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South Korea Signs On To Build Full-Scale Hyperloop System (newatlas.com)
Hyperloop Transportation Technologies (HTT) has partnered with the South Korean government and local universities to build the world's first full-scale Hyperloop system. "The agreement was actually signed back in January but only revealed this week, and sees HTT team up with the South Korean government's department of technological innovation and infrastructure, along with the Korea Institute of Civil Engineering and Building (KICT) and Hanyang University," reports New Atlas. From the report: It involves the construction of a full-scale testbed, licensing of HTT's vacuum tube, levitation, propulsion and battery technologies along with the co-development of safety standards and regulations. The agreement is a multi-year partnership intended to build a new transportation system for South Korea, one which will be known as the HyperTube Express and carry passengers between Seoul and Busan in under 20 minutes, compared to the current three-hour drive. HTT may be setting out to build the world's first Hyperloop but it is no guarantee, with fellow startups Arrivo and Hyperloop One also moving full-steam ahead with their plans. The latter in particular seems to be making solid progress, recently showing off a full-scale test track in Nevada and forming agreements with Russia, Finland and Dubai to explore the feasibility of a Hyperloop in those countries. It's too early to tell who will be first out of the gate, but the competition is certainly heating up.
shit, it's not even transistorized.
Nullius in verba
Hyperloop itself isn't designed for journeys of that length - it's designed to be optimal for intermediary length trips, with trains better for shorter journeys and aircraft better for longer journeys. That said, it is possible to make Hyperloop have a higher top speed (and thus reduced long-distance travel time) by increasing the sonic velocity of the gas - aka, via either increasing the temperature of the (highly rarified) gas inside the tube, or by using a (rarified) light gas such as hydrogen or helium. The latter requires increased tube evacuation pumping to minimize the fraction of leaked-in-air in the tubes. The former may happen to some extent on its own due to compression heating from passing Hyperloop capsules (the tube itself will be an effective thermal radiator, but the gas inside (due to its very low density) will not be very effective at transferring heat into the tube). Both lighter and hotter gases not only increase the sonic velocity, but also decrease air resistance (particularly using light gases). The low densities mean that you don't use great quantities of gases - meaning that the amounts of helium are affordable and loss rates acceptable, while hydrogen would not be prone to embrittling the tube or presenting a tube explosion hazard even when mixed with leaked-in air (although its behavior inside the capsule compressors / air bearings / etc needs consideration). Rarified water vapour, ammonia or methane atmospheres would also allow improved speeds of sound vs. air, although not to the degree of hydrogen or helium.
Another issue for long-distance travel via Hyperloop is that the faster you go, the greater the minimum bend radius. Not so much of an issue when you're going over flat plains, but once you start getting into uneven terrain it can present problems. "Floating Hyperloop" is particularly appealing for when dealing with very high speed travel due to the ability to sculpt bend radii as gently as you want over open ocean.
The Hyperloop design document doesn't consider that other technology can't or won't advance as well. But for at least intermediate-distance travel, they argue - convincingly, in my opinion - that increased aircraft speed, even if associated with improved economics, can't beat out Hyperloop. This is because of the simple reason that increasing aircraft speed means increasing altitude (to reduce the velocity-squared drag and to avoid sonic boom effects on the surface), which means increased subsonic climbing and descent times. Not a problem for long journeys, but for intermediate hops, that looks like a fairly fundamental barrier.
"99 dead duelists of Dios on the wall. 99 dead duelists of Dios! Take one's ring, pass it around..."
The expansion joints thing is just another example of why you don't turn to a biochemist for a lecture on engineering. Most HSR doesn't have expansion joints either. Lots of things don't have expansion joints. There are three standard ways in industry to deal with thermal expansion: 1) resist it, 2) let it expand by increased bend radii, 3) let it expand by increased linear length. All three are widely used. In HSR, it's common practice to use the "resist" approach - they generally lay the track hot, so that when it cools it contracts and there's built-in tension on all but the hottest days. They usually use heavy and/or anchored ties (commonly concrete) to resist track movement. Pipelines generally use some combination of #1 (e.g. overburden anchoring), #2 (e.g. expansion loops) or #3 (e.g. slip-type expansion joints). Hyperloop wants to use #3, with the dampers as slip joints (e.g. like teflon shoes on pipelines). Whoop-de-doodle-doo. Even if that sort of thing wasn't already a common solution for thermal expansion, they could always just switch to resisting expansion, with a pretensioned tube, like the rail on HSR.
"99 dead duelists of Dios on the wall. 99 dead duelists of Dios! Take one's ring, pass it around..."
Check out Thunderf00t's analysis
That's like checking to see what Ben Carson thinks of the Pyramids.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
It's basically how (and when) the rail systems have grown up, partnered and died over time.
Additionally, the northern states have generally been more industrialized, leading to "outsized" growth of rail systems there.
Chicago, when the rail lines were first coalescing, was a natural economic hub into the west and generally right on the demarcation line of what was The United States and the western territories. St. Louis also shares this to a certain extent. Heading south from there, the next major east-west hub would have been Memphis. And while it IS a transport hub, it's still a Johnny-Come-Lately due to the aforementioned dichotomy between industrialization in the north vs the south.
Additionally, for a while, every railroad venture was building on its own gauge of track. By the middle of the 19th century, there had been a major push towards a standard gauge. Current standard gauge (Stephenson gauge, international gauge or normal gauge) is 1435mm (4'8" in the US) distance between the inside of each rail. And it's used in roughly 55% of the world's track systems.
Again, the south, being behind, especially after the US Civil War was still mired in competition between rail lines. So businessmen didn't want their equipment potentially falling into the hands of rivals. So the proliferation of non-standard gauges continued MUCH longer. And because of this, lack of standardization, replacement parts were orders of magnitude more expensive. Because they had to be built on-spec, rather than just being pulled from a standard parts bin. This expense eventually became unmanageable and rail lines in the south started dying off.
What routes existing in the southern US now are either relative new builds or are legacies of rail line builders who settled (or just happen to have built) on/near standard gauge.
Chas - The one, the only.
THANK GOD!!!
I helped design submarines. Big, long metal tubes which can withstand well over 50 atmospheres of external pressure. Designing a tube to withstand a single atmosphere is trivial.
And you don't design these things to be uniform in strength so if it fails, the entire cross-section buckles killing everyone inside. You deliberately design them with weaker sections. That way if there's ever a problem, a weaker section fails first and (for a submarine) gives the crew advance warning the hull is about to fail while allowing them time to recover, or (for an airplane or hyperloop) equalizes the pressure before the entire structure can fail.
I think Hyperloop is a boondoggle in California. But I could actually see it working for South Korea. They have an extremely high population density (lots of potential customers), the maximum travel distance in the country is annoyingly too short for airliner but too long for regular passenger trains, and the geography is incredibly stable (no earthquakes).
You obviously never drive in the UK.
No I drive in Europe. Not only in Europe but regularly only the main highways between the two largest ports and trading hubs of Europe.
On motorways the trucks are often filling two of the three lanes in nose-to-tail groups of 20 or more
In many parts of Europe trucks are not allowed to overtake during the day if there's only 2 lanes on the motorway. In the parts where you are it's rarely an issue that holds up people for more than a few seconds.
Then you will see high streets in towns blocked for minutes by massive trucks delivering penny parcels to shops or fighting to pass each other in opposite directions.
I'm sure solving this middle of the town delivery issue is best done by putting a freight train down the main street. Don't conflate the last mile problem with international freight.
And all of this doesn't change the fact that by far the most cargo in Europe is carried by electric rail.