Spanish high speed

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caliwag

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Despite Spain's financial problems, the government still seem keen to press on with the high-speed network.
I don't have a view on that and the attached article is mainly concerned with Portugal's cancellation of a cross-border line! I will leave others to speculate on a Scotland/England version of same!! anyway. the interesting point is made mid-way through the article by an engineer that Spanish trains should be slowed from 350 to 200Km/Hr as the high speed is too expensive. Now the energy required for 350 must be higher, but I don't think I've seen such a view expressed by engineering professionals in this country!
Of course, it may well be one man's view, not shared by the profession...I still question, at the proposed 2 minutes headway on HS2, where are all (20,000-30,000 per hour) the passengers going to come from, and where the Hell are they all going?
HS1 has apparently still not achieved it's passenger expectations and as for freight!
However most NR re-openings have far exceeded expectations. Do you need a qualification to 'guess' at possible new line use, or is it really 'finger in the wind' stuff.

http://elpais.com/elpais/2012/03/26/inenglish/1332786230_883989.html
 
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D1009

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Are you saying that the total demand for travel between Madrid and Lisbon is comparable with that between London and British cities ?
 

Nym

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No I think it's more another dig at the passenger forecast figures for HS2 that uses HS1 as an example to discourage it's construction.

That doesn't take into account the very different profile of operation for HS2 compared to HS1, where HS2 will take the long distance services to free space on the WCML, MML and ECML for local services, the attempt on HS1 was for a premium local service.
 

142094

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Sure some of the HS lines they have recently built (including one to an airport that doesn't have any flights) have either been mothballed or had a reduction in their service.
 

gordonthemoron

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I'm sure there has been suggestıons that hıgher speeds requıre more power. However as earlıer posts have saıd, HS2 ıs about delıverıng by far the hıghest route capacıty of hıgh speed lınes ın europe, outstrıppıng even Frankfurt-Cologne so speed ıs of the essence.
 

DownSouth

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I'm sure there has been suggestıons that hıgher speeds requıre more power.
Replace 'power' with 'energy' and it is an objective truth, not just a suggestion. A higher speed requires significantly more energy, kinetic energy being proportional to the velocity squared. More power is only needed if you want to increase acceleration.

Because of this velocity squared relationship, accelerating from zero to a speed of 300 km/h (maximum speed reached in regular service by TGV-TMST sets operated by Eurostar) compared to 225 km/h (maximum speed reached in regular service by the Hitachi A-Train sets operated by Southeastern on higher speed services) would require at least* 78% more energy despite only getting 33% extra speed. Using a higher speed would also require at least* 78% more tractive effort to be applied just for maintaining cruising speed, because air resistance is also proportional to the square of the velocity.
However as earlıer posts have saıd, HS2 ıs about delıverıng by far the hıghest route capacıty of hıgh speed lınes ın europe, outstrıppıng even Frankfurt-Cologne so speed ıs of the essence.
Not correct. Twenty trains arriving every hour having all travelled at 250 km/h will empty out the same number of passengers at the terminus as twenty trains arriving in an hour having travelled at 300 km/h.

With Eurostar having a large fleet of classic-gauged stock that could be redeployed for HS2 classic-compatible service, an initial maximum line speed of 320 km/h would probably be a good move for the first stage. The 20% extra energy* needed to push it up to 350 km/h would not be worth it for such a paltry increase in speed.

* - these figures relate to simplified theoretical physics, real world figures would make for even worse reading.
 

notadriver

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Isn't high speed rail designed to compete with air travel ? For this reason I believe 300 kph should be the standard cruising speed with higher speeds available for making up time. Compared with air travel I think trains are a lot greener !
 

LE Greys

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With Eurostar having a large fleet of classic-gauged stock that could be redeployed for HS2 classic-compatible service, an initial maximum line speed of 320 km/h would probably be a good move for the first stage. The 20% extra energy* needed to push it up to 350 km/h would not be worth it for such a paltry increase in speed.

* - these figures relate to simplified theoretical physics, real world figures would make for even worse reading.
That makes a lot of sense. The trains will be a bit worn out by then, but they are mostly gauged for both Anglo-Scottish routes, although some adjustments need to be made. That would allow Eurostar to do a full stock replacement at the same time as the captive stock is introduced, probably as an addition to the same order to reduce aquisition costs. With both fleets compatible and the current 373s on domestic services only (presumably shortened to 2+14) through services would be easier to plan.
 
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