North End
Beneath Newington Causeway
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Post by North End on Nov 27, 2016 13:36:49 GMT
It would appear the Rayners Lane is likely to be shut for at least a week. I drive rail replacement buses and have got a weekend's work covering this line and I've heard they are talking of the cover going on for a week or more. This may cheer up some of the bus enthusiasts as there were at least 4 Routemasters running on Friday with some already pencilled in for Monday's service. I've never had dealings with the Picc stock, but had experience as a guard/emergency motorman on the District and Met in the early 1970s and 15 years as a BR driver. There's always been a problem with leaves on the line. In the old days when everything has prober brake blocks that rubber the wheels, the problem wasn't quite as prolific as it is today with disc brakes and regen/rheo braking on everything. I was one of those who had to suffer the first of the BR stock with regen brakes, the 508's, and had some worrying experiences with them not stopping where we wanted them to. The wheel slide protection worked too well, so well in fact that they had to put a panic button on them to isolate the WSP equipment. This then locked the wheels and the train would eventually stop! We weren't given any formal training as the problem in the 1980s hadn't really been "invented". Part of the solution was to fit trains with sanders, which seems to have had some effect. I don't think driver "training" will have much effect. when you are dealing with anything computerised such as the WSP equipment, when computer says no, then no matter what the driver does will alter that! One of the incidents I had on the SR was driving a 508 into Hampton Court, a dead-end terminus, I slowed the train to 15mph for the crossover entering the platform, applied the brake in the platform, the WSP operated all the way down the platform until the train mounted the sand drag. I was powerless to do anything. the whole episode was covered up and I was told not to report it, so I didn't. I would suggest that "cadence braking" suggested by someone above would not work on modern stock; this is in effect what the WSP equipment does. Maybe it is doing its job too well, and if the stock is fitted with an over-ride/panic button, then this is what's causing the flats as the WSP is effectively cut out, allowing the wheels to lock. You couldn't do cadence braking with Westinghouse braked stock you only had 3 brake applications with that! With the EP you can, and you can with the vacuum brake and distributor type air brakes. There is no easy answer. My niece has recently passed out as a night tube driver on the Picc, would she have any idea how to drive a train in autumn? I doubt it. You can only learn these things by experience, and experience cannot be taught in training schools, and I don't believe the current "take them off the streets" policy works. Sorry, but call me old-fashioned, but this view is taken by a lot of us from the 'old school", with main line drivers calling the newbies "boilies", boiled in the bag, ready in 5 minutes! Edited to add that rheostatic/regenerative braking has the opposite effect of putting flats on wheels. I slid through Stoneleigh one day on a 508 using the rheo brake; all driven wheels were actively going in reverse when I hit the platform and could be heard doing so! I stopped at the 12 mark..and an 8 car platform! Flats are only put on by the EP/Westcode brake causing wheels to lock up. The only real way to avoid is to drive appropriately. Know the line, know the gradients, know where and when issues are likely to occur, and drive accordingly. It's still possible to get caught out, but it shouldn't be happening to the extent that it evidently is.
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Post by phoenixcronin on Nov 27, 2016 13:37:59 GMT
All in all, the whole situation is a disgrace. Leaving a whole branch (Acton Town to Rayners Lane) without any train service for 3 days is appalling. Isn't the Picc unique though in that one branch (Heathrow) is of much greater importance than the other, and thus gets priority every time?
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Post by drainrat on Nov 27, 2016 14:00:36 GMT
It would appear the Rayners Lane is likely to be shut for at least a week. I drive rail replacement buses and have got a weekend's work covering this line and I've heard they are talking of the cover going on for a week or more. This may cheer up some of the bus enthusiasts as there were at least 4 Routemasters running on Friday with some already pencilled in for Monday's service. I've never had dealings with the Picc stock, but had experience as a guard/emergency motorman on the District and Met in the early 1970s and 15 years as a BR driver. There's always been a problem with leaves on the line. In the old days when everything has prober brake blocks that rubber the wheels, the problem wasn't quite as prolific as it is today with disc brakes and regen/rheo braking on everything. I was one of those who had to suffer the first of the BR stock with regen brakes, the 508's, and had some worrying experiences with them not stopping where we wanted them to. The wheel slide protection worked too well, so well in fact that they had to put a panic button on them to isolate the WSP equipment. This then locked the wheels and the train would eventually stop! We weren't given any formal training as the problem in the 1980s hadn't really been "invented". Part of the solution was to fit trains with sanders, which seems to have had some effect. I don't think driver "training" will have much effect. when you are dealing with anything computerised such as the WSP equipment, when computer says no, then no matter what the driver does will alter that! One of the incidents I had on the SR was driving a 508 into Hampton Court, a dead-end terminus, I slowed the train to 15mph for the crossover entering the platform, applied the brake in the platform, the WSP operated all the way down the platform until the train mounted the sand drag. I was powerless to do anything. the whole episode was covered up and I was told not to report it, so I didn't. I would suggest that "cadence braking" suggested by someone above would not work on modern stock; this is in effect what the WSP equipment does. Maybe it is doing its job too well, and if the stock is fitted with an over-ride/panic button, then this is what's causing the flats as the WSP is effectively cut out, allowing the wheels to lock. You couldn't do cadence braking with Westinghouse braked stock you only had 3 brake applications with that! With the EP you can, and you can with the vacuum brake and distributor type air brakes. There is no easy answer. My niece has recently passed out as a night tube driver on the Picc, would she have any idea how to drive a train in autumn? I doubt it. You can only learn these things by experience, and experience cannot be taught in training schools, and I don't believe the current "take them off the streets" policy works. Sorry, but call me old-fashioned, but this view is taken by a lot of us from the 'old school", with main line drivers calling the newbies "boilies", boiled in the bag, ready in 5 minutes! Edited to add that rheostatic/regenerative braking has the opposite effect of putting flats on wheels. I slid through Stoneleigh one day on a 508 using the rheo brake; all driven wheels were actively going in reverse when I hit the platform and could be heard doing so! I stopped at the 12 mark..and an 8 car platform! Flats are only put on by the EP/Westcode brake causing wheels to lock up. The only real way to avoid is to drive appropriately. Know the line, know the gradients, know where and when issues are likely to occur, and drive accordingly. It's still possible to get caught out, but it shouldn't be happening to the extent that it evidently is. Of course it shouldn't, which is why I don't believe for one minute that it's all of a sudden due to driving technique
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londoner
thinking on '73 stock
Posts: 480
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Post by londoner on Nov 27, 2016 14:00:44 GMT
Are there any videos of what flat wheel sounds like compared to a non-flat wheel?
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Post by superteacher on Nov 27, 2016 14:45:16 GMT
All in all, the whole situation is a disgrace. Leaving a whole branch (Acton Town to Rayners Lane) without any train service for 3 days is appalling. Isn't the Picc unique though in that one branch (Heathrow) is of much greater importance than the other, and thus gets priority every time? True, but completely sacrificing one branch is taking things to the extreme!
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Chris M
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Post by Chris M on Nov 27, 2016 14:52:54 GMT
This is a video of a NJ Transit train with flatspots:
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Deleted
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Post by Deleted on Nov 27, 2016 15:16:00 GMT
Last year I was on a train from Acton town to Rayners lane. The train more or less crawled the whole way. Whenever the driver tried to speed up, you could hear the wheels spin.
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Post by piccboy on Nov 27, 2016 18:04:47 GMT
The 73 stock on the Piccadilly line uses the Westcode 7 step EP braking system made by Westinghouse, although only 4 steps are used by the train. This is backed up by automatically applied Rheostatic braking on the motor cars, cars 1,3,4 and 6. Upon approach to a station, the Train Operator will select one of the Service Brake settings on the CTBC (marked as Service 1, 2, 3, 4 respectively), the train will then apply the relevant EP brake to all cars and after a few seconds (2-3?) the EP brakes in the motor cars are automatically released and the Rheostatic braking is applied. At about 10 mph the Rheostatic braking is automatically released and EP brake is reapplied to the motor cars.
So how does this relate to the problem of wheels locking up? When the Rheostatic braking appies, it tends to be more effective than the EP brake, and combined with poor rail adhesion (leaf fall and or wet / icy rails) then train wheels will be prone to locking up, and if this happens for too long can create a flatspot. The technique I was taught to avoid this was to apply the service brake and release and reapply in a cycle to avoid the Rheostatic brakes applying. This technique normally stops the wheels from locking up but factors like how poor the rail adhesion is, passenger load, speed, and braking distance are all important to the non skidding equation.
One final thought, although it has been several years since I have driven on the Piccadilly line, I can recall the 73 stock was prone to having a fierce Rheostatic brake develop in one or more motor cars or for a Rheostatic brake to stick on and release long after other cars released their brakes. This could also effect wheels locking up and flats.
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Post by rheostar on Nov 27, 2016 21:44:34 GMT
The technique I was taught to avoid this was to apply the service brake and release and reapply in a cycle to avoid the Rheostatic brakes applying. This technique normally stops the wheels from locking up but factors like how poor the rail adhesion is, passenger load, speed, and braking distance are all important to the non skidding equation. This is what I used to teach to my trainees when I was a road trainer. Drive a bit slower, use service 1, when you hear the wheels start to slide, into off and release then back into service 1.
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roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
Posts: 1,256
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Post by roythebus on Nov 28, 2016 2:58:05 GMT
So, on what you're saying is if you hear the wheels start to slide, this means the Westcode/EP brake is applied. I don't suspect a rheostatically braked axle will allow the wheels to slide as stated in my post about the 508 stock. the 508s only had a 3 position Westcode brake; it proved not to be man enough for the job, not enough variety of brake cylinder pressure.
When the 508s were introduced on the South Western we had one driver who applied the brake for Putney on the down, and ended up stopping somewhere about Mortlake. I had the episode at Hampton Court and there were numerous others.
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Post by norbitonflyer on Nov 28, 2016 7:37:42 GMT
........... and there were numerous others. Notably this one, under the noses of a certain publishing house link
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Deleted
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Post by Deleted on Nov 28, 2016 11:35:51 GMT
I do believe the signalling on that section hasn't been immunised and is not compatible with the traction equipment on S stock trains. Also, while the S stock have WSP (wheel slide protection) and presumably cope better than the 73s, they're not immune to flats either! Don't read into that too much they are a bit concerned with the 33 1/3Hz signalling supply interfering with the S stock at 50Hz. Before the east end of the District was fully immunised they were running S stocks over the same equipment and guess what happened? It all worked as designed. The only area of concern on the branch is the pointwork at South Harrow. Not my field of interest but the mitigation is to secure the points at South Harrow and ensure no other train movements between Ealing Common & Rayners Lane while "modern" stock traverses that section. The D stock is cleared on the Rayners Lane branch just needs to slow down to 10mph for a few of the bridges It was cleared to Hounslow Central but that was a few years ago now It’s 15mph in both directions under two bridges. Surface stock is no longer permitted west of Northfields apart from 7 siding and the depot. I don't think it would be allowed to operate in passenger service without a system in place to ensure that 10 mph is adhered to. The (15mph) speed restrictions are fully signed and in any case largely precautionary. Unless you can say with certainty that there are no other PSRs on the network which if ignored could potentially cause a gauging issue then these ones aren't in any way exceptional. I think you only get a flat on S stock if an emergency brake application is made as this overides the WSP. That is incorrect. On stock so fitted (1992 TS onwards), WSP operates in service and emergency braking. So, on what you're saying is if you hear the wheels start to slide, this means the Westcode/EP brake is applied. I don't suspect a rheostatically braked axle will allow the wheels to slide as stated in my post about the 508 stock. the 508s only had a 3 position Westcode brake; it proved not to be man enough for the job, not enough variety of brake cylinder pressure. If low adhesion results in the rheo braked axles slowing considerably or rheo proving is disrupted by this behaviour then the rheo will drop out on the car concerned and the air brake reapply, that is when the wheels might lock.
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roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
Posts: 1,256
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Post by roythebus on Nov 28, 2016 12:00:06 GMT
Thanks for the explanation there wr24 on the brakes. As I said, I've not worked on LT since 1974, but my experience with the 508s on BR was that the wheels could turn in reverse under certain poor adhesion events. That may have been altered with experience over the years!
As someone else said, the best way to drive a train is by experience and knowing the road thoroughly, that is in rain, sun dark, fog, tunnel, gradients, gaps, the lot. all that takes time and I would suspect the time given to learn a road on the Underground may not be sufficient. The experience only comes when the driver has passed out and is doing the job.
Maybe the current problem is caused by relatively new drivers who do not have this experience? Just a thought!
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Deleted
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Post by Deleted on Nov 28, 2016 12:12:19 GMT
Maybe the current problem is caused by relatively new drivers who do not have this experience? Just a thought! Driver training from start to finish is not long enough to guarantee that they will get any experience of driving during the leaf fall season before passing out, unless their course happens to coincide with it.
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Post by PiccNT on Nov 28, 2016 12:18:25 GMT
Being a new Night Tube driver, I was certainly taught cadence braking techniques. When you are driving in wet conditions and heading towards the Sudbury's, you have to take particular care. Due to the lack of trains, most of what I did this past weekend was shunting trains in and out of sidings and depots with a small amount of main line driving, mainly from Arnos to Cockfosters. We have 25 MPH TSR's in place and even so, on Friday night when it was dry, the rails were really slippery. I think I drove 7 different trains over the weekend and all of them had various degrees of flats on them.
There was talk that the provider of the material for the wheel tyres were supplying softer materials, whether this is right will probably come out of the investigation. In terms of inexperienced drivers adding to the problem, I think this only started last Monday with the very wet conditions so the only inexperienced drivers out on the line were with an Instructor Operator. Whether this has an effect on the introduction of the Night Tube, I doubt it. Not sure Mr Mayor will allow that! We have a launch meeting next Saturday morning at 2am (yes, you read that right!). Maybe we will get further information then.
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Post by stapler on Nov 28, 2016 14:07:16 GMT
Substandard/different spec material for tyres would surely be a serious safety concern, not just in respect of leaves......
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Post by Deleted on Nov 28, 2016 14:57:49 GMT
Did they get the wheels from Argentina like they did with the old 67 stock?
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Post by drainrat on Nov 28, 2016 15:54:35 GMT
Maybe the current problem is caused by relatively new drivers who do not have this experience? Just a thought! Driver training from start to finish is not long enough to guarantee that they will get any experience of driving during the leaf fall season before passing out, unless their course happens to coincide with it. And we were told we had too much before.
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Post by norbitonflyer on Nov 28, 2016 16:35:39 GMT
Do drivers not get refresher courses, or "Continuing Professional Development"?
It would surely not be impossible to give drivers who qualified in the early part of the year a few hours extra training when the slippery rail season arrives. Even bus drivers used to get a go on the skid pan at Chiswick!
Of course, on the roads, it is perfectly possible for someone who has just passed their test, or indeed someone who passed their test in 1964 but hasn't driven anything since, to get behind the wheel of a 7.5 tonne lorry, or a 1000hp Bugatti Veyron, or a 120 year old veteran car with hand throttle and tiller steering.
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roythebus
Pleased to say the restoration of BEA coach MLL738 is as complete as it can be, now restoring MLL721
Posts: 1,256
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Post by roythebus on Nov 28, 2016 17:44:54 GMT
A bit like expecting car drivers who live in the Hebrides to have motorway driving experience before they can pass the driving test!
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Post by fish7373 on Nov 28, 2016 17:58:46 GMT
Hi all tonight on the news update on flats BBC and ITV
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Post by Deleted on Nov 28, 2016 18:10:28 GMT
Just seen this as ITV London's Main Headline on Tonight's Bulletin is the disruption on the Piccadilly Line... Interesting to see this get the main headline! Nonetheless, had some interesting shots from Northfields Depot of repairs being undertaken and what the 'flats' look like. Also reporting on calls for the whole line to be shut down while repairs are undertaken.
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Post by domh245 on Nov 28, 2016 18:19:21 GMT
Also reporting on calls for the whole line to be shut down while repairs are undertaken. What a daft idea! It's not like the Chancery Lane situation where the trains had to be stopped, so there is no advantage to a shutdown for repairs. And besides, it is quite likely that the trains will continue to pick up flat spots for a few more months so all you'll have achieved is a week or two without any service for a week or two without any flats, to then repeat the cycle.
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Post by phoenixcronin on Nov 28, 2016 18:59:15 GMT
Are they buying new wheels or simply repairing the damaged ones?
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Post by domh245 on Nov 28, 2016 19:07:47 GMT
Are they buying new wheels or simply repairing the damaged ones? If the flat isn't too severe, then they'll probably be able to put it on a Wheel Lathe and turn it to get them circular again. If it is pretty severe (ie if they turn it so that it is circular again but the new diameter is less than the allowable diameter) then they'd have to replace the wheel.
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Post by phoenixcronin on Nov 28, 2016 19:39:33 GMT
Are they buying new wheels or simply repairing the damaged ones? If the flat isn't too severe, then they'll probably be able to put it on a Wheel Lathe and turn it to get them circular again. If it is pretty severe (ie if they turn it so that it is circular again but the new diameter is less than the allowable diameter) then they'd have to replace the wheel. That's what I thought, but what is the minimum diameter? The Rolling Stock Information Sheet states: "Wheel diameter 790mm new, 710mm worn", but I don't know if 710mm is the minimum allowed.
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Post by drainrat on Nov 28, 2016 20:39:34 GMT
If the flat isn't too severe, then they'll probably be able to put it on a Wheel Lathe and turn it to get them circular again. If it is pretty severe (ie if they turn it so that it is circular again but the new diameter is less than the allowable diameter) then they'd have to replace the wheel. That's what I thought, but what is the minimum diameter? The Rolling Stock Information Sheet states: "Wheel diameter 790mm new, 710mm worn", but I don't know if 710mm is the minimum allowed. Thats still some discrepancy between new and worn
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Deleted
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Post by Deleted on Nov 28, 2016 20:54:02 GMT
For those with internal intranet access type G2109 in the search box a quite lengthy document on wheel set defects
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rincew1nd
Administrator
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Post by rincew1nd on Nov 28, 2016 21:05:42 GMT
If the flat isn't too severe, then they'll probably be able to put it on a Wheel Lathe and turn it to get them circular again. If it is pretty severe (ie if they turn it so that it is circular again but the new diameter is less than the allowable diameter) then they'd have to replace the wheel. That's what I thought, but what is the minimum diameter? The Rolling Stock Information Sheet states: "Wheel diameter 790mm new, 710mm worn", but I don't know if 710mm is the minimum allowed. <Disclaimer: not a definitive answer> To my mind this means the diameter of new wheelsets is 790mm and they can be turned on a lathe down to 710mm. If after being skimmed to a diameter of 710mm the wheelset still has flatspots, then it's scrap.
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Post by domh245 on Nov 28, 2016 21:20:58 GMT
That's what I thought, but what is the minimum diameter? The Rolling Stock Information Sheet states: "Wheel diameter 790mm new, 710mm worn", but I don't know if 710mm is the minimum allowed. Thats still some discrepancy between new and worn Hmm, it'd be a ~10% difference, which does seem quite high, but on the flipside, as long as there are ways of coping with the variations it'll allow them to use the wheelsets that bit longer, saving a bit of money as a result. I assume that there is a way of accounting for the varying wheel diameter in speedometer readings, but I'm not sure how you'd cope with an up to 40mm variation in the height of the train.
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