SoylentNews is people
SoylentNews
Submitted via IRC for AndyTheAbsurd
Hyperloop One claims that its prototype ultra-fast train has completed a first full systems test in a vacuum, reaching a speed of 70 mph. The sled was able to magnetically levitate on the track for 5.3 seconds and “reached nearly 2Gs of acceleration,” according to the company.
The test was conducted privately but Hyperloop One offered some video that included footage from testing. Based on that footage plus a few seconds of additional b-roll shared with media, a lightweight skeleton sled uses a linear motor to accelerate, levitates briefly, and then comes to a halt as the brakes are applied.
Hyperloop One was created as an answer to a challenge from Tesla and SpaceX CEO Elon Musk, who wrote a white paper envisioning a mode of transportation that would send pods at speeds greater than 700mph using a low-friction environment and levitation using air bearings.
Source: Ars Technica
(Score: 2) by PiMuNu on Friday July 14 2017, @01:01PM (5 children)
> As I said, the tube can cope with the pressure normally. The issue is that you have several hundred miles of it exposed to the environment and every inch would have to be *meticulously* maintained.
I just disagree. A long stretch of tunnel will presumably have gate valves installed (standard tech, albeit bigger) so sections can be taken down for maintenance. Maintenance outages are what is done on e.g. UK trains and roads, where long stretches of railway and lanes of motorway are taken down every weekend for maintenance. Random result from google:
https://www.gov.uk/government/news/night-closures-planned-for-m6-cheshire-smart-motorway [www.gov.uk]
I don't see that this scheme is super dangerous/sensitive like you say. Its a couple inches thick steel walled tunnel. A dropped wrench is not going to blow it up.
This is just not high tech. If it splits, it doesn't explode or anything - that happens to gas bottles at hundreds of bar, but not a pressure vessel at 1 bar. It just lets up the pressure in the tunnel. Oh dear, we close off a section of tunnel and get a bus to bring the passengers out, or send in the rescue train, or whatever scheme they invent. Everyone grumbles because they are a couple of hours late to work.
(Score: 2) by Arik on Friday July 14 2017, @01:28PM (4 children)
That's a good idea, but (correct me if I'm wrong) not one that seems to appear in their plans. But I'll give it to you, so you can seal a section and repressurize it and work on it, wonderful!
But you don't want to do that when you have a whole procession of passenger cars hurtling down the tunnel toward that section at 600mph+. Obviously you have to first stop adding passengers, second wait for those already in to complete their journey, then THIRD you can take the section down for maintenance. This process, assuming their own projections, means a minimum of 35 minutes PLUS the actual time required on-site, for each incident.
But more importantly, it means that no matter how badly you may need to shut it down NOW you MUST wait the 35 minutes for it to clear.
You're not just stopping a mag sled that's running in a vacuum at 600mph+ with significant mass on a dime. Plus as I said their plans offer no hint as to any exit capabilities in the transit tube, even were it feasible to stop the sled without killing the passengers.
"https://www.gov.uk/government/news/night-closures-planned-for-m6-cheshire-smart-motorway"
Oh come on! That's a motorway, it's not pressurized, individual cars have their own motors and drivers (and steering) etc. The situations have virtually nothing in common, that's a joke?
If laughter is the best medicine, who are the best doctors?
(Score: 2) by PiMuNu on Friday July 14 2017, @01:56PM
> Oh come on! That's a motorway, it's not pressurized, individual cars have their own motors and drivers (and steering) etc.
> The situations have virtually nothing in common, that's a joke?
My point was for the bureaucracy - shutting down for maintenance is an accepted practice in modern transport infrastructure.
I reckon agree to disagree. I just think you are massively overegging the challenges. Anyway, hope they figure it out...
(Score: 1) by khallow on Saturday July 15 2017, @02:47AM (2 children)
Or you can divert those vehicles to another tunnel. I think the real problem with something like this is what happens when a huge stretch of the track is damaged. I don't buy that a minor leak can cascade to total collapse. But there are several sorts of accidents and sabotage that can take out a long stretch of track, say a raging forest fire, large airplane that crashes along the length of the Hyperloop, or a diligent saboteur with a lot of explosives. Replacing a lot of track lengths at once may be very difficult to do especially, if the manufacture of these components has been scaled down to maintenance level replacement. While most such normal rail is relatively easy to replace in comparison.
(Score: 2) by Arik on Saturday July 15 2017, @05:55AM (1 child)
There are only to be 2 - one running each way. Their plans are quite explicit on that.
I'm not saying this thing can't be built. I'm saying it would either be 1) tremendously and unacceptably prone to cause death if completed as presented and 2) if modified enough to avoid 1 it will no longer be competitive economically. The whole pitch here is the idea that not only can this be done, but it can be done safely and inexpensively, and that is simply bullshit. You can run add backup lanes and figure out SOME way to guide a mag sled hurtling along at 600miles an hour into it safely, you can wrap your steel tubes in concrete and more steel and install sensors and servos and...it's already going to cost orders of magnitude more to build and operate. And it no longer looks good next to the alternatives. And there are still LOTS of devils left to solve... no this is not a technology project. It may be, as another poster suggested, quite a successful scheme to get VC to develop components wanted for an entirely different project instead, but it certainly will never and could never work as advertised.
If laughter is the best medicine, who are the best doctors?
(Score: 1) by khallow on Saturday July 15 2017, @12:32PM
I don't take their plans seriously at this point. A lot of what they would need to know about viable infrastructure, they'll learn later.
You're not presenting a serious argument either. A double shell would work here. The outer shell would shield from most external impacts and provide structural integrity, and the inner shell maintain the vacuum (including a safety margin for dents and such). You don't need massive infrastructure just to maintain a volume of vacuum. We already have companies that make large and often complex steel tubes for the oil industry and such. That infrastructure can be retooled to make Hyperloop sections, should that turn out to be a viable idea.