L.A. To N.Y. In A Half Hour, 10,000 MPH Tunnel Tube System In 1972?

I think a tunnel like that would be possible if they used a series of adjustable layered casings. The outer casing for the tunnel could be the thickest stabilizing section, line it with metallic glass and it could become airtight. Build an inner casing for the train that sits on adjustable shock absorbers and the problem with earthquakes would be minimalised. Most ground movement below the surface during an earthquake is really minor anyway.

Asuming the geological issues were solved, and the vacuum issues are solved, the remaining points are pretty easilly addressable.

As far as an air supply for passengers during their trip through a vacuum, we can just use the same systems we use on any commercial aircraft or the space shuttle - a pressurized cabin. As long as the air within the cabin is sealed from leaking into the vacuum, there's no effects on the passengers regarding air supply - the pressurized interior air moves with the vehicle, just as a part of the vehicle itself would.

Additionally, in taking care of the G-force issues or acceleration and deceleration, I'm surprised that nobody has mentioned the discoveries by French scientists of a type of anti-inertial system. The system was orginally researched to prove that the flight qualities of UFOs are possible, and has yeilded some practical scientific results. Essentially, what the system is, as I understand it, is a magnetic "bubble" that reduces friction and gravitational effects on the object contained within the "bubble". If this technology pans out as legitamate, not only have we solved the inertial issues, but also possibly the vacuum issues as well, as creating a vacuum within the entire length of the tunnel wouldn't be necessary (and also, it wouldn't need to be a tunnel at all - it could be built as a ground level or elevated track, with tunnels through the mountains).

For more information on the anti-inertial technology, refer here: French Anti-Grav and Anti-Inertial research link.

Actually, wasn't this a slip to what was really happening around Dulce? I have sat in bars with men who worked for the government that talked to me about this before. People claim it's a reality.