The collapse of the Crandall Canyon Mine in Utah last August killed six miners, then three rescue workers. The intense pressure on the coal pillars supporting the mine caused them to burst, sending coal and rock flying with explosive force.After rescuers sent drop cameras down bore holes, they wanted a better view of the mine shaft. Inuktun Services Ltd. in Nanaimo, B.C., was contacted to build a robot that could descend more than a mile through 9-inch-diameter holes and crawl 300 feet.Mechanical engineer Jeff Stanway and team designed a 19.5- by 8-inch chassis based on the Versatrax 150 crawler from
