The LeTourneau Carryall pans are shown operated in tandem and singly, drawn by Caterpillar RD-8 tractors, ca. 1937.
The new $45 million Irvin Works of the Carnegie-Illinois Steel Corporation in Clairton, Pa., near Pittsburgh, was America's largest industrial project in 1937. The 300 acre hilltop site, high above the Monongahela River, required heavy grading. The excavation of five million cu. yds. of material was undertaken by a joint venture of Guthrie, Marsch & Peterson, comprised of A. Guthrie & Company, Inc. of St. Paul, Minn., John Marsch of Chicago, Ill., and the Edward Peterson Company of Omaha, Neb. American Bridge Company was employed to erect the buildings for the steel mill.
Major equipment used on the project by Guthrie, Marsch & Peterson included eight 2 1⁄2-cu. yd. (1.9 cu m) shovels, Northwest 80-Ds, Marion, and Bucyrus-Erie; three elevating graders, four U-12 LeTourneau 12 cu. yd. (9.2 cu m) scrapers used in tandem and two LeTourneau J-12 scrapers used singly; 26 Athey crawler dump wagons from 8 to 12 cu. yds. (6.1 to 9.2 cu m) capacity; 22 Euclid FDT 12 cu. yd. bottom dumps; eight Caterpillar RD-8 diesel tractors with LeTourneau bulldozer blades and 33 RD-8 tractors to pull the scrapers and dump wagons. The equipment spread achieved production rates as high as 48,000 cu. yds. (36,699 cu m) per day using three eight hour shifts.— Special to CEG