It's nice to see video footage. But I'm still unconvinced this will be practical on a large scale. Even if the cost per mile could be made cheaper than railways (and I don't see how it can), the infrastructure costs will still be enormous. If they weren't, HS2 wouldn't be costing us >£50 billion. I suppose it may work in a few cases where's there's nothing but flat, hard wasteland between widely separated cities, but everywhere else ? Nah.
http://www.bbc.com/news/av/technology-40811172/hyperloop-one-passenger-pod-tested-successfully
I'm not so sure. If they can deliver on the promised speed and convenience, this could be huge.
ReplyDeleteThe USA is geographically weird. I think people outside the States can be forgiven for underestimating how spread out everything is.
The South is a perfect example. A while back some friends and I were discussing how something as simple as a hyperloop between my town and Nashville could effect the economy. It's currently an hour drive, and if the hyperloop promises are to be believed, it could reduce a Nashville commute to a little under 30 minutes. Location and employment is a hot topic in the South, and this has the potential to reshape the whole issue.
The thing I'm still wondering about is the rather low number of passengers per hour. This is not a replacement for rush hour trains and the proposed Stockholm-Helsinki route seems like about the densest airline route it can match, so in many places you'd need several pairs of tubes.
ReplyDeleteBut it'd make a wonderful mail network. Or warehouse-fulfilment center.
It would allow for commuting longer distances than practical today bypassing the places which already have good communications but then the endpoint will be somehwere with, at least at present, probably too low population to make it viable. But you could buy land and then build a Hyperloop connection to a big city.
Japan is building a 500kmh+ system of mostly enclosed (not vacuum) maglev over a similar distance to HS2 for only £35bn-ish. Not sure what Japan Rail are doing that we can't, but there you go.
ReplyDeleteI agree that the main question about Hyperloop is whether the additional cost of vacuum/low-pressure to boost speeds is worth it. I'm not sure it is in most cases, but the distances involved in internal US travel might make it worthwhile. The cost per mile only has to be cheaper than air flight in those cases, and that's a cost which is cheap now but will only go up over time. I don't know what the LA<-->SF route is worth but I bet it's a really big number.
"nothing but flat, hard wasteland between widely separated cities" is actually a pretty good description of a remarkably large part of America.
ReplyDeleteAll good points. My main concern is whether it's really going to be economical to keep the tubes at very low pressures over very long distances. I'm also skeptical as to whether the costs of accelerating the pods up to 650 mph will really be as low as is claimed. But yeah, my European is showing with regards to widescale applicability... as the old saying goes, to the Europeans, a hundred miles is a long way, to the Americans, a hundred years is a long time.
ReplyDeleteThe plot of travel speed/passenger revenue vs pressure maintenance cost over distance is going to be an interesting one, that's for sure.
ReplyDeleteAll good points but my question is... will they have barf bags? ;-P
ReplyDeleteThe original point of hyperloop was that getting a good vacuum is very hard and expensive. But most of that is in the last 10%. Thing is, this doesn't seem to incorporate the bypass fan that was Musk's solution to the problem of air building up in front of the car, so I don't know how it works (at anything like the planned speeds) without a better vacuum than originally proposed. Unless they have an alternate solution, or plan to add the fan for higher speeds, this could be a HINO (Hyperloop In Name Only).
ReplyDeleteBut as for capacity issues, remember that for most of the trip, vehicles are moving at hundreds of miles per hour, and can be spaced rather closely. In operation, and at capacity, this is more like a near-sonic conveyor belt than a railroad. The potential downfalls are at the bottlenecks, curves and acceleration and deceleration runs, and those will be the capacity limiters. The biggest bottleneck could be the stations and end points. You need to figure out how to quickly turn the cars around, and quickly integrate them into traffic flow. Branching and parallel tubes could fix the problem, but would drive up costs as well.
As for rights of way, that's a HUGE problem for conventional or high-speed rail, but the original proposal was to elevate the track for most of its run, meaning you're buying "air-space," with limited ground footprint, and that's already business and legal area well pioneered by wind power. That isn't always practical in urban areas, and you'd probably have to underground much of that part of the route. But I think that's why Musk is investing in tunneling technology, even though he isn't working directly on Hyperloop. He knows this is a potential show-stopper, and he's trying to head it off. (I'm still skeptical of his prospects here. Tunneling is HARD.)
Cost per mile: A point to consider here is weight. A lot of the cost of a rail system is determined by this, and railroads are very inefficient in this regard. For example, a rail bridge must be built (and maintained) to hold the very heaviest freight-train possible (plus all the vibration and cycled stress involved), but on many lines, that bridge will be completely empty 90+, maybe even 99+ percent of the time.
ReplyDeleteA VERY small real-world example of this are cable driven elevated railways, one familiar example being the small elevated train used to shuttle guests between three hotels (the Excalibur, the Luxor, and the Mandalay Bay) on the Las Vegas strip. (Not to be confused with the longer Las Vegas monorail, which is a more conventional heavy elevated train, and which has a troubled history.) The cars have no motors. They're driven by a cable running through the track, which is itself a great example of a distributed engineering load). Because the cars are light, the elevated tracks can be much lighter (and consisting of an open framework, less visually disruptive) as well. Because the cars are themselves very simple, the system is HIGHLY reliable and relatively easy to maintain (the cables must be periodically replaced, but this is easily predictable, and makes planning for budgeting and change-over easy).
On a hyperloop, not only are the cars and their contents much lighter, but you deal with them one at a time, not in connected strings miles long. Even at capacity, because of the speeds, unsupported segments of track are unlikely to support more than one car at a time, and even then, loads will be evenly distributed. The engineering "worst case" and "best case" are much more the same thing. Plus, there would be very little vibration, and cycling stresses (as long as you're not repeatedly pressurizing the track and pumping it down for some strange reason) are very small.
Now, this is offset to some extent by the necessity of enclosing and depressurizing the tube, but I'm not going to go out and say it won't be as cheap or cheaper. With the right technology and if it's done as mass production, I can easily see it being cheaper as a whole, once you take into consideration construction, right-of-way and maintenance costs. Maybe it won't be, but I can see how it COULD be.