13 ms·

And noisy unless I'm mistaken.

by knightofmars 8y ago

BurningFrog 8y ago
That's where Elon's tunnels are undeniably the better 3D alternative.
- eropple 8y ago
  Sure--insofar as eventually, once they fail, the tunnels are already the correct size for a standard subway car for actual mass transit that can actually help people. 'Cause the on-street traffic jams they would--not "might", check out donoteat01's stuff for a full breakdown--create are not exactly a better situation.
- gamblor956 8y ago
  Elon's tunnels are the worst 3D alternative. The hourly capacity of a single city bus exceeds the daily capacity of an Elontunnel. For example: Elon has proposed a tunnel to Dodger stadium. However, the existing Union Station-Stadium shuttles can (and do) handle 10x the proposed Elontunnel's max daily capacity in about an hour or two depending on traffic.
  - jandrese 8y ago
    Is this assuming a single car at a time in the tunnel? Otherwise I don't see how it could possibly be true. That's absurdly low volume. Like a regular road would beat it easily.
    - eropple 8y ago
      Not a single car, but a lot fewer than Elon wants you to believe. We already know that the baseline technology being proposed works. Guided buses have been in use for a long time now. But there's a reason it's used with buses, not individual cars. And it's for a pretty simple reason: the loading process into the tunnels can't be fast. Much hay is being made about minimal surface disruption, but elevators are slow. As is driving into a guide tray that moves the car along. donoteat01 does pretty fantastic video work about a number of urban planning topics and he's shot this one full of holes already. You should watch it if you're curious. https://www.youtube.com/watch?v=4dn6ZVpJLxs https://www.youtube.com/watch?v=4dn6ZVpJLxs
      - njarboe 8y ago
        "the loading process into the tunnels can't be fast" Why is that the case and can it be fixed? I would say that this problem would be easier to solve than the problem of getting a orbital class rocket booster to go into space, launch the second stage, and then return to the launch pad and land. Musk likes to work from first principles to try and understand what is possible. What is the physics behind why you can't have a very full, steady stream of vehicles going through a tunnel? Nothing really. The vehicles just have to be very well controlled. With a good auto-vehicle you should be able to pack them in and have them enter and exit into the stream of traffic. Like a real road, only better. Why would you not want someone of Musk's caliber to not try to do this? My dad would rather have him working more on getting the automatic car working so he can continue commuting to work. I can understand that objection, but he says the Boring Company is only about 2-5% of his time. If you want something to happen you try and decide if it is possible, and then try and do it. Not spend you time figuring out how not to do it.
        eropple 8y ago
        It can't be fast because the constraints he's laid out don't allow them to. Elevators don't work that way. Neither does braking safety. (Run the numbers yourself, or go watch that donoteat01 video. It's farcical on its face.) The rest of your post is weird heroification and I'd have to bleach myself after interacting with it, so I won't.
        jandrese 8y ago
        From what I can tell the bottleneck is a single slow freight elevator. It doesn't seem like a fundamental problem with the underlying technology, just an implementation detail.
      - BurningFrog 8y ago
        > the loading process into the tunnels can't be fast True, but a loading/unloading time of 30-60 seconds only means the tunnels are less feasible for short trips.
        8y ago
  - Retric 8y ago
    That’s wildly inaccurate. First busses reduce the ability of a road to transit cars \ trucks. So actual gain is significantly less than nominal gain. Second even with a single passenger vehicle, a tunnel can move people over it’s full distance at the same time. Consider a bus moving people on a 5 minute trip vs 50 minute trip on the second case it’s got 1/10 the capacity. Sure, a 3.5 mile tunnel adds little on it’s own. But, then again it’s also short.
    - eropple 8y ago
      It's not inaccurate at all. A tunnel is strictly bound on surface traffic--because traffic has to enter and exit it--when it doesn't involve slow, failure-prone, low-capacity access points at either end. While we're at it, optimizing for number of vehicles rather than number of passengers is a very...how do I put it...rich way of thinking about things. Which jibes very well with Elon Musk's whole thing: "mass transit is great so long as I don't have to see the poors."
      - joshe 8y ago
        If you watch the talk, the plan is for autonomous pods that holds passengers with their bikes. Little buses basically. And also cars. You can’t just read the media reports, they are always about max outrage.
        stcredzero 8y ago
        I miss the days when I could mostly read news that played on awesome, not outrage. https://www.youtube.com/watch?v=rE3j_RHkqJc https://www.youtube.com/watch?v=rE3j_RHkqJc
  - njarboe 8y ago
    Couldn't one put buses in these tunnels? One could even mix buses and cars when the buses aren't taking up all the space. I don't quite get the hate for Elon's tunnels. Let him and his team try and build them and see if they work. Super cheap tunneling would be great for so many things. That is, unless you think that humans have too much power and think we should regress back to some more primitive lifestyle. "Try to help make a future that you would like to live in." Traffic congestion sucks. It would be great to get rid of it. Cheap tunnels could be one way to help. Why stop people from trying? He did start and still runs a company that makes reusable rockets. You have to try to do something before you know what is possible.
    - bobthepanda 8y ago
      As a cynical person, I've seen many US discussions of "why invest in public transport when Hyperloop and the Boring Company have the solution coming up in a few years?" Transport investment is like planting a tree. The best time to build it is twenty years ago, and the second best time to do it is now. Elon has basically given cover to NIMBYs to hide behind a supposedly new amazing future solution that may never come.
      - njarboe 8y ago
        There is plenty of capital in the world right now that there is no reason not to build all different kinds of new transportation schemes. Elon's first tunnel got NIMBYed. One main feature of tunnels is that you can, hopefully, put them lots of places where surface building is impossible. What people put in them will be up to the builders. Construction costs has not come down in price over time like many other things have. I think he hopes that the Boring Company can list a price/mile for tunneling that is much lower than current costs and let people actually budget them. Maybe sell these better machines to other construction companies at some point. He broke the cost-plus pricing for satellite launches. Just think what something like that for tunneling could do for transportation systems. Billion dollar overruns are on the digger not the public. That would be great.
        bobthepanda 8y ago
  - stcredzero 8y ago
    Elon's tunnels are the worst 3D alternative. The hourly capacity of a single city bus exceeds the daily capacity of an Elontunnel. For example: Elon has proposed a tunnel to Dodger stadium. Fixed wing airplanes are the worst flight alternative. The passenger capacity of a single hot air balloon far exceeds the passenger capacity of an airplane. For example: A Wright Flyer. Sorry, but this is a bit strawmannish. You do realize it's a proof of concept project, right? It's not like the Falcon 1 disproves the capacity of all SpaceX rockets, ever.
  - deleted 8y ago
    [deleted]
- joshe 8y ago
  Absolutely. People are super confused about this. The reporting wasn't very good and you have to look beyond it. The original idea is - little 16 person passenger pods with bikes, wheelchairs, and luggage. $1 fare. - possibly sleds for cars - you can stack tunnels (think of them as car lanes in 3D), so you can have 20, 50 or 100 lane highways - you make lane changes autonomously, so the subway pods can have different destinations - it's all electric so there isn't poisonous engine exhaust This is just people boarding a bus, the throughput is super high. Even sled loading can be pretty fast, imagine replacing 20 street parking spots with sled elevators. Then accelerated to 100 mph, that too is a lot of throughput. Here's the pod part of the Boring company talk. It's worth watching to see what they are proposing. https://youtu.be/AwX9G38vdCE?t=1372 https://youtu.be/AwX9G38vdCE?t=1372 Elon and company got excited that they built a tunnel, which is a real achievement. So they drove a Tesla through it. The media knows what you want, which is max outrage, so they reported that the 1% will get tunnels with their Teslas. You will be stuck in gridlock behind a diesel truck. They should not have driven a Tesla through it, it was a PR blunder. Here is a Heathrow pod experiment: http://www.bbc.com/autos/story/20140910-hands-off-with-heathrows-pods http://www.bbc.com/autos/story/20140910-hands-off-with-heath...
  - bobthepanda 8y ago
    These are just small trains. If it was built today you could automate the Boston Green Line too - the technology already exists. The main issue with building tunnels is cost. Tunnels aren't cheap and are hard to scale because soil conditions are extremely local and you have to tailor boring machines to ground conditions. Egress points are expensive, especially in dense urban areas where property values are sky high. You could use elevators instead of stairs, but the problem is that elevators are low-throughput and unusable in the event of unreliability. Even considering all that, Elon did build a tunnel, but the tunnel was quite short and also quite small. There's not really room for emergency ventilation, or egress walkways with exits or safety points every 300m, or really anything that modern fire codes would require. Once you add all that in the tunnel is not really narrower than a subway train, at which point you might as well build a subway train. And why not? The New York subway has a capacity of 60,000 people per hour per direction using signals from the 1930s. A highway lane only carries about 2,000 people per hour. And all of that's assuming your low-capacity elevator entry can handle all of that. PRT just combines the inefficiency of the automobile with the cost of actually building transit. There is a reason that PRT experiments have never been replicated elsewhere at large scale.
mortenjorck 8y ago
This is really the worst externality of "flying cars," or whatever you want to call short-range commuter aircraft. In absence of some exotic propulsion technology (what usually powers flying cars in science fiction), the amount of air that must be displaced to loft a vehicle carrying one to four people will always be orders of magnitude louder than a land vehicle.
- kevin_thibedeau 8y ago
  Helicopters are loud because the blades cross over the airframe and are powered by turbines. An electric multicopter based design could have significantly lower noise levels.
  - binarymax 8y ago
    If going by the noise emitted by your average consumer drone, and scaling it up, I think the opposite is probably true - it would be crazy loud.
    - kevin_thibedeau 8y ago
      Few consumer level drones make any effort at noise reduction. Blade and shroud design can significantly impact noise production.
      - stcredzero 8y ago
        https://www.dronethusiast.com/what-are-the-best-silent-drone-choices-and-what-applications-are-they-good-for/ https://www.dronethusiast.com/what-are-the-best-silent-drone...
    - 83 8y ago
      Consumer drones aren't really aiming for quiet though. My racing drones are very buzzy since the small 3-5in props are fast spinning to have quick reaction time. My heavy lift photography drone with its slow 12in props (aiming for efficiency) is way larger and much quieter.

And noisy unless I'm mistaken.

BurningFrog 8y ago

That's where Elon's tunnels are undeniably the better 3D alternative.

eropple 8y ago
Sure--insofar as eventually, once they fail, the tunnels are already the correct size for a standard subway car for actual mass transit that can actually help people. 'Cause the on-street traffic jams they would--not "might", check out donoteat01's stuff for a full breakdown--create are not exactly a better situation.
gamblor956 8y ago
Elon's tunnels are the worst 3D alternative. The hourly capacity of a single city bus exceeds the daily capacity of an Elontunnel. For example: Elon has proposed a tunnel to Dodger stadium. However, the existing Union Station-Stadium shuttles can (and do) handle 10x the proposed Elontunnel's max daily capacity in about an hour or two depending on traffic.
- jandrese 8y ago
  Is this assuming a single car at a time in the tunnel? Otherwise I don't see how it could possibly be true. That's absurdly low volume. Like a regular road would beat it easily.
  - eropple 8y ago
    Not a single car, but a lot fewer than Elon wants you to believe. We already know that the baseline technology being proposed works. Guided buses have been in use for a long time now. But there's a reason it's used with buses, not individual cars. And it's for a pretty simple reason: the loading process into the tunnels can't be fast. Much hay is being made about minimal surface disruption, but elevators are slow. As is driving into a guide tray that moves the car along. donoteat01 does pretty fantastic video work about a number of urban planning topics and he's shot this one full of holes already. You should watch it if you're curious. https://www.youtube.com/watch?v=4dn6ZVpJLxs https://www.youtube.com/watch?v=4dn6ZVpJLxs
    - njarboe 8y ago
      "the loading process into the tunnels can't be fast" Why is that the case and can it be fixed? I would say that this problem would be easier to solve than the problem of getting a orbital class rocket booster to go into space, launch the second stage, and then return to the launch pad and land. Musk likes to work from first principles to try and understand what is possible. What is the physics behind why you can't have a very full, steady stream of vehicles going through a tunnel? Nothing really. The vehicles just have to be very well controlled. With a good auto-vehicle you should be able to pack them in and have them enter and exit into the stream of traffic. Like a real road, only better. Why would you not want someone of Musk's caliber to not try to do this? My dad would rather have him working more on getting the automatic car working so he can continue commuting to work. I can understand that objection, but he says the Boring Company is only about 2-5% of his time. If you want something to happen you try and decide if it is possible, and then try and do it. Not spend you time figuring out how not to do it.
      - eropple 8y ago
        It can't be fast because the constraints he's laid out don't allow them to. Elevators don't work that way. Neither does braking safety. (Run the numbers yourself, or go watch that donoteat01 video. It's farcical on its face.) The rest of your post is weird heroification and I'd have to bleach myself after interacting with it, so I won't.
      - jandrese 8y ago
        From what I can tell the bottleneck is a single slow freight elevator. It doesn't seem like a fundamental problem with the underlying technology, just an implementation detail.
    - BurningFrog 8y ago
      > the loading process into the tunnels can't be fast True, but a loading/unloading time of 30-60 seconds only means the tunnels are less feasible for short trips.
      - 8y ago
- Retric 8y ago
  That’s wildly inaccurate. First busses reduce the ability of a road to transit cars \ trucks. So actual gain is significantly less than nominal gain. Second even with a single passenger vehicle, a tunnel can move people over it’s full distance at the same time. Consider a bus moving people on a 5 minute trip vs 50 minute trip on the second case it’s got 1/10 the capacity. Sure, a 3.5 mile tunnel adds little on it’s own. But, then again it’s also short.
  - eropple 8y ago
    It's not inaccurate at all. A tunnel is strictly bound on surface traffic--because traffic has to enter and exit it--when it doesn't involve slow, failure-prone, low-capacity access points at either end. While we're at it, optimizing for number of vehicles rather than number of passengers is a very...how do I put it...rich way of thinking about things. Which jibes very well with Elon Musk's whole thing: "mass transit is great so long as I don't have to see the poors."
    - joshe 8y ago
      If you watch the talk, the plan is for autonomous pods that holds passengers with their bikes. Little buses basically. And also cars. You can’t just read the media reports, they are always about max outrage.
      - stcredzero 8y ago
        I miss the days when I could mostly read news that played on awesome, not outrage. https://www.youtube.com/watch?v=rE3j_RHkqJc https://www.youtube.com/watch?v=rE3j_RHkqJc
- njarboe 8y ago
  Couldn't one put buses in these tunnels? One could even mix buses and cars when the buses aren't taking up all the space. I don't quite get the hate for Elon's tunnels. Let him and his team try and build them and see if they work. Super cheap tunneling would be great for so many things. That is, unless you think that humans have too much power and think we should regress back to some more primitive lifestyle. "Try to help make a future that you would like to live in." Traffic congestion sucks. It would be great to get rid of it. Cheap tunnels could be one way to help. Why stop people from trying? He did start and still runs a company that makes reusable rockets. You have to try to do something before you know what is possible.
  - bobthepanda 8y ago
    As a cynical person, I've seen many US discussions of "why invest in public transport when Hyperloop and the Boring Company have the solution coming up in a few years?" Transport investment is like planting a tree. The best time to build it is twenty years ago, and the second best time to do it is now. Elon has basically given cover to NIMBYs to hide behind a supposedly new amazing future solution that may never come.
    - njarboe 8y ago
      There is plenty of capital in the world right now that there is no reason not to build all different kinds of new transportation schemes. Elon's first tunnel got NIMBYed. One main feature of tunnels is that you can, hopefully, put them lots of places where surface building is impossible. What people put in them will be up to the builders. Construction costs has not come down in price over time like many other things have. I think he hopes that the Boring Company can list a price/mile for tunneling that is much lower than current costs and let people actually budget them. Maybe sell these better machines to other construction companies at some point. He broke the cost-plus pricing for satellite launches. Just think what something like that for tunneling could do for transportation systems. Billion dollar overruns are on the digger not the public. That would be great.
      - bobthepanda 8y ago
- stcredzero 8y ago
  Elon's tunnels are the worst 3D alternative. The hourly capacity of a single city bus exceeds the daily capacity of an Elontunnel. For example: Elon has proposed a tunnel to Dodger stadium. Fixed wing airplanes are the worst flight alternative. The passenger capacity of a single hot air balloon far exceeds the passenger capacity of an airplane. For example: A Wright Flyer. Sorry, but this is a bit strawmannish. You do realize it's a proof of concept project, right? It's not like the Falcon 1 disproves the capacity of all SpaceX rockets, ever.
- deleted 8y ago
  [deleted]
joshe 8y ago
Absolutely. People are super confused about this. The reporting wasn't very good and you have to look beyond it. The original idea is - little 16 person passenger pods with bikes, wheelchairs, and luggage. $1 fare. - possibly sleds for cars - you can stack tunnels (think of them as car lanes in 3D), so you can have 20, 50 or 100 lane highways - you make lane changes autonomously, so the subway pods can have different destinations - it's all electric so there isn't poisonous engine exhaust This is just people boarding a bus, the throughput is super high. Even sled loading can be pretty fast, imagine replacing 20 street parking spots with sled elevators. Then accelerated to 100 mph, that too is a lot of throughput. Here's the pod part of the Boring company talk. It's worth watching to see what they are proposing. https://youtu.be/AwX9G38vdCE?t=1372 https://youtu.be/AwX9G38vdCE?t=1372 Elon and company got excited that they built a tunnel, which is a real achievement. So they drove a Tesla through it. The media knows what you want, which is max outrage, so they reported that the 1% will get tunnels with their Teslas. You will be stuck in gridlock behind a diesel truck. They should not have driven a Tesla through it, it was a PR blunder. Here is a Heathrow pod experiment: http://www.bbc.com/autos/story/20140910-hands-off-with-heathrows-pods http://www.bbc.com/autos/story/20140910-hands-off-with-heath...
- bobthepanda 8y ago
  These are just small trains. If it was built today you could automate the Boston Green Line too - the technology already exists. The main issue with building tunnels is cost. Tunnels aren't cheap and are hard to scale because soil conditions are extremely local and you have to tailor boring machines to ground conditions. Egress points are expensive, especially in dense urban areas where property values are sky high. You could use elevators instead of stairs, but the problem is that elevators are low-throughput and unusable in the event of unreliability. Even considering all that, Elon did build a tunnel, but the tunnel was quite short and also quite small. There's not really room for emergency ventilation, or egress walkways with exits or safety points every 300m, or really anything that modern fire codes would require. Once you add all that in the tunnel is not really narrower than a subway train, at which point you might as well build a subway train. And why not? The New York subway has a capacity of 60,000 people per hour per direction using signals from the 1930s. A highway lane only carries about 2,000 people per hour. And all of that's assuming your low-capacity elevator entry can handle all of that. PRT just combines the inefficiency of the automobile with the cost of actually building transit. There is a reason that PRT experiments have never been replicated elsewhere at large scale.

mortenjorck 8y ago

This is really the worst externality of "flying cars," or whatever you want to call short-range commuter aircraft. In absence of some exotic propulsion technology (what usually powers flying cars in science fiction), the amount of air that must be displaced to loft a vehicle carrying one to four people will always be orders of magnitude louder than a land vehicle.

kevin_thibedeau 8y ago
Helicopters are loud because the blades cross over the airframe and are powered by turbines. An electric multicopter based design could have significantly lower noise levels.
- binarymax 8y ago
  If going by the noise emitted by your average consumer drone, and scaling it up, I think the opposite is probably true - it would be crazy loud.
  - kevin_thibedeau 8y ago
    Few consumer level drones make any effort at noise reduction. Blade and shroud design can significantly impact noise production.
    - stcredzero 8y ago
      https://www.dronethusiast.com/what-are-the-best-silent-drone-choices-and-what-applications-are-they-good-for/ https://www.dronethusiast.com/what-are-the-best-silent-drone...
  - 83 8y ago
    Consumer drones aren't really aiming for quiet though. My racing drones are very buzzy since the small 3-5in props are fast spinning to have quick reaction time. My heavy lift photography drone with its slow 12in props (aiming for efficiency) is way larger and much quieter.