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Post by snoggle on Feb 9, 2015 14:49:40 GMT
Members may be interested in this TfL panel paper on the forthcoming Heavy Overhaul Programme Lift for the 92 stock.
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Post by Deleted on Feb 11, 2015 12:59:50 GMT
I have read somewhere that the stock on the central line is currently limited in maximum speed to 87 km/h (since 2003 accident and equipment replacement, when before it used to be 96 km/h). If this is correct, I am wondering whether this programme would eliminate the reasons for current limitation and possibly lead to reintroduction of former higher speed limit.
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Post by Deleted on Feb 11, 2015 13:13:44 GMT
Unless they sort out the hunting, I dont mind the slightly longer journey times... I remember when they used to do 100kmh and it was like being inside an A62 stock compressor! Was reminded of why they only do 85 nowadays a few months ago one late evening, driver was finishing at Loughton and took advantage of the falling gradients. Whilst it rekindled memories of being 5 years old again going to London with the family it also rekindled memories of having to wait for the train to stop before having being able to talk!
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Post by stapler on Feb 11, 2015 14:23:54 GMT
It would be sensible to deal with the speed issue at the same time as the heavy overhaul, because that would improve capacity issues. the central Line is already grossly overcrowded, so fitting a few more trains into the TT would be greatly to be desired
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Post by PiccNT on Feb 11, 2015 14:27:40 GMT
That takes me back to when I used to use the Central Line and remember what seemed to be pretty high speeds in the 1956/59/62 stock trains. Approaching Bethnal Green over the points seemed to be pretty much full speed!
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Post by superteacher on Feb 11, 2015 19:55:55 GMT
They were doing some 100 kph trials a while back. Not sure what the outcome was.
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Post by crusty54 on Feb 12, 2015 6:47:29 GMT
Seems very strange to have to write a submission for routine work
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Post by Deleted on Feb 12, 2015 20:09:24 GMT
They were doing some 100 kph trials a while back. Not sure what the outcome was. If I remember orignally in certain sections when Westrace was first introduced trains did run at 100kph for a while then they turned the system down to its current operating speed
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Post by snoggle on Feb 12, 2015 21:45:56 GMT
Seems very strange to have to write a submission for routine work It may be "routine" in the sense it's needed at a point in the life cycle but it is still capital investment, not maintenance, and therefore has to be justified and approved in order to draw down from the budget. Was ever thus - I wrote papers for ticket machine improvements 20+ years ago.
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Post by snoggle on Mar 4, 2015 15:29:51 GMT
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Post by patrickb on Dec 31, 2015 18:01:56 GMT
I've been told that work on refurbishing the 1992 Tube Stock will commence at long last. There was a bit of a hiatus due to disagreements with RMT Union over agency staff etc... After nearly a 1 year delay to the project, I'm glad that the 92's will get the proper life extension work needed. I can finally stop calling them Duct Tape Stock. Are there any more details as to when exactly will refurbishment start and the first unit to undergo overhaul. Patrick
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Post by superteacher on Dec 31, 2015 19:36:37 GMT
I've been told that work on refurbishing the 1992 Tube Stock will commence at long last. There was a bit of a hiatus due to disagreements with RMT Union over agency staff etc... After nearly a 1 year delay to the project, I'm glad that the 92's will get the proper life extension work needed. I can finally stop calling them Duct Tape Stock. Are there any more details as to when exactly will refurbishment start and the first unit to undergo overhaul. Patrick That's good news, and welcome to the forum. What is the source of this news?
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Post by stapler on Dec 31, 2015 22:47:14 GMT
What will the refurb/heavy lift actually consist of?
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Post by Deleted on Jan 1, 2016 13:22:36 GMT
I have been told it is due to start 2018 sometime. There is a lot of structural to be done to the floors I believe.
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Post by superteacher on Jan 1, 2016 13:50:03 GMT
2018? Hardly seems worth it if the plan is to replace the trains in 10 - 15 years time.
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DWS
every second count's
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Post by DWS on Jan 1, 2016 14:47:50 GMT
2018? Hardly seems worth it if the plan is to replace the trains in 10 - 15 years time. No contract has been signed for any trains to replace the 1992 stock, the trains need money spent on them to keep the line's fleet in service until when ever the " New Stock" is ready to replace 1992 stock, the plan may say 10 - 15 years, But any plan needs money, no Money = No New Trains.
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Post by Deleted on Jan 1, 2016 16:44:48 GMT
Its worth keeping in mind that all the equipment off the 92's is currently in the process of being overhauled. Its just cosmetic and structural work that I believe is planned for 2018.
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Post by crusty54 on Jan 1, 2016 17:04:40 GMT
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Post by patrickb on Jan 1, 2016 17:41:36 GMT
I was told 'heavy maintenance at Ruislip' from a guy who works at Hainault who voiced his views on the lack of trains with more units outs of service on the current Central Line fleet. Anyway, I would personally take the news with a pinch of salt as it didn't seem conclusive which is also why I was hoping to get more answers here. What I do know is that there will be an interior overhaul (repaint, grab rails etc...) and inspection of radio equipment once the project is underway. Then there's the AC Traction installation which I believe was to come later. I also found this today which is good news www.rmtlondoncalling.org.uk/content/rmt-accepts-central-line-tmr-proposalAs for replacement, well it could come in 10 years, 15 years or 20 years but DWS is right in terms of no money - no trains. Still, refurbishment of stock doesn't guarantee immunity, D Stock per example.
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Post by victorialiner on Jan 1, 2016 17:47:03 GMT
I really hope that they'll find some red paint for the 'M' doors.
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Post by superteacher on Jan 1, 2016 19:11:51 GMT
Mod comment: Posts from that thread have been moved into here.
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Post by victorialiner on Jun 18, 2016 8:38:05 GMT
What is the current status of the HOPL? Has it even started?
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Post by Deleted on Jun 18, 2016 21:34:24 GMT
What is the current status of the HOPL? Has it even started? Major overhaul of equipment has started to equipment like air valves etc. The bogie work has begun, and is about to be stepped up. Work on the cars themselves is planned to begin 2018, but nothing has been said yet aout who will do this work.
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Post by victorialiner on Jun 19, 2016 15:03:34 GMT
Major overhaul of equipment has started to equipment like air valves etc. The bogie work has begun, and is about to be stepped up. Work on the cars themselves is planned to begin 2018, but nothing has been said yet aout who will do this work. Thank you for the detailed update!
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Post by patrickb on Jun 19, 2016 23:09:43 GMT
Despite the plan to have 92's replaced (probably not long after the 72's are 73's have reached their end of time in service), they are certainly going to last another 16 years at least. During this time, improvements should be made for accessibility (wheelchair bays) and security (On-board CCTV and new alarms), as well as giving interiors in general a proper make over. Could either Bombardier or Alstom be able to take on the refurbishment. Both had successfully refurbished the 73's and 95's, why should the 92's be any more of a challenge.....
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Post by drainrat on Aug 28, 2016 9:55:39 GMT
Unless they sort out the hunting, I dont mind the slightly longer journey times... I remember when they used to do 100kmh and it was like being inside an A62 stock compressor! Was reminded of why they only do 85 nowadays a few months ago one late evening, driver was finishing at Loughton and took advantage of the falling gradients. Whilst it rekindled memories of being 5 years old again going to London with the family it also rekindled memories of having to wait for the train to stop before having being able to talk! Sounds like he/she was running late and on a finish run. However, it's not because of track conditions that the trains run at 85kph. During the Chancery Lane derailment investigation it was found that the 92ts produced a resonance when approaching speeds in excess of 85kph, this resonance coupled with the over-tightening of bolts led to the plates holding the motors, fracturing and breaking off bits which loosened the motors. At the time there was no real quick fix, so the answer was to introduce a rotabolt which couldn't be over tightened, a torque machine in the depots to calibrate ratchet equipment, and to reduce the speed of the train to the fastest code speed block below the resonance speed, which is 85kph (in ATO only). In the early days post Chancery Lane derailment, if the train ever exceeded 85kph it was immediately taken OOS at reduced speed in CM. Having spoken to the Chief Rolling stock engineer last year, he seemed confident that the 92ts will once again achieve 102kph by mid/end of 2017, however, whether or not the track will keep up is another matter.
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Post by drainrat on Aug 28, 2016 9:57:55 GMT
I have read somewhere that the stock on the central line is currently limited in maximum speed to 87 km/h (since 2003 accident and equipment replacement, when before it used to be 96 km/h). If this is correct, I am wondering whether this programme would eliminate the reasons for current limitation and possibly lead to reintroduction of former higher speed limit. It's 85 kph max speed in ATO, used to be 102kph (even though speedometer shows 100 kph reading). Its worth noting though that these speed limits can only be observed in ATO and not CM.
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Post by 100andthirty on Aug 28, 2016 10:27:00 GMT
Unless they sort out the hunting, I dont mind the slightly longer journey times... I remember when they used to do 100kmh and it was like being inside an A62 stock compressor! Was reminded of why they only do 85 nowadays a few months ago one late evening, driver was finishing at Loughton and took advantage of the falling gradients. Whilst it rekindled memories of being 5 years old again going to London with the family it also rekindled memories of having to wait for the train to stop before having being able to talk! Sounds like he/she was running late and on a finish run. However, it's not because of track conditions that the trains run at 85kph. During the Chancery Lane derailment investigation it was found that the 92ts produced a resonance when approaching speeds in excess of 85kph, this resonance coupled with the over-tightening of bolts led to the plates holding the motors, fracturing and breaking off bits which loosened the motors. At the time there was no real quick fix, so the answer was to introduce a rotabolt which couldn't be over tightened, a torque machine in the depots to calibrate ratchet equipment, and to reduce the speed of the train to the fastest code speed block below the resonance speed, which is 85kph (in ATO only). In the early days post Chancery Lane derailment, if the train ever exceeded 85kph it was immediately taken OOS at reduced speed in CM. Having spoken to the Chief Rolling stock engineer last year, he seemed confident that the 92ts will once again achieve 102kph by mid/end of 2017, however, whether or not the track will keep up is another matter. The issues at Chancery Lane were: 1) the motor bolts were not over tightened; indeed they were often found loose. What follows will be clearer if I digress on how bolted joints work in shear. It is the friction between the bolted surfaces that supports the motor mass, and not directly the bolts themselves. A properly tight bolt is one that is stretched enough to clamp the two surfaces together (think of a bolt as a very strong tension spring). Loose bolts can and did fail, and even if the didn't fail, they caused movement (fretting) between the surfaces resulting in damage. The fix was to reface the mounting surfaces, and to use Rotabolts on the main motor fixings. Normal bolts are shown to be tight by reference to the torque used to turn the bolt. This is only an approximation of the stretching/clamping force because it also depends on other factors such as the friction between the threads on the bolt and nut (or housing). In contrast, Rotabolts directly indicate that the bolt has been stretched enough. New stronger safety brackets were also fitted. 2) One of the root causes was due to bearing failure on the gearbox input shaft. When this bearing failed, the motor would be subject to very significant vibration from the pinion moving in and out of mesh with the gearwheel. This vibration was much more than the motor mount could withstand. The 85km/h speed limit was imposed because a resonance in this bearing was identified at 90km/h and it was thought that this might be a contributor to the bearing failure. (It wasn't, but this was only proven 10 years later). In the short term this risk was managed by gearbox overhaul with new bearings and tight control of tolerances. Since then the bogie frames, motor mounting arrangement and gearbox bearing configuration have all been changed to eliminate all the root causes of the original accident.
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Post by drainrat on Aug 28, 2016 12:48:28 GMT
Sounds like he/she was running late and on a finish run. However, it's not because of track conditions that the trains run at 85kph. During the Chancery Lane derailment investigation it was found that the 92ts produced a resonance when approaching speeds in excess of 85kph, this resonance coupled with the over-tightening of bolts led to the plates holding the motors, fracturing and breaking off bits which loosened the motors. At the time there was no real quick fix, so the answer was to introduce a rotabolt which couldn't be over tightened, a torque machine in the depots to calibrate ratchet equipment, and to reduce the speed of the train to the fastest code speed block below the resonance speed, which is 85kph (in ATO only). In the early days post Chancery Lane derailment, if the train ever exceeded 85kph it was immediately taken OOS at reduced speed in CM. Having spoken to the Chief Rolling stock engineer last year, he seemed confident that the 92ts will once again achieve 102kph by mid/end of 2017, however, whether or not the track will keep up is another matter. The issues at Chancery Lane were: 1) the motor bolts were not over tightened; indeed they were often found loose. What follows will be clearer if I digress on how bolted joints work in shear. It is the friction between the bolted surfaces that supports the motor mass, and not directly the bolts themselves. A properly tight bolt is one that is stretched enough to clamp the two surfaces together (think of a bolt as a very strong tension spring). Loose bolts can and did fail, and even if the didn't fail, they caused movement (fretting) between the surfaces resulting in damage. The fix was to reface the mounting surfaces, and to use Rotabolts on the main motor fixings. Normal bolts are shown to be tight by reference to the torque used to turn the bolt. This is only an approximation of the stretching/clamping force because it also depends on other factors such as the friction between the threads on the bolt and nut (or housing). In contrast, Rotabolts directly indicate that the bolt has been stretched enough. New stronger safety brackets were also fitted. 2) One of the root causes was due to bearing failure on the gearbox input shaft. When this bearing failed, the motor would be subject to very significant vibration from the pinion moving in and out of mesh with the gearwheel. This vibration was much more than the motor mount could withstand. The 85km/h speed limit was imposed because a resonance in this bearing was identified at 90km/h and it was thought that this might be a contributor to the bearing failure. (It wasn't, but this was only proven 10 years later). In the short term this risk was managed by gearbox overhaul with new bearings and tight control of tolerances. Since then the bogie frames, motor mounting arrangement and gearbox bearing configuration have all been changed to eliminate all the root causes of the original accident. Interesting, the explanation given to the driver reps committee at the time by the RSE was certainly that over tightening was an issue, that each Bolt could be tightened to different tolerances depending on who fitted the bolt, which is why new bolts and tools were brought in. The rotabolts and brackets as well as a netting to catch were all mitigation. But to be honest, we were (and are) just laymen compared to the chief rolling stock engineer and maybe he was 'dumbing' it down for us. The indication to the driver of a (possible) bearing failure of on gearbox shaft was linked to a DTS message which showed as 'traction fault - no reset available' and even after the 'findings' of the report, confidence was low as by and large there was an impression left that there wasn't really any clue from those 'experts' as to what the root causes were, it was a case of 'it could be A, B or C....BUT, it could also be X, Y or Z.......However, we know it's somewhere between A-Z'. Indeed, there hasn't been a derailment since with the same characteristics as CL, so it can be taken as read that the 'mitigations' (which is all the recommendations were only ever put forward to us as) were right, maybe some were overkill so over the years equilibrium takes over to an extent. The thing at the time that sticks with me is that the derailment came as no surprise to us, just as the white city derailment hadn't either.
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Post by 100andthirty on Aug 28, 2016 17:16:10 GMT
Drainrat.......The mitigations were the Rotabolts, new safety brackets, gearbox overhaul and the traction fault indication. Each played its part. I have no idea why the impression of overtightening was given as there was never any suggestion of this. I don't know where the notion of netting came from - unless someone referred to the safety bracket as "a form of safety net"!
Since the bogie frames, motor mounts and gearbox parts were redesigned and replaced there is no further need of the mitigations (Rotabolts etc.)...the root cause has been fixed.
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