ABSTRACT

The main cables of a suspension bridge are the primary load-carrying members and are vital to the structural integrity of the bridge. The main cables transfer the suspended dead load of the deck, and all the transient loads, in tension to the ground via the towers and anchorages. The main cables of the longest-span suspension bridges are usually formed from thousands of very high-tensile steel wires. These wires are produced by cold-drawing steel rods through a series of reducing dies until the final diameter of typically around 5 mm is achieved. The diameter of wire used varies between bridges, but historically 5 mm wire was used for practical reasons, as wire with a diameter larger than this has greater stiffness and requires higher tension for handling during construction. The wires are usually galvanized to provide the first stage of a protective system.