Again, I'm referring just to the pipe alignment and orbital welding rig. The orbital welding part is a well understood problem and solution. I could call up half a dozen companies today and for $20k buy an orbital welder in the 10-20" range. That's off the shelf. If I wanted to scale that up they might have to custom fabricate the tracks to guide the welding portion, but that's trivial. It might cost another $20k if the size is really big, and make another $40k if I want to buy a REALLY big power supply so that it can weld faster but as a class of problems orbital welding is a solved one.

As far as loading tubes go, you're likely going to build a tube rolling facility. These kinds of places tend to have overhead cranes. Big ones. Cranes that can grab the tube on both ends and thus have precise control over it. Most likely the loading would be done "indoors" so weather is mostly factored out. Building semi-circular restraints that grab the tube in 3-5 places along the 50ft length is done easily enough with a water-jet or you could roll a pipe into a semi-circle and weld supports to it. Once you have the custom trailer done it's relatively straightforward. You'd build the infrastructure to handle this in a highly automated fashion, similar to how container ships get loaded and unloaded. ~350 miles is 36,960 50ft sections of tube, double it since we're doing double-wide. If you know you need that much at the beginning there's a lot of work that can be done to make the whole thing reasonably efficient and cost effective.

I don't understand why you're expanding the scope to NIMBY or access roads or stuck trucks (locate the plant near the freeway) or any of this. I was talking specifically about the loading and unloading of pipe and making a jig to hold said pipe for precise welding.

Again, when I said "The difficulty isn't making the machine, it's finding someone with the constitution to ride out the periods of uncertainty and doubt while all the bugs are being ironed out." I'm referring only to building the alignment/welding machine, not the entire Hyperloop system. I realize that building the whole thing is immensely more difficult than building the alignment/welding jig. But we're inventing very little new stuff here, mostly repurposing things or making incremental changes.

All the "final design and construction" that you're talking about has the same risks and problems for the HSR as for the Hyperloop. If I have to be exposed to an 80% cost overrun I'd rather it was on a $5bn or $7.5bn project rather than an $80bn one. Maybe Hyperloop even has a 300% cost overrun and somehow the HSR project could come in 25% under budget. Hyperloop would then be (assuming the bigger version) $22.5bn versus the rail at $60bn.

The reason I don't work at a big engineering firm is that I couldn't get hired in at a senior enough level to actually get anything done. So I work for small companies. Thus far my track record is excellent but it would probably take me another 10-15 years for me to have enough successes at difficult projects for people to stop assuming it's a fluke. And by then I might not be too interested in risking my career on every project I work on.

This is why startups are even possible. The risk aversion of senior management makes it possible for people who are too young and too dumb to know that something's "impossible" to make it happen. If you've got any ideas how I could get hired at a big construction firm at a senior level I'm all ears.

There is all kinds of crazy stuff out there: https://www.youtube.com/watch?v=E0O78AyDixY

They're using a $45mm, 45 foot diameter TBM in Miami right now that's 450 feet long, has the ability to erect concrete rings inside of the machine, and can exert crazy pressure on the rock face. http://www.portofmiamitunnel.com/faqs/tunnel-boring-machine/

I'm suggesting something with less challenging specs and suggesting it could be built for less money. I don't think it's unreasonable.