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Hyperloop Freight is a Joke

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Re: Hyperloop Freight is a Joke

#71

Post by Spooky23 »

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.

Big water infrastructure breaks too.

My wife was PM on an emergency project to replace a 72" main feeding a city that failed.

Re: Hyperloop Freight is a Joke

#72

Post by Spooky23 »

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.

Big water infrastructure breaks too.

My wife was PM on an emergency project to replace a 72" main feeding a city that failed.

Re: Hyperloop Freight is a Joke

#73

Post by Animats »

Vactrains might work out. There's nothing wrong with maglev in an evacuated tube. A system where the thing runs on open track until it gets out of the city and can switch to a vacuum tube might work. Then you can get someplace useful. Most of the "hyperloop" proposals, including the MIT demo, are really maglev vactrains.

If you're already a maglev, a tube doesn't add much. Japan's maglev has already reached 600 Km/h. The Shanghai/Transrapid maglev routinely runs at 431 Km/h, and has hit 500 in tests. At those speeds, SF-LA is about an hour. But the track cost is very high.

That's not stopping JR Tokai. The Tokyo to Nagoya maglev line has been under construction for two years now. They're taking the most direct route to get the fastest transit time. There are mountain ranges in the way. They're going straight through them. 90% in tunnel. Completion in 2027. Cost comparable to Twitter's peak market cap. Public support for this is so high that JR is being pushed to build the next section, Nagoya to Osaka, sooner.

With enough money...

Re: Hyperloop Freight is a Joke

#74

Post by knieveltech »

the_duke wrote: post #59
rootusrootus wrote: post #50

Earlier quoted context omitted.

One need look no farther than Silicon Valley to see a plethora of starry eyed investors who are either blind, dumbstruck, or simply haven't done due diligence. Isn't the bubble about to pop... again?

I don't think we are in a bubble anything like the dot com debacle. The industry as a whole is far more mature now, and paths to monetization are clearer. Competition is high, so is the competence of most VCs and investors. I'd also place an engineering project like Hyperloop in a whole different space than the typical SV stuff.

"paths to monetization are clearer." Indeed. Try to generate enough hype to bilk IPO investors or failing that get bought out by a firm that actually makes money.

Re: Hyperloop Freight is a Joke

#75

Post by nickparker »

problems wrote: post #16
dpark wrote: post #15

Earlier quoted context omitted.

Why would loss of vacuum necessarily result in loss of life? I would expect loss of vacuum to result in sudden deceleration, but not with a deadly level of force.

Air being drawn in results in pressure on the capsule, propelling it. Check the video out for a demo.

There are three mitigating points for that issue:

First, you would get choked flow at the inlet, and if you do the math it actually takes a massive opening to really make a dangerous shockwave.

Eg, if a joint in the tube disconnects and the two halves pull apart, the inlet area is the tube circumference * gap between halves. The two halves would need to separate by the full diameter of the tube (~15 ft) to get full atmospheric pressure going in both sides. A realistic gap of a couple inches to a couple feet is far less scary.

Second, these incidents will be exceptionally rare. Gaps that big are equivalent to a freeway overpass collapsing. It's a total failure scenario, so you see a single digit number of them a year in the US.

Lastly, the speed of sound isn't all that quick on the scale of this thing. It's about 13 miles/min, a fifth of a mile a second.

If you place emergency fill valves (one time use things, dirt cheap, just explosive bolts in the simplest case) you can flood a whole section of the tube with atmosphere in a controlled manner over say 15 seconds, and your shockwave will be largely stopped after 3 miles.

An emergency fill like that would also stop all pods in the region as they hit very high drag, so you don't even need to carry heavy emergency brakes on every vehicle.

Re: Hyperloop Freight is a Joke

#76

Post by eruditely »

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…

Statute law systems are the socialism of law, Common-law, this collaborative law making is the 'free market' problem, and it does not have a calculation problem via the legislator/statute marker.

Re: Hyperloop Freight is a Joke

#77

Post by dilemma »

Animats wrote: post #73

Vactrains might work out. There's nothing wrong with maglev in an evacuated tube. A system where the thing runs on open track until it gets out of the city and can switch to a vacuum tube might work. Then you can get someplace useful. Most of the "hyperloop" proposals, including the MIT demo, are really maglev vactrains. If you're already a maglev, a tube doesn't add much. Japan's maglev has already reached 600 Km/h.…

>But the track cost is very high. That's not stopping JR Tokai.

It all depends on perspective. If decision maker view the maglev as the 21st century version of the railway that let societies prosper in the 19th and 20th, then it might not be expensive at all because the return is so great and the horizon so long.

Re: Hyperloop Freight is a Joke

#78

Post by sib »

taneq wrote: post #53
Xorlev wrote: post #5

Earlier quoted context omitted.

Reading through the criticisms the consensus is "sure, this can work if you allocate 10-100x more money than estimated." I'm not sure if it's truly innovative if it costs more, places considerable stress (up to 0.5g!) on the rider/cargo (what the author calls a "barf ride"). The analysis picks apart the touted benefits of additional speed when ultimately the capacity is lower and it takes longer to depart. In the cas…

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

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.

Re: Hyperloop Freight is a Joke

#79

Post by Turing_Machine »

LordHumungous wrote: post #62

Of course the hyperloop is a joke. Elon Musk has zero experience or training in transportation infrastructure, but we are supposed to have faith in some idea he farted out in a white paper, why? Because he has skillfully cultivated his image as a "genius", and we bought it? The hyperloop was nothing more than a (savvy) PR move to cement his image as a "visionary". That it actually got funded only goes to show what gu…

"The challenges of maintaining a closed vacuum pipe that spanned a mere 17 miles were vast and expensive."

The vacuum level required for a particle accelerator (10^-11 torr or something like that) and the one posited for the Hyperloop (0.75 torr) are so far apart that they have virtually nothing in common.

Re: Hyperloop Freight is a Joke

#80

Post by agumonkey »

toomanybeersies wrote: post #66
bigger_cheese wrote: post #57

One thing the article misses is inflexibility. One of the big disadvantages of rail is that once the track is deployed it is very costly and difficult to upgrade it. One thing I'd want in any "futuristic" freight hauling method would be ease of scaling I don't think Hyperloop offers anything over rail in this regard once track is installed you are more or less stuck with the installed capacity forever. A computer ana…

> A computer analogy I'd give is to think of freight handling like information communication Unsurprisingly, a lot of the theory for transport networks maps extremely well to computer networks. Transport is essentially a literal packet switched network. You have routers (depots), routes (roads, rails, etc), packets (in many cases, literally packets), MTUs (twenty foot containers, or truckloads). Queuing theory equall…

I remember talks of propping up underground rails as internet of things, literally pushing things instead of data toward any place automatically. I'd love to test this.
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