Brian,

For 2 tons of mass to equal 2 tons of weight, you need to have done one of 3 things-

1. Persuaded Congress to repeal the Law of Gravity (which would make rockets much smaller), or
2. Beat CERN to discovering the god particle that’s supposed to impart mass to every atom in existence, thereby making an anti-gravity device possible, or
3. Gone off your meds.

To split hairs, NASA routinely ships water to the ISS. 8,000 miles plus a topoff makes almost any point in the world accessible within 24 hours. Granted, the bird of choice would most likely be a C5-A, as the situation would be motivated by political expediency rather than cost-effectiveness.

About water mass, are you calculating volume radially around the vacuum chamber, or 1 meter around the entire machine- cap banks, switches and all?

Duke, here’s a link to a borated polyethylene supplier who lists the TVT of .875 inches of lead as doing the same shielding as 1inch of his material, but around 11 times heavier. Probably costs less in materials and labor, too.

http://www.boratedpe.com/kingplasti-shieldboratedpesheet.html

Maybe we’re not stuck with quite as much weight as we were expecting yesterday….