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by crocal 1366 days ago
This correct. Power lines wear induced by pantographs is the limiting factor for TGV top speed.

The engineer that can solve this problem will allow top speeds in the range of 400/500 kph on /existing/ TGV tracks. Much better problem to solve than hacking a lame hyperloop.
1 comments
q-big 1366 days ago
> The engineer that can solve this problem will allow top speeds in the range of 400/500 kph on /existing/ TGV tracks.

How is this problem solved in China?

> https://en.wikipedia.org/wiki/Fastest_trains_in_China

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ThePowerOfFuet 1363 days ago
>However, on July 1, 2011 in order to save energy and reduce operating costs, the maximum speed of Chinese high-speed trains was reduced to 300 km/h, and the average speed of the fastest trains on the Wuhan-Guangzhou High-Speed Railway was reduced to 272.68 km/h (169 mph).
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fhrow4484 1366 days ago
They're maglev trains, so there's no pantograph involved there.

https://youtu.be/_ZZMViMDjto at 16:40 explains the problem. It's in french, but you can get the gist visually as it's a for-kids documentary.

Tldr is a wave on the cable is created at high speed, making it impossible for the train to stay in contact with the cable. The documentary also touches on another top speed limitation: how agressive the turn angles are, limiting the top speed.

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q-big 1366 days ago
> They're maglev trains, so there's no pantograph involved there.

The linked wikipedia article also lists speeds of Chinese non-maglev trains.

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fhrow4484 1366 days ago
Ah true, maybe they have higher operating costs on pantograph and/or the power lines maintenance?

(I don't fully believe GP's comment of "The engineer that can solve this problem will allow top speeds in the range of 400/500 kph on /existing/ TGV tracks.", as narrow turns is probably a bigger contraint than the pantograph problem. Maybe a few of the more straight lines can benefit, but there's more constraints to solve before taking turns at 400/500 kph!)

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