Mine expert: No urgent rush to reach miners

The coal preparation area that leads to the entrance of the tunnel into the Pike River coal mine. Photo / NZ Herald

An Australian mine expert is backing the Pike River rescuers cautious approach, saying there was "certainly not" an urgent need to reach the 29 missing miners at the risk to the welfare of the rescuers.

Professor Bruce Hebblewhite, the head of department at the University of New South Wales Mining Engineering School, understood there was a balance between reaching the missing miners quickly and risking the lives of the rescuers, however there was no urgent need to reach the men "at this point in time".

"You should be extremely cautious before any rescue - you have to ensure the rescuers lives aren't put at risk," he said. "It is absolutely essential to know there is no further risk of future explosions."

Mr Hebblewhite said it would be hard to tell what the conditions are like for the men underground, as rescuers do not know exactly where they are in the mine.

"Obviously where the explosion was, and it was a significant-sized explosion, there will be a lot of dust, product from the explosion and soot."

Gas explosions in coal mines were not common in New Zealand and Australian coal mines, Mr Hebblewhite said.

"Some parts of the world they happen on a much too frequent basis," he said. "In our part of the world, New Zealand and Australia, they are extremely rare.

"Gas in coal mines is ever present, but it is a manageable hazard.

"Whatever has happened in this situation - something has gone awry."