Pre-intermediate Workbook Cassette Total English: Аудиокассета.

There was also a lesser supporting feature called «intermediate support angle». Since all we know about the intermediate support angle, is that its support capabilities were inferior to the double and transverse trusses, we shall be generous and assume that it was similar in nature to the transverse trusses. This adds another 1764 feet, to give a total of 2004 + 1764 = 3768 feet of transverse trussing. Hence, the volume of steel in the double trusses was 4440 x 88.3/1728 = 227 cubic feet. And the volume of steel in the transverse trusses was 3768 x 39.7/1728 = 86.6 cubic feet. So the overall per floor volume of steel in the floor support system was 150 + 13.3 + 227 + 86.6 = 477 cubic feet. The total per floor volume of steel, is now the sum of that in the perimeter wall, the central core section and the floor system. This is 563 + 1210 + 477 = 2250 cubic feet. So why have we gone to all this trouble to calculate the per floor volume of steel? Well, we know that 96,000 tons of steel was used in the construction of each of the WTC towers ...»