The largest pneumatic rubber tires in the world have been designed to carry an "ice cruiser" across Antarctic wastes, the research foundation of the Armour Institute of Technology announced today. Harold Vagborg director of the foundation, said an order for six of the immense tires had been placed with the Goodyear Tire and Rubber company of Akron, Ohio, and delivery was expected about the middle of August. Rear Admiral Richard E. Byrd will use the snow cruiser on the government’s land-claiming expedition to the South Pole late this year. In designing the tires which will carry the tank-like vehicle across the snow crevices, Armour engineers decided upon a thickness of 12 ply, about twice that of the ordinary heavy duty automobile tire. The tires with be 10 feet in diameter, weighing between 1,200 and 1,500 pounds. A derrick on top of the snow cruiser and a hydraulic arrangement to lift the axle will be used in changing them. Engineers said the chief problem in designing the tires was to insure a large enough contact surface between the tire and the ice and snow to obtain the proper coefficient of friction. There will be 12 square feet of contact. It was necessary to design the tires to stand up under 75,000 pounds, the weight of the cruiser when fully loaded with scientific instruments, supplies and a five passenger airplane. Actual wear of the tires, engineers said, would not be appreciable.