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Post by superteacher on Apr 23, 2019 19:06:37 GMT
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Post by Dstock7080 on Apr 23, 2019 19:54:04 GMT
alpinejohn , In answer to your question over ATC (Automatic Train Control) mods, as of the beginning of this month there are just 5 S8’s (out of 58) and 21 S7’s (out of 134) to be converted. Currently the last S8 21109/10 is at Derby to be converted, all others have returned converted. 4 S7s are currently away being converted, 8 S7s remain in London unconverted.
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Tom
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Post by Tom on Apr 23, 2019 20:13:53 GMT
Interesting, but it is a reasonably alert person's opinions rather than any hard facts. Some of it I would disagree with quite a lot!
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Post by Deleted on Apr 24, 2019 0:14:43 GMT
After reading it twice a lot of it I would disagree with
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Colin
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Post by Colin on Apr 24, 2019 13:01:02 GMT
I too have similar thoughts.
It's almost like they've taken all the facts from this forum, added in their thoughts and then rolled the whole lot up into the linked to document....
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Post by superteacher on Apr 24, 2019 17:16:08 GMT
It seems quite an ambitious timetable upgrade before the whole of the SSR is upgraded.
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Colin
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Post by Colin on Apr 24, 2019 17:41:25 GMT
Ambitious?
By their own admission, its total guesswork!
In anycase some of their guesswork is pie in the sky.
They talk about it being no problem increasing the frequency of service to Richmond. I'd love to know how they arrived at that conclusion! Keep in mind that although CBTC signalling will be installed on the Richmond branch, it will be driven by the current Network Rail signalling which must remain in place for London Overground trains. London Overground services have been increased such that the current signalling system is already running at full capacity. It's therefore not possible to pump any more trains down there.
Moving east to Barking, they've got 15 trains per hour terminating there. How's that going to work without causing a bottle neck then? Especially as they're claiming a 30 trains per hour service between Aldgate East and Barking.
30 trains per hour through Aldgate East? In both directions? I'd be very surprised if it worked.
I just can't see much of what they say being all that realistic.
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Post by ijmad on Apr 26, 2019 11:57:45 GMT
I did get the sense this is all very speculative though, as you're all saying.
However, as to the Barking question, it's not 15tph terminating at Barking - it's 7.5tph H&Cs, plus (7.5 - X) Districts, the X being however many are terminated at Tower Hill, which they're not guessing at this point. I guess turning a bunch of trains at Tower Hill also reduces the pressure on Aldgate East junction.
It is very interesting to wonder how many trains will be able to cleanly pass through this area when under full ATO. Is the plan to have a peak of 32tph through Aldgate East in 2023?
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Post by Deleted on Apr 26, 2019 12:08:55 GMT
Tower Hill will be loosing it’s reversing bay road after the upgrade is complete but trains could be turned as an emergency
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Post by goldenarrow on Apr 26, 2019 15:30:49 GMT
Tower Hill will be loosing it’s reversing bay road after the upgrade is complete but trains could be turned as an emergency Is it being demoted to sidings similar to the bays at Moorgate or is it going the way of Mansion House?
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Post by Deleted on Apr 26, 2019 15:47:39 GMT
No Tower Hill will have a crossover at each end still for reversing moves if required but the bay road currently will become the normal westbound
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Post by ijmad on Apr 26, 2019 16:49:59 GMT
No Tower Hill will have a crossover at each end still for reversing moves if required but the bay road currently will become the normal westbound What's going to happen to the existing Westbound?
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Post by Deleted on Apr 26, 2019 18:08:37 GMT
Disconnected completely hence why the track bed at Mansion House still remains the original plan was the same as Tower Hill but lack of money blah blah blah
You have to realise this new system CBTC does not like junctions or points hence the rationing of some sites which were rarely used.
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Post by ijmad on Apr 26, 2019 18:30:51 GMT
Disconnected completely hence why the track bed at Mansion House still remains the original plan was the same as Tower Hill but lack of money blah blah blah You have to realise this new system CBTC does not like junctions or points hence the rationing of some sites which were rarely used. Forgive me if I'm wrong, but I thought I'd read Mansion House's platform was just too short for the S7 stock? Maybe I'm misremembering.
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Post by londonstuff on Apr 26, 2019 19:01:07 GMT
Disconnected completely hence why the track bed at Mansion House still remains the original plan was the same as Tower Hill but lack of money blah blah blah You have to realise this new system CBTC does not like junctions or points hence the rationing of some sites which were rarely used. What could possibly go wrong with a railway without points or junctions? My school is great without the kids too.
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Post by Deleted on Apr 26, 2019 19:02:05 GMT
Disconnected completely hence why the track bed at Mansion House still remains the original plan was the same as Tower Hill but lack of money blah blah blah You have to realise this new system CBTC does not like junctions or points hence the rationing of some sites which were rarely used. Forgive me if I'm wrong, but I thought I'd read Mansion House's platform was just too short for the S7 stock? Maybe I'm misremembering. S7’s did fit but only just very tight
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Post by Chris L on Apr 26, 2019 20:29:14 GMT
Forgive me if I'm wrong, but I thought I'd read Mansion House's platform was just too short for the S7 stock? Maybe I'm misremembering. S7’s did fit but only just very tight But not enough overlap for regular safe working under the new system.
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Post by ijmad on Apr 26, 2019 21:17:43 GMT
It would seem like if anything, two Eastbound platforms at Tower Hill would be most useful. That way you could hold a train for a few minutes if an H&C is clearing Aldgate East junction.
That sort of centralised timing coordination seems highly possible with an ATO system that is centrally controlled. I suppose you could programme it to dynamically adjust speeds across the whole subsurface network to make the right gaps at junctions.
Does the Thales system support this sort of intelligent behaviour?
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Post by spsmiler on Apr 26, 2019 22:43:46 GMT
It would seem like if anything, two Eastbound platforms at Tower Hill would be most useful. That way you could hold a train for a few minutes if an H&C is clearing Aldgate East junction. If it was an island platform, such as previously existed at Whitechapel, it would work very well.
However, not here, as with the tracks not serving the same platform it would be horrifically inconvenient for the passengers if (at the last minute) they learnt that the train they were hoping to catch will now serve a platform that is several flights of stairs away... What might work however is separate Circle and District platforms so that an inner rail Circle could be held a few minutes without delaying an eastbound District - I've seen this sort of thing happen at Gloucester Road with westbound trains, although it would be better if (after calling at this station) the waiting point for the Circle train (heading for High St Ken) was further forward so that the entire train is beyond the platform whilst it waits for an approaching eastbound District to clear the junction.
I say this because I've seen passengers trying to board stationary Circle trains which have their fronts in the tunnel but their last few cars still alongside the platform (at Gloucester Road).
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Post by spsmiler on Apr 26, 2019 22:51:21 GMT
S7’s did fit but only just very tight But not enough overlap for regular safe working under the new system. And now I learn something new - previously I only knew that it really was 'not long enough'.
A 'very tight' fit, if still safe, would be worth its weight in gold to minimise disruption at times when a train needs to travel at 15mph because it cannot communicate with the centralised train control.
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Ben
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Post by Ben on Apr 27, 2019 2:03:13 GMT
Disconnected completely hence why the track bed at Mansion House still remains the original plan was the same as Tower Hill but lack of money blah blah blah You have to realise this new system CBTC does not like junctions or points hence the rationing of some sites which were rarely used. So Tower Hill will not be gaining a bi-directional centre road from what was the bay? I thought the track and pointwork had previously gone in for that but remained unsignalled pending ATO? What on earth has changed in the meantime to make them have second thoughts - and wasn't the point in having two eastbound through roads to somewhat mitigate against the loss of Whitechapel? Or have I got the wrong end of the stick from your post? Very surprised to read that Mansion House bay would have taken an S7 in. Presumably it would have needed to pull right up to the fixed red light, and would still overhang the platforms other end by about 5m, going from the scale plans. No doubt a need to extend sand drags made this an unworkable proposition, though one wonders whether in retrospect whether two westbound platforms either side of the island for regulation would have been useful, though unnecessary.
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Post by Dstock7080 on Apr 27, 2019 6:28:25 GMT
And now I learn something new - previously I only knew that it really was 'not long enough'. Very surprised to read that Mansion House bay would have taken an S7 in. this post from 7 October 2016, gives the details of the S7 (the very last train) to use Mansion House bay: D78 formation report
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Post by uzairjubilee on Apr 27, 2019 8:47:34 GMT
Regarding the changes to the bay platform at Tower Hill, I thought that the bay track was being modified so that trains from Aldgate East could also enter it?
Edit: Just seen that Ben above has asked the same thing!
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Colin
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Post by Colin on Apr 27, 2019 9:00:58 GMT
What might work however is separate Circle and District platforms so that an inner rail Circle could be held a few minutes without delaying an eastbound District - I've seen this sort of thing happen at Gloucester Road with westbound trains, although it would be better if (after calling at this station) the waiting point for the Circle train (heading for High St Ken) was further forward so that the entire train is beyond the platform whilst it waits for an approaching eastbound District to clear the junction. I say this because I've seen passengers trying to board stationary Circle trains which have their fronts in the tunnel but their last few cars still alongside the platform (at Gloucester Road). Circle line trains on the inner rail are regulated at Aldgate where they get in no one's way. If that regulation were moved to Tower Hill you'd be creating a delay where none currently exists! And as for Gloucester Road on the outer, there is no physical room to hold waiting Circle line trains further out of the platform. If anything, the best that could be done here is to hold the train fully berthed in the platform, but by doing that you create a longer time period between the train departing the station and clearing the eastbound District track. So Tower Hill will not be gaining a bi-directional centre road from what was the bay? I thought the track and pointwork had previously gone in for that but remained unsignalled pending ATO? I too was surprised to read what @aetearlscourt wrote regarding the future layout at Tower Hill. As far as I'm aware its remaining as a three platform station with a centre road bi-directional reversing capabillity. Mind you, the crossover east of Embankment was supposed to be moving to the west of Embankment with a diamond crossover; that seems to gone quiet. The points west of West Kensington were supposed to be moving further west but that seems to have gone quiet too. Parsons Green also had planned changes but not seen or heard if that's still happening either. You have to realise this new system CBTC does not like junctions or points hence the rationing of some sites which were rarely used. And yet the DLR, with essentially the same Thales system, is fully bi-directional and has the likes of the complicated delta junction at Popular. The Northern line, which has the same Thales system, has Kennington and Camden Town junctions. I'm getting bored of all the knocks CTBC is getting with regard to its capabilities. Driver messroom's are full of it. Its a very capable system! The rationing of points is nothing to do with the capabilities of CBTC - its got everything to do with reducing maintanence costs and the lack of accessible engineering hours time to maintain stuff once we get night tube. I visited Hammersmith SCC yesterday and I have to say the attitude from those in the room has changed markedly since CTBC on SMA0.5 went live. Previously they would bang on about how it's "unsafe", "a load of rubbish" and "will fall over regularly". They are now singing its praises and saying how pleasently surprised they are that it's operating so smoothly.
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Post by goldenarrow on Apr 27, 2019 14:18:35 GMT
That sort of centralised timing coordination seems highly possible with an ATO system that is centrally controlled. I suppose you could programme it to dynamically adjust speeds across the whole subsurface network to make the right gaps at junctions. Does the Thales system support this sort of intelligent behaviour? I would say no looking from the specification outlined in 2016 for Semi-Automatic Train Operation which London Underground employ. As I believe is and should be the case, regulating of the service is down to the expertise of the Service Controller/Operative. TBTC supports applying varying levels of braking/motoring to specific sections of track (a feature that the SSR will no doubt during the leaf fall periods), but I don't see the viability of implementing dynamic adjustments on that level since you would have to assume that stations dwelling times would have to be consistent train after train and sometimes that just isn't the case. The Dubai Metro which is as easy as it gets for metro systems is also fitted with TBTC by Thales and has doesn't have a sort of dynamic performance interface with trains being held in platforms being the preferred practise. I guess again it comes down to dwell times, there's little gain if the train is "driven" defensively only for that time to be lost by a longer station stop which just can happen by way of circumstance. Holding trains at platforms is still probably the best way to consistently regulate the service ATO or not. Not only that, it's good to see that some of the skills more associated with conventional signalling have evolved into the digital railway. You can certainly tell when a more proactive controller/operator has intervened because the high frequencyon the Jubilee line especially can mean the service naturally stacks up on occasion (WB approach to Wembley Pk in particular).
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Colin
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Post by Colin on Apr 27, 2019 14:52:33 GMT
centralised timing coordination seems highly possible with an ATO system that is centrally controlled. I suppose you could programme it to dynamically adjust speeds across the whole subsurface network to make the right gaps at junctions. Does the Thales system support this sort of intelligent behaviour? I would say no looking from the specification outlined in 2016 for Semi-Automatic Train Operation which London Underground employ. As I believe is and should be the case, regulating of the service is down to the expertise of the Service Controller/Operative. So how then is the system able to recover 10% late running without any intervention?! How is it that it manages platform dwell times and give's us driver's a countdown to departure? I've been lucky enough to have the opportunity to visit the DLR control centre [which has Thales ATO/ATP] and there, the timtable is loaded into the signalling system and the signalling system just gets on with it. The only intervention that is required is if the controllers want hold the service for an ongoing incident, reform a train, make trains skip a station or when they go to & from the depot at Beckton (it has a habit of confusing itself). They can manually speed trains up or fiddle with the service as they wish, but the system is very capable of running itself without the need to micro manage it. I also trained as a controller on the Central line a few years ago and whilst their ATO/ATP is obviously not the Thales system, it too has the timetable loaded into the signalling system and is quite happy to run itself without intervention. Given the above, I therefore fully expect that CBTC is able to run itself to a timetable.
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Post by North End on Apr 27, 2019 15:46:49 GMT
centralised timing coordination seems highly possible with an ATO system that is centrally controlled. I suppose you could programme it to dynamically adjust speeds across the whole subsurface network to make the right gaps at junctions. Does the Thales system support this sort of intelligent behaviour? I would say no looking from the specification outlined in 2016 for Semi-Automatic Train Operation which London Underground employ. As I believe is and should be the case, regulating of the service is down to the expertise of the Service Controller/Operative. So how then is the system able to recover 10% late running without any intervention?! How is it that it manages platform dwell times and give's us driver's a countdown to departure? I've been lucky enough to have the opportunity to visit the DLR control centre [which has Thales ATO/ATP] and there, the timtable is loaded into the signalling system and the signalling system just gets on with it. The only intervention that is required is if the controllers want hold the service for an ongoing incident, reform a train, make trains skip a station or when they go to & from the depot at Beckton (it has a habit of confusing itself). They can manually speed trains up or fiddle with the service as they wish, but the system is very capable of running itself without the need to micro manage it. I also trained as a controller on the Central line a few years ago and whilst their ATO/ATP is obviously not the Thales system, it too has the timetable loaded into the signalling system and is quite happy to run itself without intervention. Given the above, I therefore fully expect that CBTC is able to run itself to a timetable. The Thales system will run the service “hands off” if nothing much happens, but any idea that it can recover the service on its own is completely laughable. The 10% figure is completely meaningless (not sure where that’s come from?) as no train will be able to make up anything if it ends up in the wrong order at a junction with an on-time train in front - this is something that happens very regularly at places like Camden, Golders Green, Finchley Central, Kennington, Edgware, High Barnet, Morden, Wembley Park, Willesden Green, North Greenwich, to give a few examples. In the real world the signallers are constantly making small adjustments like sliding the timings of trains or influencing the junction working so that they run as the signallers desire not how the system chooses, not to mention sorting out situations like standoffs which happen on a semi-regular basis and but for signaller intervention the trains would sit still all day! There are indeed signallers who leave the system alone more than others, get a batch of these in the room together and it’ll be one of those days when everyone is asking “why is it all running late when not much seems to have been going on?” or “why are there massive gaps everywhere for no real reason?”.
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Post by goldenarrow on Apr 27, 2019 16:45:05 GMT
Colin , If I have understood ijmad 's question correctly ( ijmad please correct me if otherwise), if say there was an City service from Uxbridge running on time and it was timetabled to follow a Baker Street terminator that was running late, would the system actively slow down the progress of the service from Uxbridge without holding at platforms to keep things in order before Harrow South Junction, the answer to my knowledge (from what I saw in 2016) was no. It would get to Harrow and be held, unless intervention followed.
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Post by North End on Apr 27, 2019 16:56:44 GMT
Colin , If I have understood ijmad 's question correctly ( ijmad please correct me if otherwise), if say there was an City service from Uxbridge running on time and it was timetabled to follow a Baker Street terminator that was running late, would the system actively slow down the progress of the service from Uxbridge without holding at platforms to keep things in order before Harrow South Junction, the answer to my knowledge (from what I saw in 2016) was no. It would get to Harrow and be held, unless intervention followed. My understanding is trains only get “slowed down” if running early according to their WTT schedule. The signalman might choose to “slide” the timings of one or other of the trains to influence things, alternatively there’s the option to select different junction working modes - although on the Jubilee and Northern these don’t really work very well and introduce pitfalls should the signalman’s attention be diverted elsewhere at the wrong moment. The system is, mostly, lovely when everything is all running as per WTT. The moment things are out of turn or individual trains are late then intervention is required to get the optimal outcome. No intervention would very possibly result in a late running train getting trapped behind an on-time one and struggling to find a means to right itself - with an increasingly frustrated driver wondering why he’s always getting put behind something else at every junction! The Northern is forever having to put right such junction issues, with measures like turning short, reforms, run rounds or messy terminus working like quick turnarounds or first in last out - all of which are of course arranged by humans not the system. In some cases this can all be avoided simply by a hold being applied at a strategic point to influence the system, but one simply can’t spot everything in time all the time. The DLR may well have an advantage that they don’t have that annoying thing sitting on an armchair at the front of the train which does unpredictable things like take 4 minutes to change ends, go to the toilet just when a quick turnaround was hoped for, or whatever. Again, the computer can’t tune the CCTV in to see which driver is going to be ready first departing a terminus, which is a feature routinely used by signallers at both Highgate and Neasden, and no doubt Hammersmith in the future.
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Post by Colin on Apr 27, 2019 18:19:54 GMT
The Thales system will run the service “hands off” if nothing much happens, but any idea that it can recover the service on its own is completely laughable. You've taken what I said far too literally! I never said it could completely recover the service on its own. What I'm referring to is the abliity to push a train along the line a little bit quicker if its falling behind time. Obviously it can only do that if the track in front of said train is clear. The 10% figure is completely meaningless (not sure where that’s come from?) I can't recall where I saw it, but I have absolutely seen or heard it somewhere. no train will be able to make up anything if it ends up in the wrong order at a junction with an on-time train in front Indeed. The signallers (or VCC operators to pedantic) would obviously need to manage that. Again I never claimed otherwise. In the real world the signallers are constantly making small adjustments like sliding the timings of trains or influencing the junction working so that they run as the signallers desire not how the system chooses, not to mention sorting out situations like standoffs which happen on a semi-regular basis and but for signaller intervention the trains would sit still all day! Even under Seltrac junctions can be worked in no out of turn or First come first serve modes. DLR uses first come first serve at all its junctions except the Tower Gateway/Bank junction which is usually always in no out of turn. There are indeed signallers who leave the system alone more than others, get a batch of these in the room together and it’ll be one of those days when everyone is asking “why is it all running late when not much seems to have been going on?” or “why are there massive gaps everywhere for no real reason?”. Much the same as now with programme machines then. Glad to see nothing changes! Colin , If I have understood ijmad 's question correctly ( ijmad please correct me if otherwise), if say there was an City service from Uxbridge running on time and it was timetabled to follow a Baker Street terminator that was running late, would the system actively slow down the progress of the service from Uxbridge without holding at platforms to keep things in order before Harrow South Junction, the answer to my knowledge (from what I saw in 2016) was no. It would get to Harrow and be held, unless intervention followed. I agree that it isn't capable of managing the entire train service in such a way that it'll deliberately delay a train to fit a path. All it can do is regulate an early running train to its timetabled departure time or speed up late running train should the track ahead be clear enough to allow it. I would expect junctions to be worked in first come first serve mode to ensure a train dosen't sit down waiting for another that's running late. If its mostly worked in no out of turn mode, that's clearly inviting trouble. The DLR may well have an advantage that they don’t have that annoying thing sitting on an armchair at the front of the train which does unpredictable things like take 4 minutes to change ends, go to the toilet just when a quick turnaround was hoped for, or whatever. Again, the computer can’t tune the CCTV in to see which driver is going to be ready first departing a terminus, which is a feature routinely used by signallers at both Highgate and Neasden, and no doubt Hammersmith in the future. The DLR's big advantage is that its a smaller network with less trains and full bidirectional capability. But yes, drivers and their whims can be an issue - in time it'll be our downfall. One thing I have become aware of since becoming an I/O is the poor recovery times at terminus's on deep tube lines. On the SSR we have the luxury of a minimum of 8 minutes; 10 or 12 minutes is very much the norm. In the peaks we get 17 minutes at Richmond! From what I gather, 5 or 6 minutes is very normal on deep tube lines. That cannot do you any favours when trying to deal with late running or train's running out of turn.
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