If the proposal is anything like the diagram linked by the OP (which I interpret as logical, not to scale), then the key benefit of the system appears to be that the speed-up/slow-down bits of the journey happen outside of the main traffic stream - so it’s a bit like a very high speed train that passengers can join without slowing it down. Obviously, the acceleration can’t be so great that it’s injurious to humans.
I’ve seen proposals for a conceptual overland train that supposedly would deliver the same benefit - sections of an upper deck detach and slow down for stations, then speed up and reunite with the next passing train. Looks like an engineering and safety nightmare.
I think the target that Musk is shooting for is public transportation that is cheaper and faster door to door than airline travel. If he can perfect a mode that can carry just a few people and depart when they want to rather than on a fixed schedule, then all he has to do is come close to matching a Boeing 747’s speed and he wins.
I don’t have any idea if he’s got it nailed but, like others in this thread, I applaud the way he is getting us thinking outside the box on transportation matters.
Let me point out that a relatively modest acceleration of 1/3 g will get you over 800MPH in two minutes. So acceleration itself is not a serious issue.
But I raise the question: If TSA clearance is involved–and it will be–the trip might take only 30 minutes, but getting through check-in and security could add two hours to the trip.
Technical issues aside, how would you get the land to build a thing like that?
I think the market would be there if the service were available.
Nobody needed jet travel until it was invented, and this is similar.
But there’s no way to build it.
I’m doubting the whole ‘pneumatic tube’ explanation, based on Musk’s hint about air hockey, which implies some sort of hovercraft, not a pneumatic tube. I don’t have any alternative explanation, but I don’t think he would choose that analogy if it wasn’t substantially similar to the principals of an air hockey table, which a pneumatic tube isn’t.
How deep would you have to go before you didn’t need permission from people above?
Every square millimeter of land from LA to SF is owned by somebody. Somebody who wants to make money.
Pylons might work. Something like a ski lift, but super fast, with little individual cars. The towers could be built inside current freeways, the median strips could be taken over and used for support foundations.
But who’d be crazy enough to ride in a thing like THAT??
This is a good question. The only reason we have railroads and freeways today is because they were built in an era when there was enough empty land that obtaining a continuous strip between, say, Boston and New York was a fairly minor problem. That sure as hell isn’t the case between LA and San Francisco in the 21st century. Even if we assume emminent domain would be used (a situation which would certainly cost countless elected officials their seats) the cost to buy up the land would easily rise into the many billions of dollars. Perhaps even into the trillions of dollars for a high-value corridor like Musk is describing.
I’m picturing the tubes deep underground, right below the 5 freeway to avoid eminent domain problems. But they’d probably have to be made with disintegrator rays to eliminate the spoil-removal problem.
That was my first thought- but there’s already stuff under there. You’d have to go down a good long way, especially under cities. Which is the whole route.
ETA: And I-5 isn’t straight enough for a high speed gadget either.
Use the dirt to build land off the coast- then sell the land.
Nothing new here-this was proposed in the 1970’s by a Rochester (NY) Institute of Technology prof… The concept is sound-just costs a lot of $$. We have more important things to blow money on…wars, F-35 “warfighters”, SSBN subs, etc.
Are you sure? All previous tunnels I’ve seen used a hard vacuum. This one is low pressure, but not a vacuum. As such, it can use (cheap) air bearings instead of (expensive) maglev.
The paper certainly goes through all the obvious objections. It should be vastly cheaper than conventional trains. The entire structure is much more compact than a conventional train system because the cars are small. The cars are small because they move so fast that they have a high throughput, and need almost no power to maintain their speed.
It’s mostly straight enough. See page 44 of the plans.
A few points:
It doesn’t run at full speed for the whole route. Curvy sections run at “only” 300 mph.
Small deviations from the route are acceptable. Tunnels are also sometimes used. They’re more expensive, but not unacceptably so as long as the fraction of the total isn’t too high. Due to the nature of the system, tunnels and right-of-way costs are much lower than with rail or road.
Because the cars can bank, a much higher G loading is acceptable. The system is designed for 0.5 gee peak. That’s acceptable if the force vector is “down” it’s not acceptable if to the side (as with a conventional train).
While it seems like the hyperloop is theoretically possible, it would highly surprise me if it was possible to build the track for anything near the costs estimated in this paper. Being able to mass produce pylons and tunnel segments definitely helps, but pouring foundations along a thousand miles of diverse terrain, transporting heavy materials, the labor involved… it just seems their estimates are way low.
However, the cost isn’t what’s going to doom the hyperloop, it’s the human factor. The pods have such a small interior that claustrophobia will be a real issue, even in people that don’t usually experience it. Being in a reclined chair with the walls and ceiling inches from your body in each direction, with no possibility of getting up, moving or escaping would, I imagine, cause regular panic freakouts from all kinds of people who didn’t expect to have a problem. Want to be in a tiny pressurized capsule shooting down a pitch-black sealed tube with possibly multiple panicked people trying get out of their tiny confined seats?
