Hi, we’re (mostly) engineers here at Hyperloop One. Ask us anything!

A semi-popular youtuber named thunderfoot has made a few videos in which he claims that the hyperloop will not work. Have you seen the videos, and if so do you have any rebuttals to specific points he made?

I've got this one. I have watched the video, and made copious notes. Thunderf00t is a well known youtube science commentator, best known for debunking religious fundamentalists and understanding the surface-maximization of liquid alkali metals, published in Nature last year.

That aside, both hyperloop videos show a complete reluctance to engage with the real arguments. Sorry, but highlighting some semi-literate comments by your critics does not amount to engaging in a useful discussion. I would like to levitate this video into the sun.

Here are some specific points and rebuttals: -Thunderf00t primarily makes reference to the Hyperloop alpha whitepaper, written by some SpaceX employees in 2013. I saw no evidence of engagement with subsequent press releases by any of the hyperloop companies. In particular, TF doesn't seem to be aware that there is more than one hyperloop company. FYI, we are Hyperloop One, the company that has raised ~$10⁸ and built the world's most powerful linear motor in 5 months. -Thunderf00t talks a good game about aerodynamics, but shows no evidence of even having read the wikipedia article on choked flow, duct flow, the Kantrowitz limit, or knowing any of the other 'first day on the job' level detail for our aero team. -One of Thunderf00t's technical gotchas was 'expansion joints are difficult', despite the fact that hydraulic cylinders exist, most steel rails are thermally pretensioned, and thermal expansion is probably something we thought of already. -Thunderf00t could have easily looked up our people on LinkedIn, checked their google scholar bona fides, whatever, but seemed more keen on a cheap take down than actually engaging with interesting and ongoing engineering challenges. -One symptom of the level of technical effort that went into TF's video is his careless assumption that 1g = 1m/s/s, as though Hyperloop was being built on some tiny moon of Jupiter. As a fellow academic, I was disappointed by TF's lack of intellectual humility in an area in which he is obviously not an expert. One would wonder why TF would put such hastily produced, easily debunked rubbish on his Patreon feed - people actually pay for that!

-Casey

Where are the efficiency gains over traditional rail or HSR, considering that the hyperloop needs to maintain pressure, and has more safety concerns? What problem is the hyperloop trying to solve?

Efficiency gains come from the fact that this is an on demand system that doesn't require you to wait and travels at high speeds - think elevator experience. Hyperloop is solving the on demand, high speed, packetized, weather-proof, autonomous system, ultra-safe transport system problem. Low magnetic and aerodynamic drag mean substantially reduced power usage.

Giegel

With the lawsuit with Bam Brogan slow down plans to get this off the ground?

No. We're heads down working on the real problems.

Engineering the Hyperloop requires overcoming many unique challenges. Do you foresee any useful alternate applications of the engineering solutions developed by Hyperloop One (for example, in the actualization of other futuristic technology)?

Yes. We're really moving the needle in manufacturing and complex system design. - Casey

Your main competitor, Hyperloop Transportation Technologies, released a video briefly outlining their levitation and propulsion systems around the same time you had your propulsion test last May. What are the main differences between their and your designs, and why do you think you've picked the better concepts?

Ours exists

Giegel

What problems do you forsee, when it comes to convincing the public about the safety of the hyperloop?

We are designing Hyperloop to be the safest mode of transportation on Earth. We will run extensive tests on all the safety features, involving third party safety assessors. As for the public, it will be like the first passenger airplanes: excitement for a new futuristic mode of transportation, together with the extensive safety test that we will run before passenger operation will make people eager to jump on Hyperloop! -Andrea

I believe it was philosopher Michel Foucault who suggested that with the introduction of the car, by necessity man had invented the car accident. Likewise, the plane crash wouldn't have been a thing if there had never been a plane.

If Hyperloop succeeds in creating a new form of transportation, isn't it inevitable that a new kind of tragedy, heretofore unimaginable to most people, will eventually come to pass?

Interesting point of view...

Does that also take into account all the passengers who choose the Hyperloop that otherwise would be traveling by car or plane?

How does that measure up in terms of documentable accident statistics?

Would those numbers be run under amount of people moved per mile, per hour, per trip, etc.?

Lots to think about before immediately jumping to worst case failure mode.

I think you and whittlinwood and you both have valid points here. No method of transportation is without risk. I take his point to be that we should not treat this as some miracle lifesaver. I get your point that any improvement in public safety is a good thing. Maybe there is something in the middle?

OK, let's get a little bit more technical here. First of all by having a fully autonomous mode of transportation, where we are able to fully control the environment, we design-out a lot of common hazards: no human error (by far the most common cause for an accident), at-grade crossing, weather related hazards, etc. Then, we are looking at various statistics (failures per trip, per mile traveled, per departures, etc.) and we are specifying our system to be better than what is currently available from any of these point of view. We are performing top-down hazard analysis and bottom-up failure mode simulations to make sure that we hit our safety targets. Soon we will be start testing our safety functions full-scale in Nevada, with real hardware. - Andrea

What's your biggest challenge going forward in terms of bringing the product to reality?

Videoconferencing. By far. - Casey

I was a suspension system designer for one of the teams that participated in the spacex competition last January. Our biggest problem was always getting enough airflow to achieve the needed levitation height from our air bearings. That's why we and many other teams switched to magnetic levitation. I'm not super familiar with your current design but can you explain what you've done to overcome this problem? Thanks and sorry for the super technical question.

Nice work - it does get pretty tricky to find enough air in a vacuum tube to use for air bearings. We ultimately went the maglev route for a variety of reasons but this was a big one.

Giegel

What CFD software are you using to model flow inside the tube/around the pod?

We're proud users of ANSYS (Fluent/CFX) as well as Star CCM.

Giegel

I heard there should be track between Bratislava - Vienna. Is your company behind this or it's a different one? And one personal question. I'm from Czech Republic, what do I need to do in order to work at Hyperloop One as a Software Developer?

Be. A. Bad. Ass. - In all seriousness, at Hyperloop we look for the ability to creatively approach common problems and remove user pain from internal and (eventually) external systems. Hit us up at https://hyperloop-one.com/careers, and make sure to show us your github - we really care about what you have done and what you can do. Internally, we leverage exciting new web technologies when possible to help facilitate the building of Hyperloops. Externally we hope to use software to revolutionize the way people think about transportation. --Kyle Wall

Will hyperloop ever come to India?

Have you applied to the Global Challenge? There are already a bunch from India!

-Giegel

How can the hyperloop tech help the medium distance commute, for example from Fremont to San Francisco (~40miles) ?

Hyperloop is practical on shorter scales as well. 40 miles is certainly doable within the network. - Casey

We think the Hyperloop could effectively make areas such as the SF/ San Jose / Bay Area function as one giant metropolis, decreasing commute times between those cities to as little as 10 minutes. - Diana

What is the work atmosphere like at Hyperloop these days???

78% nitrogen, 21% oxygen, 1% argon, trace levels of snark and LA smog. - Casey

Kick ass. From an all-hands today.

riding on the hyperloop - even if its just a test track - is on my bucketlist

what do you think where and when will it be possible to do that without any kind of "special connection" to someone of the team, just by buying a ticket?

We don't anticipate putting humans on the test track any time soon. Unfortunately, just knowing someone doesn't mean that we're any more willing to break our safety protocols ;) . But if you come and work here you can probably move stuff in the tube, which is more interesting and has better selfie opportunities. And yes, there are whole varieties of supersonic vacuum tube pokemon that were previously unknown to science. -Casey

Hi! Love your work- can I get a sticker?

Second, less important question: Are you going to get the "air cushion" to work, or are you going with boring linear motor propulsion, like those other guys?

Hi Roger - by 'air cushion' I'll assume you mean air-bearings for levitation, the answer is no. It turns out that the ride-heights of typical air-bearings are in the 100s microns to a few millimeters. To make that work, we'd have to build a track surface that has a flatness well below that level - that is super hard! Instead we are developing a passive magnet levitation system that 'lifts off' at low speed for our full system test at the end of this year.

If your question is about the propulsion system, we have a super rad linear motor that's designed to accelerate with max power of 32 MW and reach a top speed of 700 mph. Definitely not boring, and I think you'd agree if we strapped you to it during launch! -James D

Which different simulation software are you using for system simulations, CFD, controls development, etc?

Our system level simulations are being integrated in MATLAB. Here we can do both time and frequency based simulations as well as any controls designs. ANSYS is used to generate the CFD, and FEA models, which are then brought into the system level simulations.

Hi! What do you guys personally think will be the first Hyperloop route?

We don't know until we finish the Hyperloop Global Challenge -Casey

Hi there!

I’m really interested in the project Hyperloop. I prepared some questions for the test in Nevada (May 11th) made by Hyperloop One and some general Hyperloop questions.

1.) How fast was the sled going at maximum speed?

2.) What is the speed-goal of the sled on the test track (the test track used for the recent test)?

3.) What is the speed-goal of the full-system hyperloop?

4.) Is the tube fully evacuated (vacuum) or only partially evacuated (partial vacuum)?

5.) How is the train being levitated? With magnets or with air?

1) 110mph 2) 150m/s (300mph) on the POAT track 3) System speed will vary depending on customer requirements. Maximum speed limited by curve radius and (eventually) aerodynamic shock heating - very supersonic pods are physically possible. We envision systems to be a trade between curve radius (and total fraction of tunnels) and total travel time. 4) Partially evacuated - around 100Pa. 5) Magnetic levitation is our current design point. -Casey

Hi Casey Thank you for your answers! I have some other questions to your answers:

1.) At number 2 you said «150m/s (300mph)». But 150m/s would be 335mph. So what is it? 150m/s OR 300mph? And when will be that test?

2.) So is my understanding right: There are three differences between the recent test (with the sled; on May 11th) and the full-system hyperloop: - The propulsion system of the sled was not on full power - The sled was not in a vacuum - The sled was not levitating

These three circumstances show that it will be possible to get the Hyperloop going 760mph. Right?

3.) So is it physically possible for the Hyperloop to go 760mph? And will there be 760mph fast Hyperloops?

Thanks once again for your support!

Hi TechnologyGuy88, thanks for the fact check. 1) 150m/s is the design point. I'm Australian, I struggle with imperial units. We will be gradually increasing the length and power of the system - it took a while to make and we don't want to break it. 2) May 11th test was a test of the propulsion system. The final product will be quite different under the hood, incorporating many different systems. The propulsion system of May 11th was actually much more powerful than the full system. We increased the acceleration so we could go faster with a shorter track, but obviously humans don't want or need 3gs. But with a full system, you can have much more length and slowly accelerate to full speed. 3) Yes, the hyperloop's speed is not practically limited by the sea level speed of sound. For complicated reasons. As soon as we can go straight enough, we'll be going 760mph, or faster. -Casey

any thoughts on the critiques moved by the famous youtuber/scientist thunderf00t? https://youtu.be/RNFesa01llk

I addressed a similar question - good luck finding it! - Casey

Why isn't there a Time In Route calculator on the website?

Wait for it!

Hi guys I'm super stoked I live in LA and I will take this all the time up to SF. Where will the stops be in LA?

Being stuck in a wicked LA traffic jam (and having to commute constantly between SF and LA) is what inspired Elon to envision that SF-LA route in his white paper. Given the difficulty that California High Speed Rail project has had just acquiring the land it needs, we don't put a huge amount on confidence in that route getting built any time soon. We're currently focused on more likely route options in other parts of the US and the world. We have feasibility studies underway in the Nordics, Russia and Switzerland, with strong interest from the Dutch and the Port of LA & Long Beach, with many others to follow. - Bruce (not an engineer)

Will there be applications for the Hyperloop within city limits to speed up inner-city transportation?

For example a lot of the transportation infrastructure within Los Angeles is very slow and commuting from west side to the east side or to Orange County is not very quick.

Thank you.

The hyperloop network can operate in large cities with no appreciable loss of efficiency. Because transport is point-to-point and on demand, adding more stations does not cause congestion. - Casey

Thanks for doing this AMA! Have a couple of questions, answers to which will specially be relevant to those participating in the Hyperloop One Global Challenge:

1. It's very fascinating that Hyperloop One has the grand vision of creating a network of tubes, exchange points, and ramps etc that will resemble a global "internet of transport" that can transport anything anywhere at fast speeds. How will this work, and how will it seamlessly connect the world's largest transportation networks, populations and economies together?

2. How will the freight-only and passenger-only version of the Hyperloop One full-scale system be different from each other in terms of track/route layout, payload capacity, safety systems, technology used etc? What will be the approximate passenger/freight capacity between any two points? What is the plan to transition from freight-only to passenger versions of the Hyperloop?

3. The KPMG business study between Finland and Sweden shows distances as less as 60 km between Origin and Destination pairs of the Hyperloop - How will this on-demand system work between multiple OD pairs, and what speeds will it reach within such short distances?

4. What factors decide the cost-per-mile of setting up a Hyperloop track and which are the major challenges in the way of reducing this in the long run?

5. Does the Hyperloop you're developing represent a significant disruption in the advent of sustainable mass transit, or will simply adding solar panels to current electric High Speed Rail options lead to a similarly sustainable future?

1) The hyperloop network will look and smell a lot like the internet, except that we won't convert passengers to electronics for routine signal cleaning and amplification. Also, there's a topological restriction in that humans are made of fermions and light is made of bosons, so humans cannot pass through each other (Pauli exclusion principle), or turn rapidly. So, smooth curves at speed, like undercooked spaghetti. As for its final form, time will tell. - Casey

2) We're designing the system to carry both passengers and freight. Track layouts could be the same. Container payloads are pretty heavy requiring higher power. Freight pods will be cheaper to construct because goods don't need VR and oxygen. The plan is to move goods while proving the system is safe for people.

3) "You kept makin' all the stops?" -Jerry. I'm a Kramer fan, but I agree that doesn't make a lot of sense. Even if you're making one of those short 60 km journeys, you still save time.

4) Construction cost is driven by cost of the base hyperloop system, site specific civils, land acquisition, stations, pods. The challenge is why we're all here - innovating on the design to bring the cost down.

5) Adding solar to HSR would be a clean way to power rail. We can take advantage of renewables too, and we're consuming less energy and moving over 3x the speed at lower cost. - Josh

IIRC, Elon Musk's original white paper had the Southern terminus of the Hyperloop in Victorville. As anyone who lives in LA would know, Victorville is a 2 hour drive if you're lucky. Do you plan to extend the Southern terminus South to some place that is central and already serviced by public transit, such as Union Station?

Hyperloop terminal locations will be chosen to maximize system efficiency and utility. Getting through the mountains around LA is a headache for every mode of transport though, maybe we should start digging tunnels soon. - Casey

If there was a movie about the Hyperloop would it be called Tube Fast Tube Furious?

Tube funny! - Casey

Can you describe how HyperLoop will have an effect on the daily lives of people in 10, 20 and 30 years?

We're hoping to transform the way people live, the way they work and play. The idea is that people could hop into a Hyperloop in LA and get to SF for work half an hour later, less than the amount of time it would take to travel from Santa Monica to downtown LA during rush hour right now. This has tremendous implications from a real estate and housing perspective, from a work-life perspective, reduced congestion, not to mention improvement on pollution, emissions, and quality of environment! - Diana

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It is very important but you always have to learn the fundamentals - first principle physics otherwise you won't have an ability to determine if the answers out of FEM/FEA are correct. I'm a MechE and I've used it extensively over the years.

Giegel

What would be the top acceleration acceptable so people won't faint?

We intend the trip to be exciting in terms of elapsed time and otherwise like the world's coolest elevator. You don't have to be a fighter pilot to ride Hyperloop. Though if you are, that's pretty cool. - Casey

What's your opinion on tuna?

The more dolphins the better.

Fantastic project! Do you folks envision building the hyperstructures with an in house construction team? Contracting that portion out? A bit of both? Also wondering if you envision passengers having internet/cellular wireless connectivity during the ride. If so, what kind of network infrastructure could provide that given the limitations caused by high speed and enclosure in a steel tube?

We will be building at least some hyperstructures in house, especially the super cool stuff. Gigantic helical compressive concrete structures, insane spans, underwater tunnels, are much too fun to give away. Likely in the long term other partners will help us. We will have full internet/cell connectivity inside. Gotta watch the cat videos - cats in tubes are our technical inspiration. There are many ways to get data in a tube, but we need people to do that - apply to help us bring internet to the hypertubes. -Casey

Casey- That all sounds excellent and like some of the most exciting and enjoyable of all possible construction projects coming down the pike! I specialize in challenging construction projects, mainly cellular wireless sites, and I've been watching the career page on a near daily basis for ways in. So far I've applied for various construction management roles as they seem to be the closest fit to my skill set. Is there a current job role opening that I should apply to help bring internet to the hypertubes? Thanks!

You can email me your resume and I'll take a look. Don't forget to be awesome. - Casey

Do you see this as the replacement of all transportation or will cars and bikes still play their own role in commuting?
Do you see this as the first of many new methods of transportation?

We see it being a complement to other modes of transportation and fully integrated into other last mile solutions. Door to door - faster than ever before.

-Giegel

Uh, vague question incoming, how do you guys better the world, if at all?

Keeping 100+ engineers off the street - Kearns (not an engineer)

Technologies that bring people together to share culture, information, and ideas remain the most powerful driver of economic growth. The prospect of keeping that productivity flywheel going is what drives us--and what drives the public and private sectors to allocate massive amounts of capital to building new transportation infrastructure. The U.S. national highway system brought dramatic economic growth to post-war America. We don’t know what we don’t know, but we do know that there are big opportunities to arbitrage real estate values and there is great demand to knit cities into more connected regional economic hubs. The Netherlands wants to be first to build Hyperloop in their country. So does the United Arab Emirates, and Russia, and the Nordics. Stockholm has a 15-year waiting list for apartments and booming tech sector, while the Helsinki area has an abundance of housing and underemployed engineers. We’re working on a feasibility study with FS Links of the Aland Islands to connect Stockholm and Helsinki with a 20-minute Hyperloop journey, an elegant way to rebalance the economies of the region.

Besides Elon Musk, how much was this influenced by Futurama?

Hamburgers -- Kyle Wall

How many feet of test track tubes have been completed at your North Las Vegas facility?

We have 1000 feet of tube already on site and more deliveries starting next week. - Casey

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The regulatory framework for hyperloop isn't fully formed and will vary from place to place. That said, security measures are typically a trade between time, efficacy, and being desperate to look like security is taking place. Hyperloop takes security seriously and will ensure the safety of the system and passengers without adding friction to the transportation process, or taking your water bottle. -Casey

How do people poop on Hyperloop? Thanks - Diablo

Defecation is normally assisted by taking a deep breath and trying to expel this air against a closed glottis (Valsalva maneuver). This contraction of expiratory chest muscles, diaphragm, abdominal wall muscles, and pelvic diaphragm exerts pressure on the digestive tract. (wikipedia) -- Kyle Wall

And this will be the reason Kyle has to explain to his parents why he got fired from Hyperloop One.

Totally. Worth. It. -- Kyle Wall

Hi guys. Have you got any students working at Hyperloop One? Are you planning to have any placements/internships? I'm a civil engineering student in Europe and would love to help bring your work across the pond!

We had 15 interns this summer that came from all different fields. They were mainly engineers that have electrical, civil, mechanical, aerospace degrees - a large number of them worked on the SpaceX pod competition for their schools. Always looking for the best and brightest!

Giegel

Scientifically would it be possible to bang in a HyperLoop pod? Will there be a term for it like the "mile high club"

What do you think will have more impact on society HyperLoop or Lvl 4 Self Driving?

How about a combination of the 2 - SDC drives itself into a hyperloop pod?

Sorry for the delay in responding. Testing in progress. -Kearns

What are you guys looking for in the Global Challenge submission? (i.e. route map? feasibility statement? etc?)

We are looking for creative and innovative ideas that are also feasible to implement and would garner substantial government support. There are so many things that go into making the Hyperloop a reality - it's not just about the technical aspects, but also about the stakeholders, the terrain (so, yes route map would be helpful here!), the problem you're trying to solve (and feasibility statement!), etc. I would say, the more data you can provide for your Hyperloop Global Challenge application, the better. - Diana

A gigantic blank check with plenty of room for zeroes.

In all seriousness, our leading entries have awe inspiring levels of detail and full system level consideration, ranging from demand prediction to regulatory proposals. - Casey

I watched the demo video that included a rail based system but if you're going mag lev then how does the rail, as shown in the demo, fit into the equation? Is no friction still the goal?

The demo on May 11 was called POAT = Propulsion Open Air Test. i.e. we were only testing the gas-pedal... Therefore sand brakes, steel rails, and no low pressure.

This is a way for us to test sub-components in a more controlled environment before integrating them all together at the end of the year in our full system test, which will have a levitation system.

-James D

While the Hyperloop is intended to replace aging, archaic train systems do you see a scaled down version of Hyperloop offering local commuters alternatives to cars? Imaging hopping in a local air tube and flying off to work. I see a lot of advantages to air tube travel for common work, shopping and sports/entertainment locations. What are your thoughts on this possibility?

Definitely a possibility! I envision Jetsons-style travel, whizzing from home to work, school, shopping, etc. in pods. Astro not included. - Diana

Sounds great! - Casey

I'm so stoked about this project! How do you think your solution will compete with driverless cars since they're probably gonna hit the market at the same time?

The driverless car will bring you to the Hyperloop. -- Kyle Wall

Driverless cars and hyperloop are complementary mass transportation systems. Cars work on existing transportation infrastructure, while hyperloop helps integrate larger cities and networks of cities, with new infrastructure development. - Casey

Through what mechanism do you intend to compress air into and past the pod in order to avoid choked flow? As a technical lead on a SpaceX Hyperloop Competition team, we ran into several issues with power and availability of continuous compressors capable of compressing the required amount of air. Do you intend to design your own compressor? If so, what is your largest problem with design such a device?

It is indeed a non-trivial problem. We built the world's only high speed low pressure wind tunnel to test turbine designs. At a system level, I suppose you have to decide if an onboard compressor is worth the hassle. - Casey

If all goes to plan, could you picture the hyperloop being used in places like Europe? Travelling to all major cities or something?

Yes. Except London, because no-one wants to go there. - Casey

Edit: That was faster than explosive decompression. I need to find a European city with a sense of humour.

My 3 year old son : Why do they loop-te-loop?

That's a great question. We don't plan to build hyperloop that far from the ground, but maybe rollercoasters can do that? - Casey

When describing what Hyperloop is to people who do not know they fear that the g forces will be unbearable and would never be something they would ever ride. How do I soften their fears and explain how these kinds of issues are non-issues?

There was considerable apprehension about planes too - hyperloop will be chiller, faster, and cheaper than planes. So that's a good point of comparison. - Casey

What are the questions I should be asking?

What would this look like in a hyperloop pod? -- Kyle Wall (you are welcome!)

Wanna buy me and the Mrs a pizza?

Moving on. What sort of math was used to design you're thing that's never existed?

8 slices or 12?

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Pretty sure the tube and hyperstructures in general are of the ... permanent installation ... variety. - Casey

Why not put the hyperloop underground? This would minimize the currently disastrous thermal expansion issues and prevent idiots from taking pot shots at the hyper loop.

We're currently training a team of tunneling wombats. - Casey

Do you have a curve to distance ratio calculated? For instance trains can only handle so much bend in the tracks but Hyperloop may not have any of these limitations but might be limited to centrifugal force.

Yes, this one is pretty straight forward! a = v*v/r . - Casey