A truck driver was unloading precast concrete manhole assemblies at a construction site when the boom of the crane mounted on the trailer contacted a 7200 volt overhead power line, electrocuting the driver. The driver had considered the conditions at the site to be too muddy to unload. After checking with the business office, he obtained an alternate site on level ground, easily accessible, and away from overhead powerlines. However, he did not choose to use this location and, instead, unloaded the material about 200 yards away from the second site, not on level ground and close to overhead powerlines. It appeared that after removing two of the manhole assemblies from the truck, the driver moved the truck a little further away from the assemblies to have room to unload the third. In removing the third from the truck, the lessened weight on the truck allowed the crane to drift into the 7200 volt powerline. The driver was found between the truck and the manhole assemblies, in contact with one assembly. The chain attached to the boom was still in contact with the assembly, and the crane cable was in contact with the power line. Recommendations arising out of this accident included: enforcement of existing regulations concerning crane operations in the vicinity of overhead powerlines; increasing hazard awareness among employees; and choosing loading, unloading, and storage sites so as to avoid overhead powerlines.
Division of Safety Research, NIOSH, U.S. Division of Health and Human Services, Morgantown, West Virginia, Report Number FACE-86-17, 7 pages