Potts & Callahan used a Marion power shovel to load rock and dirt into tandem Athey tracked dump wagons pulled by Caterpillar RD-8 tractors. The photo was taken during October 1937.
(Caterpillar Tractor photo)
Oceans built to order with miniature ships in miniature storms...on a miniature sea at Cabin John, Md., said Caterpillar Tractor at the time. The ship testing basin near Cabin John, Md. was constructed by Turner Construction Company of New York under a $2,675,000 contract. Ground was broken on Sept. 8, 1937 and the project was completed in June 1939. The heavy site work was tackled by Potts & Callahan Contracting Company, Inc. of Baltimore, Md. The excavation included 140,000 cu. yds. of earth and 30,000 cubic yards of rock.