After driving for several hours, John (not his real name) arrived at the highway construction site. He parked the truck and trailer in the closed lane next to the barrier wall and the crane that would unload his truck. The road grade was 1.50. The semi-trailer was equipped with two A-frames with sides facing outwards that carried the precast concrete sound panels. He removed all of the load securement straps. He stood next to the concrete roadway barrier near the passenger side door while the panels were being unloaded. He was struck by a 2-foot high by 19-foot long by 16-inch wide concrete panel weighing approximately 3,770 pounds when it fell from the A-frame.
THE TRUCK OPERATOR
John worked for a small intra-state trucking firm with 16 employees, 12 of whom were truck drivers. He had been employed full time at the business for 17 years as a mechanic and as a truck driver.
The unsecured precast concrete panel that struck Tom was located on the A-frame toward the front of the trailer facing the passenger side. The crane operator was lifting a precast panel from an A-frame located at the rear of the trailer facing the driver’s side. A single looped tag line approximately 45 feet in length was in use. The incident was unwitnessed, but based on re-enactment, the following sequence of events are postulated: As the precast panel from the rear of the trailer was lifted up and over toward the truck cab, the looped tag line caught the edge of the unsecured panel at the front passenger side A-frame. John was standing near the passenger door and noticed the looped tag line catch on the corner of the incident panel. As he was approaching to move the tag line away from the panel, the tag line ran out of slack, tightened, and exerted enough force to cause the panel to fall from the A-frame, strike his right shoulder and head, and then pin him to the ground.
The foot of the A-frame supporting the panel involved in the incident was narrower than the bottom of the slab. Additionally, the wood attached to the A-frame stopped short of the bottom of the steel. The A-frames were measured at 12 degrees south to north. A crane operating with a short boom was lifting the panels. When unloading the panels facing the driver’s side of the truck, the crane operator lifted the panels up toward the cab and over the trailer. The crane operator had unloaded 5 sound barrier panels prior to the incident. The incident occurred when the crane operator lifted a 4-foot, 7,000-pound precast panel resting against the A-frame located on the driver’s side at the rear of the trailer.
Transport devices, such as shoulder bolts, should be utilized to secure individual concrete sound panels to the A-frames during transport and unloading unstrapped loads.
Standard Operating Procedures (SOPs) should include work practices that address load securement during the unloading process. When load configuration permits, truck drivers should wait to release the load securement tie down assemblies until after the material to be unloaded is secured with the unloading line or other unloading device.
- Truck driver training, in addition to training regarding SOPs, should emphasize safe driver positioning during unloading and to never enter the unloading zone without confirmation from the individual unloading the trailer.
Department of Medicine
Occupational and Environmental Medicine
909 Fee Road, Room 117 West Fee Hall
East Lansing, MI 48824-1315
Safety Issues is presented by the FACE (Fatality Assessment and Control Evaluation) Programs of California, Iowa, Kentucky, Massachusetts, Michigan, New York, Oregon, New Jersey, and Washington and the National Institute of Occupational Safety and Health (NIOSH) in partnership with the National Truckers Association (NTA). The goal of the FACE program is to prevent occupational fatalities across the nation by identifying and investigating work situations at high risk for injury and then developing and disseminating prevention strategies to those who can intervene in the workplace.
The complete detailed MIFACE INVESTIGATION REPORT: #09MI-75 includes additional report information recommendations and discussions. This report can be found at http://www.oem.msu.edu/MiFace/09MI075.pdf and is for educational purposes only. Additional MIFACE Investigation Reports, Summaries of MIOSHA Inspections, and Hazard Alerts can be accessed through the MSU Occupational and Environmental Medicine program at http://www.oem.msu.edu/miface_program.aspx
The Safety Issues and Investigation Reports are the products of NIOSH Cooperative State partners and are presented here in their original unedited form from the states. The findings and conclusions in each report are those of the individual Cooperative State partner and do not necessarily reflect the views or policy of the NIOSH.