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Comment by rwmj | Hacker News Reader

Northern Japan has a much wider range of temperatures than the UK — -20C in winter to high 30s in summer would all be considered normal — and yet they can run high speed trains all year at 200+ km/h. How is that done?

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Multiples of other solutions + expansion joints. Expanding long rails blend into fixed "tongue" rails and goes off track towards the sides.

1: (for illustrations) https://costep-webteam.hatenadiary.jp/entry/20061023/p1

2: (for illustrations) http://tarouroom.blog89.fc2.com/blog-entry-968.html

These joints are what I would have expected to be used more often.

Your 2 gives me advertising for some fat loss advert after having to give my adblocker a temporary exception. Why would that be on a blocklist at all? Is this a geo-thing?

Sorry for that. Those are free hosting predominantly for Japanese content, in turn attract little to no interest in Anglosphere. Perhaps that is why they were on a list? xrea.com is another such example.

No need to be. It was just strange and unexpected :-) So this is "homelandhosting", spamming the Gaijin from whereever with whatever by redirecting, to whatever the algorithm thinks appropriate ;->

I got redirected to some fake installer advertising despite having ABP enabled.

Shinkasen tracks have dense placement of strong fasteners and prestressed reinforced concrete slabs over thick cement asphalt mortar.

(basically tracks over concrete road over thick asphalt like road)

This is question of economics, not question of ability.

As with many (most?) high speed lines, it's done through maintenance overnight: the Shinkansen doesn't run from midnight till 6am, plus dealing with the potential expansion through additional work on the track during those overnight periods (largely by re-stressing the steel).

This is all about overnight access and about the cost of the work involved.

Is there a British train that runs overnight other than the Caledonian Sleeper? I don't think I ever saw a departure between 0:30h and 6:00h.

See, e.g., https://www.realtimetrains.co.uk/search/detailed/gb-nr:SVG/2... for services booked to run through Stevenage during that time period next Monday.

Some extreme passenger services: 0132 London Kings Cross to Peterborough (0315), plus what is likely the return working 0324 Peterborough to London Kings Cross (0451).

But also as already mentioned, there's plenty of non-passenger services too.

Freight.

They’ll perhaps use slab track, like HS2 in the UK will use.

This one? https://www.railengineer.co.uk/slab-track-paving-the-p-way/ How does this make the rails less likely to buckle? Just because it's held in place more tightly?

> The CWR is subject to compression loads due to temperature changes, which can cause buckling, or sharp lateral displacement. These phenomena are prevented using reinforced fastenings, sleepers and ballast.

https://www.ejrcf.or.jp/jrtr/jrtr15/f38_tec.html

I found the above, but it doesn't say that much about buckling. I don't think they use slab tracks however.

If buckling is the lateral movement of the track due to thermal expansion, I would imagine the old wooden sleepers would be much easier to pull sideways. Looking at the above link about slab tracks, they look far more secure and less likely to move sideways.

I wasn’t familiar with rail ballast but found this good link which explains what the term refers to and how it helps keep the rails aligned (explicitly the posted article talks about when current mitigation is indequate).

https://railroadrails.com/information/what-is-railway-ballas...

Yes. They actually talk about it in the article.

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