China to lower speeds for HSR trains.

I wonder if they will authorise the existing higher speeds if trains are running late .

It does seem that 320 km/hr or so is the pratical limit for hsr , unless some cheap energy source is found .

David Benton wrote:I wonder if they will authorise the existing higher speeds if trains are running late .

It does seem that 320 km/hr or so is the practical limit for hsr , unless some cheap energy source is found .

My local train to London hits nearly 100 mph on some segments. On the whole I think that is adequate, though there are some slower segments, which I would like to see improved. What is not acceptable is long journeys at the bizarre 79 mph. That is grotesque for modern rail systems. How much faster they should go depends on many factors. Energy usage is certainly a factor, especially as energy costs are rising everywhere (except for my solar system).

electricron wrote:http://english.peopledaily.com.cn/90001 ... 56350.html
The operators of the Beijing-Shanghai high-speed rail that is scheduled to be put into operation at the end of June will remove luxury train seats and lower the operating speed in order to better meet the needs of common passengers by charging lower fares, the railway authorities said on April 19.
The new trains for the Beijing-Shanghai high-speed railway were all produced under the standard of running at the maximum speed of 380 kilometers per hour and at the normal speed of 350 kilometers per hour. However, according to the latest provisions by the Ministry of Railways, the maximum speed of the trains will be lowered to 300 kilometers per hour and the aviation-grade luxury seats will be replaced by standard seats.
Furthermore, after the speed of a railway train exceeds 320 kilometers per hour, the costs of energy consumption for the train will double for a rise of every 10 kilometers per hour in the speed.
FYI:
350 kph = 217 mph
300 kph = 186 mph
250 kph = 155 mph

This tidbit of news doesn't reinforce the idea many wish to make that our Acela trains are too slow. Instead, it shows that they are ran economically. To go much faster consumes far more energy, causing fares to rise. Even China realizes this truth.
Newton's Second Law >>> F = MA

Another article on this at:

http://www.topchinatravel.com/community ... -speed.htm (200km/h is 125mph)

'China's high-speed railways will run at a slower speed than previously expected, according to the newly appointed railways minister.

In an interview with People's Daily published on Wednesday, Sheng Guangzu, who took on the role on Feb 25 replacing former railways minister Liu Zhijun, said high-speed trains will run at 300 kilometers per hour starting from July 1, instead of the previously announced 350 km/h.

The change to the country's high-speed rail network was made after Liu stepped down when he became the subject of an investigation for an alleged "severe violation of discipline" on Feb 12.

Sheng said in the interview that only the four east-west and four north-south artery lines of the high-speed rail network will carry trains at 300 km/h.

The inter-city lines that usually connect major centers within regions should be operated at between 200 and 250 km/h, while most railways in central and western China will operate at less than 200 km/h.

To placate passengers who complain they are forced to ride on high- speed trains and pay more because the ministry canceled slower trains, he said there will be other options. For example, the 300-km/h lines
will also operate bullet trains at between 200 and 250 km/h.

The new policy is a change from the one publicized during Liu's time.

Previously, China was expecting to build a high-speed rail network with an operational speed of 350 km/h or more.

The landmark Beijing-Shanghai high-speed railway was built to run trains at 380 km/h that could compete with airlines. But Sheng did not say whether the line will still run that fast when it opens in June.

Zhao Jian, a transport professor at Beijing Jiaotong University, told China Daily that the speeds should have been slower right from the start.

"Because, at 300 km/h or less, the high-speed rail network can operate in a more economically efficient and safer way," he said.

The energy consumption of trains at 350 km/h could be twice that of trains at 200 km/h, he explained.

For passengers, a lowered speed could mean a cut in ticket prices in the future.

Wang Yongping, spokesman for the ministry, said on Wednesday that the lowering of the operational speed will "provide a bigger price-float range", without elaborating.

Ha Yanmei, who commutes between Beijing and Tianjin every weekend, said the ticket price for high-speed trains should drop along with the speed.

"Otherwise, I will feel I am cheated by the ministry," she said.

As for concerns about whether railway construction will also slow down, Sheng said such work between 2011 and 2015 will be rolled out fast across the country, with an investment of 2.8 trillion yuan ($428 billion) allocated for it.

As planned, the country's railway network will stretch to 120,000 km by the end of 2015, up from the current 91,000 km, he said.

But he stressed that priority will be given to ongoing projects to make sure they have enough funds for construction to be completed, and emphasis will be given to projects that are in urgent demand because of economic development.

Zhao said the arrangement could mean some projects might be cut or postponed.

"In addition to cutting some projects, the ministry should also adjust some ongoing projects as well," he said, adding that the planned 350- km/h railway between Xi'an and Urumqi should be built to operate at 200 km/h.

The ministry also plans to ask passengers to provide their real names when buying bullet train tickets starting June 1.

From the end of June, the Beijing-Shanghai high-speed railway will be the first line in China to start selling tickets online. Online sales will be extended to other lines at the end of this year.'


And on Acela, it could be run economically and at a higher average speed by uprating the 79mph and 90mph sections to 125mph (200km/h). Here in the UK, I recently travelled from London to Stoke on Trent, a distance of 144 miles in 82 minutes - average speed 105 mph on a train that did not exceed 125mph.

From the OP's article:

Furthermore, after the speed of a railway train exceeds 320 kilometers per hour, the costs of energy consumption for the train will double for a rise of every 10 kilometers per hour in the speed.

That strikes me as physically absurd.

Drag force = (1/2)*Cd*A*density*v^2 (Drag coefficient - Wikipedia)
where v = velocity, A = cross-section an area, and Cd = drag coefficient, a dimensionless quantity usually around 1.

Kinetic-energy loss rate dE/dt = force*v = (1/2)*Cd*A*density*v^3 here -- yes, the cube of the velocity, not some exponential.

That means that going from 300 km/h to 350 km/h increases the air drag by almost 60%, and to 380 km/h by a factor of 2.

However, the total energy lost for a trip is force*distance, which is proportional to v^2. That's 36% and 50% more for 350 and 380 km/h relative to 300 km/h.

This is partly an issue of safety and partly an issue of economics. China has spent something like $600 billion on this system, more than the cost of our interstate. 10% of their national debt is tied to this project. And they are realizing they are never gonna come close to getting that money back. Lots of these trains are running half empty. And the poor; still the vast majority of China's population, can't afford high speed tickets. And the slower conventional trains are being removed to increase freight capacity. So now the poor are riding long distant buses.

And have you seen the rail line China built to Tibet? That must have cost tens of $ billions, and it runs through and serves absolutely nowhere. How about the billions they spent on a Maglev line that they have announced will never be extended?

China has let their central planning completely run amuck and has spent ENORMOUS AMOUNTS OF BORROWED MONEY on projects that are based strictly on prestige and politics, not on anything resembling economics. China has also built enormous "Ghost" cities for workers, and they sit empty.

http://www.businessinsider.com/pictures ... es-2010-12

China is a bubble, and it is going to burst. Slowing the trains down and taking out the "comfy chairs" is just the beginning...

Force is proportional to the square of velocity. Power is proportional to velocity cubed. So, doubling the speed of a train will increase the power requirement TO OVERCOME AIR RESISTANCE by a factor of 8. If you are going slow (i.e. freight or Amtrak), air resistance is not a large component of the forces acting on a train. But for a train going 200 mph, it is a very large force.

MikeinNeb wrote:China is a bubble, and it is going to burst. Slowing the trains down and taking out the "comfy chairs" is just the beginning...

Whether or not the Chinese economy goes into recession at some stage, at least they are investing in a transport infrastructure that doesn't rely on oil - unlike the United States.

Lots of these trains are running half empty.

I note that exactly the same is said about Amtrak by those who seem to hate the idea of rail travel (tea partiers, for example). Some of them at least have the grace to be surprised when shown the evidence that Amtrak trains are generally full (my experience whenever I have used them).

So, what is your evidence that China's trains are running half empty?

george matthews wrote:

Lots of these trains are running half empty.

I note that exactly the same is said about Amtrak by those who seem to hate the idea of rail travel (tea partiers, for example). Some of them at least have the grace to be surprised when shown the evidence that Amtrak trains are generally full (my experience whenever I have used them).

So, what is your evidence that China's trains are running half empty?

The difference here is that the Amtrak equivalent to China's system is the Northeast Corridor ( might also include the Chicago-NYC & Chicago-Wash corridors as well ). The trains operating on the Northeast Corridor are rarely half empty, the same applies to a number of Amtrak's Long Distance services ( at least those that are part of a corridor service IE: Lake Shore Limited ). If you're taking the train coast to coast, then I'm sure you'll find trains where passenger numbers aren't all that great ( you'd probably have to go West of the Mississippi to find those trains ).

The current network will suffice for a short period of time, and be able to handle increased loads. But in the longer term, a high speed dedicated passenger only network will be "NEEDED". This will avoid costly bottlenecks that delay both freight and passenger trains, which will continue to increase if no changes to the current system are made.

In China there has been a huge unsatisfied demand for travel. I would be surprised if trains are empty. In fact the main problem with conventional trains, as in India, is obtaining reservations.

In the US I am sure there is unsatisfied demand for train travel. In the absence of supply it is difficult to measure it. This demand will increase as price and availability of oil products are affected by the state of the world.

And have you seen the rail line China built to Tibet? That must have cost tens of $ billions, and it runs through and serves absolutely nowhere. How about the billions they spent on a Maglev line that they have announced will never be extended?

I missed that one.

The Tibet line was built for the same reason that the US wastes money on the military, for strategic purposes to help them hold down their colony in Tibet. Moreover, there is a plan to extend it to India - not exactly "nowhere". As to the Maglev, well they have one. The US does not. There are problems with Maglevs, mainly they are very expensive to build, much more than a conventional steel on rails system. There was a successful slow speed maglev at Birmingham airport but alas they couldn't get spare parts of it and so it has been replaced by an ordinary airport people mover.

http://www.economist.com/node/18488554
http://www.theepochtimes.com/n2/content/view/53169/
http://newcer.chinaeconomicreview.com/en/node/37261

There's plenty more of these articles. I've been reading up on them over the past month. I believe they all point to a common thread of realities. That High Speed Rail is a very expensive technology that can substitute for air transportation. But money spent on it would be far more efficiently used, and far more productive, on slower, less expensive systems that move both passengers and freight. i.e. Continental Europe's high speed rail system may be more glamorous, but Great Britain's slower but somewhat mixed system is more efficient and cost effective.

Likewise, maybe the Northeast corridor isn't that backward after-all. Could a Northeast corridor with a non-1930's electrical infrastructure and a restored freight-hauling component stop being a whipping boy and instead something held out as an example for copying and expanding?

i have also said that hsr in the USA needs high speed freight to be viable . unfirtunately people cant see anything other than double stack containers doing 150 - 186mph . It would be single level aerodynamic passenger like freight cars . the nec would be the ideal launching pad for such a service .

I think China is just admitting they overstepped the practical limits of HSR . they have shown they can do it , now theyre scaling back to the same speeds other hsr's are doing , because it is the practical limit energy wise . I think the chinese higher speeds were more of a marketing exercise for thier ability to make hsr trains .