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Comment by chgs | Hacker News Reader

I haven’t noticed any delay in london with a card, phone might be 200ms slower than credit catd. I Haven’t been to japan for a decade, are they really that much faster - and does it make a difference? What happens if a card is wrong/doesn’t scan/is invalid/etc at the higher speed?

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> are they really that much faster - and does it make a difference?

Yes and yes

> What happens if a card is wrong/doesn’t scan/is invalid/etc at the higher speed?

Then the fare gates close in time to stop that person and the next 3 or so people behind them get annoyed and go around.

Felica is virtually instant. Even faster than the original Oyster in London (which contactless card or phone is much slower than)

I'm currently on a japan train - using a suica card is essentially instantaneous. if the cards are declined for any reason the gates swing shut immediately, if that's what you're asking.

I don’t see how that’s any different to the underground

It's the complete opposite. Tokyo stations have open gates that swing shut on fail. London stations have closed gates that swing open on success.

Also, Tokyo trains have air conditioning, whereas the Underground is so hot and stuffy I'm pretty sure I got brain damage from it.

Also^2, Japanese train stations have ads for B2B services, whereas almost every ad in London stations is for a musical. I'm not sure what this means.

(Also fondly remember the surprisingly numerous signs at Kings Cross about how you shouldn't assault any train employees, and how teenagers weren't allowed to buy matcha drinks because they have too much caffeine.)

Japan's trains have aircon but often it's not cold enough, and at the parts of the year when the climate moves from hot to cold or cold to hot you might find yourself on a train with heating still on because the calendar date is still "winter" even though it's a hot and sunny day, while you sweat profusely and feel irritated about the seemingly widespread inherent inflexibility of the Japanese.

Osaka's Hankyu trains are full of ads for musicals (it owns the Takarazuka Revue), I think that all this shows is that London has a far more vibrant cultural scene, which is apparent at all levels of society. I'd rather see ads for musicals than the ads for male hair removal clinics.

Well, London obviously does have one of (the most?) vibrant cultural scenes in the world.

(Last time I was there I saw a singer from Mali, which I thought was interesting mostly because all of her backing visuals were StableDiffusion AI art and I don't know if anyone else noticed.)

But it's also the capital of a country that should have an industrial economy and increasing doesn't have one anymore, because they've decided it's all sort of beneath them.

as for the uk train stations, the temperatures are in part due to their age - London Underground was built in 1870s, and since that time rocks accumulated so much heat that it is extremely difficult to maintain human-friendly temperatures. Japan subway is 70 years younger, so it’s easier for them to maintain temps.

(And my hometown Warsaw subway is even younger - 50 years, and we don’t have AC whilst temperatures are at a perfect level).

What London underground might need is not AC, but a process to cool down rocks - importing coolness during winters. To maintain equilibrum you’d need to pump out around 1TWh heat every year. To bring it down to normal levels in say 20-30 years you’d need to pump out 2-5TWh a year.

What does that mean, “rocks accumulate heat”? Should be an even cool temp down there, as long as tunnels aren’t too deep. A few vents to allow hot air to rise should work, no?

The ambient temperature of the clay earth around the tunnels has been rising since the tube was built

https://en.wikipedia.org/wiki/London_Underground_cooling#Sou...

More input than output in assuming and vents were probably not built back in the day.

It's still a ventilation issue rather than directly an age issue : it's the equilibrium that matters at these timescales.

London surface trains have aircon, as do many underground lines.

At busy times underground gates don’t close, until someone scans the wrong card (which leads to them walking into the barrier and then the person behind walking in, then the barrier opening from the person behinds card and general chaos)

And faster throughput would just increase that.

I cycle most of the time to be fair but that doesn't tally at all with my recent experiences of peak Oxford Circus

In japan it's optimized for speed thanks to the IC working so fast so you are only slowed down if something fails. It rarely fails (if you're not a tourist...) so you see people walking through them pretty quickly and I have seen people run into each other because they assumed the next person was gonna go through.

The speed difference isn't in not phone vs. credit card, it's credit card vs. stored value card.

Stored value cards are optimized for speed and cost, and as a result have shared symmetric keys available in both card and reader. That enables extremely fast transactions.

EMV cards are (also) optimized (at least in the offline case, which transit gates use – the latency to talk to the bank backend would be too high) for security. The security model doesn't trust readers to keep keys secret, which means you need asymmetric cryptography for card authentication. The specs are old, which means RSA – which is very slow to run in cheap ICs embedded in these cards produced at scale.

It matters because you don’t have to interrupt your stride. You don’t tap the card, you kinda just hold it and walk through at full speed.

If the protocol is designed well, high speed doesn’t mean high error rate either.

I can’t rule out that at rush hour in either country it makes a difference, because I haven’t experienced it.

But I’m with you, with an express travel card set in Apple Pay (so you can just plop your phone down on the reader without opening anything) there is a beat for it to read on the Underground barriers, but it’s basically the same length of time as it takes to do the step and a half from the reader to the gate. At a normal walking speed I don’t feel as though I need to interrupt my stride.

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