
Gone - but still interested
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Post by gefw on Apr 1, 2024 17:27:40 GMT
Re xtmw note regarding the "signalling" compatibility with the revamped 92 stock CLIP train. Note the Trainborne ATP and ATO boxes are considered part of the signalling and are unaltered in CLIP. The ATO & ATP controllers software development facilities are obsolete so no functional changes can hence forth be developed. Also note the ATO functionality is very dependent on the the train traction/brake system functionality/performance (and both have been tweeked over the years to try and reduce the flats and other problems related to wheel adhesion referred to in other recent posts). So it was essential/intended that the CLIP Traction revamp did not make the situation worse and perhaps even improve the WSP and accuracy of the "speed" signal for ATO (used to determine distance travelled and recognise the PAC reference markers during the station stop). Lets hope the test train is getting plenty of mileage in various poor adhesion conditions to verify this has been achieved. Last I heard the ATP & ATO hardware obsolesce (ie ensuring spares/repairs for circa another 15 yrs) is in the scope of Signal life extn. Routine Overhaul of Train ATP Tachos & flexing cabling replacement is hopefully in the scope of the CLIP/92 refurb. |
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Post by spsmiler on Apr 1, 2024 20:16:32 GMT
No need for a service increase as the signalling can deliver around 32-34tph between White City and Leytonstone, before the disruption it wasn't uncommon to see a train every minute or two during the peak I agree with your comment re: No need for a service increase but feel a need to clarify your comment before the disruption it wasn't uncommon to see a train every minute or two during the peak The reality is that no matter what the timetable is, bunching still occurs and I still often see eastbound trains almost nose to tail - at Stratford station, eastbound, off-peak! Also, it tends to happen that several trains in a row serve either the Epping or the Hainault branches, so that when a train for the other branch finally arrives it is quite crowded. If only the eastbound GEML local / electric line (nowadays Elizabeth line) service could be that frequent again - it would help reduce on-train overcrowding. (It was prior to 1990 signalling alterations). |
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Post by jimbo on Apr 2, 2024 7:11:35 GMT
So, when the Central Line eventually gets its next generation of trains, the intention now is that they will be adapted to run with the current signalling system. Will the current signalling system need to be adapted to work with a new generation of trains? In what way might it need to be tweaked? How would its performance fall short of getting a new signalling system, as originally envisaged?
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gefw
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Post by gefw on Apr 2, 2024 8:09:13 GMT
That is the big chicken & egg question with regards the compatibility/ migration path for the Central line line train & signalling systems (including the ATP & ATO kit on the train).
I believe it is acknowledged that the ATP codes & ATO PAC principles are no longer in the siemens (or other suppliers) list of actively supported/sold systems which has many connotations - so at some stage in the incremental upgrade there is likely to be a change over to a more common interface (perhaps even something covered by the ETCS) - there would be some logic in this co-inciding with the new stock.
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Post by starlight73 on Apr 2, 2024 12:53:46 GMT
The Victoria line signalling was upgraded as the 2009 stock arrived. (Many old threads e.g. this one) As other posters have suggested, new stock could lead to some kind of upgrade? (Not that this is happening soon!) |
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gefw
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Post by gefw on Apr 4, 2024 8:21:39 GMT
The Victoria line signalling was upgraded as the 2009 stock arrived. (Many old threads e.g. this one) As other posters have suggested, new stock could lead to some kind of upgrade? (Not that this is happening soon!) Yes I believe the Vic line signalling and train upgrade (in the 2000's) is probably similar to the sequence proposed for the Central. But note that the upgrade of the Wayside signalling and the development of the Trainborne boxes commenced many years before the trains arrived (so that it provided the required new signalling messages to the new trainbourne signalling kit which is a form of CBTC). Once the old trains had all gone, the signalling upgrade could take the next step (To transfer the interlocking fully over to the new kit + replace the life expired train detection (with JTC's)). Note it was NOT considered worthwhile becoming full moving block and train position detection by trackside methods was retained. |
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Post by imran on Apr 4, 2024 17:42:16 GMT
I hate to say this, but the Signal Life Extension Works done between Woodford and Epping haven’t really worked wonders.
There was a signal failure the other day at Debden that caused disruption between Loughton and Epping, and now there was another one today at Epping, causing the same problems!
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Tom
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Post by Tom on Apr 4, 2024 19:19:55 GMT
I hate to say this, but the Signal Life Extension Works done between Woodford and Epping haven’t really worked wonders. The problems that have been encountered are nothing compared to what will happen if the existing obsolete components are not replaced with modern equivalents. I don't have the full details but I know it's b*ggered up Debden siding for the foreseeable The work has not done as you say. I know this because I wrote the restriction that applies to Debden siding - therefore I do have the full details. |
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gefw
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Post by gefw on Apr 5, 2024 7:52:09 GMT
Rather unfortunate - but a wake up call to the difficulties with remobilising the skills & processes associated with working on an old system.
Sounds like they understand the problem & limitations are better than temporary reversion to original.
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Post by imran on Apr 9, 2024 16:42:18 GMT
Another signal failure at Debden occurred today! That’s the 3rd time one has happened between Loughton and Epping since those works were done!
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Post by xtmw on Apr 9, 2024 17:37:25 GMT
If the works were not done the alternative would have been the signalling left to rot and cause catastrophic failures
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gefw
Gone - but still interested
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Post by gefw on Apr 9, 2024 18:53:14 GMT
The problem/risks to the existing systems relate to obsolescence and the very limited remaining stock of certain spare parts (typically microprocessor based/solid state cards) - so if these parts happen to fail (at any location), sooner or later they will not have the spare unit to make the fix - so the signalling at that site may become inoperative (having failed safe).
The Life extension project scope is to find an alternative obtainable part that can be used instead - This may well require alterations to cabling and mountings but adapting the old software to run on the different card and still function the same is often the more complicated challenge.
Although the original units had not failed at these sites, it made sense to perform the swop at at least a few sites to test/prove the solution, plus use the removed units to bolster the spares stock for other sites.
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Post by jimbo on Apr 9, 2024 21:02:27 GMT
I presume somewhere like Debden was chosen to start this project rather than straight into White City or Leytonstone for this very reason!
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Post by xtmw on Apr 9, 2024 22:58:34 GMT
Everything 'new' comes with issues. When the kit in the control room gets replaced it's bound to run into issues.
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Tom
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Post by Tom on Apr 10, 2024 21:04:42 GMT
I presume somewhere like Debden was chosen to start this project rather than straight into White City or Leytonstone for this very reason! Interesting that nobody mentions Epping or Theydon Bois which were also commissioned on the same weekend. |
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