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
All-dielectric self-supporting cable suspension type, only holding the weight of a span with tension transmitted through the next span of cable. Reinforcing rods are used on either side of a support and at dead-ends. Wind-induced aeolian vibration is a factor since ADSS cables have light weight, relatively high tension, and little self-damping. Anti-vibration dampers are installed on each span near the support points. Accessories must not be clamped directly to the cable but instead over reinforcing rods, to protect the cable from electrical and mechanical damage. Termination boxes are used to enclose and protect splices between the ADSS cable and "inside plant" cable