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The Boring Company FAQ

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Re: The Boring Company FAQ

#321

Post by Robotbeat »

discodave wrote: post #48

The old strategy of hiding your outlandish claim in an assertion in the first sentence! "To solve the problem of soul-destroying traffic, roads must go 3D" The word "must" is a very strong one here, there are other options: * Reduce the amount of travel that people need to do (remote work, online shopping). * Reduce the density of cities (enabled by remote work or longer commutes with better internet access). * Incre…

Reducing density of cities actually increases a lot of problems. It means you have to spend a lot more of your time traveling, which will make all these problems worse. LA is a fairly low density city and has terrible traffic problems. It reduces economic efficiency, too.

Additionally, public transport often interferes with regular road traffic, making the problem worse. The solution is to use an elevated train (Chicago) or subways. So now you're back at 3D.

And biking in a low-density city isn't a practical solution.

Re: The Boring Company FAQ

#322

Post by logicallee »

> Since concrete production accounts for 4.5% of the world’s greenhouse gas emissions,

there is no way this is even close to being correct. For a point of comparison, "Airlines account for about 2 percent of global emissions".

just how much concrete does this guy think is being produced. come on. He probably misreported a figure that said concrete production accounts for 4.5% of all construction-related greenhouse gas emissions.

Re: The Boring Company FAQ

#323

Post by noobermin »

Touche wrote: post #320
noobermin wrote: post #311

Earlier quoted context omitted.

As interest in car ownership drops as the Millennials age and take the older generations' place, that problem may fix itself.

What do you mean by interest in car ownership?

While this article[0] demonstrates that numbers have improved slightly for actual car ownership as millenials age, it still contains other tidbits and statistics (like the having driver's license by 18 stat at 60% vs. 80% in 1980) that reflect views on car ownership amongst millenials today.

Anecdote, I don't have a lot of mileage (pun unintended), but every girl I've ever dated did not have license, and neither do I, and I am 27. I live alone and bike and bus ride for the most part.

[0] http://www.latimes.com/business/autos/la-fi-hy-millennials-c...

Re: The Boring Company FAQ

#324

Post by 6d6b73 »

The problem with this idea is not with throughput of the tunnels, but with the shafts that lead to the tunnel. Lowering one car to the tunnel will take time, and unless there is some kind of elevator with multiple carts you will only be able to lower one car at a time.

Let's say that the shaft is 20m height and let's allow 2 meters for each car. We could get ~ 10 cars "stored" in the elevator, but if it takes one minute to load and unload the car it will take ~10 minutes for the car to get to the tunnel. One shaft will be able to load only 60 cars/hour. This will not solve any traffic problems and it actually may make the traffic around the shafts worse (depending on how many cars are waiting to go into the tunnel, and how large "the Boring Station" is.

There are two solutions either load/unload cars faster - possible but unlikely, or have more elevators connected to each tunnel. The problem with the second solution is that these cars have to safely join the rest of the cars that are currently in the tunnel.

If you have 10 elevators, each unloading one car a minute, you would need a system that allows one car to join the traffic every 6 seconds. If the cars are traveling at 125mph the sleds would need to have a pretty good acceleration to get to that speed as quickly as possible, or you would need longer adjacent tunnels.

Re: The Boring Company FAQ

#325

Post by dredmorbius »

dredmorbius wrote: post #281
TeMPOraL wrote: post #268

Earlier quoted context omitted.

But rock comes with supporting structure, whereas you need to build those into "sky tunnels". This limits just how much "sky tunnels" you can make in two ways - there's only so much space on the ground you can use, and there's only so much weight it can support. That, and people will get anxious if their sky is totally obstructed by highways in the sky.

Tensile-strength-to-volume ratios for many materials is ridiculously high. Tunnel wall, ceiling, and floor quantities represent massive overengineered for that purpose A cable tramway is one option for an aerial system. The load-bearing capacity of a 15mm steel cable is impressively high, and it can be strung along pylons. Not that you'd want to bolt street cars to such a system, but it's an example of a possible peo…

Also, noting: the incident inquiry found for operator error of the crew. I find that conclusion difficult to justify based on the presented evidence.

Re: The Boring Company FAQ

#326

Post by IanDrake »

>Unlike flying cars, tunnels are weatherproof, out of sight and won't fall on your head.

Anyone from Boston can tell you that's not true. I don't think this sort of hyperbole helps the case for tunneling.

Re: The Boring Company FAQ

#327

Post by glenneroo »

ascorbic wrote: post #279
Tomminn wrote: post #174

Earlier quoted context omitted.

I think the sled idea is really interesting. Imagine a conveyor belt like you have in airports. Except it moves cars at 150 mph through an underground tunnel instead of people at 15mph. Traffic is often massively asymmetric so you can just reverse the direction it travels at noon. It seems plausible that keeping a conveyor belt in good service is cheaper than keeping a fleet of railway cars is. It's also significantl…

Generously assuming that it averages 150mph, and very generously assuming 1.5 people per car and estimating from the video a gap between sleds of 40m gives a capacity of around 9,000 pax/hr per line. The Tube in London has trains with around 900 pax capacity, and they run at around 90 second intervals at peak time, giving 40 trains per hour and 36,000 pax/hr.

One point people seem to be ignoring is that Elon mentions on multiple occasions that he plans to build in 3D, i.e. not just one layer of tunnel in one direction but multiple tunnels at multiple depths in multiple directions i.e. to get your 36k pax/hr will require 4 layers.

Re: The Boring Company FAQ

#328

Post by sethrin »

prostoalex wrote: post #242
djsumdog wrote: post #151

Earlier quoted context omitted.

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 America had better trains and subways, it could move massive amounts of people. Train automation is a solved problem, and currently implemented in cities around the world. In most European cities, if you get off at train station, you're in the midst of (or very close to) the city center, office locations, touristy walking sites and plenty of choices for retail or food. In the US once you get off at the train sta…

> NYC and SF are likely to be the only exception

Portland should probably join that list.

Re: The Boring Company FAQ

#329

Post by monk_e_boy »

Angostura wrote: post #295
cel1ne wrote: post #217

Earlier quoted context omitted.

More precisely it's humans when they form a bunch / organization ;).

NO, I'm saying that even individuals are conservative in that they will tend to stay with an existing job, locale or speciality even when an alternative could potentially offer better returns. I don't check the job listings every day.

Risk vs reward. Often the risk is too great, especially for a company that is making a lot of money. Why risk R&D when there's no competitor. Companies are optimised to make money, not progress.

Re: The Boring Company FAQ

#330

Post by monk_e_boy »

lmm wrote: post #298
BurningFrog wrote: post #183

Earlier quoted context omitted.

One problem is that trains only move an insane amount of people that are all going the same way. Another problem is that all those people have to walk to and from the end station. A "packet switched" system of sending individual cars at high speed solves both those problems, and going just by my gut feel, should have a quite high throughput too.

The throughput will be tiny because cars take up so much space. http://humantransit.org/2012/09/the-photo-that-explains-almo...

And cars more inefficiently in groups. When at lights, the first car pulls away, then the second, etc etc...

There is a delay between each car which after 20 cars really adds up.

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