5 ms·

That means the system can be designed to support just one of them per pylon. The capacity of the structure is not just limited to the weight of the revenue veh

That means the system can be designed to support just one of them per pylon. The capacity of the structure is not just limited to the weight of the revenue vehicles, the structure needs to handle other loads it may encounter over the its useful life, such as snow (probably not much of an issue in central/southern CA), water (if the tunnel leaks) and maintenance vehicles (which will likely be significantly heavier than the passenger cars since they will have to be self-propelled). then put down the ties, then put rail on top of those, fasten it down, etc. Ties are in the range of 6-8" thick and then there's the ballast (rocks) which aren't light either and which are generally required to keep the ties from moving. You don't need ballast & tie track on structures. In any event, cutting the material weights in half (even if you can, which is doubtful) does not automatically cut your costs by 90 percent. You still have the environmental process, you still have NIMBYs, you still have construction mobilization costs, etc.

msandford 13y ago
That's a good point; something I neglected in my analysis. I would argue that since the tube sections would all be pre-fab that means that the installation cost of the tube would be really small. Rail installation costs are no joke due to the need to precisely align horizontally and vertically the two rails. You can make tube in 50ft sections and ship them via truck without needing any special permitting and given that the highway runs right next to the planned route, the pre-fab notion is quite a good one.
- Anechoic 13y ago
  Rail installation costs are no joke due to the need to precisely align horizontally and vertically the two rails. The hyperloop sections would also need to be precisely aligned. You can make tube in 50ft sections and ship them via truck without needing any special permitting But you may need special routing for those trucks to allow overhead clearance and turn radii, and you may need to build temporary roads for access to the installation site. There are lots of little things that tend to add up that are ignored in the whitepaper. You may be able to reduce costs by a few percent, but 90% is not a figure that I can take all that seriously.
  - msandford 13y ago
    A standard semi-trailer is 53ft long and an internal cargo area that's 8ft wide and 8ft tall. I think you can fit a 7.5ft diameter tube inside an 8ft square box. If you wanted to do the 11ft you would need a low-boy trailer to avoid height permitting and you would need "wide load" signs for the trucks individually but no lead/chase vehicles. The tube joining/welding/grinding jig could be 40ft (or 200 ft or more) long and fit inside the already assembled tube AND the to-be-welded tube. Precision alignment could be done via movable clamps. Once the tube is held in place via the jig it can be welded via a number of methods (friction stir, friction, MIG, TIG or SMAW) inside, outside or both.
    - Anechoic 13y ago
      I think you can fit a 7.5ft diameter tube inside an 8ft square box. You are not going to give yourself 6-inches of clearance for a component that weighs (using your numbers) 19.2 tons, that pipe is going on a flatbed. You also have to allow room for tie-downs, flanges, support blocks, etc. You also have to account for bridge weight limits. I'm not saying this isn't doable (the Big Dig was able to truck in 100 ft soldier piles, although they had to do it at night), it's just that it often takes extra planning and work which increases costs. The tube joining/welding/grinding jig could be 40ft (or 200 ft or more) long and fit inside the already assembled tube AND the to-be-welded tube. Are you basing this on something that already exists, or is this something you are proposing?
      - msandford 13y ago
        Yes I'm quite aware. You'd actually build a number of semi-trailers that had the proper rigging on them, welded down. My point was to say that it's entirely possible to fit that size of a tube onto a semi trailer with no hardship at all. No wide corners, no permits, no height restrictions, none of that. If it's possible to make two tunnel boring machines meet at the middle of the English channel with the starting points separated by some 20 miles, then it's entirely possible to build a pipe-section-holding jig which can ensure precise alignment. I probably can't write a check for one and have it in a year (partly because I don't have $5mm, also because the plans don't exist yet) but to suggest that it would take more than three years to design, build and verify such a machine is a bit extreme. You could probably do it in a year or less provided that you're willing to pay more. The machine as a whole doesn't exist yet but all the various component pieces of it do and they're all COTS parts. It's part tunnel boring machine (http://en.wikipedia.org/wiki/Tunnel_boring_machine http://en.wikipedia.org/wiki/Tunnel_boring_machine) part orbital welder (http://www.mecomachineandfab.com/public/images/photos/orbital-welder.jpg http://www.mecomachineandfab.com/public/images/photos/orbita...) and the rest is "glue." Make it 300 feet long so that it's always resting on pipe that's already affixed at two separate pylons and so that it doesn't deflect the pipe on either side of the joint it's about to make. An external crane (or if you get clever, one built onto the TBM/welder rig) lifts the pipe up, the jig grabs hold of it, positions it, and then makes the weld. Let the machine advance slightly and x-ray the entire weld for QA/QC and provided it passes, advance the machine to do the next section. If you wanted me to make one of these for you I'd probably quote $500k-$1mm for the initial research including a small prototype (10-20" diameter) and I would guess (+- 50%) $10mm for the big one.

msandford 13y ago

That's a good point; something I neglected in my analysis. I would argue that since the tube sections would all be pre-fab that means that the installation cost of the tube would be really small. Rail installation costs are no joke due to the need to precisely align horizontally and vertically the two rails. You can make tube in 50ft sections and ship them via truck without needing any special permitting and given that the highway runs right next to the planned route, the pre-fab notion is quite a good one.

Anechoic 13y ago
Rail installation costs are no joke due to the need to precisely align horizontally and vertically the two rails. The hyperloop sections would also need to be precisely aligned. You can make tube in 50ft sections and ship them via truck without needing any special permitting But you may need special routing for those trucks to allow overhead clearance and turn radii, and you may need to build temporary roads for access to the installation site. There are lots of little things that tend to add up that are ignored in the whitepaper. You may be able to reduce costs by a few percent, but 90% is not a figure that I can take all that seriously.
- msandford 13y ago
  A standard semi-trailer is 53ft long and an internal cargo area that's 8ft wide and 8ft tall. I think you can fit a 7.5ft diameter tube inside an 8ft square box. If you wanted to do the 11ft you would need a low-boy trailer to avoid height permitting and you would need "wide load" signs for the trucks individually but no lead/chase vehicles. The tube joining/welding/grinding jig could be 40ft (or 200 ft or more) long and fit inside the already assembled tube AND the to-be-welded tube. Precision alignment could be done via movable clamps. Once the tube is held in place via the jig it can be welded via a number of methods (friction stir, friction, MIG, TIG or SMAW) inside, outside or both.
  - Anechoic 13y ago
    I think you can fit a 7.5ft diameter tube inside an 8ft square box. You are not going to give yourself 6-inches of clearance for a component that weighs (using your numbers) 19.2 tons, that pipe is going on a flatbed. You also have to allow room for tie-downs, flanges, support blocks, etc. You also have to account for bridge weight limits. I'm not saying this isn't doable (the Big Dig was able to truck in 100 ft soldier piles, although they had to do it at night), it's just that it often takes extra planning and work which increases costs. The tube joining/welding/grinding jig could be 40ft (or 200 ft or more) long and fit inside the already assembled tube AND the to-be-welded tube. Are you basing this on something that already exists, or is this something you are proposing?
    - msandford 13y ago
      Yes I'm quite aware. You'd actually build a number of semi-trailers that had the proper rigging on them, welded down. My point was to say that it's entirely possible to fit that size of a tube onto a semi trailer with no hardship at all. No wide corners, no permits, no height restrictions, none of that. If it's possible to make two tunnel boring machines meet at the middle of the English channel with the starting points separated by some 20 miles, then it's entirely possible to build a pipe-section-holding jig which can ensure precise alignment. I probably can't write a check for one and have it in a year (partly because I don't have $5mm, also because the plans don't exist yet) but to suggest that it would take more than three years to design, build and verify such a machine is a bit extreme. You could probably do it in a year or less provided that you're willing to pay more. The machine as a whole doesn't exist yet but all the various component pieces of it do and they're all COTS parts. It's part tunnel boring machine (http://en.wikipedia.org/wiki/Tunnel_boring_machine http://en.wikipedia.org/wiki/Tunnel_boring_machine) part orbital welder (http://www.mecomachineandfab.com/public/images/photos/orbital-welder.jpg http://www.mecomachineandfab.com/public/images/photos/orbita...) and the rest is "glue." Make it 300 feet long so that it's always resting on pipe that's already affixed at two separate pylons and so that it doesn't deflect the pipe on either side of the joint it's about to make. An external crane (or if you get clever, one built onto the TBM/welder rig) lifts the pipe up, the jig grabs hold of it, positions it, and then makes the weld. Let the machine advance slightly and x-ray the entire weld for QA/QC and provided it passes, advance the machine to do the next section. If you wanted me to make one of these for you I'd probably quote $500k-$1mm for the initial research including a small prototype (10-20" diameter) and I would guess (+- 50%) $10mm for the big one.