The World Trade Center: Statistics and History - 8 views
-
-
dawnprovost on 22 Jan 18Good information for the background paragraph of the essay.
-
-
-
Faced with the difficulties of building to unprecedented heights, the engineers employed an innovative structural model: a rigid "hollow tube" of closely spaced steel columns with floor trusses extended across to a central core. The columns, finished with a silver-colored aluminum alloy, were 18 3/4" wide and set only 22" apart, making the towers appear from afar to have no windows at all.