Clough, in joint venture with Christiani & Nielsen A.S. of Denmark, completed the construction of a five span continuous prestressed concrete bridge crossing the Swan River in Perth. 

The bridge is comprised of five spans (48.8m, 70m, 97.6m, 70m, 48.8m). Its eight rows of beams, made up of precast segments 2.97m long and of varying depth, weigh up to 20 tonnes each. The bridge is post-tensioned longitudinally using the Gifford - Udall 19 wire 18mm diameter strand system, developed especially for the project. 

At the time of its opening, the Narrows Bridge was the largest precast prestressed continuous beam bridge in Australia.