The Pike River Recovery Agency is set to add an extra shift to the team underground to help pick up the pace.
Pike River Mine re-entry teams in May last year. Photo: Pike River Recovery Agency / Supplied
Twenty-nine men died in an explosion at the mine in November 2010 and work is being carried out to recover any remains and look for clues as part of a criminal investigation.
Minister Responsible for Pike River Re-entry Andrew Little told Morning Report the work was taking longer than initially thought.
"In fact, we thought roughly by now we'd be winding up the project. But because of the extra planning required, the extra measures for safety that were taken last year, including installing the Rocsil plug, the project has taken longer.
"We are about to ramp up the workforce so we can have two shifts doing the recovery work of the drift."
He said he would expect it to take roughly three months to reach the rockfall when the second team is added, with 15m from the 170m barrier already forensically examined by the lone team working underground.
"We're expecting there will be between 20m to 40m a day that will be covered when we put a second shift on ... but the critical thing is we're not going to compromise safety."
That would mean it would take roughly three months for the workers to reach rockfall, he said.
One of the most crucial areas with potential clues - Pit Bottom in Stone - was also near the rockfall, he said.
Minister Responsible for Pike River Re-entry Andrew Little. Photo: RNZ / Ana Tovey
"If there was anybody who was able to get out after the initial blast, the place they are most likely to have gone to is in the Pit Bottom in Stone.
"I don't want to hold out the possibility that we will recover human remains, it is a small possibility, but we will at least get good information from that area."
The Pike River Recovery Agency has also signalled the $36 million funding for the project won't be enough. However, Little said while the delay in schedule had increased the potential for cost blowout, that was not the case yet.
At this stage the agency was well within budget, he said, and there was no request made to Cabinet for additional funding yet.
The minister said he was keeping a close eye on the expenses.
"We know that the circumstances have changed somewhat from when [the budget for expenses] was put together two years ago."
- "The drift": The name given to the 2.3km-long entry tunnel into the mine that mostly moves through solid rock up to the main workings of the mine.
- "Rockfall": A 50m-long pile of rock just before the main workings that has fallen from the roof of the drift. It has not completely sealed off the tunnel and a small gap exists between the top of the rockfall and the roof of the tunnel. At this stage there is no plan to explore beyond the rockfall.
