>> reporter: august 31st, after a message of support from the pope and a careful review of plans, tunnelling to the chamber begins. three tunnels will be drilled something like thatly simultaneously, dubbed simply plans a, b and c. >> a key piece of machinery, that will be used to drill a hole down to the shelter 700 meters into the ground where the miners are is now being moved into place. >> reporter: plan "a" relies on a drill used to pierce ventilation shafts. plan "b" uses a drill digging water wells and will come in at an angle. and plan "c" will use a drill from oil exploration. experts from around the world have been called to consult on the engineering and the welfare of the miners. >> this is an operation that's probably unprecedented in scope. never have so many been trapped for so long and so deeply. >> reporter: the miners