In the preceding series of articles The Train-In-A-Vacuum-Tube Fantasy we examined the laws of physics which govern transport within vacuum tubes. The conclusions reached demonstrated succinctly that the use of Hyperloop technology for passenger transport is impractical, contradicting the laws of physics and raising many issues which appear to lack feasible solutions. Nevertheless, it is remarkable how many Hyperloop projects are now being prepared, on a worldwide scale.
In fairness to both Virgin Hyperloop One and Hyperloop Transportation Technologies we contacted both these companies with a series of questions raised by our research, as listed below:
1) What is the traction power (kW), braking power (kW), weight (t) and dimensions (mm) of the test vehicle on the DevLoop test track?
2) What will be the traction power (kW), braking power (kW), weight (t) and dimensions (mm) of Hyperloop vehicles used in regular operation?
3) What is the expected safe minimum distance (m, sec) between two vehicles travelling in a vacuum tube at 1,200 km/h?
4) What is the expected braking distance (m, sec) of a Hyperloop vehicle from its maximum speed of 1,200 km/h?
5) How will the heat originating from activities such as braking, starting and air conditioning be removed from the vehicle if there is a vacuum in the tube?
6) What is the expected average speed (km/h) of Hyperloop vehicles in a situation where stations are situated so close together that it would be impossible for the vehicles to reach their top speed of 1,200 km/h, or are unable to run at that speed for any great length of time? For instance, the journey time between Warszawa and Wrocław would only take between five and ten minutes.
7) What will be the minimum curve radius on a Hyperloop line? What will be the minimum vertical radius?
8) Assuming your proposed headway of 40 seconds between Hyperloop vehicle departures, what sort of station facilities will be needed on the various routes which are currently proposed? How many platforms will be required for boarding and alighting?
9) What is the consumption (in kWh) of the pumps for pumping the air out from each platform? How long will it take to drain the air between the last passenger boarding and the vehicle departing?
10) What type of Automatic Train Protection will be used? Some form of ATP will, presumably be required because a vehicle travelling at 1,200 km/h is akin to a bullet fired from a gun...
11) How will Hyperloop vehicles be able to switch from one tube to another? One would assume two tubes, one for each direction of travel. Have you developed the technology for turnouts? If so, how long (in m) will these turnouts be? How long will it take a vehicle to move from one tube to another, and at what speed would it be able to travel during this manoeuvre?
12) Hyperloop tubes will be made of steel. Under hot conditions steel expands. For instance, a 200 km steel tube will increase in length by 176 m under summer heat. So how would you cope with this, in order to ensure that a vacuum is maintained at all times within the tube?
13) When an end-to-end Hyperloop is built, rather than a Hyperloop circuit, such as in Poland or Corsica, how will vehicles be able to cross? Will twin tubes be built, one for each direction of travel? Or if only a single tube is built, for example, between Warszawa and Wrocław, would there only be one vehicle in each direction every 34 minutes? Have any theoretical timetables been worked out for such a route?
14) Supposing an operational problem occurs, such as a mechanical break-down, or a failure in the energy supply, how would passengers be evacuated from a Hyperloop vehicle and also from the tube?
15) What is the estimated cost of building a Hyperloop line, in USD per km? And how much would maintenance of 1 km of Hyperloop tube cost, in USD?
16) What would a typical Hyperloop vehicle cost, in USD? And how much would a Hyperloop vehicle cost to maintain - USD per km or per 1,000 km travelled?
17) What is the expected electricity energy consumption of a typical Hyperloop line with vehicles travelling at 1,200 km/h? How many kW of electric energy would be required to generate the vacuum for 1 km of tube to enable this speed? And what would be the relative energy consumption, in kW/per seat, of a vehicle travelling at 1,200 km/h?
18) What maintenance facilities will be required for Hyperloop vehicles? Will they need special depot facilities? And how will they be moved between Hyperloop tubes and these depots?
19) How many countries are at present actively involved in the Hyperloop projects? How many people are now actively involved in Hyperloop projects, in general?
20) What spacing will be necessary (in m) between pumping stations along a Hyperloop line, to maintain the vacuum? What power rating, in kW, will each of these pumping stations have?
21) What will be the spacing between emergency exits in a Hyperloop tube (in m)? What will be the dimensions of these exits (in mm?) How will it be possible for passengers to leave vehicles, and then the tube, if there is still a vacuum in the tube?
22) Since Hyperloop tubes are vacuums, Hyperloop vehicles will have to be fitted with reservoirs of fresh air for passengers to breathe. What will be the capacity of the storage tanks (m3)? What will then happen to stale air? It will not be possible to expel it from the vehicle while it is moving in the vacuum tube.
23) Are the Quintero vehicles, built by Hyperloop Transport Technologies, and the associated infrastructure, compatible with the Type XP-1 vehicles which Virgin Hyperloop One is developing?
In spite of our requests, neither Hyperloop Transport Technologies nor Virgin Hyperloop One deigned to answer our questions. We were not exactly surprised, since it would be difficult to provide truthful, and technically sound answers to these questions, without bringing into question the whole validity of the much-vaunted Hyperloop-hype.
And a "hype", in the pure commercial term, it is. It is amazing to see how many countries, institutions and individuals have so promptly swallowed the bait - hook, line and sinker. Few of these have ever questioned the whole technological validity of Hyperloop. Had they done so, or been capable of doing so, it would have been evident that Hyperloop's campaign would have bitten the dust some years ago.
A complete caption for picture: One of the many images published following the April 2018 press release announcing the signing of the Hyperloop construction contract in the United Arab Emirates for the vacuum tube proposed to link Dubai with Abu Dhabi. One would expect that the vehicle depicted would be an appropriate rendition of those to be used in this system. But it is still, after FIVE years of development, apparently lacking a large air tank, to provide a fresh air supply for several dozen passengers. In general, all those involved in Hyperloop projects appear ignorant of the fact (and related problems) that real, breathing people are expected to travel in a vacuum environment. Similarly, their perception of the extremely high speed of 1,200 km/h gives one the impression of a group of children playing with Scalextric model racing cars...