Leinster Underground is an underground nickel mine within BHP's Leinster mine complex. Located in the northern goldfields of Western Australia, Thiess provides technical mine services including mine planning, survey and geotechnical engineering and is responsible for ore production and underground development.

From mid-December 2015, Thiess began working approximately one kilometre below the surface to excavate around 610 metres of horizontal development in order to access nearly 230,000 tonnes of material using sub-level open stoping mining methods.

Thiess is responsible for providing turnkey mining services, including:

  • Underground mining
  • Statutory supervision
  • Plant and equipment
  • Mine planning
  • Surveying
  • Technical support
  • Supply and install of ground support
  • Load and haul
  • Drill and blast
  • Mobile maintenance.