When opened in 1909, the 1,470 foot long main span of the Manhattan Bridge was the third longest suspension bridge span in the world, after the nearby Brooklyn and Williamsburg Bridges. The Manhattan Bridge has two 725 foot long suspended side spans for an overall length of 2,920 feet. The bridge deck is supported by 4 main cables of 20.75 inch diameter, each composed of more than 35,000 individual wires. The bridge deck is stiffened by four parallel trusses of 24 foot depth, hinged at the towers.
"An essential part of the human experience is to create an aesthetic atmosphere."
The George Washington Bridge represented a departure in suspension bridge design. Chief Engineer O.H. Ammann developed a system of stiffening trusses that offered greater flexibility and saved the project nearly $10 million. Initially, just six of the upper eight lanes were paved, but Ammann designed the bridge to easily accommodate a future lower level.
Swiss-born O.H. Ammann (1879-1965) was Chief Engineer for the Port Authority of New York and New Jersey during the bridge's construction.