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Post by Deleted on Dec 20, 2010 19:35:16 GMT
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Oracle
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Post by Oracle on Dec 20, 2010 20:00:50 GMT
I come from Hounslow, and when I commuted from 1973-1981, I found that it made no difference to my journeys when trains stopped at TG. In fact it would be helpful to access the Richmond branch. I have had to change at Acton Town to get to TG and then Richmond before.
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hobbayne
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Post by hobbayne on Dec 20, 2010 20:35:26 GMT
When I came on the Picc back in 1990, we used to stop at TG on a Sunday all day.
I believe nowadays they run such an intensive service, that it would cause blocking back (queing) into Acton/Hammersmith, which LUL dont want as the signalling wont take it.
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Post by Deleted on Dec 20, 2010 20:40:43 GMT
When I came on the Picc back in 1990, we used to stop at TG on a Sunday all day. I believe nowadays they run such an intensive service, that it would cause blocking back (queing) into Acton/Hammersmith, which LUL dont want as the signalling wont take it. If all trains stop there, I don't see how it would be a problem. |
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Post by londonstuff on Dec 20, 2010 20:41:39 GMT
I'm sure that stopping at TG wouldn't actually make much difference to the total time from end to end. I worked just outside TG station for four years and it wasn't unusual at all for 6+ Picc trains would shoot past, nearly completely empty, while the District platforms got more and more busy. I believe, although I haven't got statistics to prove it, that the station has continued to grow in passenger numbers, especially as Chiswick is a nice place to visit, eat, shop, etc. This is in comparison to Barons Court which could just as easily be skipped out - it's within walking distance of both West Ken and Hammersmith and is, frankly, much easier to change at Hammersmith onto the District if you do actually need to get to Baron's Court. I keep hearing that the signalling system couldn't cope with stopping at TG, but surely this is a case of the tail wagging the dog. Everyone at TfL however seem dead against it, so I wouldn't hold your breath  |
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hobbayne
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Post by hobbayne on Dec 20, 2010 20:49:14 GMT
I keep hearing that the signalling system couldn't cope with stopping at TG, but surely this is a case of the tail wagging the dog. Everyone at TfL however seem dead against it, so I wouldn't hold your breath Hell will freeze over before LUL will have TG as a Picc station |
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Post by Deleted on Dec 20, 2010 21:23:39 GMT
They could make a train stop there once every half hour?
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Post by Deleted on Dec 20, 2010 21:28:00 GMT
They could make a train stop there once every half hour? That's the one scenario you most certainly can't do !!! All or nothing, otherwise the trains behind the 2 per hour will be impeded |
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Post by Deleted on Dec 20, 2010 21:55:09 GMT
Why not just hold them at Acton Town, Ealing Common or South Ealing for an extra 20secs or so while the train stops at Turham?
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Post by Deleted on Dec 20, 2010 22:21:23 GMT
Why not just hold them at Acton Town, Ealing Common or South Ealing for an extra 20secs or so while the train stops at Turham? because 20 seconds bears no relation to the additional run time required for a TG stop (90 seconds) It isn't even 25% of the additional time If you held the train following the TG stopper at Acton Town for the required 90 seconds, then the next train following this one wouldn't get into Acton Town = delays/blocking back/impedance as I said - all or nothing |
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Post by Deleted on Dec 20, 2010 22:52:04 GMT
I suppose it'd be too obvious to suggest accompanying signalling alterations...
Maybe they should just do a bit of a free for all... Signalling System chooses at Random what route to set for a NB Train at Acton, if a train is routed onto the Fasts it runs Non-Stop to Hammersmith - be it District or Picc. If it's sent onto the locals, it has to go All Stations.
EDIT: By Northbound I of course mean Eastbound... D'oh!
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Post by Deleted on Dec 20, 2010 23:59:46 GMT
You wouldn't need to alter the signalling if you stopped all of them there!!  |
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jazza
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Post by jazza on Dec 21, 2010 0:59:33 GMT
I may be wrong here, and please correct me if I am. However as a fairly regular user of the Piccadilly line, there seems to be so much "waiting time" built in to the timetable that it could be possible to stop at TG. I have lost count of the number of times I have been on trains and the driver has come on the intercom with a message such as- "We are being held here at Hyde Park Corner as we are running a few minutes ahead of schedule"
Edit for spelling!!
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mrfs42
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Post by mrfs42 on Dec 21, 2010 1:13:34 GMT
Why not just hold them at Acton Town, Ealing Common or South Ealing for an extra 20secs or so while the train stops at Turham? because 20 seconds bears no relation to the additional run time required for a TG stop (90 seconds) ..er.. inclusive or exclusive of the temporary increase in the Hammersmith area? Must look at when the PT galley column note came in; used to be 5 non stop and 8½ all stations (but that's from pre-1973 stock days, as I was looking at Picc, No 1 from 1970 this afternoon). From observation (and with emailable timing logs from the stopwatch) I reckon 90 seconds extra is on the generous side, TBH. If you held the train following the TG stopper at Acton Town for the required 90 seconds, then the next train following this one wouldn't get into Acton Town Hmm. WL 97 A and WL 97 B would appear to be a limiting factor in this - even though the necessary unoccupied TCs for 97 A) are well clear of the platform. Wouldn't be the first time that I've seen stand time put in at North Ealing or (I think) Park Royal to cater for such an eventuality. You can book stand time against autos in a platform, can't you?  ;D They could make a train stop there once every half hour? That's the one scenario you most certainly can't do !!! Now is not the time or place to pass comment about certain signals that have been removed since TG went over to programme machines, nor the changes in emphasis with headway calculation and SPAD mitigation. If it is the case that you "most certainly can't do it" that would indicate that the timetable compilation has seemingly gone down the route of 'cut and paste'. I have (literally) thousands of examples of this scenario - there was no extra stand time factored into following trains going west and TG stoppers were before an ex-South Harrow service. What on earth has changed? |
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Post by railtechnician on Dec 21, 2010 2:16:58 GMT
I may be wrong here, and please correct me if I am. However as a fairly regular user of the Piccadilly line, there seems to be so much "waiting time" built in to the timetable that it could be possible to stop at TG. I have lost count of the number of times I have been on trains and the driver has come on the intercom with a message such as- "We are being held here at Hyde Park Corner as we are running a few minutes ahead of schedule" Edit for spelling!! But when you are held at HPC that is usually due to the operation of Headway Control. My recollection is that HPC is the eastbound timing point and Finsbury Park the westbound timing point with headway control operating automatically between these points when switched in to regulate the service. For a long time headway control was not in auto operation but ISTR that it could be switched in or out as required by the Earls Ct. regulator. Of course when headway control was not available that was due to a fault in the non-safety control circuitry which I can recall localising and repairing at least once a few years ago. I can certainly recall being held at HPC for what seemed to be ages in the 1980s when I worked out of South Kensington depot on days and travelled home to Seven Sisters, somehow there never seemed to be the same amount of delay at Finsbury Park when travelling westbound. |
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Post by edwin on Dec 21, 2010 2:52:25 GMT
They should build an interchange to the Overground either here or at Chiswick Park. Then you get swathes of North London with a quick journey into Heathrow. And fewer tourists carrying bags at key interchanges in Central London.
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Post by Deleted on Dec 21, 2010 7:11:52 GMT
I agree with all or nothing. Currently, the next to nothing way is meaning that all the line diagrams get cluttered up with a confusing stop that effects no-one living. If they're going to continue to non-stop Turnham Green except for all of three trains at the fringes of the day, they take it off the damned map! If you're making the extra stop, the train driver can announce it. It happens when the Met stops at Willesden Green after all.
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mrfs42
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Post by mrfs42 on Dec 21, 2010 10:46:43 GMT
If they're going to continue to non-stop Turnham Green except for all of three trains at the fringes of the day, they take it off the damned map! A sensible suggestion, if it were not for the fact that the approximate figures for trains calling at Turnham Green (and these have been fairly stable for a number of years): - Westbound
- AM: 14 trains
- PM: 38 trains
- Eastbound
- AM: 17 trains
- PM: 30 trains
Further to my earlier post, my memory wasn't quite correct about the transitional stage (ie what happens either side of the last or first train stopping at Turnham Green) but I wouldn't want to bore everyone. ;D |
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Post by Deleted on Dec 21, 2010 21:07:00 GMT
because 20 seconds bears no relation to the additional run time required for a TG stop (90 seconds) ] If it is the case that you "most certainly can't do it" that would indicate that the timetable compilation has seemingly gone down the route of 'cut and paste'. I have (literally) thousands of examples of this scenario - there was no extra stand time factored into following trains going west and TG stoppers were before an ex-South Harrow service. What on earth has changed? These 'olden daye' examples you refer too, what was the train frequency between Hammersmith and Acton Town? |
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Post by mrfs42 on Dec 21, 2010 21:38:40 GMT
] If it is the case that you "most certainly can't do it" that would indicate that the timetable compilation has seemingly gone down the route of 'cut and paste'. I have (literally) thousands of examples of this scenario - there was no extra stand time factored into following trains going west and TG stoppers were before an ex-South Harrow service. What on earth has changed? These 'olden daye' examples you refer too, what was the train frequency between Hammersmith and Acton Town? Any particular decade - I've got every Picc WTT [1] in the new series and virtually complete as far back as the late 40s, then patchy until 1932. [1] bar the one that's in Tubetroll's car boot! |
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Post by Deleted on Dec 21, 2010 21:50:44 GMT
lets go for 1977 (chosen randomly !)
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mrfs42
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Post by mrfs42 on Dec 21, 2010 22:12:53 GMT
lets go for 1977 (chosen randomly !) Excellent choice - because I can play the Silver Jubilee card! TTN 136/77 'Special Train Arrangements for the Royal Silver Jubilee' which had an hours later running than WTT 12 had WB PTs at 3½ minutes. WTT 12 (77 train service) had the frequencies for Wood Green - Acton at morning busy 2 min, lunch slack hours 3 - 3½ min, evening busy 2 min and night slack hours at 3½ - 4 min. |
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Post by Deleted on Dec 21, 2010 22:25:18 GMT
lets go for 1977 (chosen randomly !) Excellent choice - because I can play the Silver Jubilee card! TTN 136/77 'Special Train Arrangements for the Royal Silver Jubilee' which had an hours later running than WTT 12 had WB PTs at 3½ minutes. WTT 12 (77 train service) had the frequencies for Wood Green - Acton at morning busy 2 min, lunch slack hours 3 - 3½ min, evening busy 2 min and night slack hours at 3½ - 4 min. so going back to the issue of a TG stopper, follwed by a non stop at which frequency level was this 18tph or 15tph? |
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Post by mrfs42 on Dec 21, 2010 22:34:43 GMT
In this particular instance 4 min; although by this time I think that several signals at Turnham Green had been removed, after the introduction of the PMs in the early/mid 60s.
Admittedly I don't have a date to hand for those signal removals - I suspect c. 1978 though it would be nice to know.
EDIT: Somewhere I did have a note of what the shortest interval on book was between the various combinations of stopping/non-stopping; unfortunately I can't at this moment find it, and I don't really fancy trawling through c.120 WTTs and TTNs, sorry!
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Post by Deleted on Dec 21, 2010 23:02:16 GMT
In this particular instance 4 min; although by this time I think that several signals at Turnham Green had been removed, after the introduction of the PMs in the early/mid 60s. Admittedly I don't have a date to hand for those signal removals - I suspect c. 1978 though it would be nice to know. EDIT: Somewhere I did have a note of what the shortest interval on book was between the various combinations of stopping/non-stopping; unfortunately I can't at this moment find it, and I don't really fancy trawling through c.120 WTTs and TTNs, sorry! This brings me back to my original point of 'all or nothing' the most common frequency on the Picc is presently 21 tph on the 4 minute service, TG stop 00 ex HAM (WB) 07half ACT, next train 04 HAM, non stop 10 ACT (based on current run times) works OK However on 21 tph, 00 to 07half (TG stopper) followed by non stop 03 to 09 doesn't work as the minimum headway scheduled into Acton Town is 2 minutes, hence delays/impedence/blocking back - call it what you will |
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mrfs42
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Post by mrfs42 on Dec 22, 2010 1:37:45 GMT
In this particular instance 4 min; although by this time I think that several signals at Turnham Green had been removed, after the introduction of the PMs in the early/mid 60s. Admittedly I don't have a date to hand for those signal removals - I suspect c. 1978 though it would be nice to know. EDIT: Somewhere I did have a note of what the shortest interval on book was between the various combinations of stopping/non-stopping; unfortunately I can't at this moment find it, and I don't really fancy trawling through c.120 WTTs and TTNs, sorry! This brings me back to my original point of 'all or nothing' the most common frequency on the Picc is presently 21 tph I have said this many times before, and I apologise sincerely for my repetition using 'tph' figures can be grossly misleading. They are excellent as an overview snapshot and yet even the current WTTs do not display the information in terms of tph. Practically speaking 21 tph does not equate to a constant interval on book: 20 tph is a round 3 minute service, 24 tph is a round 2½ 05n4te service. Unless and until the Picc WTT goes to quarter-minute resolution like the east end of the Jubilee, the Central and the Drain, then there is no practical way of showing on the galley that a rigid 21 tph service can be maintained, there will be variable headways between galley columns. Granted it would soon stabilise into a cycle of 2½/2/2/2/2½ or something similar as the temporal interstice between successive galley columns - even with quarter-minute resolution it is still a slight fudge. Times have most definitely changed. Motormen have it much easier now. Back in the really, really old days the trains had to be run to the second, and the running times were published in the Traffic Circular. As an example Hyde Park Corner to Knightsbridge would have taken 1 minute, 7 seconds. on the 4 minute service, TG stop 00 ex HAM (WB) 07half ACT, next train 04 HAM, non stop 10 ACT (based on current run times) works OK However on 21 tph, 00 to 07half (TG stopper) followed by non stop 03 to 09 doesn't work as the minimum headway scheduled into Acton Town is 2 minutes, hence delays/impedence/blocking back - call it what you will I see what you are saying - as yet I've not really come up with a sensible suggestion for Turnham Green stops in the interpeak, apart from possibly using the train before a Northfields stabler, but as yet that idea is only half-formed and would need a further visit - I haven't yet come up with something that fits into the Piccadilly 'spine' for the eastbound; and after all I'm not really looking for an answer. <playng devils avocado> A 30 second wait at WL 25 is no great hardship, if the train would ordinarily have been scheduled to at least an e or a d at Acton Town? Hmm? Just look at all those lovely d, c and the odd h at Northfields.... ;D </playing devils avocado> I am surprised that people think the knock-on effect is so great (as evidenced by the linked article), but every day is a learning day, apparently. |
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Post by v52gc on Dec 22, 2010 7:27:18 GMT
Motormen have it easier now because they don't exist as a role anymore
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mrfs42
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Post by mrfs42 on Dec 22, 2010 9:41:42 GMT
Motormen have it easier now because they don't exist as a role anymore You know what I mean! ;D To complain further about the grade comparison would be churlish: I could understand it if you went on about 1st and 2nd Gatemen! |
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Post by Deleted on Dec 22, 2010 20:08:20 GMT
<playng devils avocado> A 30 second wait at WL 25 is no great hardship, if the train would ordinarily have been scheduled to at least an e or a d at Acton Town? Hmm? Just look at all those lovely d, c and the odd h at Northfields.... ;D </playing devils avocado> I am surprised that people think the knock-on effect is so great (as evidenced by the linked article), but every day is a learning day, apparently. The stands are certainly there to be played with where possible, but an 'a' stand is required at Acton on all through Picc services, so you've got to leave those in situ, and obviously the 'h' stands at Northfields can't be decreased either One other issue to bear in mind if you were attempting to timetable selected interpeak stopping at TG, even on an 18tph, is not to bump Picc trains unnecessarily into platform 1 at Acton (the Northfields tip outs excepted). It is always best practive to preserve platform 1 for Districts when possible as occasional weekend TTN's result in Richmonds diverted to Broadway all day, and also there is quite a high throughput of Districts heading for bed WB late knockings |
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mrfs42
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Post by mrfs42 on Dec 22, 2010 21:21:21 GMT
The stands are certainly there to be played with where possible, but an 'a' stand is required at Acton on all through Picc services, so you've got to leave those in situ, and obviously the 'h' stands at Northfields can't be decreased either Go on, why? For the 'a' at Acton, I understand (as it seems to be the fashion du nos jours to insert an 'a' for cross platform interchange) but I can't unfortunately see immediately the obviousness of the 'h' at Northfields/the inability to decrease the Northfields stands. Yes, I can see the b/d (rare e) headway smoothers there for Terminal 4/Terminal 5 trains. Is the mix of h/j stands at Northfields to sort out a road into the depot? Clearly the 5/6 road question is resolved by which terminating platform at Northfields. Booked Northfields stands for stablers IIRC only came in in about 1997; in fact WRT Acton WB stands they only really started appearing in WTT 37 (20/5/2001) and were still not universal for WTT 38 (29/9/2002) - some Northfields stablers had no stand at Acton but generally a 'k' at Northfields. I think even as late as WTT 42 (17/9/2006) there was still the odd train without a WB stand at Acton - although by this stage these trains were really at the very ends of the day. One other issue to bear in mind if you were attempting to timetable selected interpeak stopping at TG, even on an 18tph, is not to bump Picc trains unnecessarily into platform 1 at Acton (the Northfields tip outs excepted). It is always best practive to preserve platform 1 for Districts when possible as occasional weekend TTN's result in Richmonds diverted to Broadway all day, and also there is quite a high throughput of Districts heading for bed WB late knockings Very true - although I'm only interested in this as a thought experiment [1], if you like - platform 1 usage had crossed my mind, and the existing structure with PT headings would be utilised, therefore the status quo would prevail in the evenings. I had indeed given one of the 'all Richmonds to Broadway' TTNs a very cursory look against a WTT, for this very reason. [1] Well, that does sound a touch harsh and does really gloss over what I know [2] - although I am really one of the 'armchair timetablers' as mentioned recently on the forum, I hope that all those who read this (and aren't bored!) would understand that this is offered as a potentially workable suggestion, rather than an enthusiast wagging his fingers to say 'You must do this' - do you get my drift?  [2] Amongst other things one of the most fascinating reads are some of the old TTO notebooks that survive, and although you're looking at roneoed galleys, rather than printed timetables, they tell a story all of their own in how the internal structures of WTTs evolve and change - as evidenced above with the differences in stand times. Howwever, I can only think of perhaps two, possibly three people that would be interested enough to read through these! |
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;D
