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Elon Musk Unveils Boring Co's First Tunnel

latimes.com

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Re: Elon Musk Unveils Boring Co's First Tunnel

#171

Post by zimpenfish »

mjg59 wrote: post #128
reissbaker wrote: post #49

Earlier quoted context omitted.

I'm not sure what you're purporting to show other than two people disagreeing with each other, without providing evidence... Sure, an individual subway car has "more capacity," but does a subway system have more capacity? For example, I rarely see BART trains come within five minutes of each other. A tunnel that allows cars within 10 seconds of each other could provide more capacity than a tunnel with higher-density…

Peak headtimes on BART are a train every 2-3 minutes, with trains carrying up to 1400 people (let's call it 1000 for the sake of argument). So at the low end, that's around 20,000 people an hour. If you had cars with a headway of 5 seconds then that's 1200 cars an hour, so you'd need an average occupancy of over 16 people per car. That's unrealistic, so yes, a subway tunnel has more capacity.

cf London Underground - Central Line does ~260M journeys a year which is ~40k/hour assuming an 18 hour day. (I suspect peak times will be ~50% higher than that average.)

Even the Waterloo & City Line, the most unloved of all lines, manages 3.5k/hr over 260 days (16M/year, 5 day week).

Re: Elon Musk Unveils Boring Co's First Tunnel

#172

Post by zimpenfish »

steve_musk wrote: post #75
endless1234 wrote: post #65

Earlier quoted context omitted.

>75 seconds is really, really long. Cars on a highway don't leave 75 seconds in between each other ..and? A car also doesn't carry 500 people.

But 75 cars spaced 1 second apart...

It's probably just me but I really wouldn't get into anything that was going to be travelling 150mph at 1s intervals. All you need is a tire to go (or something loose on the floor or a dead battery or ...) and you've got not only a huge twisted lump of metal and body parts to untangle, you've almost certainly ruined your tunnel.

Re: Elon Musk Unveils Boring Co's First Tunnel

#173

Post by TheAceOfHearts »

Luc wrote: post #132
jillesvangurp wrote: post #130

Earlier quoted context omitted.

Tunneling is currently so expensive that there are few companies doing any innovation on how to properly utilize them. A big part of the problem is actually digging them in a way that is cheap and scaleable. Another part of the problem is the organizations doing the digging and doing the exploitation are typically have misaligned incentives and goals. For example, expanding subway systems is currently in the hands of…

You're comparing a difficult but real situation with a perfect but hypothetical one. Things always are wonderful when they're research projects that don't need to conform to real-world limitations.

New York subway system is probably the best we have in the US, but it's laughably bad when compared to the top players. I've traveled to Japan and during my trips I've been amazed by their train system. It was always on time and it ran incredibly frequently, so missing a train usually wasn't a big deal. Although I haven't visited there, I've also heard incredibly positive things about China's trains.

My point here is that there's still a lot of room for improvement, even if you limit yourself to trains. It doesn't seem like such a stretch to extend it a bit further to this new emerging system.

Re: Elon Musk Unveils Boring Co's First Tunnel

#174

Post by dantheman »

tlrobinson wrote: post #54
Tiktaalik wrote: post #36

What a gong show and waste of everyone's time. https://twitter.com/elonmusk/status/1075230308545454080 How can this man honestly think this sort of system could be higher capacity than a subway?

I can think of several possible reasons: 1. most subways don't operate at 150 MPH 2. subways stop at every stop even if the majority of passengers aren't getting on or off 3. subways can't route individuals (or small groups) directly to their destination, including via normal roads

2. subways stop at every stop even if the majority of passengers aren't getting on or off

except in new york where there are direct trains and local ones -- it's a good demonstration of why #2 is such a good idea.

Re: Elon Musk Unveils Boring Co's First Tunnel

#175

Post by zwily »

semi-extrinsic wrote: post #114
semi-extrinsic wrote: post #25

Earlier quoted context omitted.

Huh, TIL Tesla Autopilot only works at speeds below 50 mph. I thought it was mainly for highway driving, but highways are more like 60-100 mph. I assumed it worked at highway speeds. What gives?

My mistake, I had to search for the max Autosteer speed and Google gave me an old article. Seems they have been upgrading steadily from 45 mph in January 2017 to (currently) 90 mph? But then my original question remains: why do they need guide wheels for this, when they can do 90 mph without them on normal roads?

Even that’s wrong. My S would do autopilot to 90 mph in 2016.

Re: Elon Musk Unveils Boring Co's First Tunnel

#176

Post by youngtaff »

pdq wrote: post #33

The elevators in and elevators out are the bottleneck. Then inside it looks like a safety and escape hazard nightmare. What happens when someone gets a flat tire?

Exit really is an issue…

You can whizz a car along at 150mph but sooner or later its's got to leave the tunnel, the external traffic will undoubtedly be flowing more slowly so ultimately traffic is going to backup in to the tunnel

Re: Elon Musk Unveils Boring Co's First Tunnel

#177

Post by kthejoker2 »

grecy wrote: post #93
snowwindwaves wrote: post #11

The tone of the article is surprisingly hostile. Maybe I'm just used to Canadian media.

American culture has shifted in the last decade to be extremely critical and scathing towards anyone or anything that attempts to change the status quo - even if it's an attempt to make things better. See all the negative comments in this thread, for example. Instead saying "Jeez, this looks interesting. I'm happy some billionaire is trying to fix the horrible traffic problem instead of just buying more McMansions an…

Not just last decade, the 70s were a real pivot point in the American attitude towards technology and science as a large cultural shift towards mistrusting power and the market.

Watching science newsreels from the 40s-60s you notice that they're the epitome of boundless optimism.

Re: Elon Musk Unveils Boring Co's First Tunnel

#178

Post by emptyfile »

konschubert wrote: post #105
npunt wrote: post #23

Earlier quoted context omitted.

I imagine it’ll also probably be hell on tires. You’d need W- or Z-rated tires to do that and those are $$. Perhaps smooth concrete will mean lower rolling friction along with lack of sudden maneouvers. Still, going that fast is expensive in all sorts of ways.

People go 250 kmh on German highways regularly (unfortunately). It doesn't seem to be unpractical.

And whats the speed limit in German tunnels? In case you don't care to find out: 80-100 km/h (50-60 mph)depending on the state.

Re: Elon Musk Unveils Boring Co's First Tunnel

#179

Post by dwild »

skywhopper wrote: post #158

> "Still, the $10 million is orders of magnitude lower than a typical subway project, Musk said." Umm, and the capacity of these tunnels is also orders of magnitude lower than a subway. It would also be a lot harder to use and available to far fewer people. This entire idea should be laughed out of existence, but despite everything, Musk still gets fawning coverage for any crazy idea he spouts. Maintenance will be im…

> Maintenance will be impossible.

How so? Maintenance happens all the times in subways. In Montreal they do it during 4 hours each nights. In ours, they close everything down, thus we can no longer use it, but if we had multiple smaller one, we certainly could close one at a time and lower the perturbation. They could still close them all, theses tunnels aren't meant to be the only ways to drive either, even the biggest highways are closed from time to time to maintains them.

> you couldn't physically fit enough cars through the tunnel to compare to real transit system

That's seriously so weird to see that kind of comment on Hacker News. Never heard of horizontal scaling? There's more than a ways to increase capacity and the size of the unit sure is one, but the number of units is another one. It's like saying Google is impossible because you could never fit that many website on a single core, yeah luckily we can just add cores.

> Given that this thing requires rigging something up to your vehicle, the onload and offload points would immediately become major bottlenecks to any serious throughput even if you could cram them in bumper to bumper.

Then they'll come back to the skate system, which would fix the tire issue at the same time (and many others).

Re: Elon Musk Unveils Boring Co's First Tunnel

#180

Post by rsynnott »

ryanmercer wrote: post #155
sschueller wrote: post #28

Is this safe? I didn't see any escape paths. What happens if there is a fire and you are in the sixth tube down? Electric trains are considered quite safe yet tunnels have a lot of escape paths and service tunnels built parallel to the main one.

>Is this safe? As safe as any cave open to the public, which there are many of in state and federal parks often with only 1 or 2 exits. Also, barring an act of terrorism, it's probably as safe as driving a car, safer than skiing (water or snow), exponentially safer than sky-diving etc. >What happens if there is a fire and you are in the sixth tube down? Compared to the feat of actually tunneling the machine, boring s…

> As safe as any cave open to the public

Actually, really, laughed out loud.

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