comrade12346 days ago
The Shanghai airport maglev used to go around that speed too (~430km/h) over twenty years ago. But these new trains are regular trains running on regular (but specialized and high quality) tracks. There's probably no more need for maglev now that you can run on regular (well not exactly) tracks.
usrnm6 days ago
Did it? I took a ride on the Shanghai airport maglev around a month ago, and it never went above 300 km/h, which was a real bummer, to be honest.
CorrectHorseBat6 days ago
I remember there were different speeds at different times last time I went, but it seems they reduced it in 2021 permanently.
xenospn6 days ago
I was there 20 years ago and it was ~500km/h, if I remember correctly.
Cyuonut6 days ago
Yes it did, at least earlier. I rode it in 2010.
alexpotato6 days ago
At these speeds, how are they guaranteeing that the tracks are in PERFECT working order?
e.g. even a small earthquake that shifts the tracks a few inches would probably cause, at minimum, a degradation in service.
Animats6 days ago
It does require really good maintenance-of-way work.
Having all trains inspect the track is feasible. The latest round of Shinkansen trains does that. They're moving away from running a Dr. Yellow track inspection train every 10 days.[1]
[1] https://www.railway.supply/n700s-trains-to-be-equipped-with-...
piva006 days ago
Japan has solved that 60+ years ago in a much more seismically active zone, it's not a major issue.
K0balt6 days ago
That’s fascinating, what do they do?
SapporoChris6 days ago
seismometers installed along the coast and near the tracks. Senses the earthquake and trains respond if necessary. I believe if the epicenter of the quake occurred directly under a moving train this system would fail(or too close react). However, that appears never to have happened and is probably extremely unlikely.
api6 days ago
Sensors all over the tracks? There’s probably many different sensor strategies you could use to detect imperfections.
I know that modern roller coasters are outfitted with a bunch of stress, vibration, conductivity, etc sensors. There’s a theme park near me where huge fast roller coasters run all day every day all season. The speeds aren’t as high but I bet given the twists and turns the stresses and tolerances are worse.
thenthenthen6 days ago
There are high fps cameras that monitor the overhead lines on every carriage, maybe also pointing at the rails? It is a engineering marvel though, the rides are so smooth, in my home country the trains have issues with leafs on the tracks … lol
pixl976 days ago
This sounds like a Plainly Difficult moment.
arethuza6 days ago
I suspect ~200 years ago in England people were saying pretty similar things!
expedition326 days ago
In my country there are special trains equiped with sensors that drive around at night to measure the tracks. Would have prevented that disaster in Spain.
rmccue6 days ago
A 450kph limit for the rolling stock is great, but how many lines are actually capable of these speeds? There's only a single line (Chengdu–Chongqing, currently under construction) which is designed for 350kph, with sections capable of 400kph. Aside from that, most lines are at 350kph - unless I'm missing something.
garte6 days ago
This is how you start something and get progress.
More lanes on the highway are not progress.
whinvik6 days ago
Wow I though 300 Kph was some kind of physical limit. I mean every high speed train in the world used to max out at 300.
Now it feels like it was just lack of competition. Maybe now other countries will start producing lines and trains capable of 400 Kph and hopefully its not a China only thing going forward.
gregoriol6 days ago
There is show and there is reality: French TGV achieved 574,8 km/h in 2007 for show, but it was under specific conditions, not in real world conditions.
While it is technically proven that it is possible to do 400+km/h on rail, it's not practical: maintenance, wear, noise, turns, embranchement, and overall cost, ... many considerations that are probably less important for Chinese railway now, which needs some "show".
litbear20226 days ago
You should update your data; in 2013, China's high-speed rail reached 605 km/h on experimental lines. The CR450 is scheduled to enter commercial service in 2026.
whinvik6 days ago
Sorry if I wasn't clear but was not talking about demo runs. There are plenty of those. Was more meaning operational speeds having a limit.
jmyeet6 days ago
Like pretty much everything else, it's an optimization problem rather than a physical limit.
So running a train at 350kph is more expensive than 300kph, both in per-distance and pre-unit time terms. But if you can run more services that way then sufficient demand might make it economical. Also, if it's too slow, people may choose flying instead.
Maglev can go even faster but those have never been made economical, really. It's much more complicated and expensive.
It's a bit like how commercial planes have actually gotten slower. 747s used to fly closer to Mach 0.9. Now most commercial planes fly at around Mach 0.8. There are physical problems flying between Mach 0.8 and 1.2 but sometimes that doesn't matter so the best private planes top out at about Mach 0.93. Even then they rarely fly that fast.
bob10296 days ago
In the case of private jets, the Mach figure is mostly a proxy for other performance metrics.
Flying an aircraft at max cruise can save a lot of time on longer flights, but it's also substantially more expensive.
bluGill6 days ago
300kph is the limit because aerodynamics make that about the best compromise on the effeciency cury. higher speeds are completely possibly - but air planes running with much less atmospheric drag start to become the better option.
of course the above is all about compromise and you can emphasize whatever numbers you want to get different results.
Edit: it is often a good idea to have everything capable of faster speeds - say 350km/h. You don't normally want to use those speeds, but if a train gets delayed (as happens) you can use that extra speed to make up time. Just don't let this become a normal thing.
Pet_Ant6 days ago
What about if they added “wings” to trains? That could generate some lift reducing the effective weight is my shower thought.
No idea how much the wings would add versus the lift help.
NuclearPM6 days ago
The friction is almost entirely from drag/air resistance, not from the resistance of the rails.
bluGill6 days ago
the losses from weight are linear with speed - at high speed completely dwarfed by losses from pushing air out of the way which is quadradic with speed.
the wings on race cars are poited down - they increase weight to keep the car on the ground at the expense of more drag, which they overcome with a bigger engine (and more fuel use)
Kuinox6 days ago
The French TGV managed to reach 574km/h, so 300km/h is not an hard limit. https://www.youtube.com/watch?v=EOdATLzRGHc
thenthenthen6 days ago
China also maintains a legacy line of trains, 绿皮火车, that drive at a slower speed and service smaller cities (btw they seem to have been upgraded a lot in the last 3 years, from hard wooden seats to cushioned seats and bed). The best thing (or the worst ;) is that you can smoke in the gangways, which just seems absolutely wild to me. But it was very welcomed during my 37 hour train ride.
ece6 days ago
These are night trains, or mostly night trains.
thenthenthen6 days ago
Good question. Before I only took them for short distances, are they ALL night connections? Makes sorta sense, I think?
ece6 days ago
The one I took was a night train to/from Xian, and had fixed beds instead of seats. It makes sense for bigger cities to have this sort of a service available, but it would also make sense if smaller cities have these as daytime trains with proper seats.
thenthenthen6 days ago
Never seen a sleeper only train! But maybe they exist?
ece6 days ago
Definitely they do, I remember not being able to sit because of the sleeper bed position, but people still smoking standing outside the cabin.
thenthenthen6 days ago
I swear I have done over 400km/h here in China (402 to be exact) and recall they lowered the speeds at some point? Cant seem to find any articles nor my own photos (the trains have a speed read out in every coach).
prawn6 days ago
Yeah, I remember 400+ km/h 10+ years ago from the airport into Shanghai. I remember seeing the speed read out creeping up, and then watching cars on the highways beside us move like snails by comparison.
thenthenthen6 days ago
That was the Maglev though?
jaen6 days ago
re: business class,
> Perhaps oddly, this is superior to first class, where seats are arranged in a 2-2 layout; second class carriages have a tighter 2-3 configuration.
I guess the writer of the article does not really ride trains, the terminology is different from airlines.
First class just means better than second class (it's usually a bit better), and 2-2 seat configurations are very common. "Business class" in trains is a neologism.
nixon_why696 days ago
I was going to guess this was a prestige project like the Shanghai airport maglev but Beijing<->Shanghai is probably a legit economic route for this.
thenthenthen6 days ago
I exclusively use trains here in China, its way chiller than flying and total time doesn't really differ.
CorrectHorseBat6 days ago
We wanted to buy train tickets the other day, but it was just a lottery and no way to actually buy tickets in advance, do you know what's up with that? Buying flights was just normal so sadly we just did that.
thenthenthen6 days ago
Tickets are released only 15 days in advance. Popular lines tend to get sold out quite fast. Especially around festivals.
nixon_why696 days ago
The sleeper cars are pretty nice for long hauls, too, why spend a day traveling when you could spend a night.
thenthenthen6 days ago
The views can be quite spectacular
mahrain6 days ago
Airline-like comfort, and airplane-like noise. It's surprising how much noisier the Shanghai Maglev gets once you approach 400kph.
madhacker6 days ago
All this talk about China makes me want to hop on a plane, but the visitor visa process is quite convoluted and laborious for stays longer than two weeks.
metalman7 days ago
450kmph !, that IS realy realy fast
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EmptyCoffeeCup6 days ago
You'd think they'd be complaints about the sonic booms...
What's that, mach 586?
Seems a bit excessive.
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bamboozled6 days ago
China has almost caught up to the USA... \s
usrnm6 days ago
In terms of the railway? I'd say it caught up with Japan or France, and the US is not even in the race
K0balt6 days ago
So wild considering that the USA would be an amazing place to visit (and live) if it were connected by proper rail. As it is if you’re not rich enough to fly private, it feels like going back to the Stone Age vs places with well developed high speed rail.
GuestFAUniverse6 days ago
coughing \s or /s stand for "sarcasm"
But thanks for stating the obvious.
jaimex26 days ago
lol, you can get a bullet train in Japan whenever to wherever and it'll be exactly on time.
No one else is remotely close to their network and won't be for a long time.
bamboozled3 days ago
Complete copium to say wherever, whenever. It's a brilliant system, but it's not that good and it is expensive.
karunamurti6 days ago
Eh, China's route is around 15 times more expansive and longer, similar punctuality, and way cheaper ticket per km, about 10-15 times cheaper. The only thing annoying for China's HSR is security check on the terminals.
jmyeet6 days ago
Personally I would’ve understood this as sarcasm on its own but the commenter even added the /s sarcasm tone indicator.
Come on now.
rafaelcosta6 days ago
Is it just for me that `kmph` stood out? Seems like such a cursed way of saying kph or km/h.
Ekaros6 days ago
Why does kph sound like most cursed option. kilo per hour? Kilo what? kilowatt, kilogram? kilolitres? Well it is most likely in context, but still when I stop and think about it it feels icky.. I can accept p instead of /. But just entirely ignoring unit feels wrong... Also is speed of something slow ph?
kqr6 days ago
Both kph and mph sort of follow a pattern of the first letter of each word in the unit being spelled out, but kmph reads ambiguously as k(mph) or (km)ph.
Of course, anyone caring about correctness would use the SI unit symbol, which is m/s.
kelipso6 days ago
km is very standard abbreviation for kilometers. Like anyone outside the US would recognize that and consequently kmph. Of course, km/h is very recognizable and k/h looks like nonsense. So I'd say kph is the objectively terrible option.
jiehong6 days ago
yes, I think it's just the US/UK doing that, else people write km/h.