A union leader at the scene of the trapped miners at the Beaconsfiled mine in northern Tasmania says it could take all day to prepare for mining the last stretch of rock separating the miners from the rescue team.
The national secretary of the Australian Workers' Union, Bill Shorten, says there is a metre of solid rock to blast through, followed by loose rubble and waste rock on the tunnel floor from previous mining operations.
He says the work is complex and difficult, as the team will be tunnelling upward, but Brant Webb and Todd Russell are mentally prepared for a long wait.
Mr Shorten says; "The horizontal mining is nearly at a conclusion, but this vertical shaft mining, it could take all day to prepare."
"They mightn't have to lie on their backs, but they might be kneeling, using drills."
"They've got to work out the density of the hard rock, they've got to work out where the crust comes in." He says.
"They've got to square off the tunnel and prepare it so that it's safe for the rescuers to start drilling upwards."