Another picture of moving metal by hand. Notice the solid steel hub in the center of the piece. A square foot of 1/4 in. steel weights 10 lb. The piece is 2 1/2 ft. tall and 3ft in diameter. Guessing it well over a ton, but calculating the exact weight would make my head hurt.

You will also notice they are on grating that extends all the way down 10 stories. Looking down 10 stories is not a good feeling when you hate heights.