Hyperloop prototype unveiling raises questions

By Transport Action | Intercity Rail and Bus

Oct 26

TransPod, a Canadian hyperloop startup, unveiled its “FluxJet” vehicle, a proposed very-high-speed ground transportation system, at the Mars Discovery District in Toronto on July 22, 2022.  The company presented its pod technology, and demonstrated a one-third sized scaled-down FluxJet pod performing a slow-speed take-off, travel, and landing procedure within a cylindrical guideway.

TransPod has proposed a hyperloop-based high speed tube system to connect Calgary and Edmonton, including intermediate stations and airport links, but has not shown how pods could be safely switched between tubes at the proposed speeds and headways. It has also previously presented its technology as an alternative to High Frequency Rail between Toronto and Montreal.

Transport Action board member Michael Olivier attended, and left with more questions than answers. In this article, he examines the science, technology, safety case, and operational potential behind TransPod’s claims.

Understanding FluxJet

The proposed FluxJet vehicles are computer-controlled, fully automated and electric pods that operate in a low-pressure tube to reduce aerodynamic drag. While its developers call it an aircraft-train hybrid, it is proposed to levitate only a few millimetres off its track, and does not appear to use aerodynamic lift.

The FluxJet would rely upon a combination of three novel technologies:

  • Power transmission by plasma flux.
  • Levitating linear induction motors using magnetic flux.
  • Sensing and control using a new field of physics called veillance flux.

The FluxJet pods are envisaged to be 25 metres long and 3.6 meters in diameter (similar to a narrow body airliner) with a capacity of up to 54 passengers with luggage, including two wheelchair spaces; or up to 10 tons of cargo for freight pods.

The promoters claim that it will ultimately be able to operate at over 620 mph (about 1,000 km/h), faster than the fastest jet airliner speeds of 580 mph, and be powered entirely be renewable energy.

The proposed line will be built on an elevated guideway 40 metres wide, consisting of tubes mounted on concrete pylons. In addition, there would be a service road for construction, maintenance, and emergency services. However, the details of how the emergency services could reach the tubes, and how passengers would evacuate the FluxJet pods in an emergency, were not revealed.

Big, Accelerated Plans

TransPod plans to continue its pod research and development, carry out an environmental assessment, acquire land, and obtain the required construction permits between now and 2024.

The company claims that a test facility is currently under construction in France, but offered no further information. Their next step will be to build a half-scale vehicle, planned for next year, which would include the first testing in a low-pressure environment.

TransPod then plans to start a two-year test of a full-scale prototype FluxJet on a 10-kilometre test track somewhere near Edmonton International Airport in 2025, conduct high-speed tests, and obtain Transport Canada certification. The European Commission is apparently the first in the world working to develop a regulatory framework for Hyperloop technology by 2025, which the Canadian promoters hope can be used by Alberta’s transportation ministry and Transport Canada.

Construction of the full intercity line between Calgary and Edmonton would then begin in 2027, and the startup anticipates that the full line would be completed between 2030 and 2035.

TransPod claims to have already raised US$550 million in financing toward the projected US$18 billion budget to build a line between Calgary and Edmonton. Guideway construction is estimated to cost US$60 million per km of track.

Given the technical challenges the promoters have discussed, and those they haven’t even mentioned, like emergency evacuation and high-speed switches, it is highly doubtful that their cost estimates are realistic. The true cost could be many times higher.

Frequency, capacity, and complexity

TransPod’s stated goal is to operate with the frequency of a subway, with pods departing from stations every 2 to 4 minutes. This level of service can provide superb flexibility for passengers, as long as the system reliably has seats available.  

Given a pod capacity of 54 passengers and throughput of 30 pods per hour, in theory the system would be capable of carrying a maximum of 1,620 passenger per direction per hour, not allowing for any freight pods or any leeway to ensure schedule robustness.

The presentation did not explain how the terminals would be arranged to allow passengers to embark and disembark, including passengers requiring assistance, or how it would permit cleaning or servicing between trips. Achieving a two-minute headway or less implies numerous platforms, requiring complex switching infrastructure.

For comparison, the hourly capacity of the Fluxjet system is slightly more than a single crowded subway train, an N700 series Shinkansen, or a coupled pair of TGV-Duplex trains. However, high-speed trains can also operate on headways of as little as three minutes, resulting in a theoretical maximum capacity of more than 20,000 passengers per direction per hour.

Fluxjet Propulsion

In contrast to the Hyperloop white paper released by Elon Musk in 2013, which visioned the use of a turbine and for propulsion and levitation on a cushion of air within a simple low-cost guide tube, TransPod proposes to use linear induction motors, although they present their technology as less expensive than the Maglev-based technologies being tried by other Hyperloop promoters.

Linear induction motors are a proven system of propulsion, used on the Vancouver SkyTrain, Toronto’s Scarborough RT, and Maglev trains, but they’ve never previously been used to levitate a vehicle at the same time. In Maglev trains, these are usually two separate systems, because the attractive forces generated by the linear induction motors otherwise interfere with the levitation control of the levitation magnets.

A paper published earlier in 2022, Combined Propulsion and Levitation Control for Maglev/Hyperloop Systems Utilizing Asymmetric Double-Sided Linear Induction Motors (https://www.mdpi.com/2075-1702/10/2/131), presents a new method for combined levitation and propulsion control in maglev/Hyperloop systems by selectively applying AC and DC modes of operation to a group of asymmetric double-sided linear induction motors (ADSLIMs).

However, the development of linear induction motors embedded on the vehicle that can levitate the heavy vehicles like the FluxJet appears to still be at the theoretical stage.

What is Veillance Flux?

TransPod’s presented touted “veillance flux” as a key technology, although no mention of it appears in the feasibility study released in June 2021.

The leading scientist researching veillance flux is Dr Ryan Janzen, a University of Toronto physicist who is also TransPod’s chief architect. As a physicist, I read through some of the abstracts to find out what it is. The word veillance comes from French, as in the word surveillance, meaning to watch.

This is a very recently emerging theoretical field, with proposed new algorithms, circuits, and devices to extend the sensory capability of machines. This includes sensor enhancement and the measurement of sensing, to provide sensing of sensing itself. This then introduces the new concept of “veillance flux,” which is the quantified capacity-to-sense. This is non-trivial, as sense capacity changes through space as light, infrared, audio, and seismic signals reflect, refract, and scatter.

A first application is believed to be cameras, to provide extreme-dynamic-range signal sensing by combining dynamic ranges from multiple sensors. The sensors themselves would be controlled in a feedback loop, to expand their range of sensing. This work would then be applied to other sensor signals, including audio, high voltage, and seismic vibrations.

Whilst the details of the application of veillance flux to TransPod were not stated, this veillance flux technology will provide some sort of signaling function, ensuring that if a pod breaks down ahead, the next generation flux sensors will be able detect it almost instantaneously. Similarly, if a tube breach, loss of pressure, misalignment of the tube or track were to occur, veillance flux is meant to detect it.

Veillance flux appears critical to the success of FluxJet. Nonetheless, this is a brand-new field and given its proposed sophistication, may not have a practical implementation for many years yet.

Technology Maturation

Railways have had 200 years of development and technological maturity. New technologies like FluxJet are largely starting from scratch. Not many new transport technologies can overcome all of the different challenges of providing reliable, safe, all-weather transportation and still be cost-effective. In the history of public land transportation, railways are the reliable, cost-effective solution.

From the first horse-drawn wagonways, though steam traction, electric urban railways, diesel, and electric intercity, to high-speed electric railways like the Shinkansen or TGV, railway technology has been able to mature and evolve to be used in many different environments, and for many different uses, based on the widespread global experience. The technology is well understood, with wheel-rail and pantograph-catenary interaction is well understood in both academic literature and practical engineering.

However, over the years, many engineers and investors have promoted technologies to leapfrog or replace railways, with little or no commercial success:

  • Atmospheric and pneumatic railways
  • Air-propelled railways (propeller, turbojets)
  • Monorails
  • Hovertrains
  • Maglev

While some of these technologies exist in niche applications, including airport people-movers, none have come close to displacing steel wheels on steel rails.

To become the “fifth mode of transportation,” FluxJet must demonstrate both technical and commercial viability.

Commercial viability

TransPod proposes to build and operate the route without any direct subsidy, so the economics of the route must work on the basis of the farebox alone, not accounting for the wider social and economic value created.

Providing a partial vacuum for 300 km of FluxJet tube in each direction will be energy intensive and expensive. This will be in addition to management and marketing; station staffing and maintenance; propulsion energy costs; and pod maintenance. With any transportation system, spreading fixed costs over a large number of passengers is vital.

TransPod state that they expect to offer fares of $90, only slightly more than Red Arrow’s motorcoach service on the route, and significantly less than Canada’s stubbornly expensive regional airfares. This fare might not be realistic.

TransPod forecasts revenues of $1.36 billion in the first year of operation, rising to $6bn by 2060. The lower figure suggests a target of 17.7 million passengers – just over 1,000 passengers per direction per hour, but the higher figure would require 3,800 passengers per direction per hour, which would only be possible at headways of 50 seconds or less. However, TransPod’s projections include a significant portion of revenue from freight, carried at $144 per tonne. This would require even shorter headways, and with those come even greater engineering challenges.

Is FluxJet more cost-effective to build and operate than existing modes?

The proposed FluxJet system is certainly less expensive than Maglev, but Maglev lines are so expensive that only a few lines have been built worldwide. Shanghai’s high-speed maglev is economically unviable in its own right, being intended largely as sales tool for the idea of a Shanghai to Beijing line, which is indefinitely shelved. Japan’s ongoing Toyko-Nagoya maglev project forecasts construction costs in excess of $160M per kilometer and is not expected to open until the late 2030s.

The infrastructure costs proposed by TransPod are similar to past proposals for high-speed rail in Alberta, and several times more expensive than restoring conventional express passenger rail service. Both those options would have scope to grow passenger numbers, while FluxJet appears to need to run at its capacity limits.

Maglev has been in development since the 1970s and still has not achieved commercial self-sufficiency despite decades of intensive research and development into the technology. It has become transport’s equivalent of nuclear fusion – a wishing well into which billions of Yen, Dollars, Euros, and Yuan have been thrown. Hyperloop, even with the lower-cost technology proposed by TransPod, seems likely to suffer the same fate.

Safety and Comfort

Sudden loss of pod power; tube breaches due to accident or sabotage; or loss of vacuum could all have catastrophic results due to the extremely fine operating tolerances of the pods and the forces involved. Few details were provided regarding safety measures.

No mention was made of how the 25m long pods will handle curves in the tube. Whilst not likely needed for most of the Calgary – Edmonton line, curves will be needed to traverse urban areas as well as switches. Another complexity for an already complex system.

Taking curves at 1,000 km/h, the pods themselves could rotate to keep the acceleration forces going towards the floor of the vehicle, but no design was presented for a high-speed switch, needed to bypass intermediate stations.

The maximum lateral force considered acceptable for passenger comfort in European high-speed railways is 1 m/s2.  At 1,000 km/h this would require a switch to be around 500 meters long. The switch design would also have to be extremely reliable, because a “derailment” would be catastrophic.

How long would it take to stop FluxJet in an emergency? Is it safe enough to be certified by Transport Canada?

Railway signaling is based upon the worst-case scenario – a train cannot come closer to the train ahead than it can safely brake. Every railway and metro system in the world operates on this principle.

For a pod traveling at 1,000 km/h, we should calculate a safe breaking distance.  We can approximate this by using high speed railway safe deceleration rates.

An emergency brake application on a TGV takes 3.4 km to stop from 320 km/h, with a maximum acceleration of around 1.15 m/s2. Stopping distance is proportional to velocity squared, so from 1,000 km/h the pod would take 33.6 km to stop, not including any system reaction time. This is the same as the pod spacing at two-minute headways, but as noted above, shorter headways appear to be required to achieve commercial viability.

TransPod may argue that its vehicle sensors and tube constitute a closed system whereby railway safety rules do not apply. We cannot see Transport Canada, or most other countries’ railway safety authorities, agreeing to this. Greater braking forces could be possible with FluxJet that with high speed rail, but these would require a passenger restraint system.  

Engineering and maintenance

Instead of magnetic levitation (maglev) like other Hyperloop proposals, TransPod aims to use linear induction to propel and lift the pods off the track. This is a proven technology, but not at high speeds the promoters are envisioning. Linear induction motors propel Vancouver’s SkyTrain, as well as Toronto’s problematic Scarborough RT line, which is to be dismantled in 2023. These motors work fine in Vancouver, but in Toronto, the trains are notorious for stalling in snowy and icy weather. Whilst TransPod will have its linear induction motors sheltered from the elements, being in the tube, the real-world linear induction motor experience demonstrates that the need for maintenance, and maintenance access, is paramount. Tight tolerances must be maintained between the reactive rail or panel and the vehicle mounted components.

This TransPod tube will also require extremely tight tolerances and large-scale ventilation over hundreds of kilometres to maintain near-vacuum. Unlike a buried or underwater pipeline, the TransPod tube will be exposed to the weather, including strong winds. Whether the tube is transparent or metal, thermal expansion in direct sunshine, especially on the Alberta prairie, will be large, as will contraction in a Prairie winter night. Railway tracks on the Prairies should be be designed for temperature ranges of -40°C to 75°C, and speed restrictions often required in extreme heat or cold. Over 300km, the thermal expansion range of a steel tube would be more than 400m.

All this will necessitate highly trained engineers and technicians with unique skills. Training labour for such cutting-edge new technology will also be quite expensive.

Unlike railways, which have broad supplier base, a single source of technology and parts for a unique system means higher prices, and high likelihood of an orphan technology should the originating company eventually go under or decide to abandon the project. From monorail companies to the French Unirail tram concept, this has happened frequently with “gadgetbahn” railway alternatives and is a risk the public and Province of Alberta would bear.


Crucial missing details

There were many missing, yet critical details in this FluxJet presentation:

  • Emergency egress in case of accident or system failure.
  • How breathable air would be provided for evacuation from a pod.
  • Number of onboard crew.
  • Practical capacity and average speed, not hypothetical top speed.
  • High speed switches to bypass stations, line up to different platforms, and allow for tube maintenance.

FluxJet is a proposal for a technology demonstrator. This is not a functioning transportation system. Nor will it be for at least a decade, if ever.

Technology that doesn’t yet exist is called Vapourware

There are a lot of innovations in play in the FluxJet concept. Many of its key technological underpinnings don’t yet exist in any practical sense, with considerable uncertainty around the potential to integrate them into a system that regulators might certify to carry passengers. This appears to be more of a technology marketing and investment attraction exercise at the moment, rather than an actual transportation line proposal.

Hyperloop remains a distraction

Hyperloop and its spinoffs like TransPod are transportation Trojan horses. They are disruptive, not in technology but in the marketplace, distracting attention from developing and delivering feasible projects using readily available technologies to provide real and rapid increases in mobility and decreases in pollution.

Moreover, Time Magazine recently revealed that Elon Musk “admitted to his biographer Ashlee Vance that Hyperloop was all about trying to get legislators to cancel plans for high-speed rail in California—even though he had no plans to build it.”

It will be many years, even a decade, before an operational Hyperloop line opens. When it does, it should be a short shuttle, to work out the kinks that always come with new technology, not a major inter-city passenger line crucial to the economic destiny of a province.

At this point, TransPod’s FluxJet is literally a pipe dream.