The remote-operated digger working inside Christ Church Cathedral has finished its clean-up a month ahead of schedule.
The digger has been working inside the cathedral nave for the past 41 days and has removed 247.92 tonnes of material, including debris, masonry and guano - a significant biohazard - and heritage fabric.
"This innovative digital solution has allowed the project's critical work plan to gain about three months. It has marked the start of the major interior clean-up and is another milestone in the cathedral's reinstatement journey," project director Keith Paterson said.
"The safe retrieval of heritage fabric has been a top priority for the Christ Church Cathedral Reinstatement Project."
Paterson said a heritage professional has found various artifacts in the material, including mosaic tiles from the tessellated panels once found on the internal west wall, coins lost over time from people's pockets and broken fragments of the stained-glass windows.
Personnel from project partners Protranz Earthmoving Limited and Aurecon, who first suggested the use of the remote-operated digger, have been operating it from an operations centre outside the cathedral using cameras with live-stream capability.
Paterson said the remote-operated digger is a safety-first approach that solves health and safety issues by keeping personnel out of the building while still getting the work done.