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Old April 15th, 2011, 09:30 PM   #1981
gramercy
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i hate to rub this in, but i called this right when they said beijing-shanghai was going to be 380; mostly because of energy -> price (380 is TWICE as much energy as 300)

i would have loved to have been proven wrong though
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Old April 15th, 2011, 09:40 PM   #1982
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i hate to rub this in, but i called this right when they said beijing-shanghai was going to be 380; mostly because of energy -> price (380 is TWICE as much energy as 300)

i would have loved to have been proven wrong though
The air friction force (and thus energy needed for given distance) grows with square of speed. Power needed grows with cube, but it is needed for a shorter time.

Note that planes are still faster than trains, so they spend more energy.
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Old April 15th, 2011, 10:12 PM   #1983
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Originally Posted by Fan Railer View Post
well... given that you can find the mass of the train.. use the formula:

Kinetic Energy = 1/2(mass)(velocity^2)

for each speed. (use kg for mass and m/s for velocity)

the answer will provide the amount of energy in joules that the train has at each respective speed... in ideal conditions.

obviously friction and air resistance will add a lot to the energy, but this is what you can get for the average base energy. seeing as the velocity term is squared, it gives you a rough estimate of how much more energy you would need to move an object at faster speeds.
According to your equation, there is a 36% increase in energy consumption from 300 km/h to 350 km/h in ideal condition. If taking consideration of air resistance (resistance is also proportional to the velocity^2 as far as I know), there is at least a 50% increase in total energy consumption from 300 km/h to 350 km/h. So there is a lot of energy saving if speed reduced from 350 km/h to 300 km/h.
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Old April 15th, 2011, 11:27 PM   #1984
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I have a question: In which dialect are the announcements at the railway stations in the south of China, Mandarin or local?
Well it depends on which station really. When I was there Guangzhou South only had English and Mandarin but I heard that Guangzhou has Cantonese and Mandarin. What I find interesting is on the Wugang HSR the attendents use both Manadarin and Cantonese.
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Old April 15th, 2011, 11:32 PM   #1985
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Quote:
Originally Posted by gramercy View Post
i hate to rub this in, but i called this right when they said beijing-shanghai was going to be 380; mostly because of energy -> price (380 is TWICE as much energy as 300)

i would have loved to have been proven wrong though
again, I don't think the decisions made so far by the ministry (or more precisely the government) are for technical reasons, especially not for energy concern. Wuhan-Guangzhou HSR has been operating at 350 for about 16 months and is quite successful in terms of safety/passenger volume/social reputation and so on, there is no obvious technical reason to reduce the speed to 300 on this line as well. 380 for Beijing-Shanghai may sound a little bit too fast, but 350 is never a problem. The government is trying to push higher end business travelers to airlines, and we know that will consume much more energy.

note that the new minister publicly said the following:
"riding in a train at 200 km/h or slower is more comfortable(than in 300km/h+ trains) because you don't feel much pressure in your ears"...
”trains running at 200 km/h or slower are safer than faster trains“
there is simply no way to count on this dinosaur to develop HSR. He was sent by the big bosses to slow the trains down, regardless if there is any technical issue.

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Originally Posted by hmmwv View Post
This seems to be a recreation of the halt of rapid airport expansion occurred in the early part of the last decade. I for one think in a year or two there will be findings suggesting there is no safety concerns about the system and the speed will be back. China operates as a single corporation, internal competition between railway and airlines are red hot and causing problems. They need to cap the growth of HSR a little bit so that domestic air travel don't get killed, thus also help create demand for the forthcoming domestic passenger jets (ARJ21, C919, etc). We all want China to have the best and fastest, but at the end of the day if it can't bring in money then China will be the loser in the long run.
I also believe that the government is to reduce the speed on HSRs because it wants it to look more affordable (thus the society seems more harmonious), and then save the sorry ass airline companies, even at the price of wasting the money that has been spent on building 350 standard tracks and trains. The anti-HSR people often criticize the 56% liability ratio of HSR, and conveniently ignore the 85%-100%+ liability ratio of the airline companies. The reduction in speed may probably affect more people. Take people in Hangzhou for instance, under the current proposed schedule, taking a train to Beijing becomes much less attractive to them. Most of business travelers between Hangzhou and Beijing will then choose to stay with air travel thanks to the speed reduction.

of course, we'll have to wait to see the performance of airlines and railways after speed reduction to give a final conclusion.
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Old April 16th, 2011, 12:21 AM   #1986
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Whats with the conspiracy theory that the government is lowering the speed to protect the airline industry? Do you really believe they want to force their citizens to choose airtravel for some sinister reason?
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Old April 16th, 2011, 01:27 AM   #1987
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Quote:
Originally Posted by chornedsnorkack View Post
Note that planes are still faster than trains, so they spend more energy.
But air density at cruise altitudes is much lower than at sea level. At 36.000ft, it is only 23% of that of sea level.
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Old April 16th, 2011, 02:28 AM   #1988
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Whats with the conspiracy theory that the government is lowering the speed to protect the airline industry? Do you really believe they want to force their citizens to choose airtravel for some sinister reason?
Believe or not, this will be the result. Distances more than 600km, planes will be choice of "rich" since trains cannot cope with their lowered speed cap at 300km/h. With 380km/h (planned 400km/h even 420km/h) the "competition" distance might have increased up to 1000km. Think about that, if the train was comparable to speed and price (mostly cheaper) of air travel up to 1000km distance, this would have been a very very tough market for airlines. I was expecting a weakening domestic airline market with a network of 380km/h trains. Now, this won't happen for some time. This is not even close to be a conspiracy, it is a very expected result. This always happens... Companies, interest groups will always affect policy.
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Old April 16th, 2011, 03:45 AM   #1989
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Quote:
Originally Posted by foxmulder View Post
Believe or not, this will be the result. Distances more than 600km, planes will be choice of "rich" since trains cannot cope with their lowered speed cap at 300km/h. With 380km/h (planned 400km/h even 420km/h) the "competition" distance might have increased up to 1000km. Think about that, if the train was comparable to speed and price (mostly cheaper) of air travel up to 1000km distance, this would have been a very very tough market for airlines. I was expecting a weakening domestic airline market with a network of 380km/h trains. Now, this won't happen for some time. This is not even close to be a conspiracy, it is a very expected result. This always happens... Companies, interest groups will always affect policy.
Perhaps it's not a bad idea to give them some time. Noone would argue that China's HSR network just dropped like an asteroid out of the blue. They built a network in 5 years which elsewhere took 30-40 years and isn't as good. Despite the obvious disappointment from the HSR fans it's probably a more rational and sustainable policy than just banging in a full network of 350-380km/h railways in a time span of just a few years. And it's also important not to let airlines go bankrupt. Globally competitive airlines are very important and I would guess that they don't get nearly as many subsidies as the railways do.
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Old April 16th, 2011, 04:44 AM   #1990
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Quote:
Originally Posted by foxmulder View Post
Believe or not, this will be the result. Distances more than 600km, planes will be choice of "rich" since trains cannot cope with their lowered speed cap at 300km/h. With 380km/h (planned 400km/h even 420km/h) the "competition" distance might have increased up to 1000km. Think about that, if the train was comparable to speed and price (mostly cheaper) of air travel up to 1000km distance, this would have been a very very tough market for airlines. I was expecting a weakening domestic airline market with a network of 380km/h trains. Now, this won't happen for some time. This is not even close to be a conspiracy, it is a very expected result. This always happens... Companies, interest groups will always affect policy.
Not necessarily true. It depends on convenience based on various variables such as frequency of both train and plane schedule, check-in rules and/or distance and traffic condition between airport and city center.
For example the distance between Tokyo and Hiroshima is about 700Km but people leaving Tokyo at 7:00AM on a weekday by Shinkansen and plane will reach Hiroshima central at around the same time since the Shinkansen has more frequency, there is a 30minute check-in rule for domestic flights and Hiroshima airport is about an hour ride by bus.
People on business trips often selects the Shinkansen over planes because of it's accuracy and the luxury of being able to leave based on their schedule and not the flight schedule of planes.
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Old April 16th, 2011, 06:50 AM   #1991
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Quote:
Originally Posted by foxmulder View Post
Believe or not, this will be the result. Distances more than 600km, planes will be choice of "rich" since trains cannot cope with their lowered speed cap at 300km/h. With 380km/h (planned 400km/h even 420km/h) the "competition" distance might have increased up to 1000km. Think about that, if the train was comparable to speed and price (mostly cheaper) of air travel up to 1000km distance, this would have been a very very tough market for airlines. I was expecting a weakening domestic airline market with a network of 380km/h trains. Now, this won't happen for some time. This is not even close to be a conspiracy, it is a very expected result. This always happens... Companies, interest groups will always affect policy.
But even so, the railway network has directly led to huge cuts in short haul flights, to the point where several regional airports built by local governments as "face projects" have become idle. The outlook for small regional flights (at least outside of Tibet, Xinjiang, etc) in China is pretty dire.
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Old April 16th, 2011, 09:11 AM   #1992
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Originally Posted by Suburbanist View Post
But air density at cruise altitudes is much lower than at sea level. At 36.000ft, it is only 23% of that of sea level.
Which means planes at sea level should be spending same energy at 48 % the speed at 11 km.

But even then, planes need to overcome drag of wings, which trains, incl. maglevs, do not have.
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Old April 16th, 2011, 09:54 AM   #1993
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Old April 16th, 2011, 10:18 AM   #1994
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Quote:
Originally Posted by foxmulder View Post
Believe or not, this will be the result. Distances more than 600km, planes will be choice of "rich" since trains cannot cope with their lowered speed cap at 300km/h. With 380km/h (planned 400km/h even 420km/h) the "competition" distance might have increased up to 1000km.
Did/do trains at 350 km/h compete with planes for 968 km distance?

What shall be the trip distance Wuhan-Guangzhou with 300 km/h top speed?
Quote:
Originally Posted by foxmulder View Post
Think about that, if the train was comparable to speed and price (mostly cheaper) of air travel up to 1000km distance, this would have been a very very tough market for airlines. I was expecting a weakening domestic airline market with a network of 380km/h trains.
What is now the price ratio between plane tickets Wuhan-Guangzhou, and train tickets at 350 km/h?
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Old April 16th, 2011, 02:12 PM   #1995
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Does the new MOR minister also have plans to cancel the 500km/h CRH-X Cobra project?
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Old April 16th, 2011, 07:32 PM   #1996
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Originally Posted by Taizu View Post
Does the new MOR minister also have plans to cancel the 500km/h CRH-X Cobra project?
I don't think there is an actual project to develop 500km/h+ commercial train (besides technical demonstrators), but even if there is it's definitely gone now.
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Old April 16th, 2011, 07:35 PM   #1997
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Quote:
Originally Posted by WatcherZero View Post
Whats with the conspiracy theory that the government is lowering the speed to protect the airline industry? Do you really believe they want to force their citizens to choose airtravel for some sinister reason?
There is no conspiracy theory, this is a fact. If I have a central planning organization who has to balance the economics strategy of a nation, I would have done the same. HSR has killed so many once popular domestic airline routes that it's not funny anymore, let alone the possibility that ARJ21 will never sell enough to break even.
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Old April 16th, 2011, 08:50 PM   #1998
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That is why central planned economies FAIL in the long term. And China's economic failure will be interesting to watch as the country grows more complex and industrialized. You can't keep the tights in the economy forever. I just hope the Chinese government fall sooner rather than later and the communist party is disbanded, but that is beyond the scope of this thread.
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Old April 16th, 2011, 09:16 PM   #1999
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Originally Posted by Suburbanist View Post
That is why central planned economies FAIL in the long term. And China's economic failure will be interesting to watch as the country grows more complex and industrialized. You can't keep the tights in the economy forever. I just hope the Chinese government fall sooner rather than later and the communist party is disbanded, but that is beyond the scope of this thread.
Lol, whut? I don't believe the Chinese economy is a central plan economy, like the Soviet and earlier Chinese economy were. Right now, it's a hybrid form. That's why they changed the name of the five-year plan to five-year program.

Besides, it's not China that is in deep economic trouble nowadays, is it?
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Old April 16th, 2011, 10:05 PM   #2000
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Err .. this thread is about the high-speed rail projects, not on whether a particular economic system will fail.
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