Mineweb technical contributor, John Chadwick was interviewed today about the Chilean mine rescue by Jonathan Charles on the GMT program on BBC World News, and that interview will be showing globally throughout the day. Chadwick discussed the worldclass technology being used to drill the rescue shaft - a machine built in Western Australia, owned by Murray & Roberts of South Africa - which should reassure the trapped men.This specific drill rig was developed and manufactured in the mining city of Kalgoorlie Boulder, which is the headquarters of RUC Cementation Mining Contractors, with input from various local companies due to long lead times in acquiring similar equipment from the traditional global suppliers.This Strata 950 raise drilling machine, said to be the most powerful of its type in the world, was developed for downhole pilot drilling at various sizes up to 400 mm in diameter either by conventional means or using Mincon’s Rotary Vertical Drilling System (RVDS) tool that will continuously self survey and correct itself to the vertical. Of course the machine is also designed to back ream from the bottom breakthrough point with the excavated material falling to the bottom of the raise. However in this case it will have to ream from the top with all the material falling down through the pilot hole.The RVDS tool will always try to establish a vertical line by internal computers and survey systems that send a message to the jacking pads giving side pressure when required to re-align the hole.The machine in Chile is one of six Strata machines that RUC Cementation Mining Contractors has produced for its own contracting requirements and the Cementation group - all subsidiaries of Murray & Roberts. The group is currently operating these units in Canada, Mongolia, Indonesia, Australia and Chile. This is in conjunction with a further 60 rigs of various capacities that the Global Cementation group operates.Cementation Canada is assisting on site while the remainder of the Murray and Roberts Cementation group is assisting with technical backup.