The first Pyrmont bridge began operating in 1857 providing the main transport route between the city and Sydney's growing western suburbs. Constructed of timber, this swing bridge allowed shipping to move in and out of Cockle Bay.
The current Pyrmont Bridge opened on 28 June 1902. It is one of the world's oldest surviving electrically operated swing span bridges. There were 42 entrants in the 1901 international competition to build the new Pyrmont Bridge. The winning design was by Australian engineer Percy Allan.
Pyrmont Bridge consists of a steel truss swing span with timber truss approach spans. Timber was used because of the high cost of iron and steel and government insistence on using local ironbark to reduce costs.
The new electrically - operated Pyrmont Bridge (1902) continued giving access to Western Sydney and was acclaimed at a 1907 London meeting of the Institution of Civil Engineers. The electrical power to operate the swing spans was originally drawn from the Ultimo Power House (now the Powerhouse Museum).
Although the 1902 bridge was closed to motor traffic in 1981, it was saved from demolition and carried the monorail and pedestrians to Darling Harbour. It is one of the world’s largest electrically operated swing bridges. It was declared a National Engineering Landmark in 1992 because of the superb design of Percy Allan’s timber girder approach spans.