BHP contracted Delta Group to design and deliver an industrial demolition works program for redundant HBI plant at their Boodarie facility in Port Hedland.

The scope of works included:

  • Demolition of existing 105 metre steel stack, including supporting ductwork structure and footings/stack-base to foundation levels.
  • Protection of the adjacent Alinta Gas Plant assets, including transformers and gas turbines.
  • Engineering study, including simulation technology for proposed deconstruction methodology.
  • Emissions, noise and vibration controls.
  • Safe removal of asbestos and hazardous waste.
  • Onsite processing, removal and transport of construction/hazardous waste materials.
  • Transport logistics, including traffic management and supervision.
  • Management of sub contractors – crane and recycling (scrap steel) operations.

Standing at 105m with a 11m diameter and a total of 750t, the felling of the steel stack required a specialised steel bracing system working along a fulcrum line to allow for even weight distribution and to reduce pulling capacity. Our felling technique was completed successfully and well within our proposed vibration controls, which were critical in protecting the adjacent live gas plant facility and assets.

The unbalanced weight distribution of the 40m high ductwork structure led to a split design methodology, involving two (front and back) sections; the front was felled & sheared, whilst an innovative skidding technique was used for the back.

The back section included two 85t sections that required two 87t excavators to skid the structure away from the adjacent gas plant so it could be safely felled and processed.