It was designed by John Whitton as the Engineer-in-Chief, of the New South Wales Government Railways and NSW Department of Public Works.

[1][2] When John Whitton planned the railway extension from Campbelltown to Picton, he was under pressure from the Government to keep costs low by using as much local material as possible.

A metal girder design had been proposed by contractors Peto, Brassey and Betts but Whitton substituted a timber bridge made from ironbark and other strong hardwoods, a relatively short 151 metres (495 ft), low level crossing.

[1] Construction of the locally quarried sandstone abutments and piers[3] were completed in October 1862 and the iron bridge was assembled ready for service by June 1863.

Their sizes and design were such that they were featured in an international text book Modern Examples of Road and Railway Bridges by William H. Maw and James Dredge, London, 1872.

[1] On the outer surfaces of the girders there are pairs of curved angle irons suggesting the inclusion of an arch, but they are purely decorative.

The iron bridge itself received only superficial damage in the accident but the stonework was not replaced, leaving the cellular cross section of the girder exposed.

[1] The principal modification has been the building of the intermediate piers in 1907 which, by halving the original spans, greatly increased the load capacity of the bridge, allowing it to still be in service, carrying modern, heavy, fast rail traffic.

[1] In 1993, consulting engineers, Dames & Moore of North Sydney, recommended a number of actions for a general refurbishment of the main bridge, including some minor repairs, cleaning up, painting and maintenance of the bearings, but no major changes.

[1] Menangle Railway Bridge was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria.

[1] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

[1] The place has potential to yield information that will contribute to an understanding of the cultural or natural history of New South Wales.

The cellular construction, whereby the top and bottom parts of the girders are made in the form of two boxes or cells, was a recent development for resisting lateral buckling arising from the famous experiments by Fairfairn and Hodgkinson for the 1849 Britannia Bridge in Wales.