Andre Sougarret, mines manager for state-run copper company Codelco and on-site rescue coordinator, said that operation was stopped Tuesday while the drill head was changed.

CNN: STORY HIGHLIGHTS

The Plan B drill continued to lead the efforts to free the men, reaching a depth of 333 meters (1, 092 feet) on Thursday, the government's rescue coordinator Andre Sougarret said.

CNN: STORY HIGHLIGHTS

Last week, rescue coordinator Andre Sougarret said initially the Schramm T-130, would be used to drill a 12-inch bore hole down to the miners to enable rescue workers to deliver larger survival items for the miners, but he said if possible the same drill would be used to widen the hole to 28 inches -- sufficient to hoist the miners back to the surface.

CNN: New drill arrives in Chile with great fanfare