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Comment by wyxuan | Hacker News Reader

tl;dr HSR can go up to 570 kmh as evidenced by French testing, but limitations such as the wheel, power delivery from the overhead lines, and changes to the track mean that meeting or exceeding this limit would be very difficult.

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Magnetic Levitation can exceed this speed limit. From the FTA:

> a Japanese maglev had set a speed record at 581 km/h. The French managers considered it pointless as well as prudent to force the experiment to exceed that speed, as they could have entered a kind of “international race” that they did not have much chance of winning. Time would prove them right: in 2015, another L0 series maglev reached 603 km/h on the Yamanashi test line.

Chinese maglev seems to run at 431 km/h and brings in losses of more than 1 billion RMBs[1]. So these trains may not be economical.

[1] https://en.wikipedia.org/wiki/Shanghai_maglev_train

When the Shinkansen was built, it was criticized for being a fancy train that would never make its money back, in a world where the automobile looked like the future. The project managers resigned due to the project exceeding its budget and schedule.

Fast forward to today, and the network is practically printing money for JR, while forming part of the backbone of Japan's infrastructure.

It takes a long term vision to make this kind of thing work.

Japan's unique situation is probably the only thing that makes the Chuo Shinkansen pencil out.

- Unlike most rail networks, the Japanese conventional rail network is narrow gauge while the Shinkansen is standard gauge, eliminating any chance of network effects from speeding up conventional trains on the high speed network as well.

- The Chuo route is extremely mountainous, so most of the route is in tunnels, and in tunnels there isn't really an increase in land acquisition costs as you increase curve radii for higher speeds.

The issue in Japan, though, is that they already have a high-speed network running on the same route, meaning that the extra gain from the maglev will be marginal.

It's a bit of a lost opportunity that neither China nor (so far) India tried leapfrogging directly from regular rail to maglev. The costs involved are admittedly staggering, but both countries would have the economies of scale to make them tolerable eventually.

> The issue in Japan, though, is that they already have a high-speed network running on the same route, meaning that the extra gain from the maglev will be marginal.

Tokyo-Osaka in an hour vs the current 2.5h, that's far from marginal, especially if you do a round-trip.

Having done that trip a couple of times recently for business, I can't wait for the Chuo Shinkansen to open.

Tokyo, Nagoya, and Osaka—the big three cities in Japan—will be within an hour of each other. It’s a big win for business activity, I think. Especially if you're comparing to air travel, which has some gnarly trips to and from the airport in all three cities.

That has a major danger of being another Concorde situation, where the second best option is still acceptably fast and much much cheaper. At the end of the day the market for people who are willing to spend an extra $2000 or $4000 to shave an hour and a half off of their travel time isn't very large.

Concorde had the issue of extremely high operating costs and low capacity. I don't think maglev has anywhere near the same problem, at least in terms of operating cost.

Nobody has built a maglev system that doesn't have very high operating costs yet. To be fair all of the extant systems are short haul or prototypes but there's still the question of if they will be able to reduce the costs with scale or if they're fundamental to the technology.

The current Nozomi Shinkansen is about $130 each way from Osaka to Tokyo. Not out of reach for a few meetings per month, but a big stretch for a daily salaryman commute. I haven’t seen any pricing for the Linear yet.

> The issue in Japan, though, is that they already have a high-speed network running on the same route, meaning that the extra gain from the maglev will be marginal.

Which is already at capacity. From this March the Tokaido Shinkansen will be able to run up to 16 trains per hour (up from 14 tph right now), which only 4 of them will stop at non-major stations. Tokaido Shinkansen runs roughly along the pacific coast, which is also prone to natural disasters.

To add some more context - the trainsets can have up to 16 cars with a capacity of up to 1300 people. So basically up to 20800 people per hour.

Also 16 trains per hour means 3.75 minutes between trains. This is actually not that remarkable & we saw that in action last years in Hiroshima, with three trains scheduled from the same platform with departures 3 minutes apart.

This is doable due to a couple of factors: - passengers are usually quite disciplined and know what to do, eq. people queue at the door before a stop for quick departure - the trains stop exactly in the same place on the station, so the are markers for each card & door on the platform - due to this people can queue on the platform for their car right where the car will be once the train arrives - the are marked areas near the door location on the platform for disembarking passengers, so they don't mix up with people waiting in the queue to get in - no chaotic "fan" of people around a car entrance with some trying to get in and others trying to get out at the same time as you often see on European train stations - all Shinkansen are EMUs with all wheels powered, resulting in rather high yet still comfortable acceleration speed - due to this the tran can quickly stop in the station and the n rapidly speed up again

The end result is a train that comes in rather quickly yet manages to stop on the spot with centimeter precision. Then people disemabark, then people get in and the train can leave & pick up speed again. We timed it once & it all took about 90 seconds.

>the trains stop exactly in the same place on the station, so the are markers for each card & door on the platform

They do this on Japanese subways too, because many stations have gates that the train has to line up with.

This would be completely impossible in America. Anyone who's ridden the DC Metro would know this: there is absolutely no way you could get American train operators to stop the train that precisely. Trains here stop with variances of many car-lengths.

I think it's helpful to remark just how amazing 16 bullet trains per hour is. That's practically a train every 3 minutes. Each train has 16 cars, with a seating capacity of 1320 -- that's like three 747s. And they depart more frequently than a downtown metro subway. It's amazing.

China was more interested in developing something that they could use to build national rail champions that other countries would buy from. No other country has ever built maglev, or really needs to, so it's not export-friendly.

I think spending $$$ is not a problem, but spending $$$ on an unproven tech is a real gamble.

They are not tens of miles experimental lines... It's 18,000mi.

The Chinese maglev is just impractical: it doesn’t go into the city and it’s quicker and about as cheap to just take a cab to the airport.

The Japanese maglev is going to be a full blown commuter alternative to the massively successful tokaido Shinkansen.

China is also build new low-speed maglevs:

https://www.cnn.com/travel/article/china-driverless-maglev-t...

There are many places where 100 mph is sufficiently fast.

The Changsha HSR-airport maglev is actually useful, but is very much a local transit option. It still doesn’t go into the city, but I’ve had to make that connection before. The Shanghai maglev doesn’t connect to anything more than a subway station.

This. They originally wanted to make the maglev line all the way to the other airport (Hongqiao) with a stop in downtown (People's Square). If they just went to People's Square, the amount of people using it would be MUCH greater.

There were actually complaints about the the dangers have maglev magnetic radiation or something like that. I don’t think they were valid, but even China has to cave into public pressure sometimes. Also, it was just too expensive to build more, so I think they decided to make it a dead end.

I took it once (back in 2006) just to experience it. It is fast, just not when compared to the whole trip being made by a taxi.

The actual cost of running the line versus ticket revenue generated is an extremely poor way of analyzing the situation. High speed, frequent, and reliable transportation can be a massive multiplier of economic activity.

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