Old Rakaia Gorge Bridge Gorge Bridge Road, Windwhistle

When the iron suspension bridge was built over the Rakaia Gorge in 1880-82 there was a possibility that it might be needed for rail as well as road traffic along this important inland Canterbury route. The proposed railway never eventuated but the strongly constructed 57 metre bridge survives as one of the few nineteenth century components in the main highway network.

It is a Bollman Truss bridge, following the design patented by a United States railway engineer in 1852, where a series of non-symmetrical trussed beams of iron are jointed to vertical members by hinged pins to facilitate construction. A sound design, it enjoyed brief success before it was superseded by more economical iron bridges and there is now only one surviving example in the United States. It is near Baltimore and though in poor repair, is recognised as a National Historic Civil Engineering Landmark. Therefore the well maintained, continually used Rakaia Gorge Bridge has international significance as the best example of this interesting phase of bridge development.

An important monument to the skills of early New Zealand engineers, this bridge is notable for its age, excellent condition and unique design.