On Aug. 5, 2010, the worst fears of 33 Chilean copper miners were realized when they were trapped underground in the San Jose mine near Copiapo. Seventeen days later a borehole reached the refuge station where they had taken shelter, and reports surfaced that all are well.
The mine owner, Empresa Minera San Esteban, had the foresight to create a refuge station. That and the availability of groundwater helped the trapped men survive until they could communicate with rescuers on the surface. Now they must wait – perhaps as long as four months – for an adequate escapeway to be drilled 700 metres to where they wait.
The rescue effort began on Aug. 6. Access via the ramp was blocked because of the collapse. A rescue team attempted to use the ventilation shaft to reach the miners, but that effort was halted by a second fall of ground on Aug. 7. The drilling effort to reach the miners is headed by teams from Codelco‘s El Teniente mine. Reports did not elaborate on the technique to be used to facilitate their escape except to say a hole of at least 600 mm diameter will be bored.
The trapped men are not restricted to the small refuge station. Instead, they can move along the ramp and stopes. The size of the openings has provided plenty of air for their survival. Although the mine is located in the Atacama Desert, one of the driest places on earth, clay seams in the mine carry groundwater into the workings.
The challenge for those underground now becomes waiting. Steps have been taken to establish communications with friends and family members on the surface. Food, water, medicine and counselling will be supplied. If it takes four months to reach the men, they won’t see the light of day until late in December. Their re-emergence would be the best Christmas present their families could receive.
San Esteban has been criticized for its lack of safety enforcement in the mine. Certainly the present situation will bring those charges to the fore. The National Service for Geology and Mining ordered the mine closed in 2007 following a number of accidents, but allowed its reopening the next year. After this latest event, Chilean president Sebastian Pinera has fired officials of the service and vowed an overhaul of the agency.
More details of the San Jose mine and a diagram of its workings are available at Wikipedia, //en.Wikipedia.org/wiki/2010_Copiap%C3%B3_mining_accident.