Hacker News Reader

Comment by grecy | Hacker News Reader

> to get high-speed trains running from Merced to Bakersfield by 2030

Isn't that going to be the world's slowest "hi-speed" train ?

220 miles per hour is nothing to sneeze at.

That’s 50% faster than Acela (150mph) which isn’t nothing, but doesn’t make much of a difference on its own. What’s actually important is maintaining high speed for most of the trip which is where Acela fails (~70.3 mph).

https://en.wikipedia.org/wiki/Acela

> What’s actually important is maintaining high speed for most of the trip which is where Acela fails (~70.3 mph).

Reminds me of high-speed rail in France vs high-speed rail in Germany. To the point that newer Siemens trains will have a lower top-speed, because "there is no demand for it".

In France, it depends a lot on the lines : Paris-Lyon has average of 270 km/h (167 mph); Paris-Bordeaux clock at around 300 km/h (186 mph) while Paris-Brest is more at 200 (124 mph). It is interesting to note that it often seems ti correlate to the age of the line, with Paris-Bordeaux being the most recent.

Yes, but they are limited by the technology used to build the line, and by how the lines were traced, but not because their high-speed trains need to stop at every city center or run on "winding" tracks, as is the case in Germany.

The Paris-Lyon line is by far the oldest, and is top-speed limited because of how it was traced. (And also because of its out-dated security system that is in the process of being changed)

The Paris-Brest line stops being a high-speed track in Rennes, so even if the first part is fast, it's still a long way to Brest on conventional tracks.

The newer lines are faster, as they are designed for theoretical operational speeds of 350 km/h, with a current operational top speed of 320. (LGV Sud Europe Atlantique, LGV Rhin-Rhone, LGV Est, and even the LGV Bretagne Pays-de-Loire going to Brest)

If I understand it correctly the definition of high speed rail in the UK is above 125mph. Apparently that's the fastest you can safely use conventional line side signalling (traffic lights).

Reply on news.ycombinator.com