Rescue for miners just arm's length away

The two Tasmanian miners trapped more than a kilometre underground for two weeks were early today only an arm's length from safety.

Hopes soared that Todd Russell, 34, and Brant Webb, 37, would be freed today from the steel cage in which they have been entombed since a rockfall on Anzac Day.

At 9.24 last night (11.24pm NZ time) a brief announcement from Beaconsfield gold mine rescue officials said a probe had broken through to the cavity where the pair were trapped.

The probe was bored upward from a completed horizontal tunnel to ensure rescuers were on target for the last stage of the marathon operation.

Australian Workers Union national secretary Bill Shorten said the probe showed that only about a metre separated Mr Russell and Mr Webb from being rescued.

He said there was up to 40cm of hard rock and as much as 70cm of rubble and fill to excavate.

"The fat lady might not have sung but I can certainly hear her clearing her vocal cords," Mr Shorten told Sky News.

But he still did not believe the men would be freed overnight. "I'm not going to get anyone's hopes up.

"It is unique, it is dangerous, it is complex," he said of the last part of the operation. "There is no way we are out of the woods - but it is progress."

Rescuers can now start drilling the vertical tunnel - the most complex part of the operation - from where Mr Webb and Mr Russell will crawl to freedom.

Late last night rescue officials were planning details of the final push upwards although hours of digging remained.

For more than 24 hours rescuers in teams of three, working rotating shifts of six hours, have chipped a 1m- diameter tunnel beneath a cavity next to the trapped miners.

The crew's target is a small cavity about 1m square, opening on to the gate of the cage.

For most of yesterday, rescuers drilled bores, packed them with a low-power explosive called PCF and blasted a honeycomb of cone-shaped holes, allowing them to break the rock apart beneath the cavity.

Work frequently paused to allow safety inspections before new blasting.

Rescuers have joked the operation may be further complicated by the size of the men, who have been eating five square meals a day, including omelettes and homemade soup passed through a narrow pipe.

"They are big blokes," said Michael Lester, a public relations officer for the mine. "They have been joking that if they keep eating as well as they have, the tunnel will have to be greased to get them out."

The men, both married fathers of three children, suffered little more than scratches in the rock fall which trapped them 14 days ago.

The pair survived for five days on a single cereal bar and by licking water seeping through the rocks around them. They were found alive when a thermal imaging camera picked up their body heat.