SpaceX Hyperloop Pod Competition
spacex.com
spacex.com
About me: full stack software engineer with a degree in Systems Engineering from University of Illinois Urbana-Champaign. I work on classic cars and build shit with my hands when I'm not coding. I'm into efficiency, and I loooove the idea of building a better, faster cheaper CA high-speed railway.
I've designed airborne laser LIDAR scanning systems and large-scale lighting solutions. I've also done a lot of work with stress and heat management, mass electronics production and packaging.
I'd be interested in taking up a project like this and seeing how far we could go with it!
If you're interested, shoot me a message: vpsanta@gmail.com.
An "also ran" was the amusing cycloped, the only non-steam entry, a horse on top of a treadmill walking the carriage forward.
This is fascinating? Where did you come across this info?
For example the one of the first railway lines was more like a toll road. A company built the tracks, and then other companies paid to run their locomotives on them. This lead to chaos where two locomotives would meet on the single track, neither was willing to back up, and so the passengers would often get out and fight each other over it.
Hahahaha..
It would be really nice to be able to travel between nearby cities in the US without spending hours driving / flying. Flying itself is not really bad if it's not because of the time you need to waste until you actually fly.
I'm not sure which would be the more remarkable achievement, getting the Hyperloop working, or obtaining the real estate to build a mile-long test track in Hawthorne.
1. "Accidentally" crash a rocket near some properties there (far enough not to do any actual damage).
2. Wait for said property prices to crash.
Nearby El Segundo is quite a different story, which I assume is part of the reason SpaceX moved from El Segundo to Hawthorne.
I also expect that they will run the test track around their current airport campus. I'm not even sure if they need to buy all that much new property to do so. They may just need to cut a deal with (or buy) the airport.
The cool thing is that this test track should be visible from the 105 freeway (along with the massive Tesla logo). So even people not familiar with the project will be enticed to find out more!
As a Hawthorne resident, I am excited!
> In addition to hosting the competition, SpaceX will likely build a pod for demonstration purposes only. This team will not be eligible to win.
It wouldn't be fair for SpaceX to be able to win.
I've had projects before where I came up with an interesting idea but dismissed it as too costly (in time or money or what have you), but it stuck in my head. So then, well maybe I'll just do a quick proof of concept... And then, well, maybe I can hack something a bit more complete together. Eventually, despite myself, it makes it to being a fully formed thing just because it was so interesting I couldn't ignore it.
I'm wondering if the Hyperloop is going to be that sort of thing for Elon et al.
He's just commission 2-4 TBMs (tunnel boring machines, about ~$20MM/each), drop them in the ground, and have them start digging hyperloop tunnels.
http://www.bbc.com/future/story/20150602-crossrail-the-monst...
Anyways, the cost of a TBM is generally not the most expensive part of a tunneling operation.
What is the most expensive part?
$250 million for a water tunnel that goes 3km. It's simpler than a hyper loop tunnel.
Also I'm not sure Crossrail is a good counter example. That's a 30 billion dollar project to go 73 miles. Saying the TBM cost $20 million is like quoting the cost of a truck without including the price of the driver or diesel fuel.
Part of Elon's design for the pylons allows the track to remain stable even when the pylons are moved by an earthquake. Which is kind of important with pods moving around Mach 1. Doing the same thing with a tunnel requires you to have cut a large enough hole to shift the tube inside of. Which is a massively harder piece of engineering.
As with everything, there are tradeoffs. Building above ground means land use issues, and the tunnel needs to be so small you can't stand in the hyperloop pods. Building underground means more support infrastructure, but you're limited less by politics and land use problems and more by engineering.
The questions is: which is cheaper to solve? Engineering? Or politics?
Take the 1906 earthquake as an example. As http://pubs.usgs.gov/gip/earthq3/move.html says, the horizontal slip was 21 feet at one point. Something like the Hyperloop has to be designed with the expectation of facing a similar event. Concrete is simply not strong enough to hold back a wall of dirt trying to move 21 feet.
Or for more recent history https://catalog.data.gov/dataset/landers-and-big-bear-califo... where the slip was 18 feet horizontally and 6 feet vertically. And that one demonstrates that it isn't enough to build something special for every slip zone you know about. Because in a real earthquake you are likely to discover slip zones that nobody noticed.
Why does the possibility of an offset result in a tunnel being an "emphatic no" while still allowing for this pylon idea?
Search for "earthquake" in http://www.spacex.com/sites/spacex/files/hyperloop_alpha.pdf to confirm that this is a design factor the Elon explicitly considered.
How, exactly, does the pylon not suffer the same design flaw as the tunnel under the use case that you yourself brought up of a horizontal or vertical offset occuring along a splay?
If each side can move the tunnel 10 feet relative to itself without breaking, you should theoretically be able to handle up to a 20 foot slip between plates. One side bends one away, the other the other way. The pylons move 20 feet relative to each other, and only 10 feet relative to the tube.
That said, my information is based on the blueprint that Elon published and I already linked to. It includes graphs showing numerical simulations of how their design is supposed to respond to earthquakes. If you have further questions, you can start with that, then download the designs that they and others have produced and do your own work.
I am not an engineer. However I do know that engineers have done exactly what I suggested and come to the conclusion that his design is feasible.
That said, your answer is an appeal to authority. Just because a feasibility study says it is feasible does not actually make it feasible. I skimmed the document you linked and nothing in it pertains to large ground movements that would occur due to fault offset - it is all with relation to ground shaking rather than fault slip. Further, it is common knowledge, in fact, that underground structures generally perform better under ground shaking as compared to above ground structures except when the structure crosses the fault which experiences the offset. That is, tunnels work better than pylons except at the point where the large offset occurs.
I understand that you may not be an engineer. I am an engineer, with my area of expertise being in geo-structural interaction, and I am telling you that your statement about a tunnel not being feasible because of earthquakes is NOT correct. There are plenty of other reasons why a tunnel makes no sense for this job, but seismic vulnerability is not a good one. Whether his design is feasible or not is a moot point.
Secondly it is very important that the tube remain still while the pylons move relative to it. Don't forget that we have objects moving down that tube at close to the speed of sound. It doesn't take a large local kink to be a fatal problem for people inside. You really don't want that tube to move. Enough so that keeping the tube still that it is an explicit design consideration to keep it still while the pylons expand and contract for thermal reasons.
Thirdly I well know that earthquakes are generally less of problems underground than on the surface. But trading an easy problem in most places with an impossible problem at fault boundaries is hardly an improvement. That is why I have only focused on the potentially impossible problem.
Fourth, your response was just as much an appeal to authority as mine. But my appeal to authority was an appeal to authorities whose credentials are independently verifiable, whose conclusions have been put up for public comment, and which other authorities have independently questioned, criticized, and mostly verified. Your authority is based on an anonymous claim of expertise made on the internet, in a thread where you made a basic mistake about how earthquakes are measured, with no actual analysis backing it up.
Which authority is more believable?
My response is not an appeal to authority - I'm not saying "it's true because I'm an engineer". I walk you through the entire logical process, so you're free to agree or disagree with any of my arguments.
This conversation clearly isn't going anywhere so I will just reiterate my point and leave it at that: an above-grade structure will perform no better than a below-grade structure if the fault deformation occurs at the location where the fault crosses the alignment. This "potentially impossible problem" is a problem for both surface and underground structures and cannot be designed around from the structural side for the magnitude of displacement that can potentially occur in CA and, in the end, it is just a risk that has to be accepted or designed around from the systems standpoint. This is alluded to in your own linked documents and noted by the the statement:
"It is also likely that in the event of a severe earthquake, Hyperloop capsules would be remotely commanded to actuate their mechanical emergency braking systems."
I guess to answer your question: I'd probably believe me.
Have a nice day.
Make a tunnel in the ground with concrete and if the ground moves, your tunnel moves too, along with it. Unless your tunnel is stronger than the ground. Which it isn't. Or if it is, it's a 10ft diameter tunnel with 40 foot thick walls. Which is SEVERELY uneconomic.
Make it out of steel and put it in the air, and things get a lot different. The air doesn't make the tunnel move so instead of being surrounded on all sides by things which can exert force (in the ground) it's instead only acted upon by the pylons.
The pylons are supposed to be around every 100 feet. That means if the earth moves 20 feet sideways between two pylons the steel has a chance to bend and move rather than be sheared. And you can design the pylons to be strong enough to hold the tube up, but not so strong as to break the tube. So if things move a long distance, the closest pylons will break free from the tube and the tube will be supported by pylons which are further apart. That reduces the angles necessary to keep the rest of the tube on the remaining pylons which support it, and that means you're asking even less of the steel.
Sure the tube might get some bends in it that it wasn't designed for, and it might even sag down. But you can give the cars braking mechanisms that'll automatically be triggered in an earthquake so that the forces experienced when encountering these new features isn't so unpleasant.
The alternative with the concrete tube in the ground is that the tube shears into two parts which are no longer connected. That means that the tube suddenly stops and you're crashing into the dirt at 500+ mph.
Now your argument that the tube will just break free of the pylons seems like it has merit; however, the question of "why do we have all these pylons every 100 ft if we only need them every XXX ft?" should immediately spring to mind. The answer obviously lies with the rigidity of the tube between support points.
In order to get into the realm of the possibility for the steel being able to take a 20 ft offset you're talking about putting supports once a mile, at most.
Again, neither the pylon idea nor the tunnel idea have a feasible/economic engineering solution for displacement along a fault if it occurs along alignment.
Because most of the time people want to have their design include a safety factor.
Further there's a huge difference between "what this system is designed to do all day every day" and "what this system will do in the 5 minutes between an earthquake beginning and the time that the system is fully halted until repairs can be made"
Have you ever seen the remains of a power pole hanging from a power line? That would seem to indicate that there exists excess strength in the system, or that the line support structures are substantially overbuilt.
http://i2.cdn.turner.com/cnnnext/dam/assets/130601193956-15-...
I suspect that in a hyperloop you could lose 5-10 pylons in a row and what would happen is that the tube would sag well beyond normal operational parameters between the remaining pylons, quite possibly even touching the ground. The reason that so much extra strength will probably exist in the system is that there's a limit to how much deflection you can tolerate without jostling passengers too much for them to buy tickets on a regular basis. And that small deflection means that there's a lot of extra strength in the system, even though it's not strictly needed just to hold things up.
This is why machine tools have giant castings well in excess of the strength needed for the machine to stay together. It's because the Young's modulus matters far more than the yield strength or the ultimate tensile strength when you're trying to build a machine that can hold a sub 0.001" tolerance.
So if you happened to be traveling in that overbuilt tube at 500mph just after it's fallen to the ground, you'd quite likely bump (or smash) your head on the sides and ceiling of your vehicle.
But what you wouldn't do is slam into the dirt that's now at the end of the tube like you would if your buried concrete tube was sheared 20ft by a fault line.
If Elon felt that it were necessary to get his pet project done, I believe he'd make time to master civil engineering and politics to the degree that it were necessary.
Basically, he's the real Tony Stark. ;)
More likely, he would just hire a civil engineering firm. Laws throughout the country are such that you can't really buy your way into the industry the same way he has with Tesla and SpaceX. Practicing civil engineering requires licensure everywhere in the USA.
Why do people (here) feel they can refer to Elon Musk as just 'Elon' - using his first name, that is? It seems overly familiar, and impolite to me. Being from the UK, I would refer to him as 'Musk' in both writing and speech, and perhaps even as 'Mr. Musk' in formal writing. Is it a SV, or even just American, thing perhaps? It seems to depend on the person, though.
For instance, the Google founders are often referred to as 'Larry and Sergey' rather than 'Page and Brin' here, although 'Eric' was rarely used, his full name seeming to be preferred instead. Similarly, nobody would talk about 'Tim' from Apple, rather 'Cook' or 'Tim Cook', although the nickname 'Jony' is often used instead of 'Ive' or 'Jonathan Ive', and 'Jobs' more often than 'Steve' although that coulkd have been due to the possible confusion over the two founders.
In general, it seems that certain engineering icons and luminaries are granted this informal status. In a similar way to actual rock stars, perhaps because the referers feel the informality gives a sense of familiarity that brings them closer to their idols?
Platforms that generate a lot of value from APIs succeed by getting developer adoption by running things like hackathons - and this effort seems no different. Kudos.
> The capsule itself would need to be small—4.43ft (1.35m) wide and only 3.61ft (1.10m) high. No standing room
No windows, pod inside a metal tube, seats reclined with minimal head room. There's no rational reason to panic in that position, but many people will not be comfortable. Video displays might help, but only to a point.
The feeling to your body would then match the view too.
It's not clear how the hatch on a stopped pod would open between service points, if at all. So you're stuck in the pod, possibly with no lights or power either to the pod or the tubeway in the case of damage.
Rescuers have to enter at the station and travel some KM to the pod, how, by crawling? If they need a rescue pod, it would have to be lifted from the ground to the service door, so they need a crane now; that's more hours.
Then there's the small matter of air supply for passengers.
For trains, linear induction motors have usually been paired with magnetic levitation, as in the Transrapid system. But they don't have to be. Many roller coasters with a linear induction motor launch system have been built; Flight of Fear at King's Dominion, by Premiere Rides, was the first, in 1996. For a 1-mile test track, outsourcing the whole job to Premiere Rides or Intamin would be a good move. Intamin, which mostly makes amusement park rides, also has a transportation division. They build monorail systems. Intamin would just have to combine the car design from their P8 monorail[1] with their linear induction motor launch system.[2] By Intamin standards, a fast 1 mile loop with no hills is easy. ("We can put in a vertical loop for a small extra charge...")
[1] http://www.intaminworldwide.com/transportation/Home/news/Sha... [2] http://www.intaminworldwide.com/amusement/RollerCoasters/LSM...
In the UK each 11 car train on the West Coast Mainline can take about 600 passengers seated + maybe slightly over 100 more standing. So around 700. We have 3 trains per hour between London and Birmingham, which adds up to a rough capacity of 2200 per hour.
This doesn't even take into account the multitude of slower trains that go between the two cities.
All these trains are generally congested as hell at peak (and increasingly off peak).
How is 840 passengers/hour enough for two big cities? I would assume making each pod bigger and heavier would require a greater stopping distance between them so the only way I can see to add more capacity is to build parallel hyperloops. At that point you've got the land take and the expense that comes with it.
Just doesn't add up.
It's also assuming that the demand at a cost of $20 and 35 minutes will be roughly the same as it is now.
http://www.spacex.com/sites/spacex/files/hyperloop_alpha-201...
It strikes me that this is a pretty good insurance policy against a poor implementation of Hyperloop being used as an argument against its feasibility. SpaceX/Musk gets to put out a proof of concept track and pod without committing to building the full thing themselves.
[1] https://mdao.grc.nasa.gov/publications/AIAA-2015-1587.pdf
[2] https://github.com/OpenMDAO-Plugins/Hyperloop
[3] http://www.popsci.com/hyped-up-startups-race-hyperloop-life
Only if the vehicles are self propelling from the ground, and if you refer back to trains really they are just pushing air in front of them, with some air escaping past them.
If there were not ventilation systems to allow the air behind the train to be filled, the train would need to work harder to essentially pull the air behind it.
At least, that's my understanding.
If the vehicles are not self propelling from the ground, and propel with air, like the original hyper-loop proposal, they are actually pushing air backwards to their direction of motion, which would stop any such forward moving air flow develop.
I would add a pod decompression, and the emergency braking emergencies. Common oxigen masks don't work above 50000' and you can not dissipate the kinetic energy of a pod traveling at 900km/h just by friction without a brake fire.
Sure you can, just use water stored onboard to cool the brakes. Obviously the only case when you would need to use friction brakes in the hyperloop is in an emergency so we're fine with just boiling away the water into the steel tube. It takes 2,261 KJ per kg to boil water in the vacuum of the tube and assuming a pod weighs in at 1000 kg and is travelling 300 m/s that gives us 45 MJ of kinetic energy to deal with. That comes out to just under 20 kg of water to stop a 1000 kg pod moving 300 m/s. That's a decent size tank when considering the form factor of a hyperloop pod but still doable.
Webpage screen grab [0]
Guidelines [1]
[1] https://drive.google.com/file/d/18IkkbuxMbrzaVKHRnqXqtWimxF5...
what does that mean? Didn't they come up with the idea of hyperloop?
> You cannot participate in the Contest if... you are a current employee (including intern), contractor, officer, or director, of Google or its affiliates.
It seems like the strength of the Hyperloop is extremely fast travel over long distances. Personally, I think having a line between Las Vegas and Los Angeles would be awesome, as the traffic can be horrible on that route, especially on weekends and probably significantly affects traffic in LA in general. Its also around 100 miles less than the LA to SF route, through mostly undeveloped desert, so it could be a lot cheaper to build.
For the Hyperloop to make any sense in a shorter distance metro setting, you'd probably want to have no stops between where you start and your destination. (So you might go directly from Anaheim to Santa Monica, for example) With smaller cars/trains, this may be possible (since you might be able to fill trains quickly enough to not make people wait too long), but potentially very expensive to build enough lanes to manage that amount of traffic with greatly varying speeds efficiently.
Without that sort of system, however, I think the additional stops would delay you so much that the gain over a traditional metro train would be small and not worth the extra expense of building it.
No, which is why it's strictly city-to-city. It's supposed to compete with short haul point to point airlines. Those don't have neighborhood stops either.
San Antonio <-> Austin <-> Dallas
Houston <-> Dallas
House <-> San Antonio
At an average speed of 600mph, it'd be about 25m commute between points, worst case.
I thought Elon wanted to create the Hyperloop. Here I was thinking I would see it in the next 5-10 years :(
Aside from that, very cool!
SpaceX and Elon Musk are behind this competition.