A case study of a worker electrocuted while guiding a load suspended from a crane was examined. A joint venture construction company was setting forms for a retaining wall on an outbound highway. On the site an 18 ton telescoping boom crane was picking forms from a 15 foot hill behind the future location of the retaining wall, placing them on the ground alongside the highway, and moving them into place to allow the carpenters and laborers to set and bolt the forms prior to pouring the retaining wall. Immediately above the site on the hill was a 34,000 Volt (V) power line, which crossed the highway at a height of about 50 to 55 feet. A carpenter was guiding a 4 foot by 8 foot metal form into place with the assistance of the boom crane. The crane touched a 34,000V power line; the carpenter was electrocuted and another laborer, who was 50 feet away, was severely burned. Electricity traveled through the crane cable, to the form, and to the ground through the carpenter. Another path was through the crane outrigger, to an overhead sign, to a temporary electrical box on the sign post, to an electrical drill, and to the ground through the arm and leg of the laborer. The victim was rushed to a local hospital where he was pronounced dead by a staff physician; the other worker was treated and released 3 days later. The authors recommend that employers should enforce existing regulations concerning crane operations in the vicinity of overhead power lines. Employers should also develop and enforce safety policies, hold management and first line supervisory personnel accountable for job site safety, ensure that work related tasks are planned to minimize hazards, and demonstrate a concern for employee safety.
Division of Safety Research, NIOSH, U.S. Department of Health and Human Services, Morgantown, West Virginia, Report No. FACE-85-15, 5 pages