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Post by Deleted on Jan 9, 2012 16:36:21 GMT
This system went live today. It basically consists of a screen located at the headwall of each westbound platform between Bounds Green and Kings Cross St Pancras.
When a train arrives in the platform determines it position relative to the trains in immediately in front and behind. The screen displays the message 'waiting for regulation'. If the train behind is closer than the train in front, 'No Regulation' is displayed and the train can proceed normally.
If the train behind is further away than the train ahead, a countdown will begin on the screen. For example, I was held twice today, once for 30 seconds at Wood Green and the second time 22 seconds at Manor House. The screen starts to flash when there are 5 seconds left, and when the display reaches zero the train can proceed.
Above the platform there is a box that is supposed to mimic the info shown on the screens for the benefit of station staff, but they were not switched on this morning.
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Post by Deleted on Jan 9, 2012 17:17:32 GMT
Is that shut the doors at zero or shut the doors at 5 seconds to go and proceed at zero?
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Post by Deleted on Jan 9, 2012 17:22:18 GMT
railtechnician I believe it is fully automatic, although the headway signal was still functioning as usual at Finsbury Park. @dave72 Depends on who you ask. The official briefing says wait until the clock goes to zero and then carry out platform duties. In practice today the clock went down to 2 seconds and then changes back to no regulation. I gave a cab ride to a couple of the engineers involved in the project and their understanding was close doors at 5 seconds so ready to go at zero. EDIT - Just looked again at my briefing note and it states that the system will be used by service control to smooth out the gaps in the westbound service. So maybe it's not as automatic as I thought.
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Post by jardine01 on Jan 9, 2012 18:09:10 GMT
good system this should stop trains running ahead to timetable causing gaps in the service
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Post by Deleted on Jan 9, 2012 22:18:47 GMT
Many thanks jardine01, I suppose if successful they will set it up for Eastbound workings to in time. Seems a really good way of regulating the service simply and effective as well. Wonder if they will do it on other lines that are not ATO yet.
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Post by Deleted on Jan 9, 2012 23:21:37 GMT
good system this should stop trains running ahead to timetable causing gaps in the service But will it not also perpetuate earlier delays and prevent the service from recovering back to timetable?
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Post by causton on Jan 9, 2012 23:26:55 GMT
That's why it can be turned off or modified - set up how often they want to send a train through so they don't build up a backlog of trains but don't cause queues in the central area
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Post by tubeprune on Jan 10, 2012 7:13:13 GMT
This is not a new idea. "Headway Clocks" were used at some stations on the Piccadilly Line from at least the 1920s. They were still working when I worked on the Picc in the 1960s. I remember there was one at Piccadilly Circus WB. It was operated by the starter replacing track and showed the driver how long had elapsed since the previous train left. It required the crew to know what the headway was and this was not always understood.
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Post by Deleted on Jan 10, 2012 17:21:15 GMT
Headway Control by another name, presumably this is a replacement for the original system but is it fully automatic or does the signal operator still have the option to switch it on and off? The controller is in charge of the system. They decide what sort of headways they want with the service, set it up on the UI on their desk and the VDTI system will do the rest. It's meant to work from Bounds Green to Kings X but the system only see's Mnr house to KX, the other section will work as and when the CTFS system is ever up and running. The Eastbound will not be done and the Sig Op needs to ensure the Finsbury headway is removed when VDTI is turned on As is said yesterday I was held at Wood Green for 30 seconds so it must be active there as well. I've been off today so will see what happens tomorrow.
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Post by Deleted on Jan 10, 2012 17:28:42 GMT
This is not a new idea. "Headway Clocks" were used at some stations on the Piccadilly Line from at least the 1920s. They were still working when I worked on the Picc in the 1960s. I remember there was one at Piccadilly Circus WB. It was operated by the starter replacing track and showed the driver how long had elapsed since the previous train left. It required the crew to know what the headway was and this was not always understood. Isnt there still one at Hyde Park Corner or some kind of holding device?
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Post by Deleted on Jan 10, 2012 19:11:33 GMT
This is not a new idea. "Headway Clocks" were used at some stations on the Piccadilly Line from at least the 1920s. They were still working when I worked on the Picc in the 1960s. I remember there was one at Piccadilly Circus WB. It was operated by the starter replacing track and showed the driver how long had elapsed since the previous train left. It required the crew to know what the headway was and this was not always understood. Isnt there still one at Hyde Park Corner or some kind of holding device? Hyde Park Corner eastbound has a balance headway signal, which can hold trains for up to 6 minutes if required.
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Post by tubeprune on Jan 12, 2012 6:53:11 GMT
Balanced headway control is different from headway clocks. Headway clocks just showed the time elapsed since the last train left, balanced headway control measures the time since the last train left with the time it expects the next train (behind yours) will arrive.
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Post by Deleted on Jan 14, 2012 6:43:13 GMT
Interesting system, and hopefully will reduce the not too uncommon Piccadilly Line bunching. If drivers don't depart promptly, I could see delays starting to develop. Maybe the "calculated" time should err on the shorter side of the average?
Paris Metro had an interesting regulation system which is now being phased out with resignaling. At the terminus the driver would be given their departure time in minutes and seconds (e.g. 34:15) by a clock. There are rarely conflicting moves out of Paris termini, so departures are usually bang on time. Then at each station, there is a delayed clock (with multiple options for times of day) which is delayed by the journey time from the terminus to that station. Thus at each station, the driver departs when the clock shows 34:15. This system however, will not solve bunching if a train is delayed, other than telling the delayed driver how much time they need to catch up.
On Vienna's Line 6 is another system which shows deviance from timetable, and counts in 5 second steps. So if a train is running on time it will show approx -0:25 secs upon arrival, and departure should be at 0:00. If a train is running 1 minute late, it will show +1:00 at departure time. I don't know if the "timetable" can be adjusted on the fly. Observations showed that drivers were unable to make up lost time anyway.
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Post by Deleted on Jan 14, 2012 9:08:38 GMT
After 5 days of driving on the line using this new system. my initial observations are that it is helping cut down on bunching. I have been held numerous times and as a result the traditional queue into Kings Cross has disappeared, at least for me anyway.
Yesterday we had a disrupted service due to a temporary speed restriction at Arnos Grove and I wondered if the screens would be switched off, but they were still in use. The timetable we have at present does have a lot of running time in it, so even though i have been held I have still arrived at Acton more or less on time.
The major benefit of the system in my mind though is that being held in platforms to allow the train ahead to get away reduces the risk of SPAD's.
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Post by Deleted on Apr 4, 2012 7:42:58 GMT
Just to confirm that it is still broken. More money thrown at something that doesn't work!
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Post by version3point1 on Apr 4, 2012 22:48:57 GMT
Just to confirm that it is still broken. More money thrown at something that doesn't work! Yeah.. all that money on an over-hyped egg timer that flashes at me in bold letters and numbers... or just blacks out halfway through a countdown leaving me to wonder whether or not I should shut my doors and go. Or other times when it holds you at Manor House for something like 1:30 and then you're still caught on the balanced headway at Finsbury Park. Gah. I think the last time I saw the things on was on Sunday, after not seeing them on for something like 4/5 weeks... but then we all got stuck for 20-25 minutes on the WB local between Acton and Northfields anyway because for some reason nobody expected there to be Northfields trains that evening..
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Post by Deleted on Apr 12, 2012 21:23:10 GMT
Well I happen to think it's a great idea and money well spent.
I also think leg warmers were a much needed addition to 1980's fashion and that all motorcycles should be fitted with ashtrays.
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Post by Deleted on May 12, 2012 18:31:58 GMT
I saw this today, although god knows how I missed it as I the Picc is my main route into London... Is it "working" yet? I ask because after waiting for a good 5 minutes for a train at Arnos, we still seemed to be held for quite a while at all stations from Wood Green - Caledonian Road. While I understand what "regulation" is, surely it makes no sense to use these when gaps between trains are quite large and platforms are getting more crowded?!
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Post by Deleted on May 12, 2012 21:48:21 GMT
I saw this today, although god knows how I missed it as I the Picc is my main route into London... Is it "working" yet? I ask because after waiting for a good 5 minutes for a train at Arnos, we still seemed to be held for quite a while at all stations from Wood Green - Caledonian Road. While I understand what "regulation" is, surely it makes no sense to use these when gaps between trains are quite large and platforms are getting more crowded?! I understand that it's been turned on again and that trains will not be held on the VDTI at each station by more than one minute.
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Post by Deleted on May 12, 2012 21:49:49 GMT
I saw this today, although god knows how I missed it as I the Picc is my main route into London... Is it "working" yet? I ask because after waiting for a good 5 minutes for a train at Arnos, we still seemed to be held for quite a while at all stations from Wood Green - Caledonian Road. While I understand what "regulation" is, surely it makes no sense to use these when gaps between trains are quite large and platforms are getting more crowded?! Regarding crowding and regulation of the service, the location from where the headway scores are measured don't know how busy the platform is - all about targets!
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Post by Phil on May 12, 2012 22:39:11 GMT
Somebody did say some decades ago that computers without eyes could be more of a problem than a solution - - - how true!!!
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Post by Deleted on May 13, 2012 4:10:44 GMT
Regarding crowding and regulation of the service, the location from where the headway scores are measured don't know how busy the platform is - all about targets! But surely crowded platforms lead to more delays in getting trains to leave the station, therefore not making any difference, meaning targets in other areas (such as general delays to journey's) surely can't be met? Somebody did say some decades ago that computers without eyes could be more of a problem than a solution - - - how true!!! E.G. Self-service machines at supermarkets...
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Post by rheostar on May 14, 2012 9:30:15 GMT
Regarding crowding and regulation of the service, the location from where the headway scores are measured don't know how busy the platform is - all about targets! Not true. The Piccadilly line's measured at four separate places chosen to give an accurate reflection of the service.
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Post by mrfs42 on May 14, 2012 9:48:36 GMT
Regarding crowding and regulation of the service, the location from where the headway scores are measured don't know how busy the platform is - all about targets! Not true. The Piccadilly line's measured at four separate places chosen to give an accurate reflection of the service. Which are where, please?
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Post by rheostar on May 14, 2012 10:09:27 GMT
Finsbury Park westbound, Hammersmith east, Sudbury Town east and Hounslow West east.
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Post by mrfs42 on May 14, 2012 10:28:17 GMT
Finsbury Park westbound, Hammersmith east, Sudbury Town east and Hounslow West east. Interesting, thank-you. I wonder why that makes it 'accurate'? Mileage-wise there's a bit of difference between Sudbury Town EB and 'ounslow W EB, perhaps it's a function of the number of berths and speed in front before Acton Town. Likewise with the two into Zone 1; FP WB is a curious one, as I can't remember there being compensatory stand time there - although the times for runs down from Turnpike Lane used to wander around a bit. I shall have to have a think.
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Post by rheostar on May 14, 2012 15:48:51 GMT
Finsbury Park westbound, Hammersmith east, Sudbury Town east and Hounslow West east. Interesting, thank-you. I wonder why that makes it 'accurate'? Mileage-wise there's a bit of difference between Sudbury Town EB and 'ounslow W EB, perhaps it's a function of the number of berths and speed in front before Acton Town. Likewise with the two into Zone 1; FP WB is a curious one, as I can't remember there being compensatory stand time there - although the times for runs down from Turnpike Lane used to wander around a bit. I shall have to have a think. Don’t look too closely for a scientific reason those particular sites were chosen! Finsbury Park west is an indicator of the westbound service going into London. Incidentally, that site gives problems with the proxy score as the balance headway’s still in effect. Missed headways can be caused simply by the balanced headway holding a train for thirty seconds longer than anticipated as the threshold for a missed headway’s quite tight. Sudbury Town eastbound gives an indicator of the service coming back from Rayners Lane and beyond. Piccadilly line trains are often held up by the Met, so the proxy score is taken at Sudbury Town to reflect those problems. Hounslow West east gives an indicator of the service from Heathrow. Hammersmith east is an indicator of the overall service going into London. The average of all four sites then gives us the line proxy. As you can see, they really were chosen to give a true picture of the service provided by the Piccadilly line.
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Post by Deleted on May 14, 2012 16:44:04 GMT
Regarding crowding and regulation of the service, the location from where the headway scores are measured don't know how busy the platform is - all about targets! Not true. The Piccadilly line's measured at four separate places chosen to give an accurate reflection of the service. These four locations are fairly new and replaced Leicester Square where the measurement was taken from for some time. Regardless of the location of the measurement trains should still be regulated and have been in the past even if the train was crush loaded as that is what the target is!
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Post by rheostar on May 14, 2012 18:17:29 GMT
You're correct in saying that the four proxy locations are relatively new. Prior to Leicester Square, about four years ago, the proxy was taken at Barons Court.
Regardless of the loading of trains, any railway should be regulated to even up gaps. Failure to do so only leads to problems later in the journey. Trains bunching up is no good for anyone.
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