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#21
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In message
, at 06:30:52 on Tue, 15 Jul 2008, Mr Thant remarked: Batteries aren't part of the base spec. It does say "Some level of onboard energy storage may provide an optimal solution overall" Vary large elastic band? -- Roland Perry |
#23
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In article ,
Mr Thant wrote: On 15 Jul, 13:05, "Paul Scott" wrote: You've summed up the flawed thinking of the DfT quite well there. *Please refer to the Thameslink Rolling Stock spec for other conflicting requirements: Roger Ford guesses a 200 hp diesel generator will need to be included under one of the carriages in each unit. It's not a terrible idea but I can't imagine a cost benefit analysis on it is positive - how often is the track navigable but the traction supply unavailable? Plus you['ve got to test the thing to make sure it's functional before the train goes out each day. Is it a critical failure if it doesn't start (which will do /wonders/ for train avaiablilty)? Personally, I rather liked UR's suggestion of a Spearfish power pack for the emergency self-propelling capability, but each use of a power-pack wouldn't be cheap ![]() -- Andy Breen ~ Not speaking on behalf of the University of Wales, Aberystwyth "Who dies with the most toys wins" (Gary Barnes) |
#24
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Roland Perry wrote:
In message , at 06:30:52 on Tue, 15 Jul 2008, Mr Thant remarked: Batteries aren't part of the base spec. It does say "Some level of onboard energy storage may provide an optimal solution overall" Vary large elastic band? It's a long time since I saw you post such a sensible proposal. You wind it up on braking, and it could occupy all that dead space between bogies. After all you can make airplane fly by that method... Jim Chisholm |
#25
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![]() "Andrew Robert Breen" wrote in message ... In article , Mr Thant wrote: On 15 Jul, 13:05, "Paul Scott" wrote: You've summed up the flawed thinking of the DfT quite well there. Please refer to the Thameslink Rolling Stock spec for other conflicting requirements: Roger Ford guesses a 200 hp diesel generator will need to be included under one of the carriages in each unit. It's not a terrible idea but I can't imagine a cost benefit analysis on it is positive - how often is the track navigable but the traction supply unavailable? Plus you['ve got to test the thing to make sure it's functional before the train goes out each day. Is it a critical failure if it doesn't start (which will do /wonders/ for train avaiablilty)? Personally, I rather liked UR's suggestion of a Spearfish power pack for the emergency self-propelling capability, but each use of a power-pack wouldn't be cheap ![]() Especially if they forget to specify they don't need a warhead... Paul |
#26
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On Tue, 15 Jul 2008, J. Chisholm wrote:
Roland Perry wrote: In message , at 06:30:52 on Tue, 15 Jul 2008, Mr Thant remarked: Batteries aren't part of the base spec. It does say "Some level of onboard energy storage may provide an optimal solution overall" Vary large elastic band? It's a long time since I saw you post such a sensible proposal. You wind it up on braking, and it could occupy all that dead space between bogies. After all you can make airplane fly by that method... And run cottonreel tanks! tom -- As Emiliano Zapata supposedly said, "Better to die on your feet than live on your knees." And years after he died, Marlon Brando played him in a movie. So just think, if you unionize, Marlon Brando might play YOU in a movie. Even though he's dead. -- ChrisV82 |
#27
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#28
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On Jul 15, 7:29 pm, Arthur Figgis wrote:
Generally the manufacturer, but the customer might own frilly bits like a fancy nose. Voyager noses have been mentioned in the past - Meridians are a bit different. AIUI the South Africans own the right to the nose of their Electrostars. I guess they nose a good deal when they see one ![]() Ahem. B2003 |
#29
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On Jul 15, 2:12 pm, MIG wrote:
gurgled happily, sounding much like they were saying: even practical. Also Thameslink has some steep sections (eg city thameslink to blackfriars) and I'm wondering if 200hp would be enough to propel a 140 ton unit up them. to snow or something. I've already bored everyone with my anecdote of a 319 failing twice to get up the slope in snowy conditions before reversing to the north end of City Thameslink and finally making it with long runup. Todays Thamelink operations - and all those of the greater operation post 2015 - seem to work OK without any resort to self propulsion. There are no significant engineering blocks where diesel working would be useful - lines tend to be closed outright rather than OLE isolations, and the SR zone tend not to indulge in traction only isolations. It is the central sections BF-City-KX that would be most vulnerable to a train failure. But the service will be so intense through there that rather than **** around with alternative power (that will be so infrequently used it will itself be a liability) you simply bring up the train behind and push out. And as others have quite rightly pointed out, the central section has some fierce grades - that from City to BF is the steepest on the network for practical purposes (although ?? might change with the upgrade ??). Bearing in mind that an EMU with more than 50% motors cut out will struggle up there, I don't see how piddly 200 hp power packs will help any. Since the new TL is supposed to be about longer trains, the chances of a train with more than 50% out reduces - because to get to that state with modules of 4car EMUs you need multiple motor failures across the train affecting more than one unit. Thats pretty rare. Even with a complete disablement of a whole train, you push out with a fully functioning train, so unless a farce arises where it just happens that it is a 4car following a failed 12car, probability suggests its a fair risk to not bother with alternatives. I have to wonder if the person who wrote this into the spec just happens to be a TL commuter and got caught one day in one of those rare events of an AC/DC changeover failure at Farringdon and has gone for sledge hammers to crack nuts approach. Those failures are very rare, I've never been involved in one in regular travel on the route ever since it opened. On top of all this, won't these days of H&S paranoia demand extraction and filtration equipment in the tunnels to remove noxious gases from diesel engines, bionic duckweed trurbines or Swordfish power packs ? -- Nick |
#30
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![]() "D7666" wrote Todays Thamelink operations - and all those of the greater operation post 2015 - seem to work OK without any resort to self propulsion. There are no significant engineering blocks where diesel working would be useful - lines tend to be closed outright rather than OLE isolations, and the SR zone tend not to indulge in traction only isolations. It is the central sections BF-City-KX that would be most vulnerable to a train failure. But the service will be so intense through there that rather than **** around with alternative power (that will be so infrequently used it will itself be a liability) you simply bring up the train behind and push out. And as others have quite rightly pointed out, the central section has some fierce grades - that from City to BF is the steepest on the network for practical purposes (although ?? might change with the upgrade ??). Bearing in mind that an EMU with more than 50% motors cut out will struggle up there, I don't see how piddly 200 hp power packs will help any. Since the new TL is supposed to be about longer trains, the chances of a train with more than 50% out reduces - because to get to that state with modules of 4car EMUs you need multiple motor failures across the train affecting more than one unit. Thats pretty rare. Even with a complete disablement of a whole train, you push out with a fully functioning train, so unless a farce arises where it just happens that it is a 4car following a failed 12car, probability suggests its a fair risk to not bother with alternatives. I have to wonder if the person who wrote this into the spec just happens to be a TL commuter and got caught one day in one of those rare events of an AC/DC changeover failure at Farringdon and has gone for sledge hammers to crack nuts approach. Those failures are very rare, I've never been involved in one in regular travel on the route ever since it opened. Whilst I agree with much of this, and am not convinced that auxiliary traction power is justified, there is also the scenario where failure of the power supply traps trains between stations. While stations are close together between Farringdon and Blackfriars, so it is difficult to conceive circumstances where more than one train could be trapped on each road between each pair of stations, between Farringdon and Kentish Town stations are more widely spaced. Kings Cross Thameslink has been retained as an emergency evacuation location, but I can imagine the difficulties if say three peak trains were trapped between Kentish Town and St Pancras, and 3000 or more passengers had to be evacuated on foot. It would be useful if feasible to be able to move a train to a platform, or out of a platform to clear it for a following train. Peter |
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