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#41
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Steve Fitzgerald ] wrote in
: In message op.uyjjm50pby8eno@sheepdog, Colin McKenzie writes The replacement for 73 stock is already out for tender. That's a bit early, isn't it? If the modernisation programme is over budget, deferring this build would be one way to spread the cost. IIRC the 73 stock went into service in 1975, so its replacements shouldn't be needed until 2015. It's (currently!) designated 13 Tube Stock so that's about right. Is there a public source for that? http://www.tubelines.com/news/releas.../20070115.aspx says that "Tube Lines is committed to introducing a new rolling stock fleet by 2014", hence the Font Of All Knowledge is calling it 2014 stock: http://en.wikipedia.org/wiki/2014_tube_stock |
#42
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wrote in message
On Wed, 12 Aug 2009 10:26:30 +0100 "Recliner" wrote: True, but the new Victoria line trains are longer, faster and more frequent, so that may account for some of the extra power. I suppose. I don't see why trains shouldn't also get significantly more efficient, more comfortable and more reliable over time (though, of course, I don't know about reliability but there does seem to be a trend of every new electric train in this country using more power than its predecessor. In the case of the 377s significantly more. This is in stark contrast to cars which despite getting heavier year on year are still using less fuel with each generation. Whatever the train builders are concentrating on in their designs, energy efficiency doesn't seem to be it. That does indeed seems to have been the trend until recently, but I think they're now getting the message. For example, after Captain Deltic described the Desiro as a lardbutt, Siemens has responded with a new lightweight Desiro City train. It claims that, "The lightweight design of the train and the bogies combined with an intelligent vehicle control system reduce overall energy consumption by up to 50 per cent compared to preceding models." http://w1.siemens.com/press/en/pressrelease/?press=/en/pressrelease/2009/mobility/imo20090736.htm |
#43
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Recliner wrote:
For example, after Captain Deltic described the Desiro as a lardbutt, Siemens has responded with a new lightweight Desiro City train. It claims that, "The lightweight design of the train and the bogies combined with an intelligent vehicle control system reduce overall energy consumption by up to 50 per cent compared to preceding models." http://w1.siemens.com/press/en/pressrelease/?press=/en/pressrelease/2009/mobility/imo20090736.htm Don't forget upgrading the power supply to cope with regen braking and the likely differences in power consumption curves between 1960s and 2000s era motors, as detailed in Cap'n D's Southern Power Upgrade stuff a few years back. It's not wholly surprising that a larger fleet of new trains running more frequently with different motor characteristics and regen would require a power supply upgrade in tandem. Tom |
#44
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"James Farrar" wrote in message
. 1.4 Steve Fitzgerald ] wrote in : In message op.uyjjm50pby8eno@sheepdog, Colin McKenzie writes The replacement for 73 stock is already out for tender. That's a bit early, isn't it? If the modernisation programme is over budget, deferring this build would be one way to spread the cost. IIRC the 73 stock went into service in 1975, so its replacements shouldn't be needed until 2015. It's (currently!) designated 13 Tube Stock so that's about right. Is there a public source for that? http://www.tubelines.com/news/releas.../20070115.aspx says that "Tube Lines is committed to introducing a new rolling stock fleet by 2014", hence the Font Of All Knowledge is calling it 2014 stock: http://en.wikipedia.org/wiki/2014_tube_stock I notice the press release says, "Requesting expressions of interest from manufacturers is the first stage of the procurement process leading to selection and contract award by Tube Lines, anticipated at the end of 2008". Well, that's not happened yet, so I guess the in-service date is also slipping. I think the 2009 stock was ordered in about April 2003, and it took more than six years for the first train to enter late night service. I assume the full 2009 stock service won't be till 2011. On that basis, if the new Picc stock really is ordered this year, the 1973 TS will probably still be in daily use when it's 40 years old in 2015. |
#45
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#46
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In message , James
Farrar writes The replacement for 73 stock is already out for tender. That's a bit early, isn't it? If the modernisation programme is over budget, deferring this build would be one way to spread the cost. IIRC the 73 stock went into service in 1975, so its replacements shouldn't be needed until 2015. It's (currently!) designated 13 Tube Stock so that's about right. Is there a public source for that? http://www.tubelines.com/news/releas.../20070115.aspx says that "Tube Lines is committed to introducing a new rolling stock fleet by 2014", hence the Font Of All Knowledge is calling it 2014 stock: http://en.wikipedia.org/wiki/2014_tube_stock I'll check when I get to work later on - I may have mis-remembered or I've seen it referred to as that on a document that's flying round. If it is 14TS then that's even closer to the 2015 date that was referred to. -- Steve Fitzgerald has now left the building. You will find him in London's Docklands, E16, UK (please use the reply to address for email) |
#47
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On Aug 12, 10:36*am, wrote:
On Wed, 12 Aug 2009 10:26:30 +0100 "Recliner" wrote: True, but the new Victoria line trains are longer, faster and more frequent, so that may account for some of the extra power. I suppose. I don't see why trains shouldn't also get significantly more efficient, more comfortable and more reliable over time (though, of course, I don't know about reliability but there does seem to be a trend of every new electric train in this country using more power than its predecessor. In the case of the 377s significantly more. This is in stark contrast to cars which despite getting heavier year on year are still using less fuel with each generation. Whatever the train builders are concentrating on in their designs, energy efficiency doesn't seem to be it. No, you're missing the point here. Power isn't the same thing as energy. Power rating is a peak; energy consumption is an average. New trains have more efficient motors than older trains [thanks to the move from DC traction to AC traction], and the weight of the 09 stock is no higher than the weight of the 1967 stock - but instead of a peak power rating of 848kW, it has a peak power rating of 1800kW. That means it accelerates to line speed faster, hence putting more load on the infrastructure, hence (alongside the regenerative braking already discussed) the need for the power upgrade. But it also means that it'll spend less time drawing the peak power rating, and more time cruising - hence overall energy consumption won't be higher (OK, there'll slight extra air resistance and friction from the fact that the train spends more time going faster, but this will be small, and more than offset by the impact of regen). With the Mk1 replacements on the Southern, it's a bit more complicated, as the new trains were heavier and had power doors, aircon, etc - but again, a lot of the difference was higher peak draw not higher overall energy consumption. -- John Band john at johnband dot org www.johnband.org |
#48
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On Aug 12, 11:14*am, Roland Perry wrote:
You might be able to apply some of the engine-improvement technology to DMUs, but can electric motors be made any more efficient? Yes: 1) three-phase induction motors instead of synchronous DC motors 2) regenerative braking These have been done. This is why overall energy consumption for new electric trains isn't substantially higher than for older electric trains, despite their much higher peak power ratings. -- John Band john at johnband dot org www.johnband.org |
#49
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In message
, at 03:53:07 on Wed, 12 Aug 2009, John B remarked: You might be able to apply some of the engine-improvement technology to DMUs, but can electric motors be made any more efficient? Yes: 1) three-phase induction motors instead of synchronous DC motors 2) regenerative braking These have been done. So you can't make them *more* efficient, then (starting today, obviously). This is why overall energy consumption for new electric trains isn't substantially higher than for older electric trains, despite their much higher peak power ratings. You seem to be talking about historic improvements which have reached a plateau. And a plateau is exactly what car engines have *not* yet reached, and what the question was effectively about. -- Roland Perry |
#50
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On Wed, 12 Aug 2009 03:49:49 -0700 (PDT)
John B wrote: No, you're missing the point here. Power isn't the same thing as energy. Power rating is a peak; energy consumption is an average. Good point. But are there any figures then for overall energy consumption for trains compared to old stock? B2003 |
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