Straits of Mackinac Bridge and Deck Trusses

This $44M (1953 dollars) project involved the fabrication and erection of the entire superstructure of a 47 span bridge crossing the Straits of Mackinac, connecting the upper and lower peninsulas of the State of Michigan.  The 18,343′ (5,591m) bridge contained 30 deck truss spans, 14 steel plate girder spans, and a 7,400′ (2,256m) 3 span suspension bridge with a 3,800′ (1,158m) main span.  The suspension bridge is a 38′ (12m) deep deck truss with transverse floor trusses.  Deck width is 69′ (21m), and the roadway surface is a combination of open and concrete filled grid.  The towers are 552′ (168m) tall (above the concrete pedestal), made from structural steel.  Main cables are 24.5″ (622mm) diameter, made from 37 airspun parallel wire strands of 340 wires each.  Total weight of structural steel is 66,023 tons. American Bridge fabricated and erected the Mackinaw City truss approach and the St. Ignace truss and girder approaches to the Mackinac Suspension Bridge.  This work included 35 deck truss spans aggregaGÊ?à`P°ÒAmerican Bridge supplied grid deck and structural X steel for the S