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Post by thc on Jun 5, 2010 15:38:29 GMT
After several years living in west or central London, I recently moved to Wendover and am now experiencing the joys of the weekday commute for the first time.
On several journeys recently, particularly in the morning, my preferred service to Marylebone is technically non-stop from Great Missenden, but crawls when passing Amersham and Rickmansworth and slows noticeably around Moor Park and Harrow-on-the-Hill. I love belting down the bank at Preston Road though... ;D
My question, then, is what impact will the introduction of 'S' stock in full service have on Met linespeeds and journey times? Assuming there is an impact, will this be passed onto Chiltern's services?
I kinda expect so, as I know the grand old ladies are restricted to 50mph and 'S' stock will be capable of 62mph *and* superior acceleration to 'A' stock, but I haven't found anywhere yet to provide a definitive answer and this seems the obvious first place to ask. I'd be very grateful, therefore, for any information you kind and knowledgeable people could share with me! Thank you.
THC
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metman
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Post by metman on Jun 5, 2010 15:54:20 GMT
The 'A' stock doesn't limit itself to 50, but it is supposed to! The S stock will be limited to 50 until the A stock is fully replaced  then it will be able to run at a higher speed. In practice as is being found on the Victoria Line, the new trains are a little quicker than the older ones The full effect will be felt after the signalling upgrade, whenever that happens! |
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Deleted
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Post by Deleted on Jun 5, 2010 19:15:36 GMT
Well, although we are technically fast from Great Missenden to London, still we have to slow down for the tripcock test at Amersham (to less than 10 mph), and also the max speed through Rickmansworth is only 25 mph. The other slow downs quoted may be due to us catching up Met trains (as we do 60 vice the, theoretically, 50 of the A stock).
Given the fact that the infraestructure is not going to change, from us diesels point of view, we are no expecting changes with the introduction of the S stock, other than perhaps we will be less slowed down by Met trains.
BTW the speed down Preston Road is 75.
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Post by tubeprune on Jun 6, 2010 17:38:06 GMT
Little will happen to journey times unless the train speed is allowed to increase. Two reasons for the present restrictions on A Stock speeds are the signalling and the braking capability. Neither are up to modern standards. If the S Stock meets the required standards then it will be up to the signal replacement programme to get the mix right for reduced journey times. Since the signal replacement programme has been delayed several years - well, don't hold your breath folks!
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Post by citysig on Jun 6, 2010 19:32:05 GMT
The A-stock are restricted mainly due to a mixture of track-borne restrictions and trying to prolong their lives until full replacement - the majority of the signalling is already up to the standard for 60mph (some areas more) working.
Certain speed restrictions - like those at Amersham and Rickmansworth - will remain. At the former, testing of safety equipment will remain the same, and so will the restriction. The large majority of trains stop there anyway. At the latter, geographical restrictions will remain. The forthcoming projects do not include straightening of the line there.
Even at 60mph, let us not lose sight that most of the trains Chiltern use cannot achieve much more than an extra 15mph.
Thc, I am sure your regular commute - although technically non-stop - is far better than your previous commute. When you enter the LU territory at Amersham it's worth remembering that you are once more within the full-on commuter belt with many hundereds of people also wanting to join trains to London - albeit on LU trains. Of course, you do still experience some of the quickest speeds on the network. West or Central London speeds are a tad slower ;D
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Post by thc on Jun 7, 2010 19:14:35 GMT
Thank you all for taking the time to reply; as I expected I would, I've learned something from each one. MetControl - my previous "commute" was a walk across two west London parks and took a total of twenty-two minutes from home to desk, so they don't come much better than that, I'm afraid! ;D I take your point about threading fast Chiltern services through Metroland, but (admittedly as a civilian rather than a railway professional) I would have expected station dwell times therein to be reasonably short given that an 8-car consist of 'A' stock has 20 double-door and 4 single-door apertures, and 4tph on the Met and 2tph Chiltern provide a stopping service from Met main line stations in the morning peak. And from what I have seen so far, the commuters are pretty adept at spreading themselves along the platform and lining themselves up at points where the doors will open; no bunching at the platform entrance for them! Part of the reasoning behind my original question is the timing disparity between the morning and evening runs. This evening, for example, I took the 1716 from Marylebone, first stop Great Missenden. Despite slowing to a near-stop at HOTH (which I now understand to be the tripcock test, thanks chillout!) it was an impressively slick 41-minute journey to Wendover. In contrast the quickest time I've experienced for the corresponding fast southbound journey in the morning peak is 48 minutes. I expect that some of the seven-minute difference is due to inbuilt recovery time at the Marylebone terminus, but is the rest all due to delays caused by station stops and threading Met trains across Harrow North Junction? (I think I'm answering my own question here...  ) I'm both impressed by and grateful for everyone's insights on this subject. Thank you once again. Tom (THC) |
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Post by citysig on Jun 7, 2010 22:33:42 GMT
MetControl - my previous "commute" was a walk across two west London parks and took a total of twenty-two minutes from home to desk, so they don't come much better than that, I'm afraid! ;D Ah. That puts a different slant on things ;D I take your point about threading fast Chiltern services through Metroland, but (admittedly as a civilian rather than a railway professional) I would have expected station dwell times therein to be reasonably short given that an 8-car consist of 'A' stock has 20 double-door and 4 single-door apertures, and 4tph on the Met and 2tph Chiltern provide a stopping service from Met main line stations in the morning peak. And from what I have seen so far, the commuters are pretty adept at spreading themselves along the platform and lining themselves up at points where the doors will open; no bunching at the platform entrance for them! Indeed, many commuters across the land have their "place" to stand on the platform to afford them either quick access to the train and available seats (which are normally the same ones each morning and evening - curse anyone "additional" who decides to catch the train and takes "their" seat) and/or quick exit at the other end. The bigger problem with A-stock is their pretty sluggish acceleration compared to all other stock on the network. Sometimes it won't seem that bad - until those few seconds occupying a section of track means that a following train then has to slow to a stop whilst awaiting clear signals. Part of the reasoning behind my original question is the timing disparity between the morning and evening runs. This evening, for example, I took the 1716 from Marylebone, first stop Great Missenden. Despite slowing to a near-stop at HOTH (which I now understand to be the tripcock test, thanks chillout!) it was an impressively slick 41-minute journey to Wendover. Not so slick for one of the other non-stop services out of London this evening. A passenger alarm - which was initially over-ridden by the driver in order to keep the train moving (after being told it was an accidental operation) went on to further delay the train at Rickmansworth - which went on to delay a Northbound Met train which was following. So one of those occasions where it wasn't the aged A-stock holding things up ;D |
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Post by superteacher on Jun 9, 2010 22:17:21 GMT
Sometimes, non stop services in certain timetables have been notorious for always stopping at stations where they are not supposed to, due to being held at a signal. This happened a few years ago on one of the fast trains out of Liverpool Street. To be honest, they should have just booked it to stop!
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metman
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Post by metman on Jun 9, 2010 23:02:38 GMT
Nothing wrong with the 'aged' Met trains. We 'did' a Jubilee train out of Finchley Road the other day. It's amazing what they can do with the field flag down! ;D
To be fair to the 'Joint Line' there are a few speed restrictions and there will be instants where Underground trains wil hold up Chiltern trains. We have to remember who owns the line? Chiltern can always use the 'long' way to Aylesbury......
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Deleted
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Post by Deleted on Jun 14, 2010 16:19:19 GMT
The S8 is set up to emulate A stock performance (S7s will emulate C and D stocks in some manner - I don't know the details).
This should stop the S stock catching up with the A and all of the problems that that would entail.
After the A stock is gone, performance could be improved but this is likely to be an incremental improvement as the signalling will rapidly become the limiting factor - again, I don't know if this is planned.
As an aside - I am fairly sure the 09TS has not had its performance limited. It certainly was the plan but by not doing this, they can make up a little of the time lost due to the new train niggles.
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Post by citysig on Jun 14, 2010 16:29:12 GMT
This should stop the S stock catching up with the A and all of the problems that that would entail. Not sure I can think of any real problems - except lots of stopping at red signals to wait for the A-stock to get ahead and out of section. Signalling in some areas will need altering if higher speeds are to be used, and also some trackwork. However, the bigger issue at present is the traction current feeding arrangements. The S-stock is one thirsty train when it comes to the juice ;D |
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Ben
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Post by Ben on Jun 14, 2010 17:41:02 GMT
Oooh, bit off topic, but how does it compare current wise to some of the old timers like the F stock?
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metman
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Post by metman on Jun 14, 2010 18:09:12 GMT
More so I would guess. It's probably up there with the all motor O stock trains!
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Post by Deleted on Jun 14, 2010 18:42:38 GMT
This should stop the S stock catching up with the A and all of the problems that that would entail. Not sure I can think of any real problems - except lots of stopping at red signals to wait for the A-stock to get ahead and out of section. Signalling in some areas will need altering if higher speeds are to be used, and also some trackwork. However, the bigger issue at present is the traction current feeding arrangements. The S-stock is one thirsty train when it comes to the juice ;D Well, you do get a little bunching as the dwells get shorter as you get close to the train in front which in turn lets you get even closer (to a point obviously) in the manner of buses. That and a bit of early running - my personal Met pet peeve. As for the power upgrade, work is underway now I think and the Met above Baker Street should be done by the end of next year. There are certainly some significant bits and bobs turning up before Christmas like Marlborough Road Sub. |
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DWS
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Post by DWS on Jun 14, 2010 19:10:40 GMT
Not sure I can think of any real problems - except lots of stopping at red signals to wait for the A-stock to get ahead and out of section. Signalling in some areas will need altering if higher speeds are to be used, and also some trackwork. However, the bigger issue at present is the traction current feeding arrangements. The S-stock is one thirsty train when it comes to the juice ;D Well, you do get a little bunching as the dwells get shorter as you get close to the train in front which in turn lets you get even closer (to a point obviously) in the manner of buses. That and a bit of early running - my personal Met pet peeve. As for the power upgrade, work is underway now I think and the Met above Baker Street should be done by the end of next year. There are certainly some significant bits and bobs turning up before Christmas like Marlborough Road Sub. Has work started on the Marlborough Road sub-station yet ? |
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Post by citysig on Jun 14, 2010 20:27:38 GMT
Has work started on the Marlborough Road sub-station yet ? Yes, very much so. |
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Post by citysig on Jun 14, 2010 20:31:17 GMT
Oooh, bit off topic, but how does it compare current wise to some of the old timers like the F stock? Put it this way. For years the current (excuse the small pun there) set up for traction current supply has been sufficient. New low-resistance current rails, new substations and shorter current rail sections - because the present-day ones cannot cope with more than 2 S-stocks without tripping out on over-load, should give some sort of broad hint at the difference between older stock and the S-stock ;D |
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then it will be able to run at a higher speed. In practice as is being found on the Victoria Line, the new trains are a little quicker than the older ones
)
