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Ask Slashdot: What Would Happen If a Hyperloop Train Failed?
dryriver writes: I've been following Elon Musk's Hyperloop initiative with great interest. The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary. I'm glad that somebody is trying to innovate in the area of land travel. My question though: When conventional trains going at much slower speeds derail or crash, the result is often serious injuries or deaths. What happens if something goes wrong with a 700 MPH Hyperloop train/pod or with part of the track? Would a Hyperloop accident at that speed even be survivable?
This is the 21st century you white cisgendered Trumpist-pig.
There's no such thing as "failure" and the HyperLoop would simply get a participation trophy and be placed in the protected trans-functional class where you can't criticize it.
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you will die. really no ifs ands or buts about it.
have you seen my sig? there are many others like it but none that are the same
They tend to stop very quickly when they hit something.
I should think a hose and shovel should do the job nicely.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
The only way that Hyperloop could possibly fail would be if it didn't generate spectacular returns for investors.
https://www.youtube.com/watch?v=RNFesa01llk
Thunderfoot has done a series of videos on this topic. Even if you assume you could make a HUGE 99% perfect vaccuum with that volume of air; any failure causes its occupants to get exploded out the end somewhere. Lots and lots of energy in that system.
Musk didn't invent the concept of the "hyperloop." The idea appeared in Popular Science/Mechanics in the 1980s, with the train moving through an airless tube at 14,000mph.
Because even if it derails it has enough momentum to still reach its destination. Granted it might bring a long a few unintended payload items, such as some cars and city buses.
Ok since Hyperloop is presurised ( no air in the tube ) if there's a leak its easy to detect pressure will drop rapidly so the train or pod will be forced to stop or at least decelerate since with air in the tube it wont be able to maintain its 700 MPH speed. So the tiniest leak should be pretty easy to know. Then its easy to stop the pod before something fatal happens. If the failure is mecanical well then it all depend on how they designed the thing to do. I suspect that there will be redudancy on all key systems and parts that are vitals. ( second sets of wheel in case primary fail and so on ) im pretty confident it will be safer than a train can be. Don't forget the environment is crutial for hyperloop so it will be monitored much closely This is not the case with a train. At the same time tho I dont think youll be spared anything you have in an airport. I mean an explosion would be as much devastating in a hyperloop than in a airplaine... can you imagine an explosion at 700 MPH how far would the debris goes!
It doesn't need to be perfect, it just needs to be better. This is pure speculation, but given a Hyperloop vehicle's more limited range of motion, and new infrastructure it should be more reliable.
Similarly, what if the vacuum failed and the pod stopped in a low pressure section pipe in the middle of nowhere. The only way out if to wait for someone to figure out the exact location of the pod and cut you out. I've yet to see an estimate for how many hours (days?) you might be stuck in there in pitch blackness, likely getting cooked inside a metal tube sitting in the sun.
Its this new fangled technology they call a HATCH DOOR every XYZ meters.
Crazy tech.
If the ground shifts above ground, you get a derailment. If you are in a hyperloop, seems like it would be full-stop - 600 to 0 in a millisecond.
If it is survivable depends on how it fails. Like in aircraft, some accidents are survivable.
Trains derail because of a century-old standard makes them very badly attached to its rail. If you run into a tube, even if the tube cracks a bit, there is a good chance you still continue in the same direction the same way I can run peas in a straw with crack. I don't think catastrophic can't occur. I just think it's inherently more secure to run in a 360 degrees boundary tube than 2 littles track with no grip else than your own weight.
IF the system started to have a slow leak the pod would have time to slow, air resistance would do it naturally if nothing else.
Also it's not like it cannot have basically "landing gear" that would be able to slow the pod from 700 MPH in the perfectly smooth sealed tube in the case that a real breach presented itself - but you do all realize that a pressure breach would not be instantaneous across the enter length of the tube, right? Then we are back to the case where pressure changes can be reacted to and the system brought to a gradual halt.
I sweat Slashdot has become a bastion of luddite nut-jobs, who seem to purposefully ignore physics. Shameful to see such a virulent example of this on the home page.
You all sound like the people who wouldn't get into the first automobiles... or modern day Amish who still will not, but at least the Amish people are generally useful.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
We don't know what will happen because it hasn't been engineered and built yet. Determining how it handles various types of failures will certainly be part of the engineering process. Worst case scenario is everyone dies, which isn't much different than a plane crash. But just like with a plane, plenty of fail safes will be there to allow for managed failures. Most catastrophic failures will probably just cause the train to come to a gradual halt.
-- All that is necessary for the triumph of evil is that good men do nothing. -- Edmund Burke
Just wow...
The only way out if to wait for someone to figure out the exact location of the pod
So you don't think they will know this every second why again???
Even if they didn't have sensors lining the tube (which is obvious) they would know the departure time and velocity until system failure.
I've yet to see an estimate for how many hours (days?)
How long does it take a car to drive from one endpoint of the hyper loop to the other? Hint: in all the proposed routes I've seen that's like 4-6 hours - from the ENDPOINTS.
All they would have to do is simply deploy a normal electric vehicle to drive down the tube and bail everyone out. Which, by the way, the pod itself would probably be ANYWAY so it would simply complete the journey at a slower pace.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
I know that the /. crowd has moved to twitter length replies these days, but how about a real discussion?
There are plenty of failure modes that would be completely survivable, in fact with little or no chance of injury. Tube loses vacuum? Unit slows down and stops. Loss of mains power? Same. Capsule loses pressure integrity? Masks from the ceiling time.
Yes, a catastrophic failure of the tube structure could result in deaths, but I can see the emergency shutdown being engaged system wide in such a case, resulting in only a few affected capsules/trains. Mind you, there are advantages to the many capsules/fewer passengers per capsule. A single failure is unlikely to approach aviation disaster numbers. Wiki Aviation Accidents.
Most of the risks are similar to high speed rail, and those seem to have been well mitigated by current operators in Europe and Japan. Now, the chances of the system getting built at all? I don't see it surviving contact with investors, incumbent system operators or property owners.
It's not just resting on a rail, it's enclosed in a tube. There is no interaction with other modes of travel, no RR crossings in which to hit cars, busses Trucks etc. Similarly no Slow moving Cargo trains sharing the track (at least at this point, if successful I could see that changing.)
Not sure of the mode of propulsion, if maglev, and it loses power it lowers onto wheels on the tracks and rolls to a stop. If just floating due to the vacuum pressure in the tube it will still have wheels to drop onto when not traveling at speed.
And it should be fairly straight forward to insert a pusher car to get it to the next station or just open emergency ports on the tube letting in air for the occupants and providing a route to exit the system. I'm sure there will be some risk but the question reads like it's trying to put the risks of standard trains onto this very different system.
Actually it would be quite safe.
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The share price would go down.
This isn't an unrealistic question. I remember reading in my history class that some people thought that traveling on a steam locomotive that went faster than 35MPH was unsafe. A fast horse, in comparison, could travel 30MPH. All kinds of weird things could happen to the human body if it traveled faster than a horse. Those fears weren't put aside until it was proven that it was safe ride at faster speeds.
That's ok, I'm game to start one. First we need to define the hyperloop as a system.
Next, we imagine, and list all of the possible failure modes for each one.
Rapid depressurization
Rapid depressurization
Thermal event
Explosive event
Then we discuss the effect of each failure mode, and steps that can be taken to mitigate it... Completing an FMEA usually takes hours in meetings with large numbers of engineers brainstorming all of the possibilities.
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
Bunch of people die or get hurt. Lawsuit, lawyers get rich. Life goes on.
- Gradual vacuum failure: Increased drag/resistance, system sensing and ordered shutdown, survivable but recovery will require process and equipment.
- Instantaneous vacuum failure: caused by or accompanied by tube failure/deconstruction - collision and rapid dissection of the capsule, probably not survivable for all passengers.
- Instantaneous maglev failure, loss of suspension: Probable contact with tube, friction or impact force causing tube or capsule failure, probably not survivable for all passengers.
- Gradual maglev failure, loss of suspension: Possible loss of propulsion, slowing, probable contact with tube, friction or impact force causing tube or capsule failure, probably not survivable for all passengers depending on speed.
- Maglev malfunction, loss of speed only: Survivable, unless suspension is dependent on same system as propulsion.
It's actually not very promising to me. the speed does make survival unlikely, but there are several failure regimes. Some are catastrophic, some not, but in practice all may be catastrophic, and that's not good.
Imagine, California, the most difficult state regulatory environment, being host to this?
deleting the extra space after periods so i can stay relevant, yeah.
It would make Hypergoop.
The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary.
You'll still need to suffer through the Hyperloop terminal and security similar to airports. There's no way TSA will allow people to just walk onto a system like this without screening. Even a fairly small bomb would kill everyone onboard.
probably about the same as what happens when a plane fails.
2cents
j
Ask a Medical Doctor in 1820 what would happen if a steam locomotive crashed... all manner of mayhem, injury and likely death - that's what the experts all said. Falling off a running horse is bad enough, but the speeds that are possible with rail transportation are far worse.
Each individual hyperloop pod has far fewer people in it than a train, so the most important consideration is to limit damage to one pod. I guess in an emergency you can brake a pod at maybe 2g which means you'd want them at least 2500m apart. Probably round up to 2 miles. You can get braking either from ablative skids on the bottom of the pod (I saw this design in an other context) or by releasing the vacuum and air-braking.
So compared to a train crash, there may be more damage, but to fewer people.
As to what happens to an individual pod, it depends what the problem is. Non-explosive loss of vacuum, or loss of magnetic levitation should result in the pod braking to a stop -- might be bumpy, but shouldn't be fatal. The pod coming apart in some way, or getting spun around so it "wedges" against the tube would be pretty ugly, as would any large foreign object managing to arrive in the tube or anything that knocks the tube seriously off straight just before a pod arrives, but these don't seem too likely.
We now have video of crashes at 200+ MPH. Tell me those look survivable.
Worst case scenario is everyone dies, which isn't much different than a plane crash.
Evidently you aren't aware that 95.7% of surviving an accident in a plane. The vast majority of people actually do survive. When the National Transportation Safety Board studied accidents between 1983 and 2000 involving 53,487 passengers, they found that 51,207 survived.
It's unclear what the statistics might be for hyperloop but assuming instant fiery death is probably not going to be correct for the majority of failure modes.
If you wanted to cause some economic/real terror you just shoot a piece of aircraft cable diagonally through the tunnel. The car arrives in the station sliced in half. The same thing happens to your investment in hyperloop.
SD
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do the math
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Hatch doors... which would be separate failure points along the way for the pressure difference to be changed.
Assume perfect seals and no malicious or accidental misuse of even a single hatch door. A tech team is sent out to to assist the passengers in getting out. You can't just open the hatch, you've 14.7 lbs of pressure per square inch trying to keep that door closed, assuming it swings out. Now you've got to pressurize either the entire system (so largely shutting it down), or the particular leg you are on. How long does this take? Now how long does it take to undo these steps?
Short of a 9/11, when there is an airplane crash, even an entire airport (or state) is shut down due to weather, the rest of the system keeps going.
This also aside from all of the issues related to thermal expansion & contraction of the materials, making the sealing even more difficult.
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I came across this Reddit discussion for their entry in the hyperloop competition. It includes a spreadsheet and comments about various failure modes and mitigations. page 1, page 2.
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Most airplanes that crash don't fly straight into the ground at 700 mph. Things like lift and air resistance come into play.
A hyperloop that lost a couple of struts wouldn't have those saving graces.
700 mph to 0 is heading into Mythbusters 'let's try to flatten this car to the width of a quarter' territory.
* citation needed
Factors: what's the size of the failure, and where on the track in relation to the pod does the failure occur.
I suggest you never ride BART between San Francisco and Oakland, as the Transbay Tube is 135 feet below sea level under the bay. Unlike the Bay Bridge above it, the Transbay Tube survived the 1989 earthquake without incident.
https://en.wikipedia.org/wiki/Transbay_Tube#Earthquakes
"We can't even keep pressurized OIL pipelines from leaking. How the hell do you VACUUM pressurize (way harder because air has no viscosity compared to thick oil) MILES of much ... We can't even keep our car tires from rupturing."
A hard vacuum is on the order of 15 PSI/100 kPa - atmospheric pressure). Tires usually have at least twice that, and are also exposed to mechanical shock and other hazards during normal operation. Oil pipelines can operate at hundreds of PSI ("708 psig is considered "moderate" for oil transmission lines. Some pipelines can run at slightly above 1400 psig...")
There is no real comparison between that and maintaining a vacuum.
"super-high-speed machines, in a pure vacuum" Oh, you're just ignorant of the technology. Hyperloop will operate at very low pressures, not in a hard vacuum - it's part of the design, since the trains will be supported by air bearings.
But, who in their right mind would replace a horse and buggy with a mechanical machine which is propelled by explosions and can go so fast that it will suck the air out of people's lungs?
"National Security is the chief cause of national insecurity." - Celine's First Law
Given all the objections people have about the length of vacume sealed tube, what about building a wind tunnel instead?
Even if one could "only" get a 100 km/h wind tunnel, that would be a fairly massive reduction in air resistance for the vehicle moving through it.
Likewise, what about using a reduced pressure environment instead of vacume? Say, half an atmosphere or something. Combine lower air density with a wind tunnel, and There would be significantly fewer risks than a total vaccume system. Also has the built in safety factor that if something manages to block the tunnel, that stops the air flow, which starts slowing down the vehicle.
Also, in terms of security, build the whole thing underground. And by that I mean a good 50m+ underground. Probably not great in earthquake areas, but for the rest of the world, it would prevent all sorts of security and accidental type problems.
Also, in terms of safety: It isn't traveling on an old fashioned railways. Those things have horrible attachment between the train and the tracks. Little more than gravity and a couple cm of steel edging. North American railways were built to standards designed around 19th century technology. There are a lot of places in the world (such as Japan) that show what can be done with trains when one upgrades the track to something a bit more modern than steam engines. Much, much safer.
And at the end of the day, no matter how dangerous it is, it will still be safer than driving a car.
Until our robotic overlords show up and remove "driving" from the list of activities that us humans are allowed to do, anyway.
Z
This is as much a terror-target as an airplane and may even be more vulnerable. Expect 3 hours or more for security-theater when using the Hyperloop.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Richard Hammond was doing 288 mph... That said, hyperloops look like death traps to me.
Air fills the vacuum at the speed of sound.
Yes, exactly. Sound is not all that fast (six seconds to travel just a mile), mostly the pod would be so remote from the source of the leak it would have plenty of time to slow down to a reasonable speed before substantial pressure reached it. Also if we are talking about small leak its not like it would INSTANTLY be a huge volume of air in front of the pod, it would be a gradual loss of vacuum and therefore simply not the "wall of air" you are scare-mongering about.
And of course, the leak would have to occur in front of a moving pod instead of behind it to even be that much of a potential danger...
A wall of air hitting you at that speed would likely kill you.
Not at 70MPH instead of 700MPH, you blithering retard.
Also I've not seen any arguments for why emergency vacuum pumps placed along the tube would help eliminate the danger from common leaks? But you didn't even think that far you were just like YABBER YABBER YABBER FLOOM DOOM!! *throws hands in air and waves frantically like muppet on acid*
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Trains are hundreds of tons and carry immense amounts of momentum and energy. A hyperloop pod would be very light, possibly weighing much less than the cargo it carries. Even airplanes are not a great comparison as they are orders of magnitude bigger and heavier than a pod. Some other fundamental differences, the pilot is not on board in a pod, a pod does not carry it's fuel. Pods will be MUCH safer for the area around the crash, and MUCH more dangerous for the passenger/s. Of course an accident could be survivable, and highly dependent on the type of accident: slow depressurization of the tube, you will slow down and be fine. blockage in the tube or fast depressurization, you will explode.
It's how fast you stop not how fast you are going that matters in accidents. You just have to have a longer amount of time to come to a complete stop. Slow deceleration = walk away. Fast deceleration = ketchup
Trains
Increased weight so a panic stop would require a mile or two of open track.
Multiple cars so effects like oscillations and jackknifing are an issue
Track open to sky so debris and weather are a factor
Tracks run both ways and there is also passing of priority trains using sidings.
Hyperloop
Low weight but high speed so a panic stop would still require a mile or two of open track
One car at a time so more individual trains to account for at a single time
Closed system that needs to be maintained to achieve the low pressure
Dedicated one way tracks make routing easier
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Ever see what a shockwave will do to equipment and human bodies?
Look at nuclear bomb tests again. Watch the shockwave there.
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THANK GOD!!!
Perhaps a more salient question is sabotage.
Explosive charges attached to the tube that detonated five seconds before the arrival of a pod would likely kill everyone on board.
The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary.
The idea that you won't have to suffer through the same "security" theater at the hyper-loop port as at the airport is naive. There may even be more as the train routes are, by their nature, fixed so any on-train incidents could be timed to inflict specific ground targets. In addition, unlike destroying a plane, destroying a hyper-loop train would also affect the actual infrastructure. So, enjoy your cavity search.
It must have been something you assimilated. . . .
Jump Sim. jump!
I would hope that if a capsule were stuck in the tube, they would have already shut it down.
Exactly. They would turn it off -- pressurize, and blow hatches for people to escape.
I suspect that if the vacuum failed at the moment the pod was drawing near, it would feel more like hitting a big air cushion, like at an amusement park. Not fun, but not fatal. We're talking about a multi-ton carriage with relatively small frontal area. If the rupture occurred further on down the line, the effect would be less violent, because in a tube, you're going to get a pressure gradient, not a "wall" as most people are describing it. Ironically, if the rupture occurs behind the pod, it would probably have no effect at all, as the pod would be outracing the pressure wave, and if the pod happened to not be traveling at full speed, the air would be trying to accelerate the pod, not slow it down.
Which has more power: the hammer, or the anvil?
The space station's pressure, such as ISS, is kept at sea level (kind of surprised, but...). That means that you have 101 kPa of pressure differential, on THIN ALUMINUM.
Seriously, all of the space stations have had leaks. Most were caused by micrometeorites that hit them. How many have blown apart because of that? NONE.
For those that are claiming that hyperloop will blow up, note that the tubes will actually be STRONGER than any of the stations.
And for those claiming that physicists are saying otherwise, I would suggest that they are NOT working in the field since they are too stupid to know.
I prefer the "u" in honour as it seems to be missing these days.
only 10% - passengers and cargo. It is a different story with a vehicle in a tube. The tube is kind of a part of the vehicle.
What would happen if a jet were to fail? A hundred people die in the crash. A few people will never fly out of fear. The majority will say, "Meh, it's still safer than an automobile".
I am not a number - I am a free man!
The hyper-loop is basically just a conventional mag-lev train in an evacuated tube. ... it's hard to imagine how that could happen without a damaged track or a collision with something (tough to do in a sealed tube). ... you slow down quickly but not catastrophically.
I've never heard of a maglev train derailing
Blow a hole in the tube(anywhere the train isn't ) and the train slows down(since the vacuum required for the very high speed is lost quickly, but not immediately in the form of a sudden wind.) pressure sensors notify the train controller who slows or stops the train if necessary (ie: if the breach is ahead of the train). This would be like running a car at high speed down a slope into water
Realistically it would take well timed deliberate action, or a freakishly unlucky circumstances to cause a "crash" ... eg: significantly damage the tube structure close enough to an oncoming train to prevent the automated safety systems from reacting. In such a case people in the proximate and trailing cars are likely to die.
"The company hasn't even engineered a prototype much less built one."
Sure they haven't. You're the one spreading FUD, you must work for an airplane company.
https://www.youtube.com/watch?...
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Pretty much the same result as if your airplane would fail.
space stations prove that you do not know what you are talking about.
I prefer the "u" in honour as it seems to be missing these days.
Thinking about possible means of failure reminds me of Heinlein's The Roads Must Roll. Can't forget politics as a possible failure point.
https://www.youtube.com/watch?...
" The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary. "
IF the Hyperloop ever became operational ( not in our lifetime ) it would most certainly suffer from the same security theater that plagues airlines today.
The same lines, the same screening and silly restrictions / rituals, all the same fun will be applied in order to keep us " safe ".
Thus, while the mechanism to move us from point A to B will differ, all the shit we loathe about the current system will most certainly be there for our continued enjoyment.
The airlines themselves will push for it because " fairness ".
It will quickly become just as horrible an experience as flying is today.
There are probably scenarios in which the pods will need to be brought to a controlled stop in the tube; much as airliners are held on the ground, or (less common today) put into a holding pattern. I'm thinking that automatic detection of some parameter (tube vibration, air pressure, temperature, who knows) being out of spec will be pretty common; less commonly some catastrophic failure far ahead of you which you can survive if you stop where you are.
What I didn't get from any of the pod diagrams I've seen is any kind of emergency egress from the pods, if the pod is stopped at an arbitrary place in the tube. At the front the entire diameter is occupied by the compressor fans, the rear is entirely occupied by mechanicals. Possibly the latter has enough design flexibility to allow an emergency escape into the (re-pressurized) tube.
And how long would it take for rescue personnel to arrive on some kind of transport? Today people freak way out when their 737 parks on the taxiway for more than a couple of hours--and that's under conditions where you can walk up and down the aisle, use a bathroom and look out the window, and where there are uniformed staff to provide some semblance of of service and (psychologically important) nominal authority. In a pod you're stuck in your seat, with random strangers, maybe in the dark, as the heat builds from the sun on the tube and the now-unfanned mechanicals.
One of the things that always raises a red flag for me is when someone asks a what-if for a particular scenario and the answer that comes back is about the low risk of that scenario developing. This means to me that there is no contingency for the scenario, and, worse, that this fact is being avoided. Admittedly I have not been following the details of hyperloop design, but in the first big hype, I remember a lot of "this is how we made failure really unlikely" and the plan that in the worst case, a pod would just glide slowly, in a fully re-pressurized tube, to the nearest emergency station, where the tube wall could be opened. So there was an explicit denial that a pod could ever become stuck, stationary, within the tube.
Let's hope that by the time these things are built there's enough left of the regulatory agencies to put some critical thinking on it.
S.
If a hyperloop lost a couple of struts, all the vehicles would initiate an emergency stop, meaning that you'd only cause fatalities if you caused catastrophic damage to the tube right before a pod passed through it (leaving no time to stop).
Hi I agree there is a risk in traveling in a "hyperloop", just as there is in flying or walking across the street. I think this topic is a great point. I think that if there is a crash with many fatalities, all the hyperloop's in the world will be shut down for a while, and a certain percentage of people will be afraid to travel in them. Of course, thousands of people die in U.S. freeway crashes each year, but we don't shut them down and most people accept the slight risk of traveling on a freeway. Tom
We could perhaps use hyperloop for perishable fruits or same day packages. Removing humans would remove a lot of the logistical and safety concerns.
when I was growing up, they built the 747. I knew ppl that thought they were experts swore that these would come crashing out of the sky because they were too big.
Amazing how stupid some of these ppl really are.
I prefer the "u" in honour as it seems to be missing these days.
Space stations are not a HUNDRED MILES LONG. And they cost BILLIONS for the relatively tiny machines they are to ensure they don't leak and kill the HIGHLY TRAINED crews--as opposed to a bunch of fat families going to Disney Land.
Is everyone left on this site a complete retard? Does anyone have professional engineering experience on their belt?
It's not an issue of SMARTS. It's an issue of PHYSICS. You can't outsmart physics. You can't make a car get 200 MPG and have it weigh 3,000 and shaped like a normal car. No matter how many people and billions you spend. The hyperloop is technologically COMPLEX multiplied by HUGE LENGTH. Those are two factors that DO NOT MESH.
The above comment has been rated -1 Too Truthful for Slashdot.
Screw my active professional experience as an engineer. WE WANT THIS SILLY THING TO WORK. Fundamental physics don't exist. We can send rockets into space for a $1, if we only have more smart people on it.
If you think this practicing engineer is stupid, and you're ACTUALLY an unbiased, open-minded person. I dare you to simply Google "hyperloop won't work / busted" and watch some videos on YouTube.
What's next, Slashdot pretending solar roads are possible--completely ignoring the scientists and engineers screaming "it won't work!" (Google eevblog solar road.)
All involved most likely will die. That is no different from airplane crash. One downside is that such crash would also render track closed for many days if not weeks and would disrupt travel plans for many. Another big issue would be hyperloop infrastructure vulnerability to terrorist attack. Unless the track would be underground (unlikely due to cost) the whole length of the track would have to be guarded in a very detailed way 24/7. Very costly and difficult task. Even small bomb would be lethal when exploded just before the incoming train.
"The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary..."
Since you're quick to dismiss the suffering, care to tell me how Elon's solution would get rid of the TSA and all other forms of pain-in-the-ass security screening that "jazz" up airports today?
I missed have missed the part where terrorist risks and unending government waste were magically eradicated from this form of travel...
It is not a crash at all....
Just an 'rapid unscheduled disassembly'
Imagine liver sausage on a mass scale. That's what.
* Carthago Delenda Est *
No no, just pull the ejection cord... parachute to safety.
Hatch doors... which would be separate failure points along the way for the pressure difference to be changed.
Oh calamity, how would someone contain the whopping 14.7psi differential.
you've 14.7 lbs of pressure per square inch trying to keep that door closed
Do you? Ever noticed that the pressure inside an airplane is higher than that outside while cruising, yet you have all that pressure *preventing* you from opening the door on the inside?
This also aside from all of the issues related to thermal expansion & contraction of the materials, making the sealing even more difficult.
Vacuum expansion breakers are a thing. Not a new thing. Not even a fancy thing.
Best to let the trained engineers solve the engineering problems.
There are no windows, it's not going to be a natural experience traveling inside the vacuum tube. Not that jet travel or flying is a natural experience but our ability to look outside helps us "ground" ourselves. It's going to be more like submarine travel. You may not even know if you've stopped moving. Oh, and why would you think this is going to be any less wretched than flying? A bit off topic, I know.
Honestly, the epic accidents aren't that interesting. You die. The end. What's more interesting to me is the question of the basic regular failures. Let's say a section of track shuts down causing the tube to jam. The people don't die right away, as the vehicle just slows to an abrupt stop. But then what? With a train, at worst, everyone exits and loads up onto buses and taken to the next station. Even in a train tunnel there is ample room for emergency exits. The Hyper Loop thing is in a tube, and there is no way to get the people out. Do you cut a hole in the tube to remove people? That would shut the entire system down for months (potentially) for repairs.
We know from submarines that small, or large leaks will not just cause the tube to implode.
We also know from multiple particle accelerator small, medium and catastrophic failures that the tubes won't implode.
Kind of like explosive decompression on airplanes in movies, this is based on fiction, not already proved scientific facts.
As for the train/pods, most of the air flooding in would go around the train. In Hyperloop 1's design the use a Maglev system. You are talking about the mass of wind vs the mass of the train and the force of the Maglev. The wind is not winning there. Even if you are talking about Elon's original proposal, the air pods would probably have enough compressed air to gently put down the train.
Microsoft, Apple, Google, Amazon what's the difference? All steal money from devs and control with walled gardens.
You can't just open the hatch, you've 14.7 lbs of pressure per square inch trying to keep that door closed, assuming it swings out. Now you've got to pressurize either the entire system (so largely shutting it down), or the particular leg you are on. How long does this take? Now how long does it take to undo these steps?
Airlocks? If you need to pressurize a section, close the nearest section before and after. How small you'd make the sections would depend on the cost, but I'm thinking your basic airtight steel door shouldn't cost that much. And once you've resolved the problem and the section is re-sealed you can let the air flow back in the tube and have vacuum pumps all along the line work together to restore operational pressure. Here's an estimate using 200 vacuum pumps for $15 million to depressurize 600km, initially it's 3-5 days. If we say one door every 6 km it should then take about an hour to re-pressurize one section. And if you work the other pumps up front so you have a stronger vacuum than needed then even less.
However, an alternative might be to have an actual airlock to let it run in degraded mode until you got a maintenance window, basically two doors the size of a pod apart. The pod comes to a halt, one door closes and the other goes up. It would incur roughly the same penalty as a station stop plus a little more to traverse the defective segment, but you're not dead in the water. To be honest as long as I'm getting an end-to-end ride I'd probably be happy, the worst if you say planned to take the train but end up doing part train, part bus, part train to get past a broken segment.
Live today, because you never know what tomorrow brings
The short but honest answer is "It will depend"...
The longer and slightly more complicated answer is to observe that there are all sorts of different ways that the Hyperloop design, as explained, could fail. Examples include things like gradual pressure increase within the conveyance tube [loss of vacuum], collisions [between a moving capsule and a stationary one], contact-leading-to-damage [for example between a capsule and the conveyance tube], and so on.
A complete and thorough answer to your [entirely valid] question would require far more time and space than slashdot typically affords us. Suffice to say that there are some excellent engineering disciplines and practices that have been developed to answer precisely the question you have asked. It is highly unlikely that us mere mortals would ever get visibility of the results of that analysis, but it is entirely to be expected that the relevant Federal/Government regulator will do so. A common framework [but by no means the only one used today] is FMEA - Failure Mode and Effect Analysis.
Readers may be interested to note that in the aviation industry, for example, each airline prepares and publishes their own Operating Procedures, Safety Manuals/Training and ensures the relevant level of awareness among employees, contractors and clients [passengers]. I do not know for certain, but suspect that this model is done from a liability perspective - if an airline followed government-mandated safety procedures [or aircraft manufacturer supplied procedures] to the letter, but an accident occurred, then in any subsequent investigation or challenge regarding legal liability, the airline would try and argue that they met every requirement made of them. Instead, by making the airline responsible for developing and following their own practices, the regulator carefully avoids ultimate authority for any failure of process design... Given the highly litigious nature of the modern world, it is likely that the safety procedures and operating practices of any commercial Hyperloop solution will be designed and implemented by the Operator, ideally with some form of Federal or governmental oversight.
You poor soul.
What makes you think you are doing to avoid the TSA taking the hyperloop train?
The only reason the TSA isn't patting down passengers on trains or searching your baggage is they are not big targets. If the hyperloop thing gets popular enough, they (the TSA) will show up and slow the process down..
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
The idea that you won't have to suffer through the same "security" theater at the hyper-loop port as at the airport is naive.
The idea that you WILL have to in a system controlled by Musk is far more naive.
Not to mention the security would be far more like a bus station than an airport. You can't hurt anyone in a pod any worse than you could hurt people in a bus if you wanted to. Have you BEEN to a greyhound station? Of course you have not.
Heck, you can even potentially drive a bus into other people or buildings, Can't really do anything with a Hyperloop pod except kill the people inside, and you could have killed a LOT more people outside with less effort.
The whole fantasy of terrorists attacking hyper loop pods reveals Slashdot luddites at their absolute unthinking ignorant worst.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Ol' Muksy would tweet about it, regurgitating a report from the actual engineers as if he understood it, while promising to fix it in the future as if he did any fucking work on it, regardless of what company it happened to or whether or not he was involved in the project.
They would fail to get more funding.
All this thing is designed to do is to suck money out of public grants.
Money that could go to fix our crumbling infrastructure. A single hyperloop route from LA to Chicago couple probably build regular light rail infrastructure for a dozen cities.
Of course the rich politicans that fund these things would never be caught dead on public transportation.
I'm a good cook. I'm a fantastic eater. - Steven Brust
Explosive charges attached to the tube that detonated five seconds before the arrival of a pod would likely kill everyone on board.
You could say something similar to that about every form of transportation including trains. Yes it's possible to intentionally kill someone. News at 11...
... fail?
It little behooves the best of us to comment on the rest of us.
It depends on the kind of failure. I am sure that the designers will make every effort to make the more likely failures (power loss, reasonable or minor track damage, etc.) survivable. You won't ever have many of the risks associated with conventional trains (inattentive conductors, cars or other obstructions on the track, excessive speed for the track, etc.) That said, if a terrorist blows up the track just short of the train in motion (less than stopping distance) you are very likely going to be red paste in the wreckage.
Compare the risk of death in an airplane:
loss of power - very likely everyone dies unless there is a runway nearby
any failure that causes loss of control - everyone dies
etc.
The main problem I see with the hyperloop is that in this era of terrorism, it is virtually impossible to secure hundreds of miles of tracks, whereas airports are fairly well secured, and planes are immune to terrorist attack from outside while in flight (so far terrorists haven't managed to design and build stinger missiles, fighter jets or SAM missile batteries.)
If you disagree, please post your argument. (-1, Overrated) isn't your personal censorship tool for views you don't like
The tube would be a vacuum. In order to leave the pod you would have to open a hatch which would suck all of the air out of the pod then walk through the dark, mostly airless pipe looking for another hatch to the outside which when opened would blow air rapidly into the pipe until the air equalizes. Granted "temporary air" canisters can be provided, and an "emergency stop" system can be implemented that automatically breaks the vacuum in the pipe. This is not an impossible problem to solve but a "hatch ever xyz meters" is an over simplified answer to the proposed issue.
The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary.
Not to mention naive - with criminals blowing up people on the London Underground from time to time, it seems likely that we will end up going through the same sort of security checks in a high-profile mass transport system like the Hyperloop.
Hatch doors... which would be separate failure points along the way for the pressure difference to be changed.
Assume perfect seals and no malicious or accidental misuse of even a single hatch door. A tech team is sent out to to assist the passengers in getting out. You can't just open the hatch, you've 14.7 lbs of pressure per square inch trying to keep that door closed, assuming it swings out. Now you've got to pressurize either the entire system (so largely shutting it down), or the particular leg you are on. How long does this take? Now how long does it take to undo these steps?
Short of a 9/11, when there is an airplane crash, even an entire airport (or state) is shut down due to weather, the rest of the system keeps going.
This also aside from all of the issues related to thermal expansion & contraction of the materials, making the sealing even more difficult.
Uh, airlock?
If the car can still move, have it drive up to the nearest egress room and line up the doors.
If the car can't move, send 2 men in with spacesuits and an umbilical tube.
Connect the egress room door / umbilical tube to the car. Pressurize the egress room, people walk out.
For evacuation, you only have to pressurize a section of the tube if the car is upside down and off the tracks or whatever. For planned maintenance, you'll have to have some sort of method for pressurizing sections individually anyway.
DID NOBODY WATCH SEAQUEST? There was an episode about this!
Safer than bicycling to work, perhaps 10x so.
“Common sense is not so common.” — Voltaire
Come on. How are they going to know when the train is close?
Proximity fuses. How do they work again?
dead iron, dead meat... big pile.
if this is supposed to be a new economy, how come they still want my old fashioned money?
Rather than figure this out, let's just rename it to the "Vorpal Train of Swiftness"
AC said "The company hasn't even engineered a prototype much less built one."
#DeleteFacebook
But he SURVIVED.
# 4 requires something to penetrate the tube almost EXACTLY where the pod is. The odds of that happening are very low. It's a meteor hitting the train while in motion, versus hitting the tracks.
Earthquake is almost certainly #2, breaking the tube at a spot where the pod is not.
In case #2, there would be an air pressure event, but note that by definition it blows the pod away from the break, back toward safety. And of course, the emergency brakes would auto-activate and they should be strong enough to protect it in this relatively common and easily planned for situation.
excitingthingstodo.blogspot.com
...since most hyper loop designs are buried?
All of the hyperloop designs presented by Musk so far have been on elevated supports. I think there has been some mention of using his boring machines to go underground, but they still show above ground on their video presentation.
So... it would get a participation trophy statue at a park in a southern state then?
If you needed to use a hatch door, presumably the entire system would be shut down yes.
I never understood the thermal expansion argument against it either. Each pylon could connect tubes with a bellows with the bellows oribatally welded to each tube and each tube mated with one cut halfway on OD and other cut halfway on ID, bellows on outside. You would have a tube welder anyway. Simple shroud, even out of plastic, could help protect the bellows. Fatigue life would be decades and failure would be slow leak.
We had participation trophies in Kansas and South Dakota in the early 70's.
I don't think the pressure differential in a nuclear blast is 15 PSI.
We didn't, Kansas/Missouri.
There were loser 'certs' in some rare cases. e.g. This certification confirms you took the president's physical fitness challenge and _failed_.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Since there isn't a "track" in the conventional sense, but a tunnel or tube, there's little to no chance of derailment. The only thing I can think of that could cause a crash is a destruction of part of the tunnel or tube. If a section of tube fails, the vacuum is lost, air rushes in and the pod slows down. My biggest engineering concern is life support. To achieve these high speeds, it will be necessary to evacuate most of the air from the tunnel. A moving platform in a near vacuum will require on board life support. In the event of life support failure, I hope they have evacuation hatches at regular intervals throughput the tunnel.
A lot of people didn't get that this wasn't satire.
Why ever would you presuppose it will be less annoying than the airport?
The public's perception of its safety will guarantee political meddling to look like they are "doing something" about hyperloop safety.
Here's the breakdown:
1) News media will figure out that they can sell more eyeballs if they sensationalize the perceived dangers.
2) Populace will demand to feel safer with hyperloops.
3) Politicians realize it doesn't politically cost them anything to hype rhetorical hyperloop insecurity.
Before I part with'em: two pennies weigh ~4.996+/-0.014g, have a zinc core, and the face of Lincoln. You can keep 'em.
The problem is that they are ONLY giving participation trophies. They do not give winner trophies because they don't want to make the people that suck feel bad for not being good at it.
Guess again
https://www.cdc.gov/niosh/dock...
Chas - The one, the only.
THANK GOD!!!
Nothing will happen.
Public money that may have been invested will be lost.
Irresponsible politicians will deflect the damage on someone else.
People will not learn to ignore unwarranted hype.
And what do you exactly mean by "failed".
With my supernatural powers, I predict it will fail to setup a working supersonic (maglev) train running in a vacuum tube between any two (major) cities in the world.
Irrelevant news and morons using moderation to mod down what they disagree on. 2018 resolution: so long.
That's your story and you're sticking to it...
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
I don't blame them - after Brexit and Trump it is now sometimes hard to tell the difference between a joke and reality.
First off, I'd suggest there would be just as much security as at a current airport given the climate of terrorism today. Secondly there are possibilities of failure of the various systems as already well highlighted, but there are simple ways to minimise any issues, such as running a pig (in pipeline terms) ahead of any passenger unit, and dead man's handle philosophy on sensors - ie no positive confirmation of system health and you stop - something you cannot do in an aeroplane. In that regard many people die in air crashes due to subsequent effects of fire, something that would not likely happen in this case - you're not carrying tonnes of fuel in the unit. There has been talk of running them underground - safer in one sense, but how do you rescue people trapped in a stuck or damaged unit?
If the vacuum is breached behind the train, it might accelerate first then crash and stop.
Because air pressure behind and less pressure in front, for a while.
To prevent this, you might want an automated emergency system to vent in front of a train (increase pressure there) if pressure is increasing at back of it.
Where are we going and why are we in a handbasket?
I'm thinking the big problem with a 700 mph vehicle encountering rapidly rising air pressure would be turbulence and vehicle oscillation leading to dynmic loads and vehicle destruction. Some good wind tunnel modelling is needed. Maybe there's a pod shape that can avoid that.
Where are we going and why are we in a handbasket?
>"The idea of getting from one city to another at 700 MPH without having to suffer through an airport and all that jazz is revolutionary"
And you REALLY think that if hyperloop takes off and gets big that their ports won't be exactly like airports? Dream on. Security Theater will be there just as much, complete with nonsense measures, nude scanning, baggage limitations, prohibited items, etc, etc. Dealing with expensive parking. Dealing with "secure vs. non-secure zones." Dealing with lost/damaged baggage and pickups. Why would that not happen with hyperloop?
The reality is you won't be avoiding the hassle of an airport as they will need to enforce the same strict rules and security for boarding a hyperloop as it would be just as susceptible to attack and loss of life and when/if something did go wrong you are basically fucked and the system will be out for weeks.
Well. I suspect it'll looks something like this: https://youtu.be/0N17tEW_WEU?t...
You can't just open the hatch, you've 14.7 lbs of pressure per square inch trying to keep that door closed, assuming it swings out.
Isn't that literally the one and only design where that problem presents itself? You cherrypicked a failed premise as your starting assumption, then said the idea doesn't work. By that logic, you could have just as easily said:
You can't fly, you've got your weight to deal with and no means by which you can generate the lift to overcome it, assuming you're strapping wings to your arms.
Sure, it's true, but it doesn't mean we can't fly. It just means that we can't fly that way. Likewise for your notion about the hatch.
For instance, here are some alternative hatch designs:
1) Rather than relying on brute force to open the hatch, use a worm gear or other form of mechanical advantage to unseal the hatch/re-pressurize the tube before you fully open it. You only need to overcome 6650 lbs. if were talking about a hatch the size of those on a submarine (i.e. [pi * 12 inches ^ 2] * 14.7 psi), so a person could easily open it on their own (e.g. worm gears can hit a 500:1 gear ratio).
2) Fully mechanize the door, that way human strength isn't a factor. It'll just open itself for you.
3) Use a sliding door for the hatch and accept that some leakage is possible and acceptable. You'd only need to overcome the friction from the differential rather than the differential itself at that point, negating the biggest of the issues. As for leakage, the hyperloop was never designed to be a perfect vacuum in the first place, so we know it's already going to be moderating the pressure as it is.
4) Try opening the door inwards. If you're concerned about the door being in the path of vehicles in the case of an unexpected opening, put it at the end of a branch from the main tube so that it can't open directly onto the tracks. That said, for as little pressure as it needs to handle, I'm not convinced it's a cause for concern in the first place, since we already build doors to handle far more than that.
All of which is to say, assuming a failed design as your starting point isn't a valid means for proving a problem can't be overcome; it's how you set up and tear down a straw man, which we shouldn't tolerate around here (even if I do agree with the point you were driving at that there are major engineering hurdles to overcome).
He also mentioned solar panels on top of the tubes, so it wasn't just an 'excitement' thing. There isn't much solar power underground...
To get an insight of how things can go bad at high speed, look at french TGV accidents
The most serious accident was acheived by derailing on a bridge because of excessive speed during a test run. Other accidents with deaths involved level crossings. Obviously none of these two case can happen with hyperloop.
Not just soft, but absorbent.
Pod levitation fails = Skids to a stop / might have landing or crash gear Pod compressor fails = Pod slowed by cushion of air. Pod depressurize = Oxygen masks deploy Oxygen masks fail = Same as plane Tube fails = Pod slowed by cushion of air. Tube fails behind moving pod destined to dead end of tube and breaks fail = pod accelerated into wall by in rush of air. Solution = Make the tube a continuous loop or have long narrow and ending sections that restrict by-pass air, overwhelming the compressor and, creating an air cushion to form ahead of the pod, forcing deceleration. The tube vacuum could also be used to clear our European-style gas attacks in a matter of seconds, in both the pod cabins and stations. Pretty good deal.
you will continue to move 700 MPH in the specific direction, until you hit something. really no ifs ands or buts about it.
ftfy.
700 mi/h = 1127 km/h
The various failure modes of the hyperloop system were described in some detail in the initial paper released by Elon Musk's team. In essence, the only catastrophic failure mode is if someone blows up the part of the tube that your pod is about to enter so that it cannot slow down in time to avoid crashing into the breach. Every other failure mode is fairly easy to deal with and the main drawback is that the failure of one pod or one tube section will slow down the entire system until they can get it handled.
The hyperloop system depends on being at very low pressure and most of the failure modes involve an increase in air pressure up towards outside pressure - either as a consequence of the failure itself or as a response to the failure. This slows down the pods safely, everything comes to a stop, and there will be some work to evacuate the passengers.
sigs are hazardous to your health
Best answer above.
Realistic answer: Modern train tunnel construction standards require escape hatches every mile. All it needs is an escape hatch in the front or back of the train, and passengers can just walk along the tube to the next escape hatch.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
I participated in Little League baseball as a kid in the late 50s. I was so poor at the sport that they'd hardly allow me to play in practice! But I persevered, and attended every practice, and sat on the bench in my perfectly clean uniform during every game.
My team won first place honors, and every member of the team received a first-place trophy.
I never had any delusions of being a good athlete, but I tried out for Babe Ruth league later on, and I actually got to play in two half innings! That team was also a first-place team.
As they say every so often in the military, "They also serve, who only stand and wait."
Go figure.
PlaynBass
https://www.youtube.com/watch?...
I believe the design includes venting through the car if there is a large pressure difference between front and rear. So not only would the tube have to be breached, this would also have to fail.
"Page not found"
Because the start of participation trophies in the 1970s marks the first wave of dumbing down of public education so everyone can graduate with a diploma that is meaningless.
I graduated high school in 1975 . I remember 74 when they trotted out participation trophies in a tournament and the nasty reaction when all the competing students blatantly dropped them in the trash after being handed them.
NRRPT/RCT
" Effect of various long duration blast overpressures and the associated
maximum wind speed on various structures and the human body. "
This is talking about the shockwave far from the initial blast, up to several miles away from ground zero.
https://www.remm.nlm.gov/zones...
http://blog.nuclearsecrecy.com...
If you're close enough to be standing at the very edge of the Mach stem, you're already dead. That's also talking about a quickly gained and then sustained overpressure, very suddenly going from 1 atmo to 2 and staying there a bit. There's not much gradient, either, as it's a supersonic wave.
The physics of a streamlined vehicle going from 2 or 3 PSI (remember nobody's planning complete vacuum) back to 15 PSI pretty suddenly through a gradient of pressures are fairly well understood. That's like going from around 35,000 feet (about 3 PSI) to 50,000 feet (just under 2 PSI) in altitude to sea level quickly, depending on air temperature. That's basically a plane that can do Mach 1 at 40,000 feet doing a near-vertical dive, only there's no necessary sudden pitch change because the pod will be near horizontal the whole time.
The failure mode of a hyperloop is not at all likely to be anything similar to going from sea level at the bottom of a 40-foot cylinder of air at 15 PSI and in milliseconds having all that air replaced by water to suddenly be under 30 PSI. That's more what you're talking about with the shockwave of 15 PSI overpressue at a few thousand feet from ground zero of a nuclear blast.
BTW, if you're close enough to a nuclear blast to worry about the full force of the overpressure wave you've already cooked by the time it's crossed your mind. Further out where you're not consumed in the heat of the fireball is where you should be worried about the air pressure.