Haven't really fast trains (sometimes maglev) inside evacuated tubes been proposed over and over again. Trying to work out what is new here.
For example: https://en.wikipedia.org/wiki/Vactrain
For example: https://en.wikipedia.org/wiki/Vactrain
Another consideration is the faster you travel the straighter your path needs to be. 4,000+MPH paths require incredibly strait designs.
The new hyperloop concept is just a fan-less capsule hovering on a MagLev track.
It’s just VacTrain over again, but more expensive and with lower capacities.
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.
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.
"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."
See wikipedia [0]: "pressurized capsules ride on an air cushion driven by linear induction motors and air compressors"
> 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 distinction between "very low pressure" and "vacuum" that is implied by the "hyperloop is not a vactrain" camp is a fantasy.
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.
Anything good you've read that explains why they've abandoned that route?
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.
[1] http://www.ansys-blog.com/20130925hyperloop/ [2] https://www.youtube.com/watch?v=yiyPQU48Ef0
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.
Don't we call that a “train?”
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.