Despite popular mythology, the bridge was not originally intended to carry a double railway track, as part of the proposed extension of the
Illawarra railway line to
Jervis Bay and possibly . The bridge was designed by American engineer Charles Shaler Smith and is considered to be of local historical significance. The bridge was completed in 1881 and is built from wrought iron with a steel approach span. The bridge had a timber deck for 100 years until in 1981 reinforced concrete was laid over steel Armco decking. The pairs of cast iron piers are original and were supplied locally by the Atlas Foundry,
Sydney. It was the largest bridge project in New South Wales prior to the 1889
Hawkesbury River Railway Bridge. Its full length is . ==Second bridge==