5 ms·

This is a suspended style, unlike the Japanese maglev- it's much more like the old transrapid[1] which used a set of coils underneath the track to pull up the t

This is a suspended style, unlike the Japanese maglev- it's much more like the old transrapid[1] which used a set of coils underneath the track to pull up the train. There are pros and cons to both. The Japanese maglev uses large unpowered copper coils in the sidewalls[img:2]. They're arranged and interconnected in such a way that they keep the train up and centered. They're quite expensive to build, but more energy efficient. The suspension style can use smaller coils but they need their own power, which is lossy and can limit the length of the track. In both cases the train typically needs its own generator to create all the power. The article says that the plan is to make the cars very light, which is plausible- train cars are way heavier than needed; they weigh several times more (~1000 lbs/person) than the people and luggage they can fit. The strength is important though, as the car needs to pull the rest of the train as well. It may limit the number of passengers per train. They'd have to build entirely new rail for the entire line from Beijing to Shanghai. That would be a very large investment, many times more expensive than just rail. China is preparing for a never-before-seen level of infrastructure and doing anything they can to avoid cars, which would be an ecological and logistical disaster for them. Maglevs are kind of questionable. The use case comes from moving between large cities- plausible in America, but China already has some of the largest airports in the world and less of a middle class to use them. 1: https://en.wikipedia.org/wiki/Transrapid https://en.wikipedia.org/wiki/Transrapid 2: https://www.jrailpass.com/blog/wp-content/uploads/2017/02/maglev-train-test-track-e1487940220972-1200x767.jpg https://www.jrailpass.com/blog/wp-content/uploads/2017/02/ma...

bobthepanda 7y ago
A side note, but the poor usage of airports is mostly due to poor reliability caused by the military restrictions on Chinese airspace. https://www.nytimes.com/2018/11/24/world/asia/china-beijing-daxing-airport.html https://www.nytimes.com/2018/11/24/world/asia/china-beijing-... > With roughly 70 percent of airspace controlled by the military (versus 20 percent in the United States), commercial aircraft flying in China are limited to narrow tunnels in the sky. This restricts options for departure and arrival routing, cutting the number of takeoffs and landings that airports can handle. Beijing Capital, for example, was the world’s second-busiest airport based on passenger volume in 2017, but it ranked fifth based on takeoffs and landings, nearly a third fewer than the world leader, Hartsfield-Jackson Atlanta International Airport. > The lack of airspace is also a key reason delays are so common in China. Last year, flight delays increased 50 percent, with only 71 percent of flights taking off on time, according to government statistics... When a corridor is blocked by a thunderstorm, for example, Chinese flight controllers often cannot reroute an airplane, because it would have to enter military airspace. That causes planes to sit on the ground or fly holding patterns when in other countries they could land or take off. > The new airport will help by initially opening four, then up to eight, new runways in the suburb of Daxing, 41 miles southwest of Beijing Capital. The number of air corridors available for civilian use stays the same, but the new runways will provide airlines with more ways to gain access to this limited airspace, allowing the Beijing area to facilitate more flights.
- fspeech 7y ago
  Also China knows how to make trains, but much less about making airplanes. So they are not as motivated to develop domestic flights. Even outside of a protectionist angle, when they need economic stimulus, they routinely go for massive HSR construction. It would have been much less effective with airports/planes.

bobthepanda 7y ago

A side note, but the poor usage of airports is mostly due to poor reliability caused by the military restrictions on Chinese airspace. https://www.nytimes.com/2018/11/24/world/asia/china-beijing-daxing-airport.html https://www.nytimes.com/2018/11/24/world/asia/china-beijing-... > With roughly 70 percent of airspace controlled by the military (versus 20 percent in the United States), commercial aircraft flying in China are limited to narrow tunnels in the sky. This restricts options for departure and arrival routing, cutting the number of takeoffs and landings that airports can handle. Beijing Capital, for example, was the world’s second-busiest airport based on passenger volume in 2017, but it ranked fifth based on takeoffs and landings, nearly a third fewer than the world leader, Hartsfield-Jackson Atlanta International Airport. > The lack of airspace is also a key reason delays are so common in China. Last year, flight delays increased 50 percent, with only 71 percent of flights taking off on time, according to government statistics... When a corridor is blocked by a thunderstorm, for example, Chinese flight controllers often cannot reroute an airplane, because it would have to enter military airspace. That causes planes to sit on the ground or fly holding patterns when in other countries they could land or take off. > The new airport will help by initially opening four, then up to eight, new runways in the suburb of Daxing, 41 miles southwest of Beijing Capital. The number of air corridors available for civilian use stays the same, but the new runways will provide airlines with more ways to gain access to this limited airspace, allowing the Beijing area to facilitate more flights.

fspeech 7y ago
Also China knows how to make trains, but much less about making airplanes. So they are not as motivated to develop domestic flights. Even outside of a protectionist angle, when they need economic stimulus, they routinely go for massive HSR construction. It would have been much less effective with airports/planes.