
A skeptical response to Musk's hyperloop - anologwintermut
http://pedestrianobservations.wordpress.com/2013/08/13/loopy-ideas-are-fine-if-youre-an-entrepreneur/
======
zeteo
The article is full of cant in more ways than one, and more about social norms
when entering a new field than the proposal itself. This is obvious from the
kind of nitpicking that goes on (no references! 4.37 m/s^2 is the maximum
motion sickness possible because an accredited expert proposed it; I've never
seen 4.9 m/s^2, but it's surely a barf comet!). Despite the author's high
opinion of his own knowledge, the criticism amounts almost entirely to basic
arithmetic and comparisons to existing systems that are built on rather
different principles. The really interesting, constructive questions: does
this low-pressure air cushion thing really work? what are some factors that we
need to explore to determine its true efficiency? etc. are of no interest to
this kind of expert, who is more interested in tribally defending his own turf
(see the unnecessary name calling) than in figuring out new ground.

In all fairness, I would give much more slack to an engineer talking about his
field. But, as the author himself points out, almost all civil engineering
technology is from the 19th and early 20th century. He seems to think that, in
between, his colleagues have been perfecting the fine forms of the art and
polishing its many facets. Except feats that were once fairly common, such as
building the Hoover Dam under budget and two years ahead of schedule [1], are
in the realm of the mythical these days.

[1]
[http://en.wikipedia.org/wiki/Hoover_dam](http://en.wikipedia.org/wiki/Hoover_dam)

~~~
akjj
> This is obvious from the kind of nitpicking that goes on (no references!
> 4.37 m/s^2 is the maximum motion sickness possible because an accredited
> expert proposed it; I've never seen 4.9 m/s^2, but it's surely a barf
> comet!)

This isn't nitpicking. Dealing with the acceleration around curves is going to
be a problem for any transit system and at higher speeds it becomes a bigger
problem. Unlike bathrooms, this is going to be intrinsic to any system that
carries human beings. As the author points out that the hyperloop proposal has
significantly higher acceleration than any other high-speed system that he
knows about.

So, how did the hyperloop designers decide that 4.9 m/s^2 would be safe? Did
they find some study which tested this level of acceleration on average
people? Did they conduct their own study which overturned conventional wisdom?
Did they look at the research which led to the 4.37 m/s^2 figure and determine
that it was fatally flawed? This is a critical issue and if the designers
don't explain themselves, then it's fair to assume they made it up.

The hyperloop proposal contains innovative elements (air suspension in
evacuated tubes) and elements which are essentially common with many other
transit systems (viaducts, human passengers). The designers deserve credit for
the former, but they can't sweep the details of the latter under the rug. The
point of references is not stylistic and not to name-check previous work. The
point is that when you're doing something, which has had lots of previous
research, you either use that research to justify your claims or you explain
why yours will be different.

> The really interesting, constructive questions: does this low-pressure air
> cushion thing really work? what are some factors that we need to explore to
> determine its true efficiency?

Those are interesting questions and if Musk had proposed just the air cushion
technology, then that's all we would be talking about. People would build test
pieces to validate the technology and then go looking for applications.
Instead, Musk choose to also include a specific proposal for a replacement for
the LA-SF high-speed rail line and to estimate the costs at a tenth as much.
That's what got the most media attention and so that's the aspect the OP chose
to criticize.

BTW, you seem to be implying that the OP is a civil engineer or a
transportation engineer with an axe to grind, but he's just an amateur and if
you look at his other posts you'll see that he has a lot of concerns for
reducing the costs of infrastructure projects.

~~~
zeteo
I agree that it's important to talk about motion sickness. I was pointing out
that the way the article deals with it (remarking that the proposed system may
involve 12% higher lateral accelerations than HSR, and instantly dismissing it
as a "barf ride") is inadequate. Here are a few questions that I don't know
the answer to, but seem a lot more interesting:

\- Do we have studies that estimate the effect of lateral acceleration on
motion sickness? What do they indicate (e.g. 0.1% of passengers get it at 4
m/s^2, 2% at 5 m/s^2 etc.)?

\- To what extent is motion sickness in HSR comparable to the proposed system?
Are the differences (no outside visibility, different vibrations model,
possibly different seating) significant and if so how?

\- To what extent do potential passengers care about motion sickness? Has
anyone compared cost and convenience trade-offs for systems with different
expectations of motion sickness e.g. ferry vs. train? How comfortable are
passengers with self-medication in such contingencies?

Etc. And motion sickness is only one of hundreds of possible serious
weaknesses in this project. But this is inherent in anything that hasn't been
tried before; anyone can think of hundreds of ways in which it can go wrong.
Does this mean we should never work on anything that isn't fully proven?

~~~
akjj
> (remarking that the proposed system may involve 12% higher lateral
> accelerations than HSR, and instantly dismissing it as a "barf ride")

You're comparing apples to oranges here. If I understand the OP correctly, the
4.37 m/s^2 (which is a claimed maximum, not actually in practice, but let's
ignore that) is in the plane of the ground. Canting will convert that
acceleration into a mixture of horizontal and vertical acceleration, as
experienced by the passenger. The hyperloop track has 11.1 m/s^2 of
acceleration in the plane of the ground based on their path assumptions (=
(480km/h = 133 m/s)^2 / 1600 m), which the OP claims can get converted to 5
m/s^2 of vertical acceleration. This 7 times greater than "track
specifications" of 0.5-0.67 m/s^2 and 5 times greater than the 0.93 m/s^2 of
vertical acceleration coming from the Transrapid's 4.37 m/s^2 in the plane of
the ground.

To step back for a minute, the issues with curve radius for high-speed transit
have existed since the beginnings of high-speed rail 50 years ago and maybe
longer. It's one of the major issues preventing Amtrak from going faster in
the Northeast corridor, for example. If there was some easy way (blocking
windows, lowering vibrations, changing expectations, self-medication) to deal
with it, our first assumption should be that someone's already tried it. If
Elon Musk had some new, breakthrough ideas in this regard, then our assumption
should be that he would somehow mention it, rather than expecting the Internet
to figure it out from the numbers he uses.

In the absence of evidence that any of the thousands of people who have
designed high-speed transit allow for such sharp turns, or that the hyperloop
designers have any way to mitigate the effects of high acceleration, I think
the most likely possibility is that they (some of whom work for SpaceX,
remember) used acceleration limits coming from the space program. Since they
seem never bothered to compare to look at actual high-speed rail systems, they
never noticed how different their assumptions where.

------
jacquesm
Alon Levy thinks that anybody that is not a 'transportation engineer' should
stick to minding their own business. His agenda is shining through pretty
strong here and his dislike for Elon Musk (who apparently succeeds in areas
where he's not qualified to succeed in the first place) is as strong as it
ever was. The more successful Elon Musk is in his endeavors the more vehement
this kind of attack seems to become.

It's quite possible that there are valid criticisms embedded in between the
vitriol but I wished he'd stick to the factual stuff and leave his bias out of
it. Calling Elon Musk a crank is an insult given what the man has already
achieved and reflects poorly on the writer.

I personally think that the best way forward with the hyperloop is to create a
scale model, the tube and carriage could be (virtually?) wind tunnel tested
and valuable information would be gathered that way offering a path to verify
the design one step at the time starting with the hardest part, the
aerodynamics.

~~~
mjn
No, Levy just thinks that anyone who wants to make a detailed proposal for a
specific line should do enough research to justify their claims, and show
their evidence. He isn't a transportation engineer himself (he's a
mathematician), so it's not some kind of turf defending. The fact that he as
an interested amateur has this information available makes it absurd that Musk
wouldn't have done at least as much research as Levy has, to back up his
numbers with data.

Alternately, the proposal could have avoided making detailed claims on cost
and routing, and instead focused on the high-level technology, more in the
direction of validating the basic idea, and leading up to a test track.
There's nothing wrong with that. But if you're going to claim you can build a
line on a specific route for a specific cost, you need to do the work to
justify those numbers credibly. Musk's existing document, at least, comes off
as very hand-wavy and lacking in empirical grounding for any of its detailed
engineering and cost estimates (that grounding could be rooted in his own
data, or in existing data, but there has to be data _somewhere_ ).

~~~
jacquesm
1) Musk states specifically it is an alpha issue and welcomes constructive
criticism

2) I did not claim Levy is a transportation engineer

3) Musk did this quite handy, he did not propose the hyperloop in a vacuum
(pun intended) but for a specific application, this increases the chances of
something being done with it

You have to start somewhere, think of this as a first proposal that can be
suitably amended or scrapped in its entirety as more insight is gained.

I'm pretty skeptical about the whole thing but Musk has a history of pulling
off impressive feats and I would not put it past him to come up with something
that might work when tweaked. So let's hear it for constructive criticism (fix
what is broken or provide actual proof why it can not work) rather than
outright dismissal.

~~~
mjn
The main thing that's broken from the perspective of #3 is that it looks at a
best-case scenario with no legal or political hurdles, and assuming the
detailed construction part will not present any surprises (and surprises that
massively increase costs).

But from that perspective conventional HSR is easy and cheap, too. You could
sketch out a reasonable LA-SF HSR system with optimistic assumptions and put a
$15 billion pricetag on it. It also has the benefit of being technically
validated, and implemented in practice: Japan, France, and China have all
built working systems for per-mile costs in that range or less. The California
HSR issues have more to do with a mixture of politics and the U.S.'s "unique"
regulatory setup, and it's not clear how hyperloop plans to sidestep those,
even assuming the technology works exactly as envisioned. If Musk has some
secret on how that's going to happen, I'd like to use it to just build
conventional HSR!

Put differently he seems to be offering a technical solution to a problem that
didn't have a technical bottleneck, and it's not even clear the technical
solution works.

------
bowlofpetunias
Okay, so this is over the top and not very constructive.

However, there is an underlying pattern that annoys me too. There are
literally thousands of people working in innovative transportation ideas, why
is the barely researched idea of a relative amateur like Musk receiving so
much attention?

The same applies to the Soylent story: people who have been working on the
problem for decades are being ignored in favor of self-promoting entrepreneurs
who's ideas lack depth.

The great irony is that the cheerleaders for these entrepreneurs are the same
people that bitch about the lack of scientific knowledge in politicians and
the lack of attention for science in general.

I can perfectly understand that this pisses people of who have been diligently
working on these problems for decades.

~~~
jhuckestein
It sounds to me that you have discovered an important and often underestimated
property of disruptive ideas. How did an 18 year old change the way we
communicate online forever? How could a clerk at the patent office usher in
the era of 20th century physics?

It's possible and maybe even easier to have truly breakthrough ideas if you're
coming from a different field. You can always catch up on all the knowledge
required to execute your idea later.

And yes, often you'll find out that your idea wasn't so great. But at least
you didn't dismiss it as out of hand because you didn't come across it in your
years of experience in the field.

~~~
hollerith
It's wrong to think that Einstein was "coming from a different field". He had
a PhD in physics from a good school. In his day, physics jobs were much
scarcer, so perfectly ordinary physicists tended to need to get non-physics
jobs for parts of their careers.

~~~
danso
Perhaps a better example is how an aspiring poet came to invent the most
effective infantry weapon of the last century:
[http://en.wikipedia.org/wiki/Mikhail_Kalashnikov](http://en.wikipedia.org/wiki/Mikhail_Kalashnikov)

~~~
lclarkmichalek
An aspiring poet who had also been a tank mechanic/weapons designer for 9~
years prior to inventing the most effective infantry weapon of the last
century

~~~
danso
Yes, but he was conscripted in his teens and had begun innovating at that
young age.

------
Osmium
We are no where near the stage where we can judge if Hyperloop is a good or a
bad idea yet. At the moment, it is just that: an idea. It needs to be refined,
torn apart, put back together, and examined thoroughly and I look forward to
that happening. I'm glad this article exists and is asking tough and valid
questions, but I feel like the article is wrong in trying to persuade people
that the Hyperloop is _intrinsically_ a bad idea when a much better response
(at this stage) is to try and improve the design.

In particular, some parts of this article are just way way off base, e.g.:

> Tesla’s train energy consumption numbers do not pass a sanity check, which
> suggests either reckless disregard for the research or fraud. I wouldn’t put
> either past Musk: the lack of references is consistent with the former, and
> the fact that Musk’s current primary endeavor is a car company is consistent
> with the latter

and

> I write this to point out that, in the US, people will treat any crank
> seriously if he has enough money or enough prowess in another field.

The article would have been much stronger if it'd left ego and silly ad
hominem out of it and reported on facts alone.

I also have concerns about the costings: the Hyperloop report didn't give
sufficient justifications for any of them. Yet I assume they didn't just pluck
them out of thin air either. We really need to know how they were calculated
before we can do a more critical analysis of them _or_ someone should try and
come up with their own rigorous cost projections. We can go back and forth all
day saying it seems too low until someone actually definitely proves it.

In particular, comparing Musk's projected costs for, e.g., viaducts to how
much the government says they cost is almost definitely a poor metric since,
after all, exactly the same could have been said for Musk's cost projections
for rocket-powered spaceflight.

~~~
makomk
What's wrong with this part?

> Tesla’s train energy consumption numbers do not pass a sanity check, which
> suggests either reckless disregard for the research or fraud. I wouldn’t put
> either past Musk: the lack of references is consistent with the former, and
> the fact that Musk’s current primary endeavor is a car company is consistent
> with the latter

If the blog post's claims are correct - and the numbers in it seem to have a
much more solid basis in fact than anything Elon Musk's come up with - then
even a simple back-of-the-envelope calculation should've been enough to show
his power consumption figures for high-speed rail are impossibly high. The
trains are simply incapable of using that much power.

------
enoch_r
While the author is annoyingly dismissive of Musk, the tribal responses here
are unusually defensive and uninformative. It seems like our identities have
expanded to encompass Elon Musk as well as Bitcoin (pro and con) and the NSA.

[http://www.paulgraham.com/identity.html](http://www.paulgraham.com/identity.html)

------
misnome
An interesting article, and seems to be nicely referenced. Most of the
detraction of the article seems to be attacking his dismissal of Musk; that
shouldn't matter, given it seems to actually quote sources for details. I
found especially interesting this quote:

> If a famous question could be solved in ten pages, it probably wouldn’t
> still be open.

Which of course isn't saying that it's impossible, but that claiming it to be
so requires overwhelming proof.

Hyperloop seems like an interesting idea, and certainly worth some
investigation and research (as is, any proposal and idea). But large scale
hand waving and dismissals of the problems as ad hominem attacks don't help
lend an air of legitimacy.

My personal view? I find it interesting that he proposed this, but initially
didn't want to do any of the development or payment himself. That doesn't
sound like someone who truly believes in their "vision".

------
tinco
Geez the author of this article is a dick. It makes it very hard to read, it
looks as though he makes some valid points, but it's interspersed with so much
personal pettyness that it's hard to take him seriously.

Why does this guy hate Elon so much?

~~~
sz4kerto
Whether or not he's a dick does not matter. Personal antipathy or sympathy
should not matter that much. That's exactly what he says btw: most people
haven't even read the Hyperloop PDF but they're already fans - just because
it's Musk, and he seems to be a nice guy.

Jobs-effect again and again.

~~~
tinco
I just explained why it does matter. His dickishness made his otherwise
interesting article agonizing to read. I did not think the author was a dick
_before_ I read the article.

Anyway, I have read the Hyperloop pdf end to end and I think it's great. I
don't agree with this author at all that Elon Musk's endeavours distract from
improving existing technology. Nor do I think that improving existing
technology is as important as inventing new potentially disruptive technology
in general.

People are fans of Musk because he succeeds and delivers in the face of
spineless critics like this one. Just as people were fans of Jobs as he
reintroduced quality into consumer electronics succesfully.

~~~
Someone
_" I don't agree with this author at all that Elon Musk's endeavours distract
from improving existing technology."_

Did we read the same article? I read a rant, sprinkled with lots of verifiable
facts that gave strong arguments why this Hyperloop idea won't fly.

For a rebuttal, I would expect claims that his sources are incorrect, that his
calculations are incorrect, or that the conclusions he draws from those
calculations are incorrect. Arguing that the author ranted too much is not
sufficient for me.

For example, what's wrong with his claim that people would get seasick in this
thing? If there's nothing wrong with that claim, what's wrong with his claim
that that is a show stopper? Similarly, wants wrong with his arguments about
the low capacity of this design?

Feel free to add some rantiness, but keep the fraction of content as least as
high as this article, please.

And, by the way, I do not think this article says Elon Musk does nothing good;
it just claims this idea of Elon Musk is not a good one because it is highly
unlikely that it is possible to fix all of its problems. For example, one can
straighten the trajectory, but then, costs would balloon to be at least on par
with the existing high speed rail system.

~~~
kolinko
As for sea sickness - don't people also get sea sick at sea? Or at an
airplane? Does it stop them from travelling this way?

He compares hyperloop with the smoothest mode of transportation invented, and
says it will fail because it doesn't meet it's standard. Why not compare it to
flying planes or sailing boats? Or riding a Marshrutka in Ukraine?

As for the low capacity - the critique's author says Hyperloop can handle 3
times less passengers per hour. But forgots to mention that you could buy more
than 3 HL lanes for the cost of one HSR lane (if I remember correctly).

~~~
jacalata
I don't think many people do get motion sickness on airplanes these days
actually (on commercial flights I've been on, I haven't seen it at all). Most
people don't travel by sailing boats. He is, quite validly, comparing it to
the actual methods of travel that potential passengers will be comparing it to
- smart money says people travelling between two cities in California have no
knowledge of or interest in how much worse it could be if they were actually
in Ukraine.

------
pmarca
It's almost like it's easier to criticize new ideas than come up with them or
implement them. Oh, wait...

~~~
mjn
It's not hard at all to come up with speculative transit ideas with some high-
level engineering guesstimates. It's sort of a hobby of a lot of people.
People have even sketched out plans for this particular idea (partially
evacuated tube transport).

Implementing them: yes, that's harder, and most transit ideas fall down at
that stage. Implementing them in a way that comes anywhere near the original
optimistic projections is even harder (see: maglev).

------
INTPenis
I for one can't get the mono rail song from the Simpsons out of my head.

But people have already pointed out that this is merely an idea and should be
treated as such. Though a town with money is sort of like a mule with a
spinning wheel...

------
scotty79
> Elon Musk, an entrepreneur who hopes to make a living some day building
> cars.

Didn't he already make all the living he needs and now just does whatever he
likes?

~~~
axefrog
You can almost completely write the article off considering he's
characterizing Musk's achievements with such dismissive condescension.

~~~
simonh
No, you really can't. How he characterizes Musk is irrelevant to whether his
criticisms of the proposal are valid or not. Just because he deploys
dismissive condescension is no excuse for also resorting to it. This is Hacker
News, not Slashdot.

~~~
vidarh
In an ideal world where we have infinite time to consider all comments, you
are right.

However if one has to choose what to spend time on, it is prudent to filter,
and for blatant subjectivity to be used as one such filter, as it is
reasonable to consider it likely that arguments made by someone who is so
obviously biased against someone in the first place is more likely to be
careless about the arguments he makes against their ideas.

So a a _time saving_ exercise, it is absolutely relevant to consider other
factors than the argument itself.

And yes, it is imperfect and will result in a lot of people discounting valid
concerns.

------
the_watcher
Musk has pretty regularly stressed that this is an alpha design, and that he
welcomes feedback and improvements. It may be true that he trashes HSR and
that it competes with Tesla. HSR is also stupidly expensive and arguably too
slow. Regardless of your feelings on HSR, it's also impossible to argue that
the CA government is likely not to screw it up somehow. It's possible that he
could both benefit from HSR failing and also be benevolently proposing that we
actually try something new. Don't forget, he's pledged his own money to this,
and now seems to be leaning towards developing a prototype. I wonder if
putting up the cash for a prototype will quiet the critics down. I, for one,
am a big fan of rich people spending their money on cool things that they
like, from Mark Cuban pushing the limits of analytics in basketball to Musk
with Tesla/SpaceX/Hyperloop to Bill Gates' humanitarian efforts.

------
msandford
This guy's main real criticism is "train viaducts cost X and Musk's proposal
is 0.1X therefore it must be wrong" is total bullshit. It MIGHT be valid under
the following assumptions:

1\. The weight of the train and the hyperloop capsules are the same

2\. The construction methods employed are identical.

But they're not! Average train car weight (if they have to comply with FRA
regulations) should be in the 60 ton range.
[https://www.ebbc.org/rail/fra.html](https://www.ebbc.org/rail/fra.html) and
[http://uk.answers.yahoo.com/question/index?qid=2006082807531...](http://uk.answers.yahoo.com/question/index?qid=20060828075317AACG9vx)
Average train car length is betwen 60 and 80 feet so we'll go with 80.

60 tons / 80 feet = 1500lbs/foot. In the case that a non-FRA compliant car can
be used, that number SHOULD drop to about 750lbs/foot.

The hyperloop cars are speculated to be 16.5 tons and 28.5 tons each. No hard
numbers on length but if you assume 3ft per passenger and 28 total (14 per
side) and add a bit of room for the other stuff, you can come up with 14 *
3+15=57 feet or for three cars, 3 * 20+15=75 feet.

33,000lbs / 57 feet = 578lbs/ft. 57,000lbs / 75 feet = 760lbs/ft

So it looks like the big-case hyperloop will weigh about the same as the best-
case high speed rail.

Now let's analyze the support mechanism. Trains run on rails (two of them) and
they weigh ~100 lbs per foot and are around 3" wide and 6" tall. These rails
need to be very precisely supported both side-to-side and up-and-down
especially if the trains are going to run at 200+ MPH. For viaduct you've got
to build the bridge, then put down the ties, then put rail on top of those,
fasten it down, etc. Ties are in the range of 6-8" thick and then there's the
ballast (rocks) which aren't light either and which are generally required to
keep the ties from moving. On bridges (viaduct) you might do something newer
and fancier but I wouldn't count on it here in the US. Overall you've got at
least 200lbs/foot for the rails and I might guess another 500-1500lbs/foot for
the ties and ballast and such. Rock weighs ~150lbs/cuft and so does concrete
so if your ties + ballast are a foot thick and 8 feet wide (rails are 4'8"
plus 20" extra on the sides) that's 1200lbs/foot.

Hyperloop runs in a 7.5 foot diameter tube with a 0.8in thick wall. 7.5 * 12 *
pi * 0.8=226 square inches cross section. Or a foot of it has 2712 cubic
inches of steel. At 0.283lbs/cu-in that comes out to be 767lbs/foot. Because
it's pipe (which has excellent structural geometry) it is self-supporting and
thus all you really have to do is get the pipe properly supported on top of
the pylons, weld two sections together and you're done.

Here's the last part. Hyperloop cars will be at least a mile apart. That means
the system can be designed to support just one of them per pylon. Train cars
will be 3 feet apart, and thus the viaducts have to support 1500lbs/foot * 80
feet per car * 10 cars = 600 tons. Versus the hyperloop car weights of 16.5
tons or 28.5 tons.

So these two systems are mildly different in terms of their car weights but
dramatically different in terms of the overall structural requirements and
design to meet those structural requirements. Train track is heavy and train
cars are heavy and trains are fairly dense (due to their length). Hyperloop
cars are about half as heavy and hyperloop track is half as heavy and
hyperloop support densities are only about half versus rail. 0.5 * 0.5 * 0.5 =
0.125 or 12.5% which isn't terribly far off from the 10% number that the
Hyperloop is quoted to cost versus the high speed rail system.

TL;DR: Cut track weight by half, car weight by half, and total support weight
by half and you get 0.125 which is suspiciously close to 0.10, the number that
the article author had such a problem with.

EDIT1: formatting

EDIT2: tl;dr

~~~
Anechoic
_That means the system can be designed to support just one of them per pylon._

The capacity of the structure is not just limited to the weight of the revenue
vehicles, the structure needs to handle other loads it may encounter over the
its useful life, such as snow (probably not much of an issue in
central/southern CA), water (if the tunnel leaks) and maintenance vehicles
(which will likely be significantly heavier than the passenger cars since they
will have to be self-propelled).

 _then put down the ties, then put rail on top of those, fasten it down, etc.
Ties are in the range of 6-8 " thick and then there's the ballast (rocks)
which aren't light either and which are generally required to keep the ties
from moving._

You don't need ballast & tie track on structures.

In any event, cutting the material weights in half (even if you can, which is
doubtful) does not automatically cut your costs by 90 percent. You still have
the environmental process, you still have NIMBYs, you still have construction
mobilization costs, etc.

~~~
msandford
That's a good point; something I neglected in my analysis.

I would argue that since the tube sections would all be pre-fab that means
that the installation cost of the tube would be really small. Rail
installation costs are no joke due to the need to precisely align horizontally
and vertically the two rails.

You can make tube in 50ft sections and ship them via truck without needing any
special permitting and given that the highway runs right next to the planned
route, the pre-fab notion is quite a good one.

~~~
Anechoic
_Rail installation costs are no joke due to the need to precisely align
horizontally and vertically the two rails._

The hyperloop sections would also need to be precisely aligned.

 _You can make tube in 50ft sections and ship them via truck without needing
any special permitting_

But you may need special routing for those trucks to allow overhead clearance
and turn radii, and you may need to build temporary roads for access to the
installation site. There are lots of little things that tend to add up that
are ignored in the whitepaper. You may be able to reduce costs by a few
percent, but 90% is not a figure that I can take all that seriously.

~~~
msandford
A standard semi-trailer is 53ft long and an internal cargo area that's 8ft
wide and 8ft tall. I think you can fit a 7.5ft diameter tube inside an 8ft
square box.

If you wanted to do the 11ft you would need a low-boy trailer to avoid height
permitting and you would need "wide load" signs for the trucks individually
but no lead/chase vehicles.

The tube joining/welding/grinding jig could be 40ft (or 200 ft or more) long
and fit inside the already assembled tube AND the to-be-welded tube. Precision
alignment could be done via movable clamps. Once the tube is held in place via
the jig it can be welded via a number of methods (friction stir, friction,
MIG, TIG or SMAW) inside, outside or both.

~~~
Anechoic
_I think you can fit a 7.5ft diameter tube inside an 8ft square box._

You are not going to give yourself 6-inches of clearance for a component that
weighs (using your numbers) 19.2 tons, that pipe is going on a flatbed. You
also have to allow room for tie-downs, flanges, support blocks, etc. You also
have to account for bridge weight limits.

I'm not saying this isn't doable (the Big Dig was able to truck in 100 ft
soldier piles, although they had to do it at night), it's just that it often
takes extra planning and work which increases costs.

 _The tube joining /welding/grinding jig could be 40ft (or 200 ft or more)
long and fit inside the already assembled tube AND the to-be-welded tube._

Are you basing this on something that already exists, or is this something you
are proposing?

~~~
msandford
Yes I'm quite aware. You'd actually build a number of semi-trailers that had
the proper rigging on them, welded down. My point was to say that it's
entirely possible to fit that size of a tube onto a semi trailer with no
hardship at all. No wide corners, no permits, no height restrictions, none of
that.

If it's possible to make two tunnel boring machines meet at the middle of the
English channel with the starting points separated by some 20 miles, then it's
entirely possible to build a pipe-section-holding jig which can ensure precise
alignment. I probably can't write a check for one and have it in a year
(partly because I don't have $5mm, also because the plans don't exist yet) but
to suggest that it would take more than three years to design, build and
verify such a machine is a bit extreme. You could probably do it in a year or
less provided that you're willing to pay more.

The machine as a whole doesn't exist yet but all the various component pieces
of it do and they're all COTS parts. It's part tunnel boring machine
([http://en.wikipedia.org/wiki/Tunnel_boring_machine](http://en.wikipedia.org/wiki/Tunnel_boring_machine))
part orbital welder
([http://www.mecomachineandfab.com/public/images/photos/orbita...](http://www.mecomachineandfab.com/public/images/photos/orbital-
welder.jpg)) and the rest is "glue."

Make it 300 feet long so that it's always resting on pipe that's already
affixed at two separate pylons and so that it doesn't deflect the pipe on
either side of the joint it's about to make. An external crane (or if you get
clever, one built onto the TBM/welder rig) lifts the pipe up, the jig grabs
hold of it, positions it, and then makes the weld. Let the machine advance
slightly and x-ray the entire weld for QA/QC and provided it passes, advance
the machine to do the next section.

If you wanted me to make one of these for you I'd probably quote $500k-$1mm
for the initial research including a small prototype (10-20" diameter) and I
would guess (+- 50%) $10mm for the big one.

~~~
Anechoic
What is your experience with large capital projects?

~~~
msandford
Very little. I've made a pretty decent career of doing things that are hard or
expensive or both, generally for cheap.

I built an semi-automated package dimensioner and barcode reader for about $5k
in parts plus my time The NRE was probably around $40k. A fully automated one
(including transport) starts at something like $80k. The company I worked for
then might have lost money on the first one (only if you look at opportunity
cost) but by the time they build three, they've saved at least $150k. Three of
them plus the employees to operate them would have a similar throughput,
higher dimensional capacity and better exception handling (what do you do with
a damaged package? Or one that's leaking?) than the one fully automated
system. An $80k system that can do 10x what your needs are is definitely more
expensive even if the per-unit costs are the same because you're paying for
idle time.

Elon Musk isn't going to call me up and ask me to build that system for him.
But if he did I wouldn't have too many problems making it happen. The
difficulty isn't making the machine, it's finding someone with the
constitution to ride out the periods of uncertainty and doubt while all the
bugs are being ironed out.

EDIT: When I've suggested that I could do the research and build a 10-20"
prototype I'm referring just to the pipe positioning jig + orbital welding
system. Not a small-scale hyperloop. That would be quite insane. Just a
precision alignment jig and associated welding equipment to do the final fit
and assembly of the pre-fabricated pieces.

~~~
Anechoic
I ask because my perception in reading your comments is that theory translates
nicely to real-world practice (which is also what I get from reading the
Hyperloop white paper), when the reality IME is that it almost never does.

For example:

 _If it 's possible to make two tunnel boring machines meet at the middle of
the English channel with the starting points separated by some 20 miles, then
it's entirely possible to build a pipe-section-holding jig which can ensure
precise alignment. _

Of _course_ it's possible, I've never claimed that it wasn't. The issue isn't
"is it possible" it's "can it be done at less cost than current proposals."
History shows numerous examples of new construction techniques that worked
great on paper, but had significant implementation flaws - for example soil
freezing was supposed to be a panecea on the Central Artery/Tunnel project,
but there were a ton of problems in the implementation and unexpected results
that needed to be dealth with. Even your Channel Tunnel example proves this
point - it used a lot of innovative technology and it came in late and over
80% over budget.

You talk about a welding rig that doesn't exist as a fait accompli. You wrote
"My point was to say that it's entirely possible to fit that size of a tube
onto a semi trailer with no hardship at all.' \- that's bull, I've seen crews
have a difficult time moving smaller and lighter pieces off and on semis. "No
wide corners, no permits, no height restrictions, none of that" \- really?
You're familiar with every possible street route along the proposed Hyperlink
corridor? Because if a truck gets stuck someplace (it happens:
[http://www.wwlp.com/dpp/news/local/hampden/truck-stuck-at-
ho...](http://www.wwlp.com/dpp/news/local/hampden/truck-stuck-at-holyoke-
underpass) ) the project is in for a bad time. And again, we haven't even
begun to address NIMBY issues.

That said (and I'm being serious here) if you have the chops to make solutions
like this work, you need to be working (or consulting) for the big engineering
firms like AECOM, PB, CH2M Hill, Jacobs, etc. Your ideas could revolutionize
the industry.

 _The difficulty isn 't making the machine, it's finding someone with the
constitution to ride out the periods of uncertainty and doubt while all the
bugs are being ironed out._

Exactly. That period is called "final design and construction." It's been the
death of many construction and A&E firms.

~~~
msandford
Again, I'm referring just to the pipe alignment and orbital welding rig. The
orbital welding part is a well understood problem and solution. I could call
up half a dozen companies today and for $20k buy an orbital welder in the
10-20" range. That's off the shelf. If I wanted to scale that up they might
have to custom fabricate the tracks to guide the welding portion, but that's
trivial. It might cost another $20k if the size is really big, and make
another $40k if I want to buy a REALLY big power supply so that it can weld
faster but as a class of problems orbital welding is a solved one.

As far as loading tubes go, you're likely going to build a tube rolling
facility. These kinds of places tend to have overhead cranes. Big ones. Cranes
that can grab the tube on both ends and thus have precise control over it.
Most likely the loading would be done "indoors" so weather is mostly factored
out. Building semi-circular restraints that grab the tube in 3-5 places along
the 50ft length is done easily enough with a water-jet or you could roll a
pipe into a semi-circle and weld supports to it. Once you have the custom
trailer done it's relatively straightforward. You'd build the infrastructure
to handle this in a highly automated fashion, similar to how container ships
get loaded and unloaded. ~350 miles is 36,960 50ft sections of tube, double it
since we're doing double-wide. If you know you need that much at the beginning
there's a lot of work that can be done to make the whole thing reasonably
efficient and cost effective.

I don't understand why you're expanding the scope to NIMBY or access roads or
stuck trucks (locate the plant near the freeway) or any of this. I was talking
specifically about the loading and unloading of pipe and making a jig to hold
said pipe for precise welding.

Again, when I said "The difficulty isn't making the machine, it's finding
someone with the constitution to ride out the periods of uncertainty and doubt
while all the bugs are being ironed out." I'm referring only to building the
alignment/welding machine, not the entire Hyperloop system. I realize that
building the whole thing is immensely more difficult than building the
alignment/welding jig. But we're inventing very little new stuff here, mostly
repurposing things or making incremental changes.

All the "final design and construction" that you're talking about has the same
risks and problems for the HSR as for the Hyperloop. If I have to be exposed
to an 80% cost overrun I'd rather it was on a $5bn or $7.5bn project rather
than an $80bn one. Maybe Hyperloop even has a 300% cost overrun and somehow
the HSR project could come in 25% under budget. Hyperloop would then be
(assuming the bigger version) $22.5bn versus the rail at $60bn.

The reason I don't work at a big engineering firm is that I couldn't get hired
in at a senior enough level to actually get anything done. So I work for small
companies. Thus far my track record is excellent but it would probably take me
another 10-15 years for me to have enough successes at difficult projects for
people to stop assuming it's a fluke. And by then I might not be too
interested in risking my career on every project I work on.

This is why startups are even possible. The risk aversion of senior management
makes it possible for people who are too young and too dumb to know that
something's "impossible" to make it happen. If you've got any ideas how I
could get hired at a big construction firm at a senior level I'm all ears.

There is all kinds of crazy stuff out there:
[https://www.youtube.com/watch?v=E0O78AyDixY](https://www.youtube.com/watch?v=E0O78AyDixY)

They're using a $45mm, 45 foot diameter TBM in Miami right now that's 450 feet
long, has the ability to erect concrete rings inside of the machine, and can
exert crazy pressure on the rock face.
[http://www.portofmiamitunnel.com/faqs/tunnel-boring-
machine/](http://www.portofmiamitunnel.com/faqs/tunnel-boring-machine/)

I'm suggesting something with less challenging specs and suggesting it could
be built for less money. I don't think it's unreasonable.

------
Symmetry
I'm really unsure about the author's assertions regarding the maximum
accelerations that people can take. Those might be the normal regulatory
limits for passenger rail, but I'm pretty sure that the accelerations I've
experienced on planes have also gone up into territories the author would
consider utterly unacceptable.

On the other hand, I think he has some good points regarding the cost numbers.
If pylons have all the advantages that Musk claims then why aren't we all
getting around city on monorails?

------
leot
If there's enough public will to make something great happen, and that
something-great is within the realm of engineering feasibility, then it will
happen.

I _love_ HSR. But I also think we as a species are capable of much, much, much
more than we're currently accomplishing. And much of the reason we're stuck
using slow, uninspiring, and polluting technology from yester-year is a lack
of public will.

So to the naysayers: if you want to harp on some bold proposal to do something
great, pretend it's 1961 and someone told you about sending men to the moon
and back. Pretend it was 1948 and someone proposed making trains that went 90
mph. Pretend it was 1850 and someone proposed linking Paddington and
Farringdon using a massive tunnel buried deep underground. Real things change
all the time. Technology can make problems go away. Bold proposals such as
Musk's -- proposals that are the good-faith effort of someone who is ultra-
competent and with a lot of social and financial capital -- are proposals that
need to be celebrated and encouraged.

Doing new things well is orders of magnitude more difficult than doing that
which has been done before. If you've never followed-through on a crazy and
bold idea, please temper your critique of those who have.

------
cousin_it
Is it possible to build viaducts for $5mil/km?

~~~
Retric
Yes, however the cost of a viaduct is largely dependent on the height
required. The Alasca pipeline came in around 1.2 million per mile dispite vary
harsh conditions but it was also rather low to the ground.

~~~
cousin_it
Maybe I'm confused about the meaning of the word "viaduct", does a pipeline
count as one?

~~~
throwaway_yy2Di
A pipeline doesn't need viaducts because it doesn't have severe restrictions
on curves. It can follow terrain:

[https://en.wikipedia.org/wiki/File:Trans-
Alaska_Pipeline_Sys...](https://en.wikipedia.org/wiki/File:Trans-
Alaska_Pipeline_System_Luca_Galuzzi_2005.jpg)

A high-speed railway needs to be flat, so it needs tall pylons to support it
above uneven terrain:

[https://en.wikipedia.org/wiki/File:SNCF_TGV_Duplex_Viaduc_de...](https://en.wikipedia.org/wiki/File:SNCF_TGV_Duplex_Viaduc_de_Cize_-
_Bolozon.jpg)

[https://en.wikipedia.org/wiki/File:Millau_Viaduct_constructi...](https://en.wikipedia.org/wiki/File:Millau_Viaduct_construction_south.jpg)

~~~
Retric
Trains often need viaducts due to those restrictions but a multi span
footbridge over a swamp is a viaduct as is the Disney monorail. My point is
simply elevating a span is not that expencive. However, as you say high speed
rail needs a vary flat track so cost estimates need to look at the actual path
vs just saying 5m/km is rediculus without any justification.

------
jpatokal
_The LA end is really Sylmar, at the edge of the LA Basin; with additional
access time and security checks, this is no faster than conventional HSR doing
the trip in 2:40._

"Security checks"? Why would Hyperloop require any more security checks than
the HSR? If anything, you'd expect security to be _faster_ for a constant
stream of departures, vs 1000+ passengers bunched together for a train.

(Or you could be sensible like the French, Japanese, Germans and Chinese and
dispense with any train-related security theatre entirely, but that would
probably be too much to ask in the land of the free and the home of the
scared.)

~~~
mehwoot
Security checks is not the main cost of time there. The hyperloop is suggested
to end up in Sylmar, which according to google, is about a 30 minute drive
from Union Station in the center of Los Angeles, where the HSR will stop at. I
don't live in LA so I'm not sure whether that 30 minutes is optimistic or
pessimistic.

------
jcox92
'skeptical' doesn't seem like the right word. I think 'loathsome' would be
more fitting. While the author makes some good points, it was hard to consider
them legitimate given that he sandwiched the article with opinionated rants
that seemed to abhor the idea of successful people having good ideas.

------
madaxe
'What is love? What is creation? What is longing? What is a star?' thus asks
the last man, and blinks.

The earth has become small, and on it hops the last man, who makes everything
small. His race is as ineradicable as the flea; the last man lives longest.

'We have invented happiness,'say the last men, and they blink. They have left
the regions where it was hard to live, for one needs warmth. One still loves
one's neighbor and rubs against him, for one needs warmth...

I see Musk as something akin to Nietzsche's superman - and this chap, the
detractor, the denigrator, the naysayer, is his last man.

~~~
philwelch
I can't believe you got downvoted. You've made explicit the sycophantic,
uncritical Elon Musk worship that permeates this thread.

------
jdietrich
Frankly, I'm sickened at the hubris involved in this kind of analysis.

Musk owns a space exploration company that is flying regular commercial
missions, yet OP thinks that Musk has made elementary mistakes in his physics
calculations. SpaceX are currently building a passenger spacecraft, but OP
thinks that nobody has factored the effect of G forces on passengers into the
design. They have reduced the cost of putting mass into orbit by an order of
magnitude, but OP deigns to assess the validity of Musk's cost estimates.

Frankly, who the fuck is he to tell Elon Musk what is possible? Musk has
degrees in both economics and applied physics. He has done the "impossible" in
three industries and is an epoch-defining figure in electronic payments, space
exploration and the motor industry. Musk isn't some crackpot with a big bank
balance, he's a genius with an astonishing track record of revolutionising
established industries from the outside, by ignoring old assumptions about
what is possible.

Hyperloop might succeed or fail, but I genuinely can't think of a single
person who has ever lived who might be better qualified to make that judgement
than Elon Musk.

