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The Boring Company FAQ

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Re: The Boring Company FAQ

#161

Post by philwelch »

djsumdog wrote: post #151
prostoalex wrote: post #131

Earlier quoted context omitted.

> But then for some reason the solution has to involve putting cars into these tunnels. If what he thinks he is on to is viable with cars in those tunnels, it's even more viable with trains carrying 1,000 passengers each coming every 3 minutes. So why aren't we building these subways with trains? Because with trains you never build just a tunnel - there are train stations, escalators leading in and out, ticketing boo…

But even with the stations, escalators and everything else, you're talking about orders of magnitude between trains and cars. London during peak hour has trains arriving less than 1 min 30 sec apart. They move an absolutely insane amount of people. Singapore's trains are entirely automated and arrive at Everything about Musk's idea seems absolutely terrible. If America had better trains and subways, it could move mas…

If you own a car company, you want cars to be a big part of the transportation system.

Re: The Boring Company FAQ

#163

Post by Baeocystin »

MacsHeadroom wrote: post #143
Baeocystin wrote: post #123

Earlier quoted context omitted.

Something that can discriminate without energy input is a form of Maxwell's Demon. If you are unfamiliar, it's a lot of fun to learn about. https://en.wikipedia.org/wiki/Maxwell%27s_demon is a reasonable start. Check valves absolutely do consume energy. Something has to resist the spring forcing them closed, or they would never open. They are convenient in that their energy is sourced from the very thing they are con…

Higher air pressure could provide the necessary energy. There are easier ways to get moisture out of a tunnel though.

Sure, there's lots of ways to do so. My only point is that none of them are 'free'.

Re: The Boring Company FAQ

#164

Post by resf »

gosheroo wrote: post #64
avn2109 wrote: post #42

Earlier quoted context omitted.

Many TBM's are already nuclear powered, in that the grid power they consume was generated in a reactor somewhere. There is no reason to bring the reactor closer to the dig site. Also, see e.g. https://en.wikipedia.org/wiki/The_Core for prior art /s

Using the grid there must be a lot of transformers and cabling involved. Plus with massive amounts of power in situ one might be able to process the waste rock differently (e.g. if it's looser material with fissures, compress it against the sides of the tunnel or perhaps even melt it rather than removing it. Admittedly I'm rather ignorant of soil and rock physics.)

Nuclear reactors require a heatsink, usually a large amount of water.

If you put a nuclear reactor underground, you have to pump water back up. This takes a lot of energy. Whereas, electrical energy travelling through cables is not affected by gravity.

Re: The Boring Company FAQ

#166

Post by lucb1e »

catmanjan wrote: post #27
theprop wrote: post #21

This is FANTASTIC! It's important to understand how massive the Earth is (even though it's a pinprick when compared to the sun). You can EASILY go 3-D or deep. The deepest mines in the world are around 12,000 feet deep. This is about 6x the height of the tallest building in the world (2000 feet tall). Imagine, thus, putting in a tunnel at what would be every 5th floor of a skyscraper and that you could fit 6 skyscrap…

I'm just imaging a 150 way 3-d lane merge at the other end :O

When imagining a 150 way merge I can't help but feel like it'll pollute enough to make nearby trees crumble in a matter of days. 150 ways at approximately 1 car per second (a very full highway) and 1.1 people per car (I hardly know anyone who carpools), there's 1501.1120 = ~20 000 people every two minutes. Trains can operate at the same frequency, carry a few thousand each and pollute a lot less -- heck, electric ones can draw from solar panels, reducing pollution to near zero. Give it ten tracks and you have equivalent capacity to 150 stinky lanes.

Re: The Boring Company FAQ

#167

Post by rtpg »

There's some interesting stuff in here, I'm excited to see what comes of it.

But I'm a bit worried about the thought process in the intro:

> A large network of road tunnels many levels deep would fix congestion in any city, no matter how large it grew (just keep adding levels)

this is untrue in the general case. Notably, if everyone wants to drive to the city center, then there will be congestion, because at one point you must get to the destination.

It's not just volume, but throughput that causes congestion.

When the traffic flow isn't spread out nicely, your traffic can only go as fast as the weakest link.

You know what has higher throughput than cars? trains

Re: The Boring Company FAQ

#168

Post by lorenzorhoades »

I think people are missing the strategic importance here. Tesla is going to be in the game of self driving cars. Once self driving cars happens, there is no longer going to be anyone who buys cars, they will simply hail a ride using the self-driving Telsa(Uber, Lift, Google) network. Soul-Crushing-Traffic is going to be optimized heavily, using certain algorithms and the inter connectivity of the cars. However, one HUGE advantage that Tesla cars are going to be able to have are these tunnels. I think this is of huge strategic importance, because they can reduce the cost for transportation across cities, because they don't have to deal with all the traffic. As discussed in plenty of places on hackernews, ride-hailing is going to be a commodity similar to the airline or ocean transport industry. It will be solely based on cost. If Tesla can make the cars at cost, owns the self-driving tech, are all electric with a huge network of free fuel, and have tunnels that allow you to bypass traffic then they will own the future transportation industry, while everyone else tries to catch up.

Re: The Boring Company FAQ

#169

Post by rurban »

djsumdog wrote: post #151
prostoalex wrote: post #131

Earlier quoted context omitted.

> But then for some reason the solution has to involve putting cars into these tunnels. If what he thinks he is on to is viable with cars in those tunnels, it's even more viable with trains carrying 1,000 passengers each coming every 3 minutes. So why aren't we building these subways with trains? Because with trains you never build just a tunnel - there are train stations, escalators leading in and out, ticketing boo…

But even with the stations, escalators and everything else, you're talking about orders of magnitude between trains and cars. London during peak hour has trains arriving less than 1 min 30 sec apart. They move an absolutely insane amount of people. Singapore's trains are entirely automated and arrive at Everything about Musk's idea seems absolutely terrible. If America had better trains and subways, it could move mas…

Absolutely. And the biggest problem is what to do with all those cars in the city. It's an enormous waste of space to park all those cars, besides the enormous hazards of the moving cars, not being to be able to walk. It destroyed cities.

That's why public mass transport was created and was so successful in the big cities. US big automotive destroyed most of this working infrastructure in the last century (E.g. Los Angeles, Houston, ...) but it's still cheaper to build mass transport than to support individual transport. Just ask a New Yorker or a foreigner.

Tunnels are a hazard for individual traffic. That's why pods do help. But trains are still preferred.

It's a good alternative idea to build long range tunnels. He is right. But the focus needs to be mass transport, not individual. It's a matter of costs.

Re: The Boring Company FAQ

#170

Post by njarboe »

ktta wrote: post #116
zild3d wrote: post #100

Earlier quoted context omitted.

"A large network of road tunnels many levels deep" It's not just one tunnel...

See I don't know what specifics they're talking about when they say 'a large network'. It'll obviously be more efficient to dig a wider tunnel than multiple tunnel on a single route. So, unless I'm wrong, to me it looks like it'll only be one tunnel, with one track to and one track back. How many people do you think can be transported in a direction in a 'sled' in one lane? I'm talking about one point to another poin…

The car in the video looks like Model S size. About 16 feet long. Add 2 feet on each end for an even 20 feet for the sled. At 125mph one gets 660,000 feet per hour. So if you can pack the cars next to each other, the maximum is 33,000 cars per hour. So 33,000 people per hour with each person getting a space that would rent in SF for $1000/month. Pack that sled space with people at the same density as a train at rush hour (50?) you get 1.65 million per hour. Mix and match your people density and sled packing to determine your own rate. Seems like in reasonable scenarios you could get train like rates with one tunnel.

Bart says at peak commute it does 60,00 per hour. Maybe other systems do better, but those BART trains are full.

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