Socioeconomic and political environments

After the Civil War, Washington returned to the family business, assisting in completing two more suspension bridges across the Ohio River (Invention Factory 2007). During this time Washington’s father, John, became interested in building a bridge across the East River. New York legislators finally realized the need for a route over the East River and passed a bill for some sort of construction. The largest restriction that the plans for the structure had to abide by was its height over the river, which was set to avoid contact with masts of ships that passes under it.

Aramid Fibers

Fiber type Density (g/cm3) % Elongation Modulus, Gpa Tenacity Kevlar 29 1. 43 3. 6 70 20-23 Kevlar 49 1. 45 2. 8 135 20-26 Kevlar 119 1. 44 4. 4 55 N/A Kevlar 129 1. 45 3. 3 99 N/A Kevlar 149 1. 47 1. 5 143 18 Nomex 1. 38 22 17 5. 8 (www. chem. uwec. edu) Kevlar Kevlar was first synthesized by Stephanie Kwolek in a DuPont research laboratory in 1964. It was only in 1971 that Kevlar was marketed because of the problems they encountered in processing this rigid and very insoluble fiber. Kevlar's chemical composition is poly para-phenyleneterephthalamide or para-aramid.