Spit Bridge, Bascule bridge in Mosman, Australia

Spit Bridge is a steel and concrete girder bridge over Middle Harbour, linking Mosman and Seaforth. It has seven spans totalling 227.2 m, four traffic lanes and a 1.5 m footway on each side. The single-leaf bascule span, with an open mesh steel deck, pivots on Pier 4, a box-like concrete pier housing the machinery and operator's cabin.

A rowing boat crossed Middle Harbour here from 1829, followed by a hand-operated punt in 1850 and a steam punt in 1889. Manly residents first requested a bridge in the 1870s. A timber bridge opened in 1924; the current steel and concrete bridge, built by Cleveland Bridge & Engineering Company of Middlesbrough, opened on 19 November 1958 after steel shortages delayed work begun in 1952.

The bridge serves as a major crossing point between different Sydney neighborhoods, with locals and visitors regularly walking across to reach beaches and parks on the other side.

The bridge lifts its central span on a regular schedule to allow sailboats and tall vessels to pass through. Pedestrians can use the walkways at any time but may experience brief pauses when lifting occurs.

Concrete piles driven deep into the harbor bed sand provide the foundation for the Mosman end, hidden beneath the water's surface. This underwater support system is rarely noticed by pedestrians but allows the bridge to remain stable in the marine environment.