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New York to London in an hour - by train

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Re: New York to London in an hour - by train

#61

Post by Symmetry »

ChuckMcM wrote: post #11

Good luck holding a vacuum under the ocean. I read stuff like this and I think, "Gee, I don't think these people have actually built anything." because if they had they would realize that if it costs $1M a foot too build subways [1] in cities with moderately skilled labor, its going to cost $10 - 25M/ft to build something like this. That's half a quadrillion dollars (448 trillion dollars). What sort or rate of return…

Other countries with different building laws have very different costs. Say what you will about Spain, they can build subways or rail for one tenth as much as it costs in the US. French and British trains are also, I believe, much cheaper though not quite that much.

Re: New York to London in an hour - by train

#62

Post by Someone »

Eliezer wrote: post #42
ChuckMcM wrote: post #23

Earlier quoted context omitted.

Would love to see how they costed that out. Given that I don't know of a single engineering company that can build straight up light rail track for at $2.5M/mile even if you give them the land for free. Edit: add this update -- Interestingly this link: http://www.freerepublic.com/focus/f-news/843626/posts claims that the ET3 bid was 1.2B$ which is $12.5M/mile which is a lot more credible (still low though since the s…

How the hell does light rail track cost $2.5M/mile? How did people build railroad tracks back in the days of horses and buggys?

They built awfully bad ones, by today's standards. Rails weren't prestretched and welded together. Instead, they left gaps between rails to cater for temperature differences (http://en.wikipedia.org/wiki/Track_(rail_transport)#Joining_...)

Modern trains also are heavier and accelerate and decelerate faster than the trains you see in westerns. Both mean that they exert greater forces on the rails.

Finally, safety standards are way higher. That means that material must be of higher quality and tested better, both at the factory and after installation.

Re: New York to London in an hour - by train

#63

Post by jamesaguilar »

ChuckMcM wrote: post #51
Eliezer wrote: post #42

Earlier quoted context omitted.

How the hell does light rail track cost $2.5M/mile? How did people build railroad tracks back in the days of horses and buggys?

That is a great question, I wish I could reasonably answer it. I'm a big fan of rail, and while San Jose was celebrating their first 4 miles of light rail (in just 10 years from the start of the project!) I was looking that the marker in the Sacramento Rail museum (recommended) commemorating the laying of 10 miles of the Union Pacific rail line in one day . Part of it is that some folks really hate rail, so much so t…

Isn't this part of why rail is a lot easier to do in Europe? My understanding is that it is a lot harder to sue over stuff like this there. Maybe someone familiar with Europe's rail situation can chime in.

Re: New York to London in an hour - by train

#64

Post by allenlavoie »

planetguy wrote: post #44
Retric wrote: post #33

Earlier quoted context omitted.

A large chunk of the costs of projects like this is building the long flat tunnel/level ground over significant distances. The actual costs of building a moderate vacuum is not that significant. Where this project falls down is in the maintenance and safety side of things not the infrastructure to send the first train down the line. Don't forget every 10m adds 1atm water pressure. Building a glass enclosed under sea…

There are two problems here. Firstly: As I see it, an evacuated tunnel at 20m is a very different proposition to a non-evacuated tunnel at 30m, even if the pressure difference is the same. Why? Well, your big problem is always going to be leaks. In an air-filled tunnel you can get away with microscopic cracks, no problem; you've got a small direct interface between water and air, and the surface tension of the water…

Is there some reason that sandwiching air between the evacuated tube and the water wouldn't work? Granted it would add to the cost.

The ocean depth point is interesting. The article says "engineers would tether the tunnel at a fixed depth." I take this to mean tethering to the bottom and relying on buoyancy to keep the tunnel floating at the right depth, which presumably could be 30m or so.

Re: New York to London in an hour - by train

#65

Post by DeepDuh »

moocow01 wrote: post #22

I never have understood people's fears about getting on an airplane... this though I'd be scared to death of. You have any unfortunate shift in the tectonic plates (which happens daily and unpredictably) and you could be dead in an instant.

Here's how the Japanese high speed trains deal with earthquakes: They have emergency break systems (I think its small ceramic globuli or something of the sort) and a really good forewarning system. 2011-3-11 all Shinkansen were at a halt when the big one hit and noone was harmes on them. I don't see why you couldn't do the same here.

Re: New York to London in an hour - by train

#66

Post by simonsarris »

melling wrote: post #55

I live in NJ, about 4 miles away from my office in Manhattan and I have a 45 commute. Can anyone figure out how to solve that problem? It's a lot of fun to kill the afternoon talking about something that's never gonna happen. In the meantime, millions of people are wasting days a year crawling to and from work.

> Can anyone figure out how to solve that problem?

4 miles? Why don't you walk or cycle?

I live in NH and walk to work every day. 4 miles would make a good jog/walk too if you are looking for more exercise time (depending on what you take to work with you).

Re: New York to London in an hour - by train

#67

Post by planetguy »

allenlavoie wrote: post #64
planetguy wrote: post #44

Earlier quoted context omitted.

There are two problems here. Firstly: As I see it, an evacuated tunnel at 20m is a very different proposition to a non-evacuated tunnel at 30m, even if the pressure difference is the same. Why? Well, your big problem is always going to be leaks. In an air-filled tunnel you can get away with microscopic cracks, no problem; you've got a small direct interface between water and air, and the surface tension of the water…

Is there some reason that sandwiching air between the evacuated tube and the water wouldn't work? Granted it would add to the cost. The ocean depth point is interesting. The article says "engineers would tether the tunnel at a fixed depth." I take this to mean tethering to the bottom and relying on buoyancy to keep the tunnel floating at the right depth, which presumably could be 30m or so.

>Is there some reason that sandwiching air between the evacuated tube and the water wouldn't work?

Yep, because now you've just got your air rushing into the vacuum through the cracks, instead of water.

The ocean depth point is interesting. The article says "engineers would tether the tunnel at a fixed depth." I take this to mean tethering to the bottom and relying on buoyancy to keep the tunnel floating at the right depth, which presumably could be 30m or so.

Even if you could get it to be neutrally bouyant at 30m (realistic estimate? dunno) you're now stuck with a tube, five thousand miles long, floating free in the ocean and anchored only to the bottom. Even neutrally bouyant, there'd have to be huge strains on the joints due to ocean currents, plus presumably some up-and-down forces as the season changes the water temperature and... heck, even a whale headbutting such a flimsy structure sounds like a disaster waiting to happen. And remember, you can't afford to get any imperfections in your tube or it'll leak -- that probably eliminates anything you might have used to build in a bit of flexibility.

Re: New York to London in an hour - by train

#68

Post by iwejfweoifjweif »

DanBC wrote: post #57
melling wrote: post #55

I live in NJ, about 4 miles away from my office in Manhattan and I have a 45 commute. Can anyone figure out how to solve that problem? It's a lot of fun to kill the afternoon talking about something that's never gonna happen. In the meantime, millions of people are wasting days a year crawling to and from work.

Get a pushbike. Persuade everyone you know to get a pushbike. Make them persuade everyone they know to get a pushbike. Start a campaign for people to only use their cars if they i) Have to or ii) are travelling over 10 miles. Make workplaces have facilities for cyclists. (Perhaps going as far as treating car-parking spaces as a taxable perk). Make schools have facilities for cyclists. Make shops have facilities for c…

There is a river in between. You would need to bike up to the George Washington assuming he lives in Hoboken and commute to Midtown. Either way you go from a 45 minute commute to maybe a 2-3 hour commute if you are lucky. Even worse since now using a bike his commute is ~20 miles instead of the 4 in the first place.

Re: New York to London in an hour - by train

#69

Post by moystard »

marvin wrote: post #29
United857 wrote: post #21

Earlier quoted context omitted.

Indeed, there's already a vacuum we already have above our heads that could be used for this purpose... i.e., suborbital space flight. I can't imagine it'd be more expensive than tunneling 3000 miles under an ocean.

That's what I've been thinking as well. This might be an unintended consequence if SpaceX is able to reliably deploy the reusable rockets they are drawing today. It might actually require less energy to launch a passenger vehicle above the atmosphere and let it glide/freefall all the way to the destination than it does to push the same vehicle through the atmosphere. I haven't actually done any calculations, though.…

The disadvantage of your solution is the environment impact of such a transportation system. An electricity based solution seems to be much cleaner (especially if we imagine the same kind of traffic as the plane one today).

Re: New York to London in an hour - by train

#70

Post by StephenFalken »

I remember seeing a Discovery documentary named "Extreme Engineering: Trans-Atlantic Tunnel" that precisely details this concept. It's available online in five parts:

http://www.youtube.com/watch?v=frYWTrEfPRs

http://www.youtube.com/watch?v=YKaVQ5Tt_Zk

http://www.youtube.com/watch?v=4zci_6AOCAo

http://www.youtube.com/watch?v=Z2c6vzcmULU

http://www.youtube.com/watch?v=zoPI2doRkgA

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