GREYMOUTH, New Zealand — The bid to rescue 29 New Zealand coal miners trapped underground by a massive gas explosion ran into more problems Tuesday as a mechanical robot broke down inside a tunnel and hard rock layers slowed progress on drilling to test the air.
Police superintendent Gary Knowles said the army robot sent in to transmit pictures and assess toxic gas levels was damaged by water and out of commission.
Authorities were urgently seeking other such robots from West Australia and the United States to replace the broken one, Knowles said.
“I won’t send people in to recover a robot if their lives are in danger,” he said. “Toxicity is still too unstable to send rescue teams in.”
Making matters worse, the drilling team boring into the mine tunnel had hit “very hard rock” overnight, Knowles said.
The police superintendent’s statements came as rescuers waited impatiently for a chance to test if air quality underground was safe enough for them to go in to pull out the miners, who have been trapped for nearly five days.
Family members have expressed frustration with the pace of the response as officials acknowledge it may be too late to save the miners, who have not been heard from since a massive explosion ripped through the Pike River Mine on the country’s South Island on Friday.
A buildup of methane gas is the suspected cause of the explosion. And now the presence of that gas and others — some of them believed to be coming from a smouldering fire deep underground — are delaying a rescue over fears they could still explode.
A diamond-tipped drill was put to work as workers hit layers of hard rock and came within 33 feet (10 metres) of the tunnel where they believe some of the miners are trapped, police superintendent Gary Knowles said.
The 500-foot (160-meter)-long shaft they are creating will allow them to sample gas levels — including explosive methane and carbon dioxide — and determine if rescuers can finally move in days after the blast.
Knowles said rescuers planned to drop a listening device down the hole to see if they could hear anything — such as tapping sounds — that might indicate that the miners were still alive.
“This is a very serious situation and the longer it goes on, hopes fade, and we have to be realistic. We will not go underground until the environment is safe,” Knowles said.
Two workers stumbled out of the mine within hours of Friday’s explosion, but there has been no contact at all with the remaining 29.
A phone line deep inside the mine has rung unanswered.
Those trapped include a teenager who was so excited about his new job he persuaded mine bosses to let him start his first shift three days early — on the day of the deadly gas explosion — his mother told local media.
Joseph Dunbar was one day past his 17th birthday and the youngest among them when he joined his fellow miners in the pit.
Mine shift supervisor Gary Campbell said Dunbar was desperate to be part of the team.
His mother, Philippa Timms, said her son “got offered this chance to have a career — and that’s how he saw it, as a career,” she told TV One.
Police have said the miners, aged 17 to 62, are believed to be about 1.2 miles (two kilometres) down the tunnel.
Each miner carried 30 minutes of oxygen, and more fresh air was stored in the mine, along with food and water that could allow them to survive for several days, officials say.
New Zealand’s mines are generally safe. A total of 181 people have been killed in the country’s mines in 114 years. The worst disaster was in March 1896, when 65 died in a gas explosion. Friday’s explosion occurred in the same coal seam.