scope:

Description of Driving Event:

On 09 September 1993, at approximately 1853 hours, the construction safety office was notified of a mishap at the H-1 Test Stand Construction project at the intersection of lateral access and KDT roads, SSC. The field engineer informed ASRM Construction Safety that a wheel mounted crane, operated by a construction contractor employee, had come into close proximity of the bottom phase of the 13. 8KV electrical service line crossing lateral access road west of kneel down transporter (KDT) road. The field engineer reported visible electrical arcing between the crane boom and electrical phase for approximately 10-15 seconds. The field engineer stated the operator appeared to be uninjured. Construction safety asked the field engineer to secure the mishap scene and traveled to the job sit to meet with the field engineer, the operator, and the project superintendent to investigate.

At approximately 1840, the crane was moved from the motor conditioning building steel frame and was being staged for pick up by the Equipment Rental Co. the following morning. The operator asked the project superintendent where to stage the crane and was directed, by the Project Superintendent, to the intersection of KDT and lateral access roads. The operator drove the crane to the staging area with the boom elevated approximately 30-35 degrees. In his original statement, the operator stated he approached the staging area he saw and was cognizant of the location of the boom tip referent to the electrical service line. In a follow up interview and statement, the operator reported that he saw the power line from a distance of approximately 20 feet. His attention was then given to an Ensley track hoe parked to his front (under the power line) and he never looked back at the power line until the arcing began. The operator stated and reaffirmed he stopped the crane with the boom tip approximately 1-2 feet from the line and set the parking brake. The operator reported and reaffirmed the crane rolled an additional 12-18 inches after the parking brake was set. When the crane stopped the electrical arcing began. The operator immediately exited the crane cab and dismounted the crane by grabbing the metal handrail on the door of the cab and jumping 6 feet 3 inches to the ground out and away from the crane cab. The operator reported being shocked when he grabbed the handrail but stated he was uninjured as a result.