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The Boring Company FAQ

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Re: The Boring Company FAQ

#191

Post by so33 »

maxander wrote: post #158
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…

The Boring Company isn't just looking to build tunnels either- there's going to be a bunch of interesting infrastructure to get cars onto those electric sleds and operating them, and that'll need maintenance and access and etc too. For what its worth, it hints that those sleds will also become public transit platforms as well - "if one adds a vacuum shell, it is now a Hyperloop pod" - but Musk will want to call it so…

>For what its worth, it hints that those sleds will also become public transit platforms as well

So this is something I've been trying to address all thread, so excuse me picking your comment.

You can only create a public transit platform by having _dedicated_ infrastructure. We know this because cities like London and Paris (and not-so-big Vancouver) all have mostly-to-fully automated trains with 90-second headways between each train at rush hour. This basically means that if once a train pulls out of the station, the next one pulls in mere seconds later. These trains are usually packed to the gills. Even one single-occupancy vehicle would decrease the overall efficiency of that system.

Heck, you can create a tunnel in each which sled contains one bus and it'd still be less efficient than the London Tube because the whole thing will take up more space, physically (these trains squeeze in every last passenger). This is what Seattle tried to do with the downtown bus tunnel and they're evicting all the buses there in favor of light rail.

I think it will always make sense for subway trains in dense city cores, but I think the discussion about dedicated rapid transit is hampered in more suburban areas because of the whole notion that we have to fit in cars into rapid transit corridors, or else it's not worth it. But this ends up making buses less reliable and gives them their crappy reputation (see: https://en.wikipedia.org/wiki/Bus_bunching).

Grade-separation is absolutely necessary for good rapid transit.

Re: The Boring Company FAQ

#192

Post by politician »

rurban wrote: post #169
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…

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 A…

> And the biggest problem is what to do with all those cars in the city.

Tunnels are great parking structures. Cars on sleds provide a great interface to said parking structure. Heck, NYC has automated parking structures with car elevators and sleds. The only imagination required is not having to dig a big hole down to the depth of the lowest level of the garage first.

Re: The Boring Company FAQ

#193

Post by nihonde »

rangibaby wrote: post #101
nihonde wrote: post #85

Earlier quoted context omitted.

Tokyo is a much bigger city. They solved the problem by building elevated toll highways. Much simpler solution than digging new holes everywhere and keeping those silly carts running.

OTOH JR Central is in the process of building a tunnel from Tokyo to Nagoya: https://en.wikipedia.org/wiki/Chūō_Shinkansen

Yes, for a MagLev train that achieves the fantasy of hyperloop (but is actually happening now). From my perspective, hyperloop and TBC are each 100% upside down in terms of their approach. America can only dream of 505km/hr interstate ground transport. I'm writing this from aboard the Nozomi express Shinkansen at around 300km/hr, by the way. Just left 名古屋駅.

Re: The Boring Company FAQ

#194

Post by gfodor »

so33 wrote: post #35
windlep wrote: post #5

Earlier quoted context omitted.

Indeed, strange how that's not mentioned at all. Or whether any transportation engineers have evaluated what kind of traffic reduction would occur from using all these tunnels for a subway system instead of just moving a few cars around. Edit: The more I think about it, the worse it seems. Compare how much space is eaten out of the road above for a few cars... per minute?...to go up/down to this tunnel vs. how many a…

>Even if the car's were relatively crammed close together in the tunnel, I can't imagine it would be anywhere near the density you could fit on subway trains. Indeed. The problem always fundamentally reduces to geometry, and the only way to solve it is to increase density. People always say, "we can just build more tunnels", but you'll just end up with congestion at interchange and entry/exit points, just like on fre…

arguably layering tunnels is increasing the density of humans in transport along the Y axis. right now its approximately one.

Re: The Boring Company FAQ

#195

Post by sathishmanohar »

> No. Once a TBM is below a certain depth (approximately two tunnel diameters – or 28 feet in this case), the tunneling process is almost impossible to detect, especially in soft soil.

They missed an important FAQ, Will this tech increase bank heists?

Re: The Boring Company FAQ

#196

Post by gfodor »

so33 wrote: post #45
CodeWriter23 wrote: post #32

Earlier quoted context omitted.

This IS public transit. Public transit without the last mile (or in LA, the last 5 miles) problem. This freedom-supporting tech also thwarts the tyranny inherent in public transit (schedules, robbing your life with all the waiting, limited load carrying capacity, forced interactions with antisocial individuals, etc.)

But there is still a last mile problem, you have to enter and exit out of the tunnels. That's the last mile. Or do you suggest that tunnel building will become so viable from an economic and engineering standpoint that everyone will have an entry point in their garage? > This freedom-supporting tech also thwarts the tyranny inherent in public transit (schedules, robbing your life with all the waiting, limited load ca…

nobody said that cars are the only thing that these sleds would shuttle around. use your imagination a bit and i think you can probably imagine how this can be use for a public transit system.

Re: The Boring Company FAQ

#197

Post by so33 »

njarboe wrote: post #170
ktta wrote: post #116

Earlier quoted context omitted.

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…

>each other, the maximum is 33,000 cars per hour.

Yeah, but that's 33,000 cars per hour without any of the cars stopping to exit the tunnels. The trains used in BART and other public transit systems can very easily exceed 60+mph already, but they don't because they have to stop, bringing down the average speed of the system.

BART, by the way, does 28000 passengers per hour per direction in the Transbay Tube (https://en.wikipedia.org/wiki/Transbay_Tube). You can probably fit over 200 people into a BART train car at absolute crush capacity.

Re: The Boring Company FAQ

#198

Post by gfodor »

ktta wrote: post #127
xyzzy_plugh wrote: post #104

Earlier quoted context omitted.

Well hang on. Do we understand the impact of, for example, just a single lane, one-direction tunnel with respect to rush hour traffic in LA? It's like a shunt. Sure, more is better, but we're not talking about replacing freeways. We're looking at a way to improve traffic.

(If you're taking about inter-city travel) I really doubt one person on a lane can be faster than a freeway with 4+ lanes (in one direction) no matter how fast it is going. Another thing you'll have to consider is that there will be a logistical problem at the exit stops if you want to take advantage of all the high speeds being talking about. I'm talking about passengers getting stopped off there. There have to be a…

Presumably we would get better at building more tunnels after the first one, and presumably once an existence proof is in place the economics will justify accelerated R&D, resulting in a technological feedback loop.

You can only layer so many roads above ground. But as said in the post, tunnels have no such limit. 100 years from now one could imagine a very thick subterranean transportation network. The interchange and routing problems I'd guess are solvable iteratively over the course of decades, since you have a lot of free space to work in with minimal constraints once you are deep enough to allow "forking" the network as you build more advanced technology.

Slapping two freeways together is not strategy that lands you ultimately in that future, but starting on the problem building cheaper tunnels is.

Re: The Boring Company FAQ

#199

Post by espadrine »

Animats wrote: post #61

So, the key ideas are: - Smaller diameter tunnels. 14' is suggested. This is slightly larger than the deep London Tube lines. - Electrically powered TBMs. Those exist. However, often the business end of the machine is hydraulically powered. Musk is probably thinking of going all electric, at least for the cutter head. After all, he has lots of experience with high-torque electric motors. - Do cutting and tunnel ring…

> Issues glossed over: Soil variability. … The back end.

Good points. And beyond the technical aspects, there's a lot that the FAQ doesn't say about the service:

- How do you tell your sled where to go? Does it always go to the same place? If so, do you merge lanes? If you merge lanes, wouldn't there be jams there? If instead you build many parallel tunnels, don't you remove the gains you had from building smaller tunnels, by having many more tunnels?

- How is it meant to compete on price or human bandwidth with subways? Surely at 200 km/h you need to maintain space between sleds in case one fails. Plus, the sleds are not large, which limits human bandwidth. Finally, if you have lots of tunnels (at least one for each origin/destination, instead of subways with many stops), you will need to maintain and repair that infrastructure, which will require service tunnels and backup tunnels, which adds to the cost.

Another thought: they don't mention how they'll design the tunnel network yet. My guess is that it will be backboned by double circular tracks (one for clockwise driving, the other for anticlockwise), from which you have regular exit/entrance ramps at each stop. The circularity would avoid having a terminus where everyone slows down.

Still, any design would have a maximum capacity corresponding to how fast vehicles can exit in the worst case, if they all suddenly decided to leave at the exact same stop.

Re: The Boring Company FAQ

#200

Post by Angostura »

cel1ne wrote: post #187
josephg wrote: post #148

Earlier quoted context omitted.

> But then we should ask why don't we do that anyway? Sure. Why didn't we have electric cars before tesla? Why didn't Boeing or Lockheed Martin make reusable rockets? Alan Kay said something[1] recently that has been bouncing around my head for the past few days. He said that many people think darwinian processes (like the economy) optimize. "One my degrees is in molecular biology, and I can tell you, any biologist w…

Off topic: The more I think about organizations the more I they seem to be the key players preventing change to me. (Which is not necessarily a bad thing) Business says: We had this great idea, now let's freeze everything in time and let's make money of this snapshot forever, because who knows when we'll find gold again. Entertainment industry likes to do that especially.

That's not businesses - that's humans. Or do you apply for a new job every two weeks whenever you see a higher salary advertised?
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