Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Hyperloop Freight is a Joke

pedestrianobservations.wordpress.com

Post reply on HN
Print view View original

131–140 of 177 posts

Re: Hyperloop Freight is a Joke

#131

Post by toomanybeersies »

Tade0 wrote: post #36
cmrx64 wrote: post #17

Earlier quoted context omitted.

Where do you get all that helium?

I don't know, maybe from the 175 million cubic meters produced annually? For a 300km, two lane stretch you'd require around 7.5mln cubic meters - sure, that's a lot, but it's not an impossible amount.

So almost 5% of global production of Helium? Add to that the fact that helium tends to leak at a much higher rate than any gas, and that sounds prohibitively expensive.

Especially since the current price of Helium is artificially low, and it's not a renewable resource at current extraction rates, so the price is not going to remain so low in the future.

Re: Hyperloop Freight is a Joke

#132

Post by zerooneinfinity »

jheriko wrote: post #111
D_Alex wrote: post #82

Earlier quoted context omitted.

Elon Musk had zero experience building cars, yet he made Tesla happen. Perhaps a high intellect and a good general purpose engineering training can accomplish more than you think. You, on the other hand, are overwhelmed by the challenge of maintaining vacuum in a tube that spans a mere 17 miles. At the very least, you should restrain yourself from using language like "...some idea he farted out...".

be careful, tesla is not successful as a car company yet, and its not in good shape to become one either. one day it might be, and more generally i do hope that we see more progress in the electric car world... but for now tesla only turns a profit as a car company coupled with government incentives. even then, outside of the US (and inside actually) their market share is tiny or zero with very little growth. saying…

In terms of their mission statement which is convince people that electric cars can be 'cool', practical and inexpensive he has succeeded much more than you are giving him and the people at Tesla credit for.

Re: Hyperloop Freight is a Joke

#133

Post by thesimpsons1022 »

wilam wrote: post #129
jheriko wrote: post #111

Earlier quoted context omitted.

be careful, tesla is not successful as a car company yet, and its not in good shape to become one either. one day it might be, and more generally i do hope that we see more progress in the electric car world... but for now tesla only turns a profit as a car company coupled with government incentives. even then, outside of the US (and inside actually) their market share is tiny or zero with very little growth. saying…

year over year grown >50% seems a lot for a car company.

If I build 2 cars last year and sell 3 this year then I bet you'd be really impressed huh?

Re: Hyperloop Freight is a Joke

#134

Post by toomanybeersies »

Retric wrote: post #121
sib wrote: post #78

Earlier quoted context omitted.

The issue is not acceleration front/back, which can be dealt with in design and is fairly stable and consistent, but acceleration as much as 0.5G side/side, which is also more intermittent and against which it's difficult to build seats that would protect customers.

Really it's just a question of track design as these are 100% predictable G forces. If you really need to turn you can just roll the cabin and keep these g's directly under you and or slow down apraoching it. Elevators can also quickly have a fairly wide range (0.8 to 1.2) g's and people don't really get sick in them. Highways for example have fairly wide banks which people rarely notice. https://sterlingpearce.files…

Aeroplanes are probably a more accurate approximation of what you'd feel. You get hardly any G force from banked highways, your speed is just too low. Now I don't really get plane sick, I will quite happily sit through a few barrel rolls (which is far more extreme than the hyperloop (although that would be fun)), but there's plenty of people who would get sick from a few 1.5 G banked turns.

Elevators are different because you don't spend more than about 1 minute in an elevator.

Re: Hyperloop Freight is a Joke

#135

Post by taneq »

mypalmike wrote: post #106
taneq wrote: post #53

Earlier quoted context omitted.

A train that accelerates at 0.5g to 1200kph would be awesome and I would ride it at every available opportunity.

What about one where you feel that, acting in various directions, at every curve, every speed transition, and every elevation change. Because that's the "barf ride" being discussed, not merely getting thrown to the back of your seat during initial acceleration.

That sounds even more fun. :D

Although as the poster mentioned below, a passenger service would gradually rotate the passenger compartment to keep the G-forces vertical, a la a banking aircraft, so all you'd likely notice would be feeling heavier for a few seconds.

Re: Hyperloop Freight is a Joke

#136

Post by mcguire »

Retric wrote: post #47
Spooky23 wrote: post #32

Earlier quoted context omitted.

Forces of nature or other things never suddenly disrupt infrastructure. See: http://whns.images.worldnow.com/images/22787728_SA.jpg

It's an elevated track so it really could be designed to deal with that kind of break. Water, Oil, and Gas pipelines for example have long dealt with those issues without breaking when designed correctly.

Absolutely.

http://www.snopes.com/photos/accident/graphics/gasline2.jpg

Re: Hyperloop Freight is a Joke

#137

Post by [deleted] »

D_Alex wrote: post #115
LordHumungous wrote: post #83

Earlier quoted context omitted.

The tolerances on each part must be very tight. If there is a single flaw in one part, the whole vacuum fails. The challenges become exponentially greater as you scale up the diameter of the pipe, since the force on the pipe is proportional to the square of the radius. The LHC had a 50mm diameter pipe, the hyperloop proposes an 8+ foot diameter. You do the math.

When you said that you worked on the LHC for several years - what was your role, and how were you involved with the vacuum system? Because your answers show a serious lack of understanding. First, part tolerances are not a particularly important issue with engineering of high vacuum systems (sealing is effected by compression of gaskets, usually soft stainless steel gaskets for UHV systems). Secondly, the difficultie…

[deleted]

Re: Hyperloop Freight is a Joke

#138

Post by mcguire »

treelovinhippie wrote: post #7
Russell91 wrote: post #2

I always come to these hyperloop criticisms expecting to find some sort of fatal flaw in the physics of energy efficient supersonic travel. But to my surprise, they instead tend to be pessimists saying things like, "You'll never get past my friends: the regulators, the government bureaucrats, and especially the lawyers!. We will drive up your costs and make you look foolish". First, no one said that designing this th…

Pessimism seems to be the default for the HN hivemind. Would be cool if we all just encouraged everyone working on moonshots.

Theranos.

Re: Hyperloop Freight is a Joke

#139

Post by [deleted] »

D_Alex wrote: post #115
LordHumungous wrote: post #83

Earlier quoted context omitted.

The tolerances on each part must be very tight. If there is a single flaw in one part, the whole vacuum fails. The challenges become exponentially greater as you scale up the diameter of the pipe, since the force on the pipe is proportional to the square of the radius. The LHC had a 50mm diameter pipe, the hyperloop proposes an 8+ foot diameter. You do the math.

When you said that you worked on the LHC for several years - what was your role, and how were you involved with the vacuum system? Because your answers show a serious lack of understanding. First, part tolerances are not a particularly important issue with engineering of high vacuum systems (sealing is effected by compression of gaskets, usually soft stainless steel gaskets for UHV systems). Secondly, the difficultie…

[deleted]

Re: Hyperloop Freight is a Joke

#140

Post by Lazare »

Russell91 wrote: post #2

I always come to these hyperloop criticisms expecting to find some sort of fatal flaw in the physics of energy efficient supersonic travel. But to my surprise, they instead tend to be pessimists saying things like, "You'll never get past my friends: the regulators, the government bureaucrats, and especially the lawyers!. We will drive up your costs and make you look foolish". First, no one said that designing this th…

> I always come to these hyperloop criticisms expecting to find some sort of fatal flaw in the physics of energy efficient supersonic travel. But to my surprise, they instead

Except, as the article points out, it's not actually faster, cheaper, or efficient than competing technologies. Those seem like really fatal flaws.

> Countries without common law legal systems get around these unnecessary costs much easier.

That same logic also applies to the competing technologies. The same magic wand that lets you build a hyperloop for 1/10th what it would cost in the US also lets you build the tracks for HSR for 1/10th what it would cost in the US. You can't compare the cost of building a hyperloop in China to the cost of building HSR in California and get a meaningful answer.

Nobody is saying that the hyperloop is impossible; they're saying that it's a plan to build something objectively worse than high speed rail at prices that seem broadly comparable.

Post reply on HN