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#91
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In message , at 11:36:24 on Sun, 10
May 2009, Andrew Heenan remarked: Once a bit of ageing has occurred, a railway doesn't look too bad at all - just part of the scenery. Compare a four track with overhead wires to any motorway, and tell me what looks best. It does depend quite a lot on whether the OHL is gantries, or masts. I agree that the ECML doesn't look too bad, but the WCML eg around Rugby (especially with all the "extra" high level stuff they've put in recently) is much more ugly. -- Roland Perry |
#92
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On 10 May, 12:26, Roland Perry wrote:
In message , at 11:36:24 on Sun, 10 May 2009, Andrew Heenan remarked: Once a bit of ageing has occurred, a railway doesn't look too bad at all - just part of the scenery. Compare a four track with overhead wires to any motorway, and tell me what looks best. It does depend quite a lot on whether the OHL is gantries, or masts. I agree that the ECML doesn't look too bad, but the WCML eg around Rugby (especially with all the "extra" high level stuff they've put in recently) is much more ugly. -- Roland Perry But the ECML is notoriously unreliable as a result, whereas the WCML ,,, oh hang on ,,, |
#93
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On 10 May 2009 05:22:45 GMT, Matthew Geier
wrote: On Sat, 09 May 2009 09:13:15 +0100, Peter Masson wrote: "Matthew Geier" wrote road transport doesn't have the ability to use this rather simple and (relatively) cheap means of getting mains power in via overhead lines. I used to enjoy travelling by trolleybus. But has any one ever built a trolley-lorry or a trolley-car ? http://en.wikipedia.org/wiki/Trolleytruck The common theme seems to be mining or large-scale construction projects. Can you imagine a line of cars zipping down the road with a pair of trolley poles on each ?. And the chaos when one de-wires and the driver has to hop out and relocate the pole on the wire. There should be more trolley buses about though. |
#94
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I only lifted quoted material from the blog - no opinion in there.
David "Mizter T" wrote in message ... On May 9, 3:10 pm, Chris wrote: On 7 May, 13:43, "DW downunder" noname wrote: C. http://www.alwaystouchout.com/project/60 5) "TfL would like Airtrack "to be developed in a way that is consistent with the possible extension of some Crossrail trains to Staines via Heathrow." [TfL response to South Western franchise specification] " http://www.alwaystouchout.com/project/1#Stations This is about Crossrail ... This means that Crossrail would only run to Heathrow Central and Terminal 4 - not to Terminal 5. Passengers would be able to transfer at Heathrow Central to the Heathrow Express for free connections to T5. Hmmm - TfL have their work cut out getting BAA / NR / DfT to take that on board, then!!! :-) www.alwaystouchout.comappears to be a personal blogspot, and therefore about as reliable as this forum, which at least has some informed people on here. alwaystouchout was a project of a former contributor to this newsgroup, who was most certainly a well informed person - be in absolutely no doubt about that. However as you can see they're not updating it any more, so the information presented on it is frozen in time. With a project such as Crossrail, things can of course change - look at the Thameslink Programme, where the final service pattern is far from certain. |
#95
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![]() "Christopher A. Lee" wrote in message ... On Sat, 9 May 2009 21:16:22 +0100, Tom Anderson wrote: On Sat, 9 May 2009, GazK wrote: Tom Anderson wrote: IMHO It is very likely that I Kingdom Brunel would welcome electrification. He seemed very keen to find a better, cleaner form of motive power. He would have insisted on using 3 phase 37.278kV* electrification at 16.25Hz fed through side contact 3rd and 4th rail - and bugger the through running! * there is a logic behind this number. See if you can work it out! Dunno, but getting three-phase power through two conductors is an interesting idea. ... running rail(s) for the third phase. I'm not making this up, it has been done before, in Italy and elsewhe http://en.wikipedia.org/wiki/Railway...urrent_systems That seems a little bit ... yikes. Thinking about it, though, it's no worse than using the running rails for current return in a one-phase system, is it? I'm not sure why i thought it would be. I don't know about the Italian system but the American one had single speed locomotives because the AC motors were synchronous. Which didn't really matter for the slow speed freight trains in the Cascades. tom 1) Interesting outcome when one loco in a set failed, the other just sat there and ground away at the rail, stationary. This was 1920s, no headlights, the crew had no idea. Can't recall the source - a book I read somewhere. 2) Back to the 37.278. Well 37.278/ sq rt 2 = 26.34kV ... my AC maths is too primitive, but sq rt of 2 is a component of the reason. David down under |
#96
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![]() "disgoftunwells" wrote in message ... On 8 May, 10:07, wrote: On Thu, 7 May 2009 19:19:48 +0100 Paul Terry wrote: It would be daft to develop Crossrail in the hope that adequate battery technology would be available by the time the trains have to be ordered. However, battery trains have been used for suburban rail - Dublin to Bray between 1932 and 1950. In .uk a battery MU operated between Aberdeen and Ballater in the early 1960s, while battery locos Probably lines with very light traffic and low top speeds. have been used to haul engineering trains on LU in the dead of night when the power's een switched off. They still are AFAIK. Although I agree with the basic premise, battery technology is becoming increasingly impressive - parts of the new Rome trolleybus system currently run on battery power for some miles, and Alstom's trams for Nice also run on batteries in the city centre. These are vehicles capable of carrying a large number of passengers in heavy traffic, although probably not on the scale required for the far reaches of Crossrail. Theres a big difference between accelerating a 20 ton tram to 20mph and a 200 ton train to 60mph quickly enough so it keeps to the timetable. Moreover when the batteries are not being used you're hauling around god knows how many tons of dead weight - hardly enviromentally friendly. Plus most EMUs these days seem to be pretty lardy anyway. I suspect if batteries were thrown into the mix axle loads could become a serious issue. hmm - some numbers. E = 1/2 200,000kg x 30^2 = 100MJ = 30KWhrs. That's about 200kg of Li-ion battery, for the energy load. But the power requirement is much tougher - you would need some of these fast charge batteries, which actually have less energy storage. Without looking up the W/kg figures, I'd guess a few tons. Hybrid technology is certainly useful for trains, but you'd probably want to use ultra caps to capture the braking energy. You got it, and the super caps can then be used to release the regenerated charge to the lithium and lead based units at their life-optimising charge rates, if it's not drawn down promptly (such as would occur at a terminal) for acceleration. For runs beyond the range of battery-only, I envisage using a lightweight gas-turbine genset running at its optimum efficiency - with the batteries buffering the peaks and troughs of current consumption. But that raises a question about fuel tanks in tunnels which have stations ..... I'm not sure where that is at today, but suspect the bureacracy would regard it as a major no-no. David down under |
#97
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![]() "Chris" wrote in message ... Apologies for the length of this post, but I've chosen to answer many posts in this one, rather than several....but there's a LOT of misinformation in this thread! On 5 May, 16:28, Mizter T wrote: On May 5, 4:05 pm, Barry Salter wrote: There have been plenty of comments on these newsgroups in the past that getting Crossrail to Reading might not be all that it's cracked up to be in certain quarters, what with a Crossrail train from Reading into central London being slower that a fast non-stop service to Paddington (where interchange with Crossrail would of course be available). Plenty of *uninformed* comment too, to boot - why doesn't everyone READ the CrossRail website contents, and if you're that interested, ensure that you attend one of Network Rail / CrossRail exhibitions??? SNIP Would do if they mounted one in Perth, Western Australia. I might be one of maybe 50-100 that'd come and look. Don't think my contacts at Crossrail would entertain the idea, though ![]() David down under |
#98
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On 11 May, 17:17, "DW downunder" noname wrote:
"disgoftunwells" wrote in message ... On 8 May, 10:07, wrote: On Thu, 7 May 2009 19:19:48 +0100 Paul Terry wrote: It would be daft to develop Crossrail in the hope that adequate battery technology would be available by the time the trains have to be ordered. However, battery trains have been used for suburban rail - Dublin to Bray between 1932 and 1950. In .uk a battery MU operated between Aberdeen and Ballater in the early 1960s, while battery locos Probably lines with very light traffic and low top speeds. have been used to haul engineering trains on LU in the dead of night when the power's een switched off. They still are AFAIK. Although I agree with the basic premise, battery technology is becoming increasingly impressive - parts of the new Rome trolleybus system currently run on battery power for some miles, and Alstom's trams for Nice also run on batteries in the city centre. These are vehicles capable of carrying a large number of passengers in heavy traffic, although probably not on the scale required for the far reaches of Crossrail. Theres a big difference between accelerating a 20 ton tram to 20mph and a 200 ton train to 60mph quickly enough so it keeps to the timetable. Moreover when the batteries are not being used you're hauling around god knows how many tons of dead weight - hardly enviromentally friendly. Plus most EMUs these days seem to be pretty lardy anyway. I suspect if batteries were thrown into the mix axle loads could become a serious issue. hmm - some numbers. E = 1/2 200,000kg x 30^2 = 100MJ = 30KWhrs. That's about 200kg of Li-ion battery, for the energy load. But the power requirement is much tougher - you would need some of these fast charge batteries, which actually have less energy storage. Without looking up the W/kg figures, I'd guess a few tons. Hybrid technology is certainly useful for trains, but you'd probably want to use ultra caps to capture the braking energy. You got it, and the super caps can then be used to release the regenerated charge to the lithium and lead based units at their life-optimising charge rates, if it's not drawn down promptly (such as would occur at a terminal) for acceleration. For runs beyond the range of battery-only, I envisage using a lightweight gas-turbine genset running at its optimum efficiency - with the batteries buffering the peaks and troughs of current consumption. But that raises a question about fuel tanks in tunnels which have stations .... I'm not sure where that is at today, but suspect the bureacracy would regard it as a major no-no. When Connex introduced the new trains on the South Eastern line to Hastings, they didn't realise that the new trains, accelerating at twice the rate of the old ones, needed twice the power. This led to delays, whilst the grid was strengthened. I wonder if today's solution would be to use super capacitors to reduce peak current draw down. A quick google gives 300W/kg for super capacitors, so 1 ton gives a peak of 300KW. How does that compare to a train motor? I'm not convinced about batteries just yet. When every bus is electrically driven, then it'll be time to consider trains. |
#99
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On 5 Mai, 18:49, D DB 90001 wrote:
and then they can remove that anomaly. Talking of branches there would still be the outstanding issue of Henley trains which would almost certainly run under the wires in the peaks on the slows anyway, because that branch will * never* be electrified.- ditto for the Marlow and Windsor branches. But wouldn't these be no brainer candidates for the much vaunted infill alectrification scheme, if ever it takes off? |
#100
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On 9 Mai, 20:36, GazK wrote:
... running rail(s) for the third phase. I'm not making this up, it has been done before, in Italy and elsewhe is still done on many mountain railways in Switzerland and elsewhere. |
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