The Department of Conservation has to spend $320,000 installing an escape tunnel from its underground coal museum at Denniston, in the wake of tighter regulations post-Pike River.
It was revealed almost a year ago that the new tourist attraction, located 170m inside an abandoned mine, may have to install an emergency exit.
The lack of a second escape tunnel was a major focus of the Royal Commission of Inquiry into the Pike River Mine disaster.
Work on enlarging the existing emergency exit tunnel at Denniston is now well under way. Contractors work when visitor tours are not taking place.
Geotech Ground Engineering is carrying out the work and staff are nearly halfway through the 179m-long tunnel.
