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Post by hummusn on Sept 25, 2024 16:46:33 GMT
This has been going on for several days now (or at least it feels like it) - what's happened exactly and why's it causing so many delays?
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Post by Dstock7080 on Sept 25, 2024 21:09:42 GMT
W361 on DOWN after East Putney tunnel failing.
An NR asset.
Trains from Edgware Road serving Wimbledon
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Colin
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Post by Colin on Sept 25, 2024 22:06:32 GMT
This has been going on for several days now (or at least it feels like it) - what's happened exactly and why's it causing so many delays? It was believed to be a cable fault and was actually rectified for a short period of time today, but the failure returned at the start of the evening peak. The reason it's causing extended delays is, in part, because it's a Network Rail signal that is failing. Every single train that has pass it needs authority to be given by the signaller. Once authority is gained, each train has to pass it and become front tripped; this forces a 10mph maximum speed restriction on the train for three minutes. The signal in question is just before the tunnel at East Putney and trains are almost at Southfields before the three minute time delay times out. Because of the length of signalling sections on this part of the District line, the Network Rail signaller isn't likely to authorise a train to pass the failed signal until the previous train has departed Southfields station. Hopefully you can see why it takes so long to get trains through and why its causing so much disruption as many Wimbledon trains are diverted or terminated early at Parsons Green. Trains from Edgware Road serving Wimbledon It's not that clear cut at all. It very much depends on which controller is on duty as to how the train service has been operated. On Sunday only the even numbered Edgware Roads went through with odds terminating at Parsons Green and everything else alternating to Ealing or Richmond. On Monday all the Edgware Roads went round at High Street Ken (going to & from Wimbledon); ex city trains went round at Parsons Green and all Richmond's went to Ealing. On Tuesday Chelsea were at home and Wimbledon only had two platforms available. Some ex city trains went through to Wimbledon, some went round at Parsons Green. Edgware Roads ran Parsons Green to High Street shuttles (a couple were diverted elsewhere). Today ex city trains went through to Wimbledon and Edgware Roads all went round at Parsons Green however that has since changed (current time 23:00) with ex city trains going round at Parsons Green and Edgware Road's running Wimbledon to High Street Ken. |
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Post by londonboi1985 on Sept 25, 2024 22:40:06 GMT
Had a feeling it would go down again shortly after it was fixed earlier and wasnt wrong.
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Post by uzairjubilee on Sept 25, 2024 23:06:14 GMT
I've just checked the TfL website and the District line is suspended between HSK and Edgware Road. Apologies if I've missed something but why is a signal failure near East Putney causing a suspension much further up? Is this a case of trying to recover the service in a way that I just don't understand?
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Post by londonboi1985 on Sept 26, 2024 4:29:51 GMT
I've just checked the TfL website and the District line is suspended between HSK and Edgware Road. Apologies if I've missed something but why is a signal failure near East Putney causing a suspension much further up? Is this a case of trying to recover the service in a way that I just don't understand? It is basically for service recovery. Trains loose time having to through the signal failure. So by cutting the Edgware Road service which they are running down to Wimbledon at High Street Kensington you can run the trains back to time for the working from high street to Wimbledon. |
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Post by jimbo on Sept 26, 2024 6:09:15 GMT
Recovery of the service is in the best interests of the public. The timetable is the plan for the day, and if it works then each train has a driver, who is relieved at the right time and place. But if a signal problem means that trains get back late from Wimbledon, each trip will accumulate more delays, and you will end up with staff running out of time at places where there is no replacement available. Trains have to be stabled here and there, and the service then really falls apart. If by turning trains short at High Street, they can return south at the right time, then crew reliefs at Earl's Court should work fine, and problems on following Richmond and Ealing service crew reliefs will also be avoided.
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Post by hummusn on Sept 26, 2024 6:53:46 GMT
This has been going on for several days now (or at least it feels like it) - what's happened exactly and why's it causing so many delays? It was believed to be a cable fault and was actually rectified for a short period of time today, but the failure returned at the start of the evening peak. The reason it's causing extended delays is, in part, because it's a Network Rail signal that is failing. Every single train that has pass it needs authority to be given by the signaller. Once authority is gained, each train has to pass it and become front tripped; this forces a 10mph maximum speed restriction on the train for three minutes. The signal in question is just before the tunnel at East Putney and trains are almost at Southfields before the three minute time delay times out. Because of the length of signalling sections on this part of the District line, the Network Rail signaller isn't likely to authorise a train to pass the failed signal until the previous train has departed Southfields station. Hopefully you can see why it takes so long to get trains through and why its causing so much disruption as many Wimbledon trains are diverted or terminated early at Parsons Green. Trains from Edgware Road serving Wimbledon It's not that clear cut at all. It very much depends on which controller is on duty as to how the train service has been operated. On Sunday only the even numbered Edgware Roads went through with odds terminating at Parsons Green and everything else alternating to Ealing or Richmond. On Monday all the Edgware Roads went round at High Street Ken (going to & from Wimbledon); ex city trains went round at Parsons Green and all Richmond's went to Ealing. On Tuesday Chelsea were at home and Wimbledon only had two platforms available. Some ex city trains went through to Wimbledon, some went round at Parsons Green. Edgware Roads ran Parsons Green to High Street shuttles (a couple were diverted elsewhere). Today ex city trains went through to Wimbledon and Edgware Roads all went round at Parsons Green however that has since changed (current time 23:00) with ex city trains going round at Parsons Green and Edgware Road's running Wimbledon to High Street Ken. Very thorough, thanks! I will admit that having many trains terminating at Parsons Green has given me the occasional empty train in the mornings, which is certainly something I can’t complain about. |
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Post by roman80 on Sept 26, 2024 10:12:05 GMT
Sadly not as pleasant at Putney Bridge in the morning peaks. The circa ten minute service, effectively 33% of normal at times, has meant many trains arriving crush loaded and passengers not able to board. Coupled with train indicator boards being blank so no idea when the next train is has been very unpleasant. TFL advising 'minor delays' is clearly PR and not fact.
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Post by tut on Sept 26, 2024 16:23:31 GMT
The reason it's causing extended delays is, in part, because it's a Network Rail signal that is failing. Every single train that has pass it needs authority to be given by the signaller. Once authority is gained, each train has to pass it and become front tripped; this forces a 10mph maximum speed restriction on the train for three minutes. The signal in question is just before the tunnel at East Putney and trains are almost at Southfields before the three minute time delay times out. Because of the length of signalling sections on this part of the District line, the Network Rail signaller isn't likely to authorise a train to pass the failed signal until the previous train has departed Southfields station.
Of course Network Rail rules do not require such a maximum speed for any period of time after passing a signal at danger; it is only necessary to proceed at caution, which is defined as proceeding at a speed which takes account of conditions (such as the distance you can see to be clear), that will allow you to stop the train short of any train, vehicle or other obstruction, or the end of your movement authority. Also 15 mph over points (not relevant in this case).
Indeed if the signal was fitted with TPWS a driver of a National Rail train would be explicitly required by the Rule Book to operate the TPWS train-stop override button when authorised to pass a signal at danger so as to avoid the train being brought unnecessarily (and sharply) to a stand.
Intentionally tripping past a signal and speed control after trip is 100% LU.
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Post by spsmiler on Sept 26, 2024 17:43:07 GMT
If the only trains between HSK and Edgware Road are Circles then I assume that they are somewhat crush loaded?
If Network Rail cannot get this sorted then maybe LU need to gain control of the signalling - and also be able to run a more frequent service, even if it means some trains regularly terminate at HSK.
Especially in the evenings some passengers who change trains at Earls Court will welcome Wimbledon trains that came from HSK, as these will be more likely to have vacant seats.
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Post by t697 on Sept 26, 2024 18:31:54 GMT
All very well to complain about the 10mph SCAT provision on LUL trains in tripcock areas compared to NR 'speed so as to be able to stop before any obstruction', but the collision record prior to the automatic 10mph limitation was really not acceptable. SCAT has been a very effective safety boon over the last 40 or more years on LUL.
Obviously my sympathies to those being delayed by an ongoing signal failure but better that than a significant collision risk I feel.
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Colin
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Post by Colin on Sept 26, 2024 23:30:58 GMT
Of course Network Rail rules do not require such a maximum speed for any period of time after passing a signal at danger; it is only necessary to proceed at caution, which is defined as proceeding at a speed which takes account of conditions (such as the distance you can see to be clear), that will allow you to stop the train short of any train, vehicle or other obstruction, or the end of your movement authority. Also 15 mph over points (not relevant in this case). Yes, it is a fact that the SCAT speed limit and time delay are an LU rolling stock issue, but has Network Rail updated it's rule book recently? Last time I looked caution on Network Rail was defined as 50mph. I have recently had a period of time off work; perhaps I've missed the change  For clarity to non railway staff, when we (LU drivers) receive authority to pass a failed signal by the Network Rail signaller, they say "proceed at caution and obey all other signals". They know our rolling stock has the very limiting SCAT system fitted but they still use the same language and the same Network Rail definition still applies to us even if we can't achieve their defined speed. If the only trains between HSK and Edgware Road are Circles then I assume that they are somewhat crush loaded? Whilst the Circles have certainly been very well loaded over the past week, they have coped perfectly well. As posted above by roman80, trains between Parsons Green and Wimbledon have been so crush loaded customers have been left behind on platforms. |
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Post by londonboi1985 on Sept 27, 2024 5:43:57 GMT
The reason it's causing extended delays is, in part, because it's a Network Rail signal that is failing. Every single train that has pass it needs authority to be given by the signaller. Once authority is gained, each train has to pass it and become front tripped; this forces a 10mph maximum speed restriction on the train for three minutes. The signal in question is just before the tunnel at East Putney and trains are almost at Southfields before the three minute time delay times out. Because of the length of signalling sections on this part of the District line, the Network Rail signaller isn't likely to authorise a train to pass the failed signal until the previous train has departed Southfields station. Of course Network Rail rules do not require such a maximum speed for any period of time after passing a signal at danger; it is only necessary to proceed at caution, which is defined as proceeding at a speed which takes account of conditions (such as the distance you can see to be clear), that will allow you to stop the train short of any train, vehicle or other obstruction, or the end of your movement authority. Also 15 mph over points (not relevant in this case).
Indeed if the signal was fitted with TPWS a driver of a National Rail train would be explicitly required by the Rule Book to operate the TPWS train-stop override button when authorised to pass a signal at danger so as to avoid the train being brought unnecessarily (and sharply) to a stand. Intentionally tripping past a signal and speed control after trip is 100% LU.
When you trip past a NR signal on the S stock and any tube stock that operates on NR bakerloo included the SCAT still kicks in and the train is limited to 10mph for 3 minutes still so the delay soon stacks up the same as it would be if the train tripped on a lul signal. |
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Post by londonboi1985 on Sept 27, 2024 14:13:25 GMT
Normally running of services restored earlier this morning and signal working normally so trains no longer tripping past.
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Post by roman80 on Sept 28, 2024 12:28:02 GMT
Back to issues this afternoon (September 28th). What is so particular to this failure that makes it so difficult to repair? If it persists until next week, TFL should be forced to be honest with commuters and not lie that the delays are minor.
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Post by tut on Sept 28, 2024 14:46:41 GMT
All very well to complain about the 10mph SCAT provision on LUL trains in tripcock areas compared to NR 'speed so as to be able to stop before any obstruction', but the collision record prior to the automatic 10mph limitation was really not acceptable. SCAT has been a very effective safety boon over the last 40 or more years on LUL. Obviously my sympathies to those being delayed by an ongoing signal failure but better that than a significant collision risk I feel. Of course I wasn't necessarily complaining about it as such, merely making a point of order for those readers who are not as familiar with the Network Rail Rule Book. Colin was of course very careful to say that the reason the delays are so great is only 'in part' because it's a Network Rail signal, but in his explanation of the precise issues being encountered I felt the average reader might assume that everything he outlined was down to Network Rail rules & regs. That is not the case. Indeed there is no doubt about it, the ultimate cause of the issue is a Network Rail signal failure and that is NR's responsibility. However the 10 mph limit for 3 minutes regardless of circumstances is not part of Network Rail's rules & regs and National Rail trains would not suffer such heavy delays as they would not be restricted in that way. Therefore, while there is no doubt that Network Rail's signal failure is the primary cause of the delays it is a bit misleading to imply (however unintentionally) that the very extensive delays caused by front-tripping and SCAT are Network Rail's fault. In fact that is the application of LU rules & regs to a section of line signalled to NR standards on which the NR Rule Book applies. The decision to do that, however justified, is LU's. But on the topic it could reasonably be argued that what may have been desirable in the dark tunnels between Stratford and Leyton in 1953 with 1953 lights and 1953 brakes is perhaps not as vital in the open air in 2024 with LED lights so bright they burn your eyes right out of your skull and modern brakes (even with the standard gauge East Putney tunnel (which was lit last time I was there but perhaps it isn't anymore)). Another important point to mention is that Network Rail's signalling and procedures are different. As Colin says every single train passing the signal needs authority from the signaller; the ability for drivers to pass automatic signals at danger on their own authority was taken out of the Network Rail Rule Book years ago. And the indications in Wimbledon ASC can be relied upon. The signaller in Wimbledon ASC does know if a train is occupying a signal section (indications failures or track circuit failures aside, which of course come with their own rules). As such the risk of a train being in the section when a second train passes a signal at danger is controlled on Network Rail by requiring the driver to get the authority of the signaller. On LU that risk historically needed to be mitigated by enforcing a very low speed when passing a signal at danger. Now, of course, mistakes can be made. In fact you could easily have "two in a bed" when "S5-ing" (authorising signals to be passed at danger). There's a lot going on. So yes the driver of a train passing a signal at danger cannot make assumptions. Yes they must indeed proceed at caution. That is necessary. Is it necessary to proceed at 10 mph all the way to Southfields when the driver can clearly see the line ahead is clear? Not really, no. Of course one other thing to suggest is that heavily crush-loaded trains (and heavily crush-loaded trains being front-tripped!) come with health and safety risks of their own.
Yes, it is a fact that the SCAT speed limit and time delay are an LU rolling stock issue, but has Network Rail updated it's rule book recently? Last time I looked caution on Network Rail was defined as 50mph. I have recently had a period of time off work; perhaps I've missed the change 50 mph is a speed that comes up in a number of places. It is the maximum speed, for example, during single line working when travelling in the wrong direction. It is also the maximum speed during a failure of a block instrument on absolute block lines. I do have a vague sense that I heard that number mentioned as an upper limit when proceeding at caution as well, perhaps that is a Train Operating Company policy or an unofficial best practice. The Rule Book however defines what it means by proceeding at caution in module TW1 Preparation and movement of trains regulation 25:
This rule has not changed since before September 2018 (which is the oldest issue I have easy access to). And in fact the Rule Book goes out of its way to differentiate between scenarios where a train may proceed up to a maximum speed of 50 mph (for example during temporary block working) and scenarios where a train must proceed at caution (for example when entering a temporary block working section to assist a failed train).
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Post by t697 on Sept 28, 2024 16:02:21 GMT
LUL had some serious accidents where the T/Op misjudged 'proceed at a speed so as to be able to stop short of an obstruction'. Contributing factors included fog (Kilburn) and sighting distance round a curve (Leyton - twice).
It's difficult to see how to safely and automatically moderate the 10mph limit now imposed by SCAT when at appropriate places with good sighting distances and with good weather prevailing at the time. And the 3 minutes was selected so that in most cases the train would have reached the next signal (which might be part of the same failure) within the 3 minutes.
I seem to recall serious assessment being done to change the limit to 15mph and D78 stock may even have started with that, but the regulator of the day (HMRI I think) wouldn't accept it.
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Post by hedgehogofthesouth on Sept 29, 2024 21:27:08 GMT
Again the signal failure has reoccurred. Tfl have got to be honest with passengers if this continues into the working week and explain what is happening.
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Post by Chris M on Sept 29, 2024 23:55:33 GMT
What would you like them to say? The delays are due to a recurring signal failure on Network Rail infrastructure, which they have basically said (if not quite in those exact words). Things like "speed control after tripping" are just meaningless words to most people.
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Post by hedgehogofthesouth on Sept 30, 2024 8:12:17 GMT
How about they put some information on their website stating that the signal is owned by network rail and their engineers are attempting to fix it and unfortunately at this stage have been unsuccessful. We don't know at this stage when it will be fixed and delays will occur ranging between minor and severe. We advise if possible that you take an alternative route or leave lots of extra time.
Just constantly putting minor delays everyday isnt helping.
And you're completely right. The average passenger doesn't need the full jargon but could perhaps understand it and have a bit more sympathy if simple further information were given.
This is just my opinion and always happy to be questioned on it and correctes. 😃
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Post by Tom on Sept 30, 2024 11:42:27 GMT
LUL had some serious accidents where the T/Op misjudged 'proceed at a speed so as to be able to stop short of an obstruction'. Contributing factors included fog (Kilburn) and sighting distance round a curve (Leyton - twice). Four times - Two on the Eastbound (1946 and 1953) and two on the Westbound (1979 and 1984). |
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Post by 35b on Sept 30, 2024 20:20:06 GMT
How about they put some information on their website stating that the signal is owned by network rail and their engineers are attempting to fix it and unfortunately at this stage have been unsuccessful. We don't know at this stage when it will be fixed and delays will occur ranging between minor and severe. We advise if possible that you take an alternative route or leave lots of extra time. Just constantly putting minor delays everyday isnt helping. And you're completely right. The average passenger doesn't need the full jargon but could perhaps understand it and have a bit more sympathy if simple further information were given. This is just my opinion and always happy to be questioned on it and correctes. 😃 I agree with that messaging, but why is the Network Rail ownership relevant to the public? As a user, I don’t care about the ins and outs of who are responsible for the bits and bobs, just that who I’ve paid to provide me with a service are on top of the job. |
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Post by xtmw on Sept 30, 2024 22:43:59 GMT
I've noticed status updates [between Gunnersbury - Richmond, East Putney - Wimbledon] now say 'due to a network Rail issue', from first glance it gives the message to the commuter that 'Oh... That! As you can see it's not our problem and you can't blame us because it's Network Rail infrastructure.'
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Post by hedgehogofthesouth on Oct 1, 2024 6:11:53 GMT
Delays occuring again this morning. Good service it said....
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Post by Chris M on Oct 1, 2024 11:15:47 GMT
I travelled that way yesterday mid afternoon. While I was at Earl's Court the official status was minor delays, but the driver of the train (going only as far as Parsons Green) described it as severe delays with the next Wimbledon train not due for 16 minutes.
The official service status has long (always?) been at best a very coarse guide to what service you experience on the ground, in part because the status is to some extent political (within the organisation, not party political) but also because there are three factors that impact what you experience that are semi-independent of each other that get rolled-up into the single description:
*How frequently the trains are running (on average)
*How even the gaps between trains are
*How long the journey takes once you are on the train.
Even with normal journey times and the right number of trains running on average if there are uneven gaps you can be lucky or unlucky. For example on the Jubilee line the other day there was an 8 minute wait for the first train when I got to the platform but the interval between the following trains was only 1-2 minutes each. This was advertised as a good service. I experienced minor delays but someone arriving just 7 minutes after I did would have experienced a good service.
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Post by roman80 on Oct 1, 2024 16:27:14 GMT
Just received the following from TFL customer services after emailing them last week after seeing the number of morning peak commuters unable to board trains at Putney Bridge. Posted verbatim below:
'Unfortunately we do not have direct influence on the maintenance of signals or response to signal failures between East Putney and Southfields as this part of the line is maintained by Network Rail. As District Line Service Control we have done our best to encourage, support and cajole a fix for the fault.'
The question on why Putney Bridge has zero information on the departure boards was ignored.
Any well managed organisation would have a service agreement with Network Rail rather than attempting to encourage, support and cajole. When 95% of the trains running on said section of track are TFL, its actually not surprising that Network Rail have no interest in fixing things, who can blame them. The fact TFL has no recourse is a TFL management failure.
As for describing the delays as minor when gaps between trains in the peak were ten minutes or more, and even then people could not board and indicator boards showed no information, let alone the next service, the response was:
'Additionally when deciding how to describe our service, we have to assess a number of different factors. Factors such as the amount of late running trains, the number of cancelled trains, the time of day, and passenger numbers all affect the service we provide. It is also important to describe the service accurately on the line as a whole.
Sometimes localised issues can affect a small number of customers for a short period then soon clear up. To advertise this could actually cause further inconvenience for customers across the line, as they change their journeys unnecessarily.' It would be nice if TFL could just tell the truth to those affected.
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Post by Colin on Oct 1, 2024 16:52:06 GMT
All this talk of Network Rail assets and Network Rail being blamed - ironically the Wimbledon branch is actually owned by London Underground! That being said, control of the signalling & traction current systems as well as maintenance and repair is all "sub contracted" to Network Rail and it's providers. How much of an incentive there is for Network Rail to fix London Underground's asset's on this branch..........clearly there isn't much!..... Sadly things have been compounded this afternoon by a one under at Fulham Broadway. And just to clarify a point from earlier in this thread: Colin was of course very careful to say that the reason the delays are so great is only 'in part' because it's a Network Rail signal, but in his explanation of the precise issues being encountered I felt the average reader might assume that everything he outlined was down to Network Rail rules & regs. That is not the case. You are quite correct. What I meant (but wasn't clear in explaining) is that there are less signals and they are a greater distance apart on the Network Rail signalled parts of the District line compared with traditional London Underground signalled sections. In essence it takes much longer for trains to clear a single Network Rail section than it does to clear a single London Underground section and it's therefore a lot longer time wise before the next train can be authorised past a Network Rail failed signal. I hope that makes sense and clears up my point. |
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Post by brigham on Oct 1, 2024 17:01:17 GMT
Once again, built-out flaxibility comes into play.
How is it that a train can be instructed to pass a failed signal, only to be tripped as if the driver has passed without authority?
I wonder what they wouuld do if it was a catch-point?
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Post by wonderwaller on Oct 1, 2024 18:02:56 GMT
Once again, built-out flaxibility comes into play. How is it that a train can be instructed to pass a failed signal, only to be tripped as if the driver has passed without authority? I wonder what they wouuld do if it was a catch-point? The same as they’d do at any signal with set of points in advance of it , secure the route before authorising trains past it. Ultimately the SCAT circuit can lead to delays (north end of the Met it can be particularly destructive to the service) but that’s obviously considered acceptable for the undoubted safety benefits it brings |
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