Testing 40 ton crane, Springwells Station treatment plant during construction, Detroit water supply system

View of men watching a 40 ton crane lift railroad car loaded with cast iron pipe in the Springwells Station treatment plant during construction, Detroit water supply system. Printed on front: "4-9-31. Testing 40 ton crane. Car loaded with cast iron pipe. Total load on crane hook 800020#. Total deflection with load at middle of span 0.039'." Stamped on back: "Manning Bros., commercial photographers. 504-505 Lincoln Building. Corner State and Park Sts., Detroit, Mich." Handwritten on back: "Testing 40 ton crane. Car loaded with cast iron pipe. Total load on crane hook 800020#. Total deflection with load at middle of span 0.039'."