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The Hyperloop vision is a transport system able to travel at speeds of 700 mph (1,130 km/h) in normal atmospheric conditions at sea level, which is simply not achievable.
The land speed record is held by Thrust SSC http://www.landspeedrecord.org/thrust-ssc-andy-green/ at 763mph (1228 km/h) and that required 110,000hp, burning fuel at a rate of 18 litres/second.
Hyperloop’s intention is to operate in a partial vacuum of 100 Pascal’s (or.1% of atmospheric pressure) within a tube to overcome the massive problem of atmospheric aero drag.
In order to achieve this objective the tube construction will be required to withstand pressure, (created by external atmospheric pressure on the tube) of 10 ton per m2 (square metre)*, and remain sufficiently and continually well sealed to maintain the internal vacuum at all times.
To extract the atmosphere from a tube with such a large internal volume (as envisaged), and maintain the vacuum would require an enormous amount of powerful mechanical air pumping equipment. This alone would be an extremely complex and complicated engineering exercise.
The whole thing then becomes more complex and complicated by the fact that to breathe and survive occupants of the vehicle would require the vehicle’s interior to maintain normal atmospheric pressure, as a vacuum is a lethal and very dangerous environment. The vehicle’s construction will therefore be required to contain the same 10ton per m2 (square metre) outward pressure.
The vehicle would be required to exit and re-enter the tube while somehow the vacuum is retained within the tube. In atmospheric conditions air is used for the cooling of mechanical components, electronics etc., therefore without air a multitude of cooling problems will be encountered.
If this is to be attainable, 100% reliability would be essential. In the event of a tube or vehicle failure the result would be a catastrophic explosion, implosion or both. It would therefore seem that this so-called visionary system would be unrealistic and unachievable without first understanding and addressing these issues.
*Atmospheric ground pressure = 101325 Pa (1.01325 bar) or 14.696 psi.
14.69lbs per square inch = 6.66 kg per square inch.
Square inch = 2.54cm x 2.54cm = 6.45 square centimetres.
6.66 kg per square inch ÷ 6.45 square centimetres = 1.03 kg per square centimetres.
1.03 kg per square centimetre x 10,000 (centimetres to square metres) = 10,300kg (10.3ton)
1 square metre = 1550 square inches x 14.69(psi) = 22778 lbs. ÷ 2240 (lbs. per ton) = 10.16 ton
The common misconception is that a vacuum creates suction. Not possible. Air is required to create suction and if there is no air there cannot be suction. When there is no air (as with a vacuum) external pressure is the only influencing force.
Reference: Suck the air out of a tube and this is the result of the external pressure on the structure.
https://www.youtube.com/watch?v=UpWeU2fvFGs and this collapse takes place while still at 20%
atmospheric pressure.
Believe me, Hitachi high speed train engineers know all this.
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