... Safety practices in tunneling operations at the Hetch Hetchy water-supply project, city and county of San Francisco, Calif. By S. H. Ash and C. R. Rankin [cover title]. [Washington, D. C.]: United States Department of Commerce, Bureau of Mines, 1933. 26.8x20.5 cm, pp. [1-2]  2-15 [16: blank], 6 full-page figures (not counted in the pagination), printed self wrappers, side stapled. First edition. Cover title. At head of title: "I. C. 6726 June, 1933 Department of Commerce United States Bureau of Mines Scott Turner, Director Information Circular." The purpose of this engineering report is to show "the methods followed at the Hetch Hetchy water-supply project, whereby accidents and their resultant suffering and cost have been minimized because safety has been given a prominent place ... The data given are based upon the experience in the Hetch Hetchy tunnels constructed by the forces of the city and country of San Francisco, and cover the period from October 1, 1920, to September 30, 1931, inclusive, during which the compensation insurance item of the industrial insurance cost has been carried with the State compensation insurance fund. The data given in the report should have value to those interested in the relationship of tunneling operations to accident occurrence and accident costs." A fine copy. (#165510).
No statement of printing.