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Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

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Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#81

Post by vannevar »

nickik wrote: post #53
vannevar wrote: post #50

"...digging sure sounds easier than building a rocket that lands vertically." It isn't. Just ask the builders of the Chunnel. It's only 31 miles long and went 80% over budget and 20% behind schedule. A tunnel from New York to DC would be nearly 10 times as long and run under some of the most densely populated land in the country. Rockets and electric cars are trivial by comparison.

20% behind schedule? 80% over budget? Look at some of the projects by SpaceX.

Or look at the Big Dig in Boston. It ended up costing $24B (10 times the original estimate) and was eight years behind schedule. And that was for less than 4 miles of tunnel under a major city.

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#82

Post by galdosdi »

stcredzero wrote: post #66
ProblemFactory wrote: post #21

Is technology really the slow and expensive part of boring tunnels? To me it has always seemed that tunnels are expensive because: * Planning the traffic impact and how it interacts with other transport lanes, all the above-ground building work to make the tunnel useful, * Emergency ventilation and escape routes, and all other infrastructure that goes into the hole, * Avoiding any building foundation piles, unmapped…

Planning the traffic impact Solution: Do not connect the tunnel directly to the road network. Emergency ventilation Solution: Build a kind of infrastructure that only allows onboard backup as emergency ventilation. Escape routes Solution: Minimize escape shafts and provision emergency rescue vehicles capable of transporting an entire pod. Maximize reliability by exploiting the increased reliability of electric drivet…

Those problems are hard for a reason. XKCD puts it succinctly: https://xkcd.com/1831/

> Solution: Do not connect the tunnel directly to the road network.

Then how do people get there? Train? OK, then you have to plan how it interacts with the train network's traffic and schedules, duh.

At least that's easier than car traffic... OH WAIT! Train stations usually have parking, or even if they didn't, are in the middle of a city, not at the top of a tower in the himalayas. So even if you don't want them to, people can drive to near an entrance and park. There will be induced traffic, and there is no way to keep the two networks unrelated without making the tunnel network totally useless.

> Solution: Build a kind of infrastructure that only allows onboard backup as emergency ventilation.

FWIW This also means you have to ban internal combustion engines (which should be OK). Just to deal with ICE exhaust, the Holland tunnel replaces all the air inside it every 90 seconds.

> Solution: Minimize "all other" which is not simply the hole.

You don't even know what "all other" is, do you? I don't either, but this whole set of solutions is really borderline "Why don't they just make the whole plane out of the black box?" ignorant sounding.

> Solution: Go deep enough to avoid all of these.

And I'm as ignorant as you, but I remember reading somewhere that digging costs can be exponentialish as depth increases, for a bunch of reasons.

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#83

Post by surrealize »

stcredzero wrote: post #80

Something just occurred to me: Is the levitating vac train concept just a feint? The technology developed for building electric semi trucks would also be useful for building highly streamlined electric trains. With automated piloting, the difference between the two would be blurred! Is Elon aiming to become the railroad tycoon of the 21st century? I don't think air resistance is the largest cause of expense in transp…

> I don't think air resistance is the largest cause of expense in transportation.

If you want to go fast (the plan for the hyperloop) then air resistance becomes a significant cost. The power it takes to overcome aerodynamic drag increases with the cube of velocity.

I imagine the hyperloop design where cars are independent makes drag costs worse compared to trains (compared at the same speed).

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#84

Post by dragonwriter »

bpodgursky wrote: post #73
kbenson wrote: post #63

Earlier quoted context omitted.

Every mining company will lobby against that. It's probably easier to do it with easements and eminent domain.

This concept already does exist, and is used by mining companies, so no they won't lobby against it. There are a lot of cities in Pennsylvania with coal mines a mile underneath them.

> This concept already does exist,

No, it doesn't. You are confusing the severability and frequent separate sale of mineral rights to a federalization of all subterranean property.

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#85

Post by Diederich »

baron816 wrote: post #67

I have a feeling that Musk loves being mocked for this. Wouldn't you love it if you pitched a crazy idea for which everyone made fun of you for, and then you delivered?

For example:

1. A new, successful car company.

2. A new, successful space launch company.

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#86

Post by stcredzero »

surrealize wrote: post #83
stcredzero wrote: post #80

Something just occurred to me: Is the levitating vac train concept just a feint? The technology developed for building electric semi trucks would also be useful for building highly streamlined electric trains. With automated piloting, the difference between the two would be blurred! Is Elon aiming to become the railroad tycoon of the 21st century? I don't think air resistance is the largest cause of expense in transp…

> I don't think air resistance is the largest cause of expense in transportation. If you want to go fast (the plan for the hyperloop) then air resistance becomes a significant cost. The power it takes to overcome aerodynamic drag increases with the cube of velocity. I imagine the hyperloop design where cars are independent makes drag costs worse compared to trains (compared at the same speed).

I imagine the hyperloop design where cars are independent makes drag costs worse compared to trains (compared at the same speed).

However, autopilot cars don't have to operate independently over long distances, in ways that specifically reduce air resistance!

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#87

Post by surrealize »

stcredzero wrote: post #86
surrealize wrote: post #83

Earlier quoted context omitted.

> I don't think air resistance is the largest cause of expense in transportation. If you want to go fast (the plan for the hyperloop) then air resistance becomes a significant cost. The power it takes to overcome aerodynamic drag increases with the cube of velocity. I imagine the hyperloop design where cars are independent makes drag costs worse compared to trains (compared at the same speed).

I imagine the hyperloop design where cars are independent makes drag costs worse compared to trains (compared at the same speed). However, autopilot cars don't have to operate independently over long distances, in ways that specifically reduce air resistance!

Presumably you mean they could follow one another very closely. If they're traveling at several hundred mph, that doesn't give following vehicles much time to react if there's a problem with a leading vehicle.

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#88

Post by stcredzero »

galdosdi wrote: post #82
stcredzero wrote: post #66

Earlier quoted context omitted.

Planning the traffic impact Solution: Do not connect the tunnel directly to the road network. Emergency ventilation Solution: Build a kind of infrastructure that only allows onboard backup as emergency ventilation. Escape routes Solution: Minimize escape shafts and provision emergency rescue vehicles capable of transporting an entire pod. Maximize reliability by exploiting the increased reliability of electric drivet…

Those problems are hard for a reason. XKCD puts it succinctly: https://xkcd.com/1831/ > Solution: Do not connect the tunnel directly to the road network. Then how do people get there? Train? OK, then you have to plan how it interacts with the train network's traffic and schedules, duh. At least that's easier than car traffic... OH WAIT! Train stations usually have parking, or even if they didn't, are in the middle of…

Then how do people get there? Train? OK, then you have to plan how it interacts with the train network's traffic and schedules, duh.

Your reasoning applies equally to airports. Congrats, you just "debunked" the airplane! (duh!)

So even if you don't want them to, people can drive to near an entrance and park. There will be induced traffic

This is vacuous. There will always be induced traffic for such a project. But the kind of planning required for the kind produced by an airport is materially different from the kind produced by an entirely new highway. Also, if your new "airport" requires the construction of a new road in the future, this isn't as big a short term barrier as those around an entirely new major highway, and will be borne by the local government.

FWIW This also means you have to ban internal combustion engines

FWIW, I'm glad you finally caught up with my actual idea!

You don't even know what "all other" is, do you?

That's not relevant at this level. I don't have to know all the details of building a road to know that not building a road and flying a cargo will avoid those expenses and incur different ones. What is your point, here?

(Here's a hint, when discussing major infrastructure, don't automatically ascribe to others straw man positions of zero cost! That's not exactly a "charitable" reading.)

And I'm as ignorant as you, but

...a little soft in the reasoning. If digging costs are exponential with depth, then this would be an interesting point. I'm not sure if I should really credit that. Well, I guess one would deserve credit for bringing that to attention. So your comment makes, charitably, a "half point."

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#89

Post by stcredzero »

surrealize wrote: post #87
stcredzero wrote: post #86

Earlier quoted context omitted.

I imagine the hyperloop design where cars are independent makes drag costs worse compared to trains (compared at the same speed). However, autopilot cars don't have to operate independently over long distances, in ways that specifically reduce air resistance!

Presumably you mean they could follow one another very closely. If they're traveling at several hundred mph, that doesn't give following vehicles much time to react if there's a problem with a leading vehicle.

You basically have the same problem with high speed trains, or even ordinary trains. It's just that all of the "control" is entirely passive. If your drive and control systems can be made as reliable as the passive systems linking train cars, then that should meet the same level of safety. Also, have you been on the highway during rush hour? There's not that much buffer against a pileup, in a system much more prone to failure!

Re: Elon Musk’s Tunnel Plan Isn’t as Crazy as SpaceX or Tesla

#90

Post by dragonwriter »

stcredzero wrote: post #88
galdosdi wrote: post #82

Earlier quoted context omitted.

Those problems are hard for a reason. XKCD puts it succinctly: https://xkcd.com/1831/ > Solution: Do not connect the tunnel directly to the road network. Then how do people get there? Train? OK, then you have to plan how it interacts with the train network's traffic and schedules, duh. At least that's easier than car traffic... OH WAIT! Train stations usually have parking, or even if they didn't, are in the middle of…

Then how do people get there? Train? OK, then you have to plan how it interacts with the train network's traffic and schedules, duh. Your reasoning applies equally to airports. Congrats, you just "debunked" the airplane! (duh!) So even if you don't want them to, people can drive to near an entrance and park. There will be induced traffic This is vacuous. There will always be induced traffic for such a project. But th…

> Your reasoning applies equally to airports.

That's not really in dispute.

> Congrats, you just "debunked" the airplane! (duh!)

If by “debunked the airplane” you mean “demonstrated the already widely-accepted fact that air travel only is effective with considerable attention to the surface transport connecting airports to the places people actually want to go to and from in the area serviced by the airport”, sure.

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