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There's no way you can get people from LA to SF in that timeframe without some combination of massive tunnels and viaducts due to what's known as minimum vertic

There's no way you can get people from LA to SF in that timeframe without some combination of massive tunnels and viaducts due to what's known as minimum vertical curve radius. If he's going to build this for one tenth the cost of a predominantly at-grade high speed rail system, then the real breakthrough isn't his don't-call-it-a-vacuum evacuated air hockey tube, it's a magical ability to lay massive amounts of concrete and bore hundreds of miles of tunnel for several orders of magnitude less money than is currently required. If he's figured that out, the resulting company would be worth far more than tesla, SpaceX and any asteroid mining venture he could conceive of combined. I don't think he's figured that out.

EthanHeilman 13y ago
>it's a magical ability to lay massive amounts of concrete and bore hundreds of miles of tunnel for several orders of magnitude less money than is currently required. He isn't boring tunnel but building it above ground. Not that that changes your other points. The devil is in the details and we don't have enough details to evaluate it.
- kinofcain 13y ago
  See my reply to IanDrake, building it entirely above ground at those speeds would require viaducts so tall that boring tunnels would be cheaper.
IanDrake 13y ago
>bore hundreds of miles of tunnel It's elevated, not below ground. But I think most of your point stands. Just getting through the politics alone would be impressive.
- kinofcain 13y ago
  The Tejon pass (grapevine) is over 4000 feet. Minimum vertical curve radius on Britain's High Speed Two, with a top design speed of 250mph, is 56 kilometers. This thing will need to operate at an average speed several times that. As you make the train faster and faster, the route must asymptotically approach a straight line. A straight-ish line that goes over the mountains between LA and the central valley would either require viaducts hundreds, if not thousands of feet tall, or it will require tunneling, or it will require a mixture of both.
  - jack-r-abbit 13y ago
    But it is not a train. It is a short, tube-shaped vessel inside of another tube and magnetically elevated. I am assuming that the magnetic "elevation" is all around the vessel which would prevent it from slamming side-to-side or top-to-bottom. I'm not saying there won't be problems but I don't think it will need the curve radius like you are thinking for a train.
    - kinofcain 13y ago
      It has nothing to do with the ability of the train to stay on the tracks, it has to do with the ability of the passengers to keep their lunch in their stomachs.
      - jack-r-abbit 13y ago
        ah. I understand that. thanks for clarifying.
hnriot 13y ago
You must have skimmed the article, this isn't miles of tunnel that he's proposing.

EthanHeilman 13y ago

>it's a magical ability to lay massive amounts of concrete and bore hundreds of miles of tunnel for several orders of magnitude less money than is currently required. He isn't boring tunnel but building it above ground. Not that that changes your other points. The devil is in the details and we don't have enough details to evaluate it.

kinofcain 13y ago
See my reply to IanDrake, building it entirely above ground at those speeds would require viaducts so tall that boring tunnels would be cheaper.

IanDrake 13y ago

>bore hundreds of miles of tunnel It's elevated, not below ground. But I think most of your point stands. Just getting through the politics alone would be impressive.

kinofcain 13y ago
The Tejon pass (grapevine) is over 4000 feet. Minimum vertical curve radius on Britain's High Speed Two, with a top design speed of 250mph, is 56 kilometers. This thing will need to operate at an average speed several times that. As you make the train faster and faster, the route must asymptotically approach a straight line. A straight-ish line that goes over the mountains between LA and the central valley would either require viaducts hundreds, if not thousands of feet tall, or it will require tunneling, or it will require a mixture of both.
- jack-r-abbit 13y ago
  But it is not a train. It is a short, tube-shaped vessel inside of another tube and magnetically elevated. I am assuming that the magnetic "elevation" is all around the vessel which would prevent it from slamming side-to-side or top-to-bottom. I'm not saying there won't be problems but I don't think it will need the curve radius like you are thinking for a train.
  - kinofcain 13y ago
    It has nothing to do with the ability of the train to stay on the tracks, it has to do with the ability of the passengers to keep their lunch in their stomachs.
    - jack-r-abbit 13y ago
      ah. I understand that. thanks for clarifying.

hnriot 13y ago

You must have skimmed the article, this isn't miles of tunnel that he's proposing.