•Each tower was 1375 ft. tall, with 110 floors of 12.5 ft.
•Each consisted of
a perimeter of 244 structural steel columns forming a square plan,
with horizontal bracing (spandrels) and extremely rigid chamfered corners.
cores, of dimensions 79X139 ft., was a veritable forest of 47 columns, horizontal
and diagonal cross braced.
•The 47 core columns
varied in thickness with floor height. Individual core columns in the lower
core measured 52 x 22 in. (in plan), and were formed of 5 and 3 inch plate
into almost solid steel shafts that weighed up to 56 tons. This construction
changed to relatively light I-beam cross section above the 85th floor.