This challenging project called for McMahon Services to remove asbestos sheeting and then demolish the obsolete “A” Station Chlorinator House overhanging the wharf at Playford A Power Station in Port Augusta.
To remove the asbestos bonded roof sheeting the project team utilised a 100 tonne crane with man cage before they could commence precision demolition works.
Demolition and removal of the internal steel structure was undertaken by oxy cutting the steel frame at the base and lifting the concrete structure, again using the 100 tonne crane.
To demolish the lower concrete wall and floor, a PC 300 Excavator was called in with an extended boom and pulverize attachment. A sieve bucket was then attached to load out materials from the sea bed into semi-tippers and removed from site.
A key challenge of this project was the demolition of steel supporting columns and braced at least 0.2 metres below the sea floor level. McMahon Services worked closely with the Whyalla Diving Service to perform underwater oxy cutting of the steel columns to then lift the columns from the ocean floor with a 100 tonne Grove crane.
Due to the instability of the wharf, all plant and equipment had to remain approximately seven metres back from the edge of the structure. Furthermore, the Chlorinator House was also completely overhanging the water side of the wharf. To provide a practical and safe solution, McMahon Services fitted a long reach boom to both the excavator and crane.
The divers then completed a final clean-up of the ocean floor of all remaining small debris, while McMahon Services project team removed obsolete pipework along the wharf.