Humber Bridge July 1981. With a centre span of and a total length of , the Humber Bridge was the longest single-span suspension bridge in the world for 17 years, until Japan's Akashi Kaikyō Bridge opened on 5 April 1998. The road-distance between Hull and Grimsby was reduced by nearly as a consequence of the bridge. The bridge's surface takes the form of a dual carriageway with a lower-level foot and cyclepath on both sides. There is a permanent speed limit on the full length of the bridge. Each tower consists of a pair of hollow vertical concrete columns, each tall and
Suspension bridge major wire-cable suspension bridge was the in Philadelphia, Pennsylvania. Designed by Charles Ellet, Jr. and completed in 1842, it had a span of 109 m. Ellet's Niagara Falls Suspension Bridge (1847–48) was abandoned before completion. It was used as scaffolding for John A. Roebling's double decker railroad and carriage bridge (1855). The Otto Beit Bridge (1938–39) was the first modern suspension bridge outside the United States built with parallel wire cables. The main forces in a suspension bridge of any type are tension in the cables and compression in the pillars. Since almost all the force on the pillars is