Each car would have an ejection chamber. Riders wishing to get off at the next designated station would gather there, and be ejected as the train passed the station. No need to stop or even slow down.
Just a hundred feet after each ejection point there would be an injection station. Here, riders wishing to board would gather at the designated place on the platform. As the train passes (with its now-unpopulated ejection stations in each car), the waiting riders would be sucked in. Again, no stopping or slowing down.
Or, there’s another alternative technology that might be developed: Short-range transporters. Now for sure, the Star Trek style transporters (that can transport over long distances) aren’t going to be feasible for a while. But we could develop short-range transporters, sufficient to transport a group of passengers from the platform into the train as it passes, or to transport disembarking passengers from the train to the platform. All without any need to stop or slow down.
BUT . . . (See next post for the other side of this story . . . )
. . . BUT, if this mode of long-distance transportation gets popular (e.g., a hyperloop train from S. F. to L. A.), we’ll find it defined to be a big security matter. There will be security theater just like at airports. (In fact, isn’t that happening at some commuter train stations already?)
That 800 mph trip from SF to LA could happen in about a half hour! Well, not counting the three hours of security. By the time you can get from home to the station, and get through security and out to the platform and on the train, all in addition to the travel time . . .
We’ll all be wondering if you might as well just drive, for a trip of the SF-to-LA distance.
This isn’t news. This is already the case with air travel. It’s about a half-hour flight, but what with transportation to/from the airport at both ends, and security, you almost might as well drive. If this hyperloop train turns out to be a major transportation mode, the same thing will happen.
James Bond: Relax Georgi. Our engineers have spent months perfecting this.
General Koskov: How many times have you done this before?
James Bond: You’re the first!
The problem with comparing this to airline travel is that airlines can alter the routes they cover–and therefore the costs they incur–to reflect actual travel market demand. The owners of airports (typically municipalities or municipally-owned corporations) have to absorb the costs of the infrastructure but can adjust to some extent in terms of operations costs. The Hyperloop concept, however, is a hard infrastructure dependent, i.e. a pair of tubes has to be maintained regardless of the volume of travelers using it. This means that there needs to be a minimum guaranteed travel volume to justify construction and maintenance of a tube, notwithstanding the easement and right-of-way issues with constructing and maintaining such a system. (Bear in mind that every pylon and the area underneath the tube needs to be accessible for construction and maintenance by a ground crew, so it isn’t as if the tube can just pass over any piece of land.) These are issues and costs that airlines don’t have to deal with, so as expensive as it is to operate an aircraft, they can control their expenses to scale with usage in a way that this system cannot.
This is setting aside the technical and security issues with such a system, and the consequences of a catastrophic failure. I’m aware of the claims that there will be sufficient interlocks and protections against that sort of failure, but until such claims are practically demonstrated I view that with the same skepticism as I’ve viewed spaceplanes and fuel-from-air proposals as being not physically impossible but so technically impractical that one might as well wish for a visit from the ghost of Sanctus Nicolaus on Saturnalia. The promotional video linked in the o.p. gives zero technical content to evaluate, not only in how the system would actually work but in what they actually intend to do to validate the basic practicality of the system. All that can be told from the video is that they’ve made some neat-o animations and they’ve got two segments of tube which they’re trying to align.
My question would be how it compares with high-speed rail, which is proven technology, including in earthquake-prone areas like Japan. (In Japan, the Shinkansen slows down before earthquakes, because they monitor the tremors that occur before earthquakes. Will this tube transport have time to slow down from 800 mph in an earthquake?) How would the cost of building a tube compare wit building high-speed rail?
If the tube is kept partially evacuated so that it has lower-than-ambient air pressure in it, then it will be buoyant and it will float. It could be held more-or-less in place by tethers. This way, it will be unaffected by earthquakes.
A floating hyperloop tube is also easy to move around, to reconfigure the routes as the travel market demands.
ETA: Some of the routes could also connect up with wormholes, for the really long-distance routes.
Assuming these tubes are made of some kind of real world structural material such as steel or aluminum, and not some science fantasy pixie fart aerofoam, there is no way that they will weigh less than the air they displace and be capable of resisting external pressure without buckling even before adding the dynamic loads of having capsules flying through them.
The higher speeds of hyperloop mean more exacting construction tolerances. An airtight tube require more material than two metal rails. It’s is up on pylons, which is more expensive than running at grade. All of these factors mean that cost per mile will be higher (probably significantly higher) than cost per mile of HSR, even after all the engineering challenges have been solved.
Higher cost, lower passenger count, unproven technology, serious safety issues, abysmal passenger comfort, what’s not to love?
Up until about 1950, many large cities had a pneumatic tube system for sending mail across town. Some of them lasted longer; I think the one in Paris was still used up until about 1980 or so.
I expect if they ever get one of these working, it’ll first be used for packages. They could make it much smaller than one meant for passengers.
Would there be a significant benefit to scaling it up? One 2meter diameter, 6 meter long capsule ‘seats’ 4 people & luggage. Load it up, stuff it in the pipe, shut the airlock and off they go whenever they want to go, to whatever destination is served by The Tube.
Deference to usedtobe: some kind of rebreather system would need to be part of the design. But access doesn’t need to split the whole capsule–think airplane door for a reasonably-sized seal.
Entertainment would be easy–just have digital cameras every 50 feet that deliver their image to a viewing screen inside. At a speed of 800 mph that’s about 16 frames/second and would give a decent illusion of motion. Plus, the cameras double as a surveillance system to ensure exterior tube integrity/security.