The World As We See It , or as we missed it.Group January 2010
Kangaroo Valley, NSW
Designer E M DeBurgh
Builder Loveridge and Hudson of Bowral
Construction years 1895 – 1898
Physical description The structure is a suspension bridge crossing a gorge with sheer cliffs on one side and steep banks on the other, with the Kangaroo River running westward beneath it. With a clear main span of 77m, a sag in the cables of 15m, sandstone tower height of 16.8m and height above water also of 16.8m, it is an impressive structure in the local landscape.
The main cables of the bridge consist on each side of fourteen 36mm diameter wire ropes, each with a specified tensile strength of 79.6 tonnes. They are anchored vertically in pits at either end of the bridge and have facility for length adjustment. From here they run upwards, over turning shoes in a sandstone pillbox, turn again at the towers on turning shoes which have rocker bearings, and cross the span with a low point approximately one metre above deck level.
The sandstone towers, constructed from sandstone quarried on the site (and possibly elsewhere) are of Gothic style akin to that used for its larger relative, the suspension bridge at Northbridge in Sydney (the central span of which is now a reinforced concrete arch). Each tower has two columns, joined by an arched crossbeam above traffic height. The suspension saddles are located near the level of the top of this beam, and each tower is then topped with an enlarged battlement.
From the cables, suspension rods hang in an inclined plane to support the deck. They terminate through crossbeams which were originally timber, but are now of galvanised steel. Sitting on these cross beams, the deck is of longitudinal timber stringers supporting transverse and longitudinal timber sheeting, and is stabilised by vertical side trusses. These have upper and lower longitudinal chords and verticals in timber, with steel rod cross diagonals. Each side of the bridge has two such trusses meeting at the centre of the span at a hinge connecting the lower chords only. This arrangement allows the bridge to articulate as loads move across it, the primary articulation being at the hinge, with secondary articulation provided by the flexibility of the trusses themselves. Lateral bracing is provided by steel angles bolted in a diagonal pattern to the bottom of the crossbeams.
The bridge is signposted for a maximum truck load of 42.5 tonnes, with no more than one truck to be on the bridge at a time, and is lanemarked to only provide a single lane (leaving two moderately narrow pedestrian walkways).
Some 50m upstream there is a modest weir, and the waters below the bridge sustain a canoe hire operation.
Hampden Bridge, Kangaroo Valley
Hampden Bridge is listed in the Australian National Heritage List
Australian Heritage Database