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The Hyperloop: BUSTED
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coppice:

--- Quote from: EEVblog on August 22, 2019, 01:19:06 pm ---
--- Quote from: technix on August 22, 2019, 12:11:51 pm ---There was even a debate on how Beijing-Shanghai HSR should be built - railways or maglev, and in early years the maglev solution was actually preferred since it is fundamentally faster.

--- End quote ---

I got the impression that it's a much better technology in most respects, especially the elevated tracks, it just seems to be an energy requirement thing.

--- End quote ---
The big thing with maglev is the need for extremely rigid track. Trying to stabilise a train on a flexible track has defeated engineers so far. Making the track really rigid, rather than just strong enough to support the load, means the maglev in Shanghai uses an enormous amount of concrete. I don't think there is any particular issue with the track being elevated, but if they had made it at ground level it would have needed just as much piling, and just as thick a concrete bed to achieve the required rigidity.

Most people who think maglev should be low loss compared to a train seem to think of a train like a car. However, steel wheels have very low losses. As a kid we used to push lines of freight carriages around the local sidings at night. With persistence, even 3 or 4 small boys could get an enormous mass moving quite fast, because the rolling resistance is so low. If you look at the massive long distance freight trains in America, they don't go all that fast, but they are able to sustain the movement of kilometres of carriages with just the pull on one traction unit.
boffin:
The incremental speed from 300kmph to 400 isn't really going to save you that much in total time, once you factor in start/stop.  It would have to be a pretty significant distance before it was enough difference

What's the longest non-stop high-speed rail journey?  (The Ave Madrid-Barcelona have a few non-stops @ 625km /2h45m it's damn damn impressive; but most journeys make a couple of stops)

Plus, you can use high speed rails for lower (but still fast) speed stuff as well; such as freight hauling.

Sadly, I live in North America, where the car rules supreme, and people are too short-sighted to see rail really work well.  Once you take a 300kmph rail journey, you really wonder why the whole world doesn't do it.
technix:

--- Quote from: boffin on August 22, 2019, 04:11:52 pm ---The incremental speed from 300kmph to 400 isn't really going to save you that much in total time, once you factor in start/stop.  It would have to be a pretty significant distance before it was enough difference

What's the longest non-stop high-speed rail journey?  (The Ave Madrid-Barcelona have a few non-stops @ 625km /2h45m it's damn damn impressive; but most journeys make a couple of stops)

Plus, you can use high speed rails for lower (but still fast) speed stuff as well; such as freight hauling.

Sadly, I live in North America, where the car rules supreme, and people are too short-sighted to see rail really work well.  Once you take a 300kmph rail journey, you really wonder why the whole world doesn't do it.

--- End quote ---
On Beijing-Shanghai HSR, there is a 617km/1h59min non-stop ride between Nanjing South and Jinan West, on the Shanghai Hongqiao to Beijing South train G2. The whole journey is 1318km/4h28min with those two stops.
EEVblog:

--- Quote from: technix on August 23, 2019, 03:00:40 am ---On Beijing-Shanghai HSR, there is a 617km/1h59min non-stop ride between Nanjing South and Jinan West, on the Shanghai Hongqiao to Beijing South train G2. The whole journey is 1318km/4h28min with those two stops.

--- End quote ---

It's only 900km or so from Sydney to Melbourne. If the train could take 4 hours I'd certainly take it. Current train is about 11 hours.
vk6zgo:

--- Quote from: EEVblog on August 23, 2019, 03:11:27 am ---
--- Quote from: technix on August 23, 2019, 03:00:40 am ---On Beijing-Shanghai HSR, there is a 617km/1h59min non-stop ride between Nanjing South and Jinan West, on the Shanghai Hongqiao to Beijing South train G2. The whole journey is 1318km/4h28min with those two stops.

--- End quote ---

It's only 900km or so from Sydney to Melbourne. If the train could take 4 hours I'd certainly take it. Current train is about 11 hours.

--- End quote ---


Over on Whirlpool  there was a discussion about shorter distance High Speed Trains.

They quoted a time duration for a HST trip from central Melbourne to Geelong.

On looking up the distance between the two, & comparing it with a trip over a similar distance between central Perth & Mandurah, it turns out that the existing narrow gauge commuter train on that service does the equivalent trip in a shorter time than their projected HST.

The difference, of course, is both topography, & that the Geelong trip would go a roundabout route via various "legacy" stations, whereas the Mandurah train goes straight down the centre of the Freeway.
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