Vacuums get much more costly as you get ever lower pressure. Hyperloop is an interesting cost / benefit between fast travel and lower construction and maintenance costs which is why the speeds are relatively low. The vehicle is also closer to an electric aircraft than an electric train. Note the big fan on the front: https://en.wikipedia.org/wiki/Hyperloop#/media/File:Hyperloo...
Another consideration is the faster you travel the straighter your path needs to be. 4,000+MPH paths require incredibly strait designs.
I don't think that qualifies as 'HyperLoop' even if they keep the name. It's like building an airplane except you use it underwater, sorry that's a sub.
That said, it suggests that the HyperLoop concept is not viable which is not that surprising IMO. However, it might also just be a case of lower R&D costs.
Well, obviously they want to keep the hype alive. So it’s understandable that they’d refuse to change the name.
Sadly, this also means we have a lot of people think this is something revolutionary, although I guess that’s intentional.
It’s really annoying when you consider how the US refused a proposal from japanese companies a few years ago to build a MagLev system between Boston, NY, Washington, with capacities around 10k people per hour.
Hyperloop One is by far the most credible project, with HTT somewhere behind them in second. They haven't revealed anything about their compression systems or lack thereof. HTT has backed off air levitation, but they're still using Inductrack which is radically cheaper than conventional MagLev and hasn't been applied commercially yet.
Several of the competition teams (like the one in this article) have built MagLev sleds with nice brakes, but they're just trying to win a speed record competition. That has no bearing on the real Hyperloop. Other teams are focusing more on scalable tech and doing some pretty innovative work.
The lower per-vehicle capacities also aren't a negative if launch cadences can be kept high enough to maintain throughput. Smaller vehicles let the network operate in a more point-to-point manner instead of the stop-and-go crap that trains have done since day one.
The tube would not be evacuated. The train sucks the air in front of it and pushes it around and especially below, creating an air cushion just like an air hockey, further decreasing energy requirement for movement. That way you also get rid of the air evacuation cost.
The tube would be evacuated on earth. Which is why they need a tube in the first place:
Mars
According to Musk, Hyperloop would be useful on Mars as no tubes would be needed. This is because Mars' atmosphere is about 1% the density of the Earth's.[10][45][46] For the hyperloop concept to work on Earth, low-pressure tubes are required to reduce air resistance. However, if they were to be built on Mars, the lower air resistance would allow a hyperloop to be created with no tube, only a track.[47] https://en.wikipedia.org/wiki/Hyperloop
The important point is 0.01 ATM is a long way from high vacuum. Pumps can get down to that pressure very easily and individual Pumps can cover wide sections of track.
The original design did not have a 'track' along the full route. Cars would more or less hop between different sections. On Mars that represents clear reliability issues, but the ability to avoid building load barring bridges over gorges could be a major cost savings.
Sure, but I think it's fair to call a train that is powered with electromagnetic pulses from stationary coils something different than a train that is powered by an onboard engine.
Yes, although I think maglev trains use continuous linear motors while if I understood the original proposal correctly, the hyperloop would be more like a series of railguns evenly spaced along the route.
"Hyperloop is a conceptual transport system in which passengers are loaded into pods and fired through vacuum tubes at more than 600mph (1,000km/h)....
"Pumping the air out of the tubes reduces resistance, allowing high speeds to be achieved, potentially using less energy than a train."
> incorporating reduced-pressure tubes in which pressurized capsules ride on an air cushion driven by linear induction motors and air compressors.
So the tubes are low pressure. Perhaps not vacuum, but in reality so called vacuum tube delivery systems aren't actually a vacuum either, that's why a more accurate name for them is Pneumatic Tube Systems.
I'm not sure what it is exactly you're trying to argue, above you made it sound like the system isn't low pressure at all.
The MIT prototype, and some of the other proposals, are really a maglev system. The original Hyperloop proposal called for aerodynamic support, with very tight tolerances, but that turns out to be iffy.
A maglev system needs a much more expensive track and/or a lot of energy from the vehicle to power the lift. This is the big problem with maglev - track cost. Maglev works fine; the Transrapid system in Shanghai has been running for 12 years now without serious problems. Top speed 300 MPH.
The Hyperloop is only interesting if it's far cheaper than a maglev. The Transrapid maglev system has far more capacity, can corner better, and can climb steeper grades.
The Berkeley team proposed aerodynamic suspension. There's an analysis with ANSYS which indicates that the design can be tweaked so that at no point does the air go supersonic.[1] But nobody seems to have published a stability analysis for the vehicle in the tube.
The "flying height" in the original proposal was to be about 1mm, so this thing has to be really well behaved aerodynamically. And the tube has to be really smooth. (Expansion joints, emergency escape hatches, pressure doors, and switches would be problems.) The whole point of the Hyperloop is that it's cheap because the tube is simple and dumb.
When you look at the MIT design [2] it's really a maglev monorail that operates in an evacuated tube. (Or outside of one, as they've demonstrated by sending down a rail). It doesn't have any of the fan propulsion or air cushion lift or tight tolerances from the original Hyperloop proposal.
Same source: "The Hyperloop resembles a vactrain system but operates at approximately one millibar (100 Pa) of pressure." That would be a "medium vacuum" according to Wikipedia.
For the design of the vehicle, yes, for the design of the infrastructure, not so much. Those 100 Pa are actually much lower than what previous vactrain proposals suggested. The only difference is that hyperloop is trying to do something useful with the unavoidable trace atmosphere instead of just overcoming it.
As with most very large scale projects, PR is the game changer. Elon Musk's backing of the concept and investment into competitive solutions for a hyperloop has created publicity and driven interest. The hyperloop doesn't need to be an innovative technological advancement to benefit society. It just needs to be safe, fast, and cost effective.
The whitepaper was more than just usual PR: he got lots of input of top engineers in the travel space and made the design free. I don't remember the CEO of Boing or BMW or any other transportation company doing anything similar.
Another consideration is the faster you travel the straighter your path needs to be. 4,000+MPH paths require incredibly strait designs.