I look forward to offering opinions and thoughts in this blog on some of the most interesting technologies in the exploding robotics arena–and to reading your comments, which we really welcome.
Today, I’m thinking of years ago, in the 1970s, when I worked as a welder’s helper along side the then largest open pit mining trucks, which at that time weighed in at well over 300 tons a piece. As noted by Eric Bland at DiscoveryNews on MSNBC.com, the Caterpillar 797, at a total operating weight of 700 tons and with a payload capacity of up to 240 tons, is today’s largest ore hauling truck in the world–and it will soon be the largest robot of all!
In college in the 70s in Tucson, I worked summers at the Sierrita and Experanza open pit copper mines welding parts and pieces of new warehouses, ore processing machinery and the like. Before moving out into the 100 degree desert temperatures to get to work assisting professional welders, the day would start in a giant multi-story, sheet metal lined warehouse and garage that was also where the giant ore hauling trucks were serviced. The wheels were 13 feet tall and the driver had to climb two sets of ladders to get behind the wheel, perched well above the towering wheels.
I’ll never forget the start sequence as one of these behemoths roared to life. A piercing howl rising in tone screamed out across the warehouse as the starter motor kicked into action to start a gasoline truck engine–which roared to life as it was gunned. That truck engine, buried in the hauler, was the actual starter. It revved up a giant diesel engine that rumbled to life. That big diesel, in turn, spun up a huge generator that added to the deafening noise reverberating through the metal warehouse. The generator now fed massive power to what actually moved these goliaths–the giant brushless motors mounted in the hubs of each wheel. And then the big beast would come to life and slowly move out of the multi-story garage bay.
Out in the field one baking afternoon we were watching a truck dump waste rock at the edge of a huge man-made hill of dumped material. About a hundred yards away, we clearly saw the back wheels begin to sink into the edge of the waste dump hill crest on which it was perched–the truck was falling backwards. The driver, 15 feet up, jumped for his life (he suffered a broken ankle) and the truck tumbled down. For weeks workers scrambled over the bent chassis in the warehouse garage, like ants, trying to straighten the chassis out and save the giant ore hauler, but it was a loss. On another occasion, one of these trucks backed over an empty pickup truck and all that was left was a crumpled flat mass of metal (think crushed soda can) with a lump representing the engine block. Certainly, automating these monsters so that they are robotically driven will create a safer environment in open pit mines–and I can attest to this personally. And that is in addition to much longer operating hours that are projected.
Times have changed and the trucks have doubled in carrying capacity with new power systems. Eric Bland reports that the new Caterpillar trucks are powered by 3,550-horsepower 24-valve engines, and that Carnegie Mellon University is involved in development of the robot that will be at the wheel. Professor Tony Stentz of CMU holds that over the next five to 10 years, the technology now in development for mining trucks may find applications in other contexts outside of mining–see Bland’s report for details. And we pose a question to you–will there ever be larger robots than the Caterpillar 797?