Timber builds bridges into our heritage

Generally, the lifespan of a wooden bridge is 50 years before it is replaced with concrete, which should last 100 years.

Paynter Creek Bridge was opened in 1953 and replaced by a new concrete bridge in 2011.  Old Rattley on the North Arm of the Maroochy River was built in the 1930s and replaced by a high-level concrete bridge in 1996.

The Sunshine Coast hinterland has several one-way wooden bridges in need of replacement, for example at Caboolture Creek, Bli Bli Road and on Rocky Creek, Kiamba Road.

Builders of wooden bridges speak proudly and nostalgically about their skill in using great wooden piles of ironbark or blackbutt and thick planks of sawn hardwood.

Different methods of preservation were used. Many years ago, the bridge gang would be equipped with arsenic to be dusted on any termite tracks. This was a certain method of destroying the nest.

Creosote was also used as a white ant deterrent. Applied with a stirrup pump, creosote saturated the timberwork. The bridge would be dripping creosote straight into the creek or riverbed.

On a hot day, workers suffered from skin burns on the arms and legs and as the pump sometimes burst, resulting in facial burns.

Old wooden bridges may be part of our timber heritage but there are other problems as well as the white ants and time. They are narrow and hazardous to modern-day traffic. Many are low and flood easily. Upkeep is expensive.

You could believe that the era of wooden bridges has passed, but a new method of bridge building with wood has made history.

Recently, the Sunshine Coast Regional Council installed a new bridge over a small, un-named creek on River Road (by the Maroochy River).

It was a flat pack of imported Douglas fir, which is native to the United States and Canada. The timbers are impregnated with chemicals to ensure longevity for, it is said, the next 100 years. The one-way bridge has a curved single span. Once assembled it was dropped into place by a large crane.

Old maps show the route of the Nambour to Coolum cane tram opened in 1923 and closed in 1935. On River Road, bridges with tracks for the cane trams were built over the small creek and Yandina Creek.

Some time later, running boards were placed on the bridges so vehicles could cross.  When the Moreton Central Sugar Mill in Nambour closed in 2003, tram tracks were pulled up. Decking was placed over the piles for vehicles to cross but few have needed to use this road. More recently, damage from heavy loads to the bridge over the small creek brought about the need for its replacement.

Towards the end of River Road is a car park for visitors to Yandina Creek Wetlands where a walking path has been established. At the end of River Road is a turn-around with gates to private properties. Wallum is the name given to this swampy, tidal area.

Nearby, the cane tram lift bridge over the Maroochy River, which was always a spectacular sight, was opened in 1922 but has been destroyed by floods and neglect since the sugar mill closure.

Stories of our early transport, our roads and bridges are part of our heritage.

Audienne Blyth is a member of the Nambour Historical Museum, open Wednesday to Friday, 1pm-4pm and Saturday 10am-3pm. All welcome.