Project Overview
Demolition and removal of 90 metre high stack.
McMahon Services was engaged by BHP Billiton to undertake a high risk stack demolition at the Olympic Dam mine site in Roxby Downs. The 90 metre high stack had buckled at the base, causing serious safety concerns, with fears that the 20 tonne weight of the stack could potentially collapse at any given time.
The 90 metre stack was removed in addition to a 20 metre elbow stack towards the base that fed into a filtration plant. The main steel structure supporting the stack was to remain. Scaffolding was erected the entire way up the stack in 15 metre sections and the stack braced to four points of the steel structure for additional support.
The project team removed the stack with precision oxy cutting in two metre sections beginning at the top and working downwards. Once cut, each section was lifted out using a 250 tonne crane and brought to ground for the client to dispose of on-site.
The main challenge of this project was the extremely windy conditions. When winds exceeded 10% no crane lifts were conducted to ensure safety remained at the forefront of the operation.
