Prior to the bridges being built, river crossings were often dangerous in times of rain, which caused bulk freight movement to be prohibitively expensive for most agricultural and mining produce.

Only the high priced wool clip of the time was able to carry the costs and inconvenience imposed by the generally inadequate river crossings that often existed prior to the trusses construction.

[1] Timber truss bridges were preferred by the Public Works Department from the mid-19th to the early 20th century because they were relatively cheap to construct, and used mostly local materials.

The de Burgh truss is the first to use significant amounts of steel and iron, and did so in spite of its high cost and the government's historical preference for timber.

[1] Middle Falbrook Bridge over Glennies Creek was listed on the New South Wales State Heritage Register on 20 June 2000 having satisfied the following criteria.

[1] This Wikipedia article was originally based on Middle Falbrook Bridge over Glennies Creek, entry number 1474 in the New South Wales State Heritage Register published by the State of New South Wales (Department of Planning and Environment) 2018 under CC-BY 4.0 licence, accessed on 13 October 2018.