Now,
the company hyper loop Transportation Technologies Inc. (which is not
affiliated with Musk or Tesla) has inked a deal with landowners in central
California to build the world's first hyper loop test track, according to
market research firm Navigant Research. The 5-mile (8 km) test track will
be built along California's Interstate 5.
Separately,
Musk has said he plans to build his own 5-mile test track, likely in Texas, for
companies and students to test out potential hyper loop design.
How
hyper loop will work
Musk
laid out his plans for the hyper loop in a paper published on the Space X
website. He has described the super speedy mode of transport as a "cross
between a Concorde, a rail gun and an air-hockey table."
The
idea is, passenger pods will travel inside tubes under a partial vacuum, and
will be accelerated to blistering speeds using magnets. A set of fans
attached to the pods will allow the train to rest on a cushion of air. The
system would be powered by solar panels along the length of the tube.
The
world's fastest magnetically levitated (maglev) train travels at
about 310 mph (500 km/h). Maglev trains work by using magnets to produce both
lift and propulsion. By contrast, the hyper loop would only use magnets for
propulsion, relying on compressed air for lift. Maglev trains are in operation
in Shanghai and Tokyo, and South Korea plans to open one in June.
Hyper
loop pods could theoretically travel very fast, because they wouldn't have to
overcome friction between the wheels and track that a typical train uses, or
the air resistance that conventional vehicles experience at high speeds.
"You
can go a couple of hundred miles an hour with a wheel, as the French and
Germans and Japanese have proven," said Marc Thompson, an engineering
consultant at Thompson Consulting Inc. in Boston, who has worked on maglev
systems. But, "as you go faster, the drag force on the train becomes a
very high energy cost."
The
design Musk proposed would travel at speeds of up to about 760 mph (1,220
km/h), but the test project, which aims to break ground in early 2016, would be
tested at 200 mph (322 km/h) to prove it works and is safe, Navigant reported.
At
that speed, the air drag is still possible to overcome, but beyond that, the
power needed to exceed the drag increases as the speed cubed, said James
Powell, a retired physicist and co-inventor of the superconducting maglev
concept.
Is
it feasible?
The
Hyper loop has the potential to be a faster, cheaper and more
energy-efficient form of travel than planes, trains or buses, its
proponents say. However, it's not yet known if the technology is feasible, or
safe.
For
one thing, the tubes have to be very straight, leaving very little room for
error. "The guide way [track] has to be built to very fine tolerances,
because if the position of the wall deviates from straightness by a few
thousandths of an inch, you could crash," Powell told Live Science.
The
tubes also have to maintain low-pressure air. "The problem with traveling
in an evacuated tube is, if you lose the vacuum in the tube, everybody in the
tube will crash," Powell said. In addition, the vehicle's compressor —
which produces the air cushion on which the pods rest — can't fail, or the pods
will crash into the walls, he added.
"The
whole system is vulnerable to a single-point failure," Powell said. For
example, somebody could blow a hole in the tube's side, or an earthquake
(no rarity in California) could shift the tube by a fraction of an inch, both
of which would cause the vehicles to crash. In superconducting maglev, by
contrast, the magnets are very stable and operate reliably, Powell said.
"It doesn’t require continuous control to keep it suspended."
What
will it cost?
The
5-mile test track is estimated to cost about $100 million, which Hyper loop
Transportation Technologies hopes to pay for with its initial public offering
(IPO) later this year, according to Navigant's blog. Assuming building costs
remain the same, a 400-mile (644 km) track between Los Angeles and San
Francisco would cost about $8 billion (not including development costs),
experts estimate. This price tag is still far less than that for California's
planned high-speed rail project, which could cost $67.6 billion, according to
the California High-Speed Rail Authority.
But
Powell questions whether the Hyperloopwould really be as cheap as promised.
"The main cost of these high-speed systems is in the cost of the
guideway," he said. And because the track must be built so precisely, it's
going to be more expensive, he added.
Even
if the Hyperloop is successful, Powell doesn't think it will fix the United
States' transportation problems — namely, congested highways and airways.
"A few isolated high-speed rail corridors in the United States really
won't address our big problems," he said.
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