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Post by A60stock on May 29, 2018 19:52:16 GMT
im just wondering that once the new signalling is in place, whether the met trains on the fast lines (and between wembley and finchely road) will run at a faster speed than present. I always feel like the jubilee line are running alot quicker since the move to automation
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Post by jetblast787 on May 30, 2018 21:04:42 GMT
While the signalling will improve speeds and reduce headways, I think the limiting factor along that section is mainly to do with the track quality. Would anyone else agree?
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Post by goldenarrow on May 30, 2018 23:09:47 GMT
New signalling will introduce ATO into new territory as the Metropolitan introduces a lot of rare scenarios for a moving block system one which is sustaining speeds above 45mph for long distances.
A lot of the track has already been brought up to modern standards (I think even the bull heads SB before Willesden Green are due to be replaced).
NB Finchley Rd to Kilburn is 50 then up to 60 all the way to Wembley Pk where it's 30mph for the local and 50mph for the fast.
SB I think it's 40 for the points at Neasden, then 60 up to Kilburn, 50 for the bridges over the North London Line and then 45 at the end of West Hampstead to Finchley Rd.
With conventional signalling presently particularly in the peaks these speeds may not be reached.
ATO will inevitably lead to changes but most of these speeds limits are due to the course of the railway and surrounding infrastructure so I don't expect many drastic speed increases on many parts of the MET.
I'm not sure what the Jubilee 96's acceleration is compared to 1.3m/s^2 for the S stock (I think that's right) but the gains on the Jubilee are in the open sections some what lost by what some would say is the over cautious braking curve making trains crawl in at as low as 20mph.
I was recently on a Met train that chased a Jubilee line train that had left Finchley Rd 3mins earlier, there was a signal failure at Kilburn earlier and the train averaged about 30mph but sill got to Wembley over a minute before the same Jubilee train, with trains on the MET being capable of much higher speeds, headways/average speed particularly between Finchley Rd and Wembley Pk should be interesting to watch.
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roythebus
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Post by roythebus on May 30, 2018 23:33:50 GMT
The Met n/b fast speed through Wembley Park used to be 60 mph in the 1960s and 70s. And if I remember correctly, south of Wembley was 60 all the way to finchley Road. the Met was definitely faster in those days.
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metman
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Post by metman on Jun 1, 2018 22:27:07 GMT
I would also imagine the gear ratios on the 96 stock differ from the S stock? I’m not sure what the ratings on the motors are? The 96 stock have 16 motored axels per 7 cars where the S stock have 32 axels per 8 cars.
I’ve only seen an A stock beat a 96 stock out of Finchley Road once and the flag was down......
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Post by A60stock on Jun 2, 2018 11:08:22 GMT
and i bet this was before the jubilee switched over to ato! (was this northbound or southbound btw?)
Re the gear ratio, doesnt this mean the s stock will be quicker off the mark than the 96 once using ato? Surely 2010 is an upgrade over 1997!
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Post by goldenarrow on Jun 2, 2018 11:32:14 GMT
I think that presently the 96's have the upper hand even though the S8's axels are all motorised but manually driven so it's more down to individual driving style than pure numbers on the MET. Certainly on the SB the Jubilee has a falling gradient to aid it with 35mph opposed to the 30mph for the SB MET.
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metman
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Post by metman on Jun 3, 2018 8:09:35 GMT
and i bet this was before the jubilee switched over to ato! (was this northbound or southbound btw?) Re the gear ratio, doesnt this mean the s stock will be quicker off the mark than the 96 once using ato? Surely 2010 is an upgrade over 1997! It was Southbound and can’t remember to be honest! |
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Post by spsmiler on Jun 3, 2018 22:46:57 GMT
The Met n/b fast speed through Wembley Park used to be 60 mph in the 1960s and 70s. And if I remember correctly, south of Wembley was 60 all the way to finchley Road. the Met was definitely faster in those days. Its a shame that these speeds have not been retained.
The fact that trains would have regularly travelled at those speeds (and I bet even higher!) proves that such speeds were perfectly safe. If anything, since present-day long welded rails are actually better (and can provide a better ride quality) than the jointed bullhead track of yesteryear so speeds should be higher than they were in those days. The only reasons which I can think of why there are lower speed limits today relates to track maintenance not being the same as in those days (not a topic I feel comfortable talking about) and that the railways have fallen down the same black hole as road traffic and speeds are reduced simply because of an idealogical dislike of fast travel.
When distances are involved then faster acceleration is of very limited benefit. Its higher line speeds which count.
Simon
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Post by philthetube on Jun 4, 2018 18:59:24 GMT
I think that presently the 96's have the upper hand even though the S8's axels are all motorised but manually driven so it's more down to individual driving style than pure numbers on the MET. Certainly on the SB the Jubilee has a falling gradient to aid it with 35mph opposed to the 30mph for the SB MET. nothing to do with driving style, An S stock departing north at the same time as a 96 from Finchley road will not reach the same speed as the 96 until the drivers cab is on line with car six of the 96, at which point the 96 is beginning to slow up. I am sure that they will be much faster under ATO. I have heard that 95 stock is capable of much higher speeds and current maximums are down to the software, please don't quote me on that as I don't know if this is correct |
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Post by goldenarrow on Jun 4, 2018 19:15:00 GMT
philthetube , Perhaps I was contextualising a poor example, the main opinion I was trying to convey was that I didn't think an S8 in manual could match a 96 in ATO on pure acceleration (scenario where both are on 630V) . For an S8 to floor it from the Pilot Light/Door Closed Visual would not be the most comfortable per say but on the 96, it's not like you really have a choice.
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Post by Deleted on Jul 29, 2018 14:07:50 GMT
I think that presently the 96's have the upper hand even though the S8's axels are all motorised but manually driven so it's more down to individual driving style than pure numbers on the MET. Certainly on the SB the Jubilee has a falling gradient to aid it with 35mph opposed to the 30mph for the SB MET. nothing to do with driving style, An S stock departing north at the same time as a 96 from Finchley road will not reach the same speed as the 96 until the drivers cab is on line with car six of the 96, at which point the 96 is beginning to slow up. I am sure that they will be much faster under ATO. I have heard that 95 stock is capable of much higher speeds and current maximums are down to the software, please don't quote me on that as I don't know if this is correct
Yes they are capable of 60 at least. When they were tested years ago they flew along the Barnet branch and the decision was taken to reduce the power, that and the fact that the extra volts were not available.
The 95 stock has a much more advanced traction package, they are essentially the same as an IGBT main line train. However due to them running on just 630 volts they don't have full power available. Think of an 09 stock the 95 stock is cabable of that type of acceleration too.
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Post by Deleted on Jul 29, 2018 14:53:42 GMT
The Met n/b fast speed through Wembley Park used to be 60 mph in the 1960s and 70s. And if I remember correctly, south of Wembley was 60 all the way to finchley Road. the Met was definitely faster in those days. Its a shame that these speeds have not been retained.
The fact that trains would have regularly travelled at those speeds (and I bet even higher!) proves that such speeds were perfectly safe. If anything, since present-day long welded rails are actually better (and can provide a better ride quality) than the jointed bullhead track of yesteryear so speeds should be higher than they were in those days. The only reasons which I can think of why there are lower speed limits today relates to track maintenance not being the same as in those days (not a topic I feel comfortable talking about) and that the railways have fallen down the same black hole as road traffic and speeds are reduced simply because of an idealogical dislike of fast travel.
When distances are involved then faster acceleration is of very limited benefit. Its higher line speeds which count.
Simon
Driver training has a lot to do with it too. When you teach drivers to keep to time they will get you from a to b as quickly as possible. If you teach them to maintain passenger comfort they will not exceed a certain speed which makes the journey a lot slower! The 1996 stock trains for example were never exactly slow under manual, it was down to the drivers that kept coasting at 30mph. I have been on some journeys in my time where a ride on the Jubilee felt more like the Northern Line!
Higher line speeds do count which is exactly why the HST is far better than the IET. The IET is quicker off the mark but put one alongside an HST and after a while the HST will fly past.
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