Hyperloop Bankrupt and Busted.

[Uttamattamakin]

3 hours ago, Kisai said:

The proper way to build passenger rail is grade-separated, straight-as-possible, grade-level as possible. As soon as you deviate from any of those you have to slow down. Tunnels have to always be as straight as possible for some pretty obvious reasons (cut and cover under roads, or tunnel boring parallel to roads.) You can't snake around underground services.

Fun fact everybody.  All the googling about Hyperloop has Youtube feeding me videos about trains.    ONE BIG ISSUE glossed over has been the laws that govern anything that we'd call a train.  Hyperloop would in the absence of any other laws made just for it have to obey those laws.   The USA has certain laws and standards that govern how you can get on and off a train and accessibility and on and on and on. 

 

 

3 hours ago, Kisai said:

 

Like realistically, what makes Japanese high speed rail good and the rest of the world a bit less good is that European and American rail networks stubbornly refuse to close grade crossings. There are no grade crossings on the shinkansen.  Most accidents on rail systems, high speed or not, causing multiple deaths are due to overspeed and training failures resulting in overspeed. Most others are due to trucks at a grade crossing (really, two of amtracks recent accents involved a garbage truck and a dump truck at a grade crossing.) 

True.  Chicago being a big hub of rail has a TON of these crossings.  There are still towns along the tracks where "downtown" is right by the train station and every single street crosses the tracks.     So if you want to get from the grocery store to the post office you  have to wait on that miles long freight train.  Hopefully you are in your car with the heat/AC working and didn't just get off the Metra  (or sometimes Amtrak). 

 

3 hours ago, Kisai said:

 

Like when everyone heard what was actually delivered in Las Vegas there was a round of "facepalm". Sure it was a cheap tunnel, and it has pretty much no ability to do anything useful.

 

This was supposed to be an example of something that wasn't the hyperloop but another concept Musk had in which instead of above ground streets there would be below ground tunnels. 
 

That is not a fundamentally stupid idea it would just be VERY expensive to do it by digging.  A better way to get that, and is what was done in Downtown Chicago (a real downtown) and just the older part of the city is to raise "street level " one or two stories up then have streets that are below grade.   These are dark and scary but also don't get as messy in winter. 

 

You... but then you need to be willing to raise whole city blocks up on hydraulic jacks.  The kind of thing we'd just do in the 1800's but wouldn't attempt now for some reason. 

In that case Chicago has had a loop for a while hasn't it.   We could accomplish this by having electric cars and putting a "roof" on top of the expressways which are all underground.    Then turn the at grade level into a wide boulevard  or something of the sort.   

[Donut417]

3 hours ago, Sauron said:

Planes don't require building tracks to reach their destination.

While that's true. Traveling by air sucks. The airlines nickle and dime you. Airport security sucks and they couldn't stop a terrorist if one came up and bit them in the ass. They cram as many people in to a plane and make it uncomfortable, especially to larger people.

[SADS]

it's crazy to me that people can get away with this stuff.

[CarlBar]

@Uttamattamakin no worries on the mistakens, and again sorry if i got a bit snappy.

 

Some quick notes on things you've mentioned, though i've only had time for a quick skim.

 

The 1/100th rule is a rule of thumb, not a hard limit, and is mostly set with the idea of higher stresses in mind, (a gas pipeline can have a pressure differential of upto a hundred atmospheres for example). Steel hulled nuclear attack subs, (they do use stiffeners), seem to have a typical hull thickness of 2-4 inches, thats 5-10cm and they are built for 20 atmospheres of differential pressure.

 

You will find mentions of upto 10 inch hull thicknesses out there but i believe thats for certain russian titanium hull designs. Titanium requires a higher thickness and the design diving depths are even greater, (i believe they go down to 30 atmospheres of pressure difference), so it has two factors raising the thickness.

 

The vacuum chamber you linked is so think for several reasons, first and foremost having a huge assdoor in there compromises the strength along one side, so more thickness is needed to handle it. In addition the provision of the door in there with seals puts limits on the flexing beyond the normal strength related limits as too much can be damaging for both. In addition extremly low vacuums have serious issues with off-gassing and that often requires special grades of material that may result in sacrifice of material strength for the low off-gas. Inherent radiation in the material can be a concern too. And more besides.

 

As a final note be really careful about the internal pressures you assume. Some concepts do talk about dropping it down to 100 pascals or so but your really do not need to run it anywhere near that low. From an air resistance PoV you could run upto at least 10,000mph at that pressure. Getting everything else to function at that speed is doubtful at best. But there's a pretty large gap between that speed and "significantly faster than high speed rail". In reality i'd expect the actual pressure used to be either constrained by extra costs on the carriage safety side associated with going lower, or by the lowest you can go with a "normal" vacuum pump. In the event neither of those is a limit, the tradeoff between operating costs and construction costs likely will be.

 

For example at a pressure equivalent to concorde's cruise altitude you could operate a train at upto 450mph without exceeding the drag induced running costs of normal high speed rail. And a maglev operating at bullettrain running costs could be run at upto 1100Mph, (assuming you can get the rest of the setup to handle that).

 

 

[Uttamattamakin]

On 1/22/2024 at 5:17 AM, CarlBar said:

@Uttamattamakin no worries on the mistakens, and again sorry if i got a bit snappy.

 

Some quick notes on things you've mentioned, though i've only had time for a quick skim.

 

 

All good points.  Said nicely.  A sign of my appreciation and in hopes we can all lighten up.

 

< removed by moderation >

 

 I just think about these videos I've seen of you know thin steel containers that can hold in a fair bit of pressure totally getting owned by the atmosphere if you vacuum out the air. 

 

You are probably right that the easiest solution for that is lower the air pressure but don't lower it to something like 100 pascals.  Less air means less air resistance even if it's not like a full vacuum.  Plus internal pressure makes it much easier to build a working system.  It uses nature in our favor.  The consequences of a breach or imperfection would be more like...what happened on the 737 Max9 which lost a door plug.

 

There is a claim that in China a maglev train inside a so called low vacuum tube has been tested at something like a full scale.  Notice how big that tunnel is.  

 

 Now I've been thinking this , ever since EEV blog mentioned it in a video , how do we ever know if these supposed tests are in anything like vacuum since without vacuum in the tunnel is it really hyperloop?  

 

I mean can we just install some pumps that will lower the pressure a little bit in the subway and call it a hyper loop? I mean come on.  It makes me wonder if we could not achieve the same speeds by applying more aerodynamic principles to designing trains.  Somehow get ninety percent of the benefit in terms of speed but none of the risk of implosion.

Edited January 24 by LogicalDrm

[Sauron]

9 hours ago, Donut417 said:

While that's true. Traveling by air sucks. The airlines nickle and dime you. Airport security sucks and they couldn't stop a terrorist if one came up and bit them in the ass. They cram as many people in to a plane and make it uncomfortable, especially to larger people.

I don't expect the cramming and "nickel and dime"ing to be any lower on a system that needs to pay back such insanely expensive infrastructure. Airport security does suck but it's more of a political problem than anything inherent to the technology. There have also been advancements in security scanner technology that make it less annoying, for example in some airports you can now take bottles of liquids with you and you don't need to take your belt off.

3 hours ago, Uttamattamakin said:

There is a claim that in China a maglev train inside a so called low vacuum tube has been tested at something like a full scale.  Notice how big that tunnel is.  

I don't think that's supposed to be a full size train in the picture. It looks like an unmanned test pod. The tunnel is likely only 2-2.5m wide if that track is the width of a normal maglev track.

[wanderingfool2]

On 1/21/2024 at 9:12 AM, Sauron said:

No, the argument is not "higher cost = bad". Extreme cost for something that isn't worth it is bad, is the argument - and the inevitable attempt to cut costs resulting in the thing not working, or being dangerous, or significantly cutting back on features as has been the case with the Las Vegas loop. Cars can be made cost effectively, they are a solved engineering problem (although there's always room for improvement). Making the hyperloop cost effective would be impossible.

Except it's not exactly an extreme cost; extreme cost is when it makes up for a large % of the project.

 

As I said earlier a 2m sized tube could account for less than 5% of total project cost for the material.    You can't simply compare it to projects that would say be just rail.

 

Like I said before, I think there are other areas why Hyperloop doesn't make sense or won't ever become a thing, but harping on the cost aspect of things is wrong.

 

It's like looking at an EV market and saying that it doesn't make sense to own an EV because every person will have to charge at expensive super-chargers and it won't save you on money.  Or also the reverse as well, the people who insist that EV's make sense for everyone because you can "charge from home" and save money.

 

On 1/21/2024 at 9:12 AM, Sauron said:

We're having this discussion over the corpse of the company that attempted it for a decade and has nothing to show for it.

And you know how close we were to having EV's not being a thing?  Had Tesla fallen back in the day we would not be where we are, as there would be little incentive for car manufacturers to optimize their EV pricing (the majority of manufacturers are still losing money on every EV they sell).

 

On 1/21/2024 at 9:12 AM, Sauron said:

Those lines are expensive for a reason, and that reason is not that standard rail is somehow comparably expensive to maglev in those projects. They likely have to route it through inhabited areas, acquire land, obtain grants, run simulations and go through bureaucracy - that's what makes them expensive. A hyperloop would be no different in this regard. Those are costs on top of the cost of the system itself.

Do  you not understand?  The fact that ANY system meeting those conditions means yes it's important to do a cost analysis on a viability of a project based on all in costs.

 

To make it extreme, imagine to lay down track cost $1/km, and highspeed rail track cost $2/km...but the overall project costs $1billion/km.  It would be outright stupid to install a normal track over a highspeed rail track because the highspeed rail track only contributes to a small fraction of the overall budget..  You have to consider the entire project cost when analyzing viability.

 

It's like graphene based batteries, they have no business being in EV's at the moment BUT the insane cost can be justifiable on an electric airplane (where weight/size/fuel savings trumps overall cost).

 

On 1/21/2024 at 9:12 AM, Sauron said:

That's a ridiculously terrible example because 1) as I mentioned just because it's an expensive railway doesn't mean a hyperloop wouldn't be subject to the same extra costs and 2) 20km of urban railway have absolutely no need to go faster than like 100kph, which would mean going the entire distance in 5 minutes. It's arguably the worst example you could make of a use case for a 600kph train.

You lack basic economic insight...YES it is a good example because it shows the predominating cost ISN'T the cost of the rail itself.

 

 

You fail basic comprehension of what I am referring to.  I am referring to the overall cost; again it's asinine arguing about cost per km IF the overall project cost already greatly exceeds the cost of picking one technology over the other (and lowering drag could make a difference in terms of efficiency)...but again my argument has been over your insistence that the cost is too high; not the practicality of it being implemented on a short route.  So yes, it's a good example of the costs being extremely high.

 

On 1/21/2024 at 9:12 AM, Sauron said:

Why would you just assume that? 1 billion is just the track cost for 10km of maglev vs less than two million for the same length of conventional high speed rail. You'd be (at a minimum) almost tripling the overall cost for a project that has no need for a higher speed. Of course if the cost difference for the rail were like 10% more this wouldn't be an issue (although again there really wouldn't be any reason to do that since low speed trains are perfectly adequate for the task), but we're talking literally 100 times the cost.

You are assuming that you would be restricted to maglev, instead of still using a rail track.  Yes, rolling resistance adds to the overall efficiency, but currently on CanadaLine I can tell when the train is coming even with my eyes shut and headphones on...do you know why?  The train pushes the air and through the tracks and overall the air pressure/drag is a major contributor.

 

On 1/21/2024 at 9:42 AM, Uttamattamakin said:

Yeah but if you are just chatting on the net for giggles ... are deep penetrating numerical computations really needed?  Shall we I don't know boot up a totally not pirated copy of Solid works or write some Phython or Matlab code to simulate various sizes of Maglev hyperloops and see how we can break them... do some failure mode analysis.  

No one is suggesting that, but you are pulling ThunderF00t here, where you see a real world example where they are telling you the size; then magically pulling a number out your butt that is wildly wrong and using it as though it's bonified truth.

 

Simple fact is, HyperLoop's one pipe was 3.3m, SpaceX's test pipe is 2m.  It's crazy to think that the pipe will be 10 meter, or even above 5 meters; or it's very malicious to use such absurd figured.

 

 

 

[Kisai]

5 hours ago, wanderingfool2 said:

 

 

It's like looking at an EV market and saying that it doesn't make sense to own an EV because every person will have to charge at expensive super-chargers and it won't save you on money.  Or also the reverse as well, the people who insist that EV's make sense for everyone because you can "charge from home" and save money.

 

And you know how close we were to having EV's not being a thing?  Had Tesla fallen back in the day we would not be where we are, as there would be little incentive for car manufacturers to optimize their EV pricing (the majority of manufacturers are still losing money on every EV they sell).

 

Doubtful, extremely doubtful. The only reason Tesla got any footing at all is from building their own cars and not waiting for GM and Ford to do it. If Tesla was not here, that market would be driven primarily by Toyota since they were the ones already doing hybrids and had a direct migration path to EV's. Other hybrids were not as good. Just like other EV's are not as good primarily because they are sticking Electric motors in what are otherwise gasoline vehicles. Toyota figured out the right way to do that with their hybrid system's planetary gear CVT transmission.  Tesla EV's lack most of the mechanical parts that a conventional Gasoline/Diesel or Hybrid have. So ultimately it's cheaper to build once all the tooling is built for it. None of that is Elon.

 

But ultimately I've soured on Tesla and everything else Elon is involved with when Elon threw away his credibility from the Thai Cave comments. With good reason. https://www.wired.com/story/tesla-cybertruck-two-years-late-still-crazy/ , as stupid as this vehicle is, I think this is gonna be the "Canyonero" of the Tesla vehicles. Something that gets relentlessly mocked for things Elon said.

 

 

 

[Sauron]

16 hours ago, wanderingfool2 said:

You fail basic comprehension of what I am referring to. 

No, you're the one failing at the most basic math. The costs of maglev, with or without a vacuum tube, are two or three orders of magnitude higher than standard rail and would easily double or triple the cost of that $1 billion 20km line by changing nothing other than the railway itself.

16 hours ago, wanderingfool2 said:

You lack basic economic insight...YES it is a good example because it shows the predominating cost ISN'T the cost of the rail itself.

That's because standard rail is cheap. Using maglev would make the cost of the rail tower over everything else in the project. It's like saying the cost of a GPU is a small part of the cost of a $500 laptop with an iGPU and therefore adding a $2000 RTX 4090 would not increase it significantly. I have already isolated the variable we should be looking at and the costs are obviously and unjustifiably much higher, for little or no gain in the context given. You've provided no numbers on hyperloop other than "trust me bro it's not that expensive".

 

I don't see the point of discussing this further if you refuse to understand a concept a 10 year old would have no trouble with.

16 hours ago, wanderingfool2 said:

You are assuming that you would be restricted to maglev, instead of still using a rail track.

Yes, because that was the definition of the concept. If hyperloop was going to build a normal railway in a vacuum tube they could have bloody well said so and maybe tried to actually build it. You don't get to completely change the parameters of the project and then act as though the original proposal made any sense. I am not considering the use of standard rail because that's not what was on the table. If your argument relies on this being done with standard rail then I have no interest in the conversation, it's not what I've been talking about at any point.

 

Plus, the whole premise of this being an alternative to the supposedly poorly handled california HSR would kind of fall apart if you were going to build it anyway and just add a vacuum tube, wouldn't it?

16 hours ago, wanderingfool2 said:

And you know how close we were to having EV's not being a thing?  Had Tesla fallen back in the day we would not be where we are, as there would be little incentive for car manufacturers to optimize their EV pricing (the majority of manufacturers are still losing money on every EV they sell).

EVs are another beast entirely but do consider that in practical terms, were it not for the environmental impact, ICE vehicles still give EVs a run for their money in many ways. The hyperloop can't seriously claim it's better for the environment than standard electric HSR. Also while EVs are generally more expensive than ICEs (although as mentioned by @Kisai this is more of a market problem than a technical inevitability) they are certainly not multiple orders of magnitude more expensive.

[leadeater]

35 minutes ago, Sauron said:

If hyperloop was going to build a normal railway in a vacuum tube they could have bloody well said so and maybe tried to actually build it

I don't think rail track would be possible at 500mph+ and only minutes between trains/carriages because the friction would cause the tracks to heat up and without sufficient time to dissipate that heat they'll just get hotter and hotter until failure. Highspeed rail is in open atmosphere with long time between trains so plenty of ability to cool down and time to do so. Without an atmosphere and in an enclosed tube you're going to need an actual cooling design to keep the tracks cool (active or passive).

 

Very highspeed aircraft fuselage get hot in low pressure atmosphere so rolling track would likely be higher friction and higher specific heat, worse situation.  

[Sauron]

1 hour ago, leadeater said:

I don't think rail track would be possible at 500mph+ and only minutes between trains/carriages because the friction would cause the tracks to heat up and without sufficient time to dissipate that heat they'll just get hotter and hotter until failure. Highspeed rail is in open atmosphere with long time between trains so plenty of ability to cool down and time to do so. Without an atmosphere and in an enclosed tube you're going to need an actual cooling design to keep the tracks cool (active or passive).

 

Very highspeed aircraft fuselage get hot in low pressure atmosphere so rolling track would likely be higher friction and higher specific heat, worse situation.  

Certainly, the promised speeds and throughput would not be achievable without maglev. At most you might be able to claim power savings on roughly the same speed and throughput due to reduced air resistance (depending on how much power the vacuum pumps would need). And then the trains would need to be airtight as well... it's just a shitshow all around for almost no benefit. But I still take issue with people here pretending something like this would be remotely close to the original concept just to win the argument for daddy Elon.

 

And yeah, I hadn't even thought about how the heck they would cool the whole thing with a reduced atmosphere, especially in an underground tunnel.

[Uttamattamakin]

5 hours ago, leadeater said:

I don't think rail track would be possible at 500mph+ and only minutes between trains/carriages because the friction would cause the tracks to heat up and without sufficient time to dissipate that heat they'll just get hotter and hotter until failure.

Not just time, without air the only way for the tracks to cool down would be by radiation.  No air, no cooling. 

 

Quote

Well of course then the tracks would be hollow and filled with LN2 you dolt!  You don't even know how to count how can a stacked anime waifu like you be a physicist!!!!

The problem of Hyperloop, the fundamental issue is that to make it work we need to use so much know how to work against the natural forces of nature.  Work to get rid of the atmosphere ... only to then have to actively cool rails.  Instead of using rails ... use maglev.    We can solve some by not evacuating all the atmosphere but then we still have atmospheric drag which if the pressure isn't very low causes about the same issue as if we didn't just make a more aerodynamic train. 

 

Right now the land speed record is over 1200 km/hr.  If a train can be designed to do even 50% + of that through aerodynamic design, then why have hyperloop at all?  There is a good chance that while a hyperloop is being built if it is ever tried for real that is what will happen.    The fastest maglev in the world is already 600 km/hr as it is. 

[wanderingfool2]

5 hours ago, leadeater said:

I don't think rail track would be possible at 500mph+ and only minutes between trains/carriages because the friction would cause the tracks to heat up and without sufficient time to dissipate that heat they'll just get hotter and hotter until failure. Highspeed rail is in open atmosphere with long time between trains so plenty of ability to cool down and time to do so. Without an atmosphere and in an enclosed tube you're going to need an actual cooling design to keep the tracks cool (active or passive).

 

Very highspeed aircraft fuselage get hot in low pressure atmosphere so rolling track would likely be higher friction and higher specific heat, worse situation.  

Heat dissipation is one of the reasons I used why I don't think hyperloop would necessarily be practical, and yes heat dissipation would be a valid concern, not necessarily for the track but I would think for the train itself.

 

Although, the Chunnel famously thought they would have a heat issue as well, so they built a cooling station that pumps chilled liquid through the tunnel.

 

Rail track's might not be possible at speeds of 500mph+, but that does assume that implementations would also travel at those high rates of speed...even if you match it so that it's high speed rail speeds you could see the benefits of the lower drag.  From the practical examples, we know that bullet trains can already hit 200mph+ without the maglev system.

 

4 minutes ago, Uttamattamakin said:

Not just time, without air the only way for the tracks to cool down would be by radiation.  No air, no cooling. 

The chunnel has liquid cooled; it's already something that happens and is dealt with on normal rail.

 

6 minutes ago, Uttamattamakin said:

We can solve some by not evacuating all the atmosphere but then we still have atmospheric drag which if the pressure isn't very low causes about the same issue as if we didn't just make a more aerodynamic train. 

Aerodynamics can only be brought so far, especially in tunnel environments.

 

Reduce the air by 1/2 - 3/4 and you effective would have to reduce the aerodynamic drag by 1/2 - 3/4 to get the same effect...which is something where you quickly realize isn't going to happen because our modern bullet trains are already getting to their limits of optimizations.  The skin force effect also starts taking place on longer trains as well.

 

6 hours ago, Sauron said:

No, you're the one failing at the most basic math. The costs of maglev, with or without a vacuum tube, are two or three orders of magnitude higher than standard rail and would easily double or triple the cost of that $1 billion 20km line by changing nothing other than the railway itself.

Again, you don't NEED to use maglev.  Highspeed rail doesn't and you can still benefit from lower drag as a whole.

 

6 hours ago, Sauron said:

I don't see the point of discussing this further if you refuse to understand a concept a 10 year old would have no trouble with.

Please don't insult my intelligence when you are too ignorant to realize that I haven't been proposing maglev...I'll give you a hint, even the white paper didn't mention maglev as a solution; so stop with this stupid shoe-horning of maglev into the discussion as though it's the be all and end all when it comes to hyperloop.  At it's heart hyperloop is a technology that was mean to run essentially a vacuum...which is what I was discussing.  It's not my fault you can't read

 

6 hours ago, Sauron said:

Yes, because that was the definition of the concept. If hyperloop was going to build a normal railway in a vacuum tube they could have bloody well said so and maybe tried to actually build it. You don't get to completely change the parameters of the project and then act as though the original proposal made any sense. I am not considering the use of standard rail because that's not what was on the table. If your argument relies on this being done with standard rail then I have no interest in the conversation, it's not what I've been talking about at any point.

That's a stupid argument; first it's like saying SpaceX won't do reusable rockets because the original concept included a second stage which was meant to be reusable isn't (after real world testing they found it's just cheaper for the upper stage to be abandoned).  Or like how they thought catching the fairing was a good idea, when they realized that the fairing float well enough and can be tweaked to have vital components protected from the salt watt to allow a cheap refurbishment.

 

Lets see, if you even go by the whitepaper Musk released (which frankly is overly optimistic)...lets see, reads it, oh look

Quote

A viable technical solution is magnetic levitation; however the cost
associated with material and construction is prohibitive

So lets stop with this idiotic reasoning that maglev technology was considered practical.  Even with the hyperbole of what Musk usually says, his original white paper mentions magnetic levitation isn't something that would be viable.

 

The actual proposed solution in the whitepaper is to use the current atmosphere to effectively float along the track more so (with a distance where ground effect would come into play), and you guessed it air bearings...oh wait you kept going on about maglev...but I still would contend that the more practical drop in solutions would utilize rail as you still reduce a major issue.

 

 

To address the "they would have already built it".  Well no, you can't build something like that practically without properly showing a bit of viability.  No government wants to award a multi-billion dollar project without proof of concepts and overall they need to test which technologies are the viable technologies.  You are talking about something that probably needs multi-billions of funding to even get it to the provability stage.

 

Take TB treatments as an example, we have had the drugs needed to treat the resistant TB for years; but the clinical trials for drugs that were already on the market treating other things would cost too much to actually do (although finally a company did do it).  As a result the treatment regiment has been greatly reduced and cost reduced...but had it been up to the drug companies to actually do it, we would still be where we are with an expensive regiment of drugs to treat it.

[Uttamattamakin]

1 hour ago, wanderingfool2 said:

The chunnel has liquid cooled; it's already something that happens and is dealt with on normal rail.

 The more you know.  Thanks. 

1 hour ago, wanderingfool2 said:

Aerodynamics can only be brought so far, especially in tunnel environments.

The idea is that we wouldn't have a tunnel or a tube.  It would just be high speed rail / ultra high speed maglev.  The fastest of which is going 600 km/h .  A Boeing 737 Cruises at about 800 km/h.  Once we have a train that is going at jet speed that's fast enough. 

 

 

1 hour ago, wanderingfool2 said:

 

Reduce the air by 1/2 - 3/4 and you effective would have to reduce the aerodynamic drag by 1/2 - 3/4 to get the same effect...which is something where you quickly realize isn't going to happen because our modern bullet trains are already getting to their limits of optimizations.  The skin force effect also starts taking place on longer trains as well.

 

This does not quite work like that.  Drag forces are non linear.  So, a small amount of drag force will have a greater effect at higher velocity.  

Air resistance will be lower if you have less atmosphere BUT it would not mean there is no heat.  

 

My proof of this the heating caused during re-entry.  

Now yes of course these trains will be going a lot slower so there will not be heat BUT there will still be air resistance .  The heat is caused by the presence of that resistance and the high velocity.    Even at the much lower but still high velocities of a hyperloop that resistance stil has to still be considered even at 1/2 or 1/3 of an ATM.   

 

@HenrySalayne That a Hyperloop would need to be about the size of a passenger train for reasons of accessibility and practicality is not imagination.  It is law.  Anything that is legally a train has to obey the laws made for trains.   The USA has regulations that tell you how high the steps have to be, how steep a wheel chair ramp can be etc etc.    During testing it is enough to shoehorn test subjects in.  When actually making a real thing real people will have to use it will have to at least be something kin to a subway tunnel within a city, or a full on Amtrak single decker if intra city in the USA. 

 

What would work really well is if the pressure was reduced by far FAR less and technology used to make trains more aerodynamic was used. 

 

What would work for this if you insist on vacuum being part of it is to go for a much more modest vacuum. 

 

IF this is done then there is no need to build such a robust tunnel or tube.   Take a Maglev exactly like the L0 one I linked that goes 600 KM/h right now.  Lower the pressure to something equivalent to what is encountered at 10000 feet above sea level and get on with it.  In fact at 10k feet above sea level pressure a plane can fly without being pressurized or supplemental oxygen.   In theory people could go into such a tunnel and board without issue... no need to even pressurize the cabin.  

Just not vacuuming it all the way down makes this "hyperloop" much more practical. 

[wanderingfool2]

20 minutes ago, Uttamattamakin said:

This does not quite work like that.  Drag forces are non linear.  So, a small amount of drag force will have a greater effect at higher velocity.  

Actually it does.  I never said they were linear; but we are comparing variables which means yes there is a relationship between density and the aerodynamics and the square gets cancelled out

 

Notice on that section I wasn't referring to velocity because velocity doesn't come into play as they cancel each other out when comparing the forces [as I previously had stated in the numbers a reduction to 1/4 atm gives you ~2x the velocity...but that means nothing when comparing atm vs aerodynamic efficiency].

 

This is still not the entirety

https://www.grc.nasa.gov/www/k-12/VirtualAero/BottleRocket/airplane/dragco.html#:~:text=The drag coefficient Cd is,times the reference area A.&text=This equation gives us a,value for the drag coefficient.

Cd = D / (A * .5 * r * V^2)

https://by.genie.uottawa.ca/~mcg3341/AerodynamicsOfHighSpeedTrains.pdf

 

Of course we are comparing D in this example, instead of calculating the Cd.

D₀ = Cd * A * 0.5 * r * V^2

 

We are comparing the effects of lets say lowing Cd by lets say x, vs the r variable (density) by x

 

D₁ = Cd/x * A * 0.5 * r * V^2

vs

D₁ = Cd * A * 0.5 * r/x * V^2

 

 

Both of which simplify to the following

D1 = (D0)/x

 

So yea, It's like I was saying, if you are comparing making it more aerodynamic vs lowering the air pressure there is a linear relationship between the two.

 

Modify the coefficient of drag down to 1/4 of what it was before is pretty much equivalent of reducing the density of air by 1/4 (which as I've mentioned before allows a doubling of speed).

 

Doing a preliminary search as well you can easily find
https://iopscience.iop.org/article/10.1088/1757-899X/184/1/012015/pdf

 

 

Notice the drag co-efficient between the baseline and M3 drops by half...but also notice the diminishing returns.

 

Modern highspeed trains already have adopted an even more streamlined model of M3 as well; so it's talking about making it even more efficient.

 

51 minutes ago, Uttamattamakin said:

Anything that is legally a train has to obey the laws made for trains.   The USA has regulations that tell you how high the steps have to be, how steep a wheel chair ramp can be etc etc.    During testing it is enough to shoehorn test subjects in.  When actually making a real thing real people will have to use it will have to at least be something kin to a subway tunnel within a city, or a full on Amtrak single decker if intra city in the USA. 

Again, there are already transits in place that have the vehicles which would be able to fit into a 3.3m tunnel.  Also laws can be overall flexible if the introduction of a new form of transit that is put in place.

 

53 minutes ago, Uttamattamakin said:

technology used to make trains more aerodynamic was used. 

You are making assumptions that you can make it more aerodynamic.  High-speed rail and bullet trains already have had innovations in aerodynamics, but it's the law of diminishing returns.  Just like pulling a vacuum is a law of diminishing returns.  It's easy enough to pull 1/2 atm but much harder to pull 1% vacuum.  (See above why aerodynamics is not and cannot be the solution).

 

On top of that, again you have the skin force effect which will also be effected by air density (which you can't design aerodynamics to really minimize that)

[leadeater]

8 hours ago, Uttamattamakin said:

Not just time, without air the only way for the tracks to cool down would be by radiation.  No air, no cooling. 

You would just have the tracks thermally connected to the outside, even the tube itself being metal is a heat sink. I don't know what would be enough but more just saying you'd have to actually design for it since you aren't having a train going over a specific track section once every hour or longer with the heat also able to spread down the track. Since they are talking about seconds/minutes between hyperloop trains dissipation along the track is not possible since there is no down time and space between friction/heat generation.

 

Water cooling the tracks also wouldn't be difficult either and relative cost wise not that expensive, everything just adds to the complexity of design.

 

I'd question the point since hyperloop trains aren't going to be that heavy nor need to be levitated that far off the tube surface so the energy required to do this is well below that of a high speed train, also lower per/kg as well. How much lower energy/kg I don't know but it will be "less". Which also means rail tracks might not actually be cheaper but I have no way to gauge that at all.

[leadeater]

8 hours ago, Uttamattamakin said:

Right now the land speed record is over 1200 km/hr.  If a train can be designed to do even 50% + of that through aerodynamic design, then why have hyperloop at all?  There is a good chance that while a hyperloop is being built if it is ever tried for real that is what will happen.    The fastest maglev in the world is already 600 km/hr as it is. 

ThurstSSC has ~101,379hp while hyperloop POC done so far have around 3,000hp. Little different amounts of power don't you think 

[CarlBar]

1 hour ago, leadeater said:

ThurstSSC has ~101,379hp while hyperloop POC done so far have around 3,000hp. Little different amounts of power don't you think 

 

Half the speed means a quarter the drag at normal atmospheric density, at a tube running a pressure equivalent to 60,000ft half speed would have 1/56th the total drag, thats the equivalent of needing around 1800HP. Honestly though for an electrically driven system the HP requirements of a given sped aren't a huge concern, it's the cooling aspects as noted that are a major pain in terms of carriage design, that and safety.

 

8 hours ago, HenrySalayne said:

People don't seem to follow how high-speed trains are mostly capped around the 300 km/h region. Even the speed record holding TGV with more than 500 km/h reaches the 300-km/h-mark rarely in everyday use

 

By it's nature a hyperloop is going to need reinforced and very levelled tracks. Thats actually how i expect it to come into use if it ever happens. We keep improving on existing high speed rail with the ever increasing track strength and track smoothness requirements to the point we start building it either elevated or below ground to let us control the smoothness to extreme amounts and eventually the extra challanges of pumping it down are just a minor addition to an allready complex program so we start building it in, (probably at a fairly high value, say 0.7-0.8 atmospheres, a value for which you don't need to seal the carriage as it's perfectly breathable), and we just scale it bit by bit until were running low pressures and super speeds.

[Kisai]

1 hour ago, leadeater said:

You would just have the tracks thermally connected to the outside, even the tube itself being metal is a heat sink.

I think the bigger problem there would be the metal fatigue. Metal expands when heated, and shrinks when cold, and if it's used as a heatsink, that would just accelerate the metal fatigue.

 

The Skytrain here, which operates using LIM's, have intrusion pressure plates at the stations which appear to double as heatsinks on the LIM rail (if even only anecdotally,) since during rain/cold weather, you can see steam rise off them where tracks are exposed, which means they're at least hot enough from braking to do that. But that may also be the reverse, the physical brakes only being used during wet weather, in addition to regenerative braking. Either way there is more surface area.

 

The stations without the plates use a different intrusion system and don't seem to generate very much steam when they are wet since the stations are more enclosed. The Canada Line stations (which are conventional motors) don't do this at all since there's no LIM strip.

 

At any rate, I think most of the arguments about if the hyperloop could/would work come right back to needing materials that are immune to thermal expansion and have tensile strength to support cycling air pressure as many times as needed.

 

Extended range Airplanes have a life span much longer than short-haul aircraft. 

 

At any rate, I do feel the thread has kinda turned into a discussion of arm-chair discussion of the viability of the hyperloop.

https://www.tesla.com/sites/default/files/blog_images/hyperloop-alpha.pdf

Quote

Constraining the Problem

 

The Hyperloop (or something similar) is, in my opinion, the right solution for the specific case of high traffic city pairs that are less than about 1500 km or 900 miles apart. Around that inflection point, I suspect that supersonic air travel ends up being faster and cheaper. With a high enough altitude and the right geometry, the sonic boom noise on the ground would be no louder than current airliners, so that isn’t a showstopper. Also, a quiet supersonic plane immediately solves every long distance city pair without the need for a vast new worldwide infrastructure.

The first mistake was mentioning supersonic aircraft. 

https://ntrs.nasa.gov/citations/20205009400

 

Quote

Supersonic aircraft would be bad for the planet at above Mach 1.5 it appears.

 

The problem is that Super sonic aircraft are not economically viable unless they are fast, the Concorde was Mach 2, and new aircraft are proposed at Mach 1.7.

 

So back to the Hyperloop proposal:

Quote

So, no maglev. These are LIM's (like the Skytrain) but on vehicle pods that are about the same size as the MK I skytrain with half the capacity:

Quote

 

So at just under Mach 1, at 100 Pascals at 20 degrees C.

Quote

So it's not maglev, it's just being lifted by "air bearings."

Quote

So theoretically each "hyperloop" capsule costs 54 million dollars.

 

Let's compare that to trains, and airplanes:

http://www.axonaviation.com/commercial-aircraft/aircraft-data/aircraft-pricing

A 737-900ER is about $112Million, or slightly more than double the "hyperloop pod", and the plane can carry 220 passengers, vs Hyperloop pods 28.

 

Before the 2017 accident, the new Talgo VIII trains that Amtrak Cascades had cost $38m, 13 cars long, and seats 285 people.

http://web.talgoamerica.com/about-us-menu/news/49-odot-purchases-talgo-passenger-trains

 

So we're right back at to the logical costs. So if a tube had to be built, and the pods cost more than entire high speed trainsets (and for the sake of argument, yes the cascades are capable of 125MPH (200kph) to 250kph but are only run at 79MPH (127kph.)) Which is still faster than the highway speed on I5.

 

But of course we're talking about California HSR, not Seattle.

 

 

Quote

So note the hyperloop doesn't run at 760mph except during the long "I5" coasting sections. The rest of the time it's 300mph.

 

Compare to the California HSR:

https://hsr.ca.gov/communications-outreach/info-center/get-the-facts/

Quote

So the top speed of the HSR is well below the "bottom speed" of the hyperloop, but is also about as far away as the Talgo trainset Seattle uses that is capable of 250kph (155mph), but the "slowest" speed, is also well above the "fastest" speed Amtrack Cascades seattle-to-portland service is (110mph vs 79mph)

 

Now, I don't think anyone is actually proposing the HSR or hyperloop to actually plow straight into a city center at top speed and then stop on a dime. The G forces would be quite... a mess. That said, under any metric used, the Hyperloop looks good on paper until you look at the costs, and pretty much come to the conclusion that it wouldn't be economically viable to build if the pods alone cost more than a train with 10x the capacity. Even if the train is 3.5 times slower, it's still capable of delivering more people... and in a more comfortable mode.

 

You build the track once, but you have to replace the trains every 30 years. When the pods cost as much as a plane or a complete train it looks extremely dubious. You need to move a lot of people quickly, and it's cheaper to send a train or airplane on schedule even if it's half empty than than it is to wait until it's full because of the cost of energy/fuel to keep it idling. You can right-size your schedules, and thus people can plan their trips around it and get more customers.

 

Anyway, personally, I still feel the hyperloop was pretty stupid, and while the paper looks researched, it makes some pretty bold asks on unproven technology. Meanwhile we have proven technology in both Japan and Europe, all that was needed in California was some will to build it. 

 

Also keep in mind that if the HSR is capable of 220MPH, that puts it above most operating Shinkansen routes (which top out at 260kph (160mph)), we have "high speed" capable trains in the US, we just don't have high speed routes/tracks.

 

 

[Uttamattamakin]

7 hours ago, wanderingfool2 said:

Actually it does.  I never said they were linear; but we are comparing variables which means yes there is a relationship between density and the aerodynamics and the square gets cancelled out

 

You didn't say it but the way you were and are discussing it is using a linear approximation to a non-linear effect.   The basic equation to start from is here. 

 

 

The assumption in your thinking is that the drag force is the one on top.  When for this it needs to be the one on the bottom.  When you analyze this using the energy-momentum formulation, aka Hamiltonian mechanics you see that this velocity certainly does not drop out.   The faster you go the stronger drag becomes and the more energy you loose to it... until at the highest velocities you get the heat of re-entry from space.  We aren't going anywhere near that fast but computer models take account of it.  

 

The research you found is good but it does not use a linear model This graph does not show the alleged diminishing returns you speak of. 



Note in the graph from your own citation the sharp nosed train encounters less than half the drag just by being sharp nosed. The faster the train is going the more of a difference it makes.  Also note the lines are curved, hence it is a non-linear effect.  In a linear model the lines would be straight.

Since you were nice about this I am very grateful. 

 

  NOW since drag is non linear this means that a small reduction in pressure to the equivalent of 10,000 feet... or better still 8000 ft (An allowed cabin pressure inside the Boeing Business Jet http://www.b737.org.uk/pressurisation.htm#:~:text=The pressurisation system of all series of 737,of 8.99psid above 37%2C000ft) to increase passenger comfort.)  We could run a "Hyperloop" that won't have the worry of implosion to the same degree as a more extreme vacuum and be able to breath inside without having to have a pressurized cabin inside an evacuated tunnel.  

What I am saying is something @leadeater commented towards a few pages ago.  So credit him with making me think this over.  IF the pressure is just a BIT lower AND the train a BIT more aerodynamic we can get 80% or 90% of what we'd get out of a hyperloop without needing to do anything quite so radical and potentially dangerous.  Getting a trip time comparable to a high speed turboprop out of an intracity mass transit system would be pretty good.

 

Not discounting what you said and did.  None of that is necessary.  We don't have to re-invent high speed rail to apply some fo what has been learned from Hyperloop projects to it in a modified and more practical form. 

2 hours ago, leadeater said:

ThurstSSC has ~101,379hp while hyperloop POC done so far have around 3,000hp. Little different amounts of power don't you think 

True and what you said about the tracks ... I guess that depends if we are abandoning having a strong vacuum chamber for this to run in maybe we don't need a steel tube ... which means that having a giant heat spreader is lost.  So maybe we want a thinner steel tube that could be cooled by cooling the lower pressure air inside it a bit and keeping it moving. 

I am thinking the problem with this idea was and is not having a mag lev in a tube it is the demand that it be at an air pressure so low that it becomes a problem in and of  itself. 

You're a sys admin right?  It's like making a custom water cooled server for the Lulz when air cooled will do. 


 

 

11 minutes ago, Kisai said:

I think the bigger problem there would be the metal fatigue. Metal expands when heated, and shrinks when cold, and if it's used as a heatsink, that would just accelerate the metal fatigue.

This is a good fundamental point that I did not think of.  Even if this is not one big piece, but ... acts like one since everything would be welded together, expansion and contraction due to heating and cooling would over time cause cracks.  

IF this is done at high vacuum then a tiny crack means implosion and sudden death to many.   If this is done at a low vaccum, similar to the pressure inside the cabin of a jet when cruising, then this will be much less of a problem.   A train derailing with injuries VS an un survivable catastrophe. 

 

11 minutes ago, Kisai said:

At any rate, I think most of the arguments about if the hyperloop could/would work come right back to needing materials that are immune to thermal expansion and have tensile strength to support cycling air pressure as many times as needed.

So, we are back to needing Adamantium and Vibranium.    

OR being brave and visionary enough to see that Carbon Fiber is perfect for holding up under extremes of temperature and pressure. 

 

(I wonder how much Carbon Fiber was mentioned in various Hyperloop promotional materials.  There was a time there when EVERYTHING was being made with carbon fiber when it was meant to be "space age" and advanced.   Like everyone thought they were Burt Rutan of Scaled Composites designing an aircraft). 

 

11 minutes ago, Kisai said:

So theoretically each "hyperloop" capsule costs 54 million dollars.

So less than the DOD spends on a toilet at some top secret base somewhere I'll bet. 

 

11 minutes ago, Kisai said:

Now, I don't think anyone is actually proposing the HSR or hyperloop to actually plow straight into a city center at top speed and then stop on a dime. The G forces would be quite... a mess. That said, under any metric used, the Hyperloop looks good on paper until you look at the costs, and pretty much come to the conclusion that it wouldn't be economically viable to build if the pods alone cost more than a train with 10x the capacity. Even if the train is 3.5 times slower, it's still capable of delivering more people... and in a more comfortable mode.

... all that and as others have said to keep cost down corners would be cut  which would make it less safe.    I predict if someone does build a hyperloop, in the strong sense of the word.  100 pascal vaccum, pods just small enough to get into, all of that... it may work well for a while then it will suddenly catastrophically fail.  Basically it will be like the Hindenburg. 

Edited January 24 by Uttamattamakin
Lightening the mood.

[wanderingfool2]

Can you seriously stop posting those annoying NSFW gif's that have nothing to do with the topic.  I don't open this thread with anyone around because of images like that.

 

1 hour ago, Uttamattamakin said:

The assumption in your thinking is that the drag force is the one on top.  When for this it needs to be the one on the bottom.  When you analyze this using the energy-momentum formulation, aka Hamiltonian mechanics you see that this velocity certainly does not drop out.   The faster you go the stronger drag becomes and the more energy you loose to it... until at the highest velocities you get the heat of re-entry from space.  We aren't going anywhere near that fast but computer models take account of it.  

What is frustrating about your comments is you intentionally ignore the basic level common sense.  If you look at the formula that I stated IN MY POST you wouldn't have to make a faulty assumption because *gasps*...I am using the bottom one; you just are failing to comprehend that the point I was talking about doesn't refer to the velocity variable

 

AGAIN it's basic level arithmetic;  I'm thinking you are lacking the understanding that there is a drag coefficient vs drag force

 

You are the one that was talking about the fact that you could achieve the same effects by making current trains more aerodynamic.

 

I'm not arguing about velocity contributing a square to the equation.  I'm arguing that saying to make things "aerodynamic" has a linear relationship when compared to the same effects of reducing density

 

Let me spell it out for you:

We are talking about manipulating the aerodynamics of the vehicle (i.e. drag coefficient, represented as the variable C in your image)

We are also talking about manipulating the density (i.e. p in your image)

 

 

i.e. If you are travelling at 100 km/h, and you reduce the drag co-efficient by half (i.e. make it more aerodynamic), the drag force reduces by half...which if you reduce density by half you have the same effect

 

The only variable that doesn't have a linear effect on the result is velocity; which again, if you had any basic understanding of the formulas you would realize why I said a reduction from 1 atm to 0.25 atm meant you could double your velocity.

 

So again, let me be VERY VERY clear.  Reducing aerodynamics has a linear effect and in fact the same linear effect as reducing density.

 

1 hour ago, Uttamattamakin said:

Note in the graph from your own citation the sharp nosed train encounters less than half the drag just by being sharp nosed. The faster the train is going the more of a difference it makes.  Also note the lines are curved, hence it is a non-linear effect.  In a linear model the lines would be straight.

Since you were nice about this I am very grateful. 

You are either being dense or you seriously do argue in bad faith.

 

You showed a graph comparing the drag to velocity; which if you took 2 seconds to look at the formulas I've already stated doesn't matter because I have never suggested that changing velocity was linear.  I said that the effect changing the co-efficient of drag (not drag force) is linear...which if you look at the graph, the ratio between the drag compared to drag co-efficient at velocity 20 vs velocity 40 is the same.

 

i.e. if you have D(vel, drag co-efficient) as your input  D(x, 0.5)/D(x, 0.25) = 0.5 for all values of x

 

1 hour ago, Uttamattamakin said:

NOW since drag is non linear this means that a small reduction in pressure

No that's wrong, the drag is non linear in association to change in velocity; but you are manipulating the pressure variable which has a linear effect

Look at a basic level equation y = (Ax)² + Bx + C

A is said to contribute non-linearly

B contributes to a linear effect

and

C has a constant effect/offset

 

Your suggestion of making it aerodynamic is manipulating a variable that has a linear effect.  It's why you have to reduce the drag co-efficient (not drag force) by 4x in order to achieve doubling the velocity with the same force.

 

1 hour ago, Uttamattamakin said:

Not discounting what you said and did.  None of that is necessary.  We don't have to re-invent high speed rail to apply some fo what has been learned from Hyperloop projects to it in a modified and more practical form. 

You were the one saying that we could just achieve better aerodynamics, which is not practical/limited...given that bullet trains already have a low drag co-efficient.  How do you suggest making high-speed trains or bullet trains better?  If you claim aerodynamics like you are, you need to have the basic understanding that even if you assume it's compared to a 0.5atm hyperloop you are talking about needing to reduce the drag co-efficient by half to achieve the same effect (which see below in regards to diminishing returns).

 

1 hour ago, Uttamattamakin said:

The research you found is good but it does not use a linear model This graph does not show the alleged diminishing returns you speak of. 

Do you seriously not get what I mean by diminishing returns?

 

Let me break it down like this,

You have the boxy baseline, which has ~0.5 drag co-efficient

You have streamlined M3, which has ~0.2 drag co-efficient

Current high-speed rails sits actually beyond the M3 design (i.e. modern high speed/bullet trains have a lower number than the M3)..from what I can tell the current ones are ~ 0.12+0.0075x
https://www.jstage.jst.go.jp/article/jsme1958/8/31/8_31_390/_article

 

Now what do you propose to beat the ~0.12, an airfoil as per NASA can reduce drag down to 0.045...but achieving that would be hard, and only would amount to the equivalent of reducing the atm down to 0.34 atm.

 

That's what I mean by diminishing returns, it gets harder and harder to achieve a given result the more you progress in the design.  It's easy to go from a boxy frame to something like M3...but it takes a lot more work to get it from M3 to the current, and even tougher if not impossible to get it to the most idea shape of 0.045

 

Just like reducing the ATM from 1 to 0.5 ATM is pretty trivial compared to 0.5 to 0.25ATM and more so going from 0.25 to 0.125ATM.

[leadeater]

6 hours ago, Uttamattamakin said:

(I wonder how much Carbon Fiber was mentioned in various Hyperloop promotional materials.  There was a time there when EVERYTHING was being made with carbon fiber when it was meant to be "space age" and advanced.   Like everyone thought they were Burt Rutan of Scaled Composites designing an aircraft). 

Carbon Fibre was literally never considered viable for space usage, wonder material sure, space age attributed no. It's the same reason only one person/company ever tried to use carbon fibre the way they did and died and took the lives of others while doing it.

 

Actual engineers don't listen to Nat Geographic etc and treat materials as wonderous things perfect for everything, that is not a thing. Only those that ignore common sense do, they die while doing it.

 

As you may have noticed Virgin used Metal not Carbon Fibre for the tubes, they had common sense, it was never even considered.

 

6 hours ago, Uttamattamakin said:

True and what you said about the tracks ... I guess that depends if we are abandoning having a strong vacuum chamber for this to run in maybe we don't need a steel tube

Why abandon a strong vacuum? What is a strong vacuum?

 

If ThrustSSC were operating in 0.5atm how much thrust(hp) would it have needed? How much at 0.25atm?

 

Obviously low air density is a massive benefit and you can't do that out in open air aka earth atmosphere without flight so trains must do it in a contained environment.

 

High speed trains that can go above 200mph require greater than 10,000hp. Which then my next question would be how much do you think they would need to go 500mph?

 

At some point it is actually more viable, more cost effective and more reliable to just put the train in low pressure than to throw the equivalent amounts of energy at the situation as a contained large explosive bomb continuously.

 

If you look at every factor that contributes towards what is required to move, velocity, and you aim to minimize every single one of them the most cost effective way then you'll have the best chance at achieving the lowest total cost of ownership than to focus on only one or a select few and have to do something revolutionary i.e. ThrustSSC.

 

In principle Hyperloop is exactly this, looking to optimize every factor to achieve the peak possible at the lowest practical effort for each factor. There are just a lot of things we don't do that is needed in a hyperloop that make it expensive or not fully understood. Do consider that if you never do it then you'll never understand it and you'll also never create the knowledge, tooling and supply chain to make it cheaper and thus commercially viable.

 

Space flight was always said to not be commercially viable and nation state only, now we have multiple different companies in different countries all achieving what was said to not be "commercially viable". Opinions of the day can be correct, that doesn't mean they stay that way in to the future forever. Those that are able to see those future changes and further that for their own gains are the ones that become billionaires or remembered as revolutionaries that brought about real social change i.e. personal vehicles for the masses (freedom of movement).

 

One of the easiest things in life is to say no, the easy path is not always the best path.

[CarlBar]

34 minutes ago, leadeater said:

Carbon Fibre was literally never considered viable for space usage, wonder material sure, space age attributed no. It's the same reason only one person/company ever tried to use carbon fibre the way they did and died and took the lives of others while doing it.

 

US navy built deep diving underwater RoV's with it. In fact the designs are so similar that it looks a lot like they scaled up the US navy RoV design. The issue seems to be more to do with how they manufactured the hull and the safety margins they assigned.

[leadeater]

22 minutes ago, CarlBar said:

 

US navy built deep diving underwater RoV's with it. In fact the designs are so similar that it looks a lot like they scaled up the US navy RoV design. The issue seems to be more to do with how they manufactured the hull and the safety margins they assigned.

Potentially also one of those scale effect situations? Good when small, bad when bigger? 

[CarlBar]

4 hours ago, leadeater said:

Potentially also one of those scale effect situations? Good when small, bad when bigger? 

 

Probably not,whilst it's not an ideal material for compression loads you can use it there with the right method of construction and a lot of very careful behind the scenes design and testing work. Oceangate where just really slapdash about the whole thing, and when your pushing a material into an area thats not well understood thats not a good idea.