A spokesperson from the mine said it took workers 10 hours to move a pre-constructed sky shaft almost 60 metres into a head frame, a piece of infrastructure previously used to sink the mine's 1000-metre shaft in preparation for underground mining.

The project relied on pin-point accuracy to place the sky shaft inside the head frame, which was just 30 centimetres taller than the incoming structure.

The spokesperson said four self-propelled modular trailers specially designed to move heavy infrastructure were used to drive the 380-tonne sky shaft into place.

Now that the sky shaft is in place the winder drum (an integral part of the hoisting system) can be hooked up in order to bring ore to the surface in skip bins.

The mine's overland conveyor was structurally completed in January and will be connected to the structure to transfer crushed ore to the mine's stockpile for use at the concentrator.

The spokesperson said the project was on track to meet its completion date in May. Ernest Henry Mining's conversion from open pit to underground mining will double its production to six million tonnes a year.