4 ms·

The first thing that springs to mind is how amazing smooth the rails were in the V150 test. The lines I use the most, here in the UK, are way too bumpy and tha

The first thing that springs to mind is how amazing smooth the rails were in the V150 test. The lines I use the most, here in the UK, are way too bumpy and that’s at a mere 70mph. I understand the legacy of the rail network but it would be embarrassing to get to the 22nd century without any improvement. On that note, for the price of HS2, I’d rather see: 1/ smoother tracks 2/ a strong, unified, national brand 3/ dead simple smart phone ticketing 4/ tickets checked when you get off the train, not on 5/ tickets purchasable on the train you are actually on, lower prices, and an end to the railcard / discount / split ticket confusopoly 6/ simpler utilitarian rolling stock, again with unified branding, no adverts, and simple monochromatic signing and buttons all following a unified design language Perhaps a simpler list though would be: 1/ fire everyone 2/ hire from scratch and completely rethink the rail network in terms of being 100% focused on the passenger, instead of an internal market of contracts between infrastructure, train operators, and unions. (“Simpler”!)

masklinn 7y ago
> The first thing that springs to mind is how amazing smooth the rails were in the V150 test. High speed lines are necessarily extremely smooth and with very small tolerances. French lines come out the factory in rail pieces 200 to 400 meters long and are thermite-welded together after adjustment. They have no expansion joints except around bridges (and even then not necessarily)
- jandrese 7y ago
  So how do they handle thermal expansion? Just let the whole system build up huge pressures in the summer? Special alloys that don't expand so much in the heat?
  - masklinn 7y ago
    > Just let the whole system build up huge pressures in the summer? Pretty much yes, that's why the rails have to be adjusted very precisely, otherwise they're going to kink / bend in summer (if pressure gets too high) and crack in winter.
  - labcomputer 7y ago
    I learned recently that rail (especially continuously welded rail) is generally kept under tension (I don't understand how it is secured at the end of the line, though). So when it heats up in the summer, it is simply under less tension. Unless it heats up too much, and then it buckles and you get derailments.

masklinn 7y ago

> The first thing that springs to mind is how amazing smooth the rails were in the V150 test. High speed lines are necessarily extremely smooth and with very small tolerances. French lines come out the factory in rail pieces 200 to 400 meters long and are thermite-welded together after adjustment. They have no expansion joints except around bridges (and even then not necessarily)

jandrese 7y ago
So how do they handle thermal expansion? Just let the whole system build up huge pressures in the summer? Special alloys that don't expand so much in the heat?
- masklinn 7y ago
  > Just let the whole system build up huge pressures in the summer? Pretty much yes, that's why the rails have to be adjusted very precisely, otherwise they're going to kink / bend in summer (if pressure gets too high) and crack in winter.
- labcomputer 7y ago
  I learned recently that rail (especially continuously welded rail) is generally kept under tension (I don't understand how it is secured at the end of the line, though). So when it heats up in the summer, it is simply under less tension. Unless it heats up too much, and then it buckles and you get derailments.