Gilbert River Bridge
Unique in its marine projects is Southern Cross’s demolition of the old Gilbert River bridge during August 2009 near Normanton Northern Queensland. Two issues made this project unique in that due to its remote location everything had to be brought to the works from excavators right down to life’s basics such as water and food. The other issue that made these works special is that a croc cage was required to be transported to site to provide protection to our personnel during in water works. This was due to the local crocodile population that inhabited the area.
This project was undertaken directly for the Qld Government via its Roadtek division and involved the use of explosives for blasting to avoid the need for people to constantly enter the water and minimise any danger from the native inhabitants. Protective croc cages were also employed to ensure the safety of any personnel in the water. It was also necessary to estimate the number of pylons that were underpinning the bridge as due to recent floods and the muddy nature of the river water then the pylons could not be seen clearly. Pylons were removed down to river bed level and then platforms were floated to each pylon that were then drilled vertically to accommodate the loading of explosives to remove the piles to the contract level of 1 m below river bed level.
The project was schedule to take place over four weeks and particular care was taken with weather forecasting so as not to have workers, plant and equipment exposed to risk and isolation due to the potential of inclement weather. Exclusion zones were enforced and the use of very small explosive charges (fish scare) were used to move crocodiles and marine inhabitants away from the immediate area prior to the main charge being used. As with all our blasting works particular care was taken with all blasting procedures and the use of sentries, radio controlled personnel, exclusion zones, timing, warnings signals, thorough checks and handling were all successfully employed and contributed to a positive outcome.
