Up in the northern Canadian wilderness they need tough vehicles to tote heavy freight to the mines and haul ore out. Even tractor treads may be Fouled on a rock, mired in swampland or caught in treacherous ice. Two Canadian inventors have just patented an amphibian tank designed to travel where no road exists, over swamp, snow ice, water or rugged hillside. An adaptation of the plan would make it a rolling military fort. Its bargelike body, thirty-five feet long and eleven feet wide, would weigh about twenty tons and carry an eighteen-ton load; afloat, it would displace 12,000 cubic feet of water. Breaking from the two-rut tradition that dates from days of chariots, the plan calls for three gigantic wheels, the front wheel being twelve feet high by six feet wide; the other two, mounted for steering beneath two swivels, each six feet high and three feet wide. Each watertight drumlike wheel is separately driven, the front wheel having a forty-horsepower electric motor on each side, and each rear wheel having a twenty-five-horsepower motor. Steering controls at both ends permit driving in either direction. The front wheel rides in a cradle allowing it to wobble with inequalities of the road, the three-point body suspension relieving torque; this cradle is controlled with a system of oil pumps and valves so that it can be tilted at will and permit a shift in the center of gravity if needed while negotiating steep slopes sidewise. An electric circular saw could be mounted on an extensible arm to cut down trees in the path of the tank, and a crane on top could hoist obstacles out of the way. Power would be furnished by a 200-horsepower Diesel.