Safety Issues


Truck driver crushed between semi-trailer and loading dock

John (not his real name) had finished his delivery.  He pulled the truck a short distance away from the loading dock but then realized that the tie-down strap was left inside the warehouse.  Standing between the semi-trailer and loading dock, he banged on the roll-up door.  The receiving company employee opened it, handed him the strap, noticed the semi-trailer moving, and yelled a warning but John was pinned. 


 John had worked for the company for approximately 5 years.  He had recently returned from retirement (or partial retirement) to working part-time (approximately 16 hours/week) to maintain company benefits until he could fully retire.  He typically made “local” deliveries within 100 miles of his home terminal. Although not required for the work he was doing at the time, he had received and passed the medical exam for his CDL. 



 John was driving a rented tractor to pull the company trailer.  The company trailer was not normally used for frequent local deliveries as it was normally dedicated to night trips.  John made other deliveries that day without incident.  Just before the incident, he pulled his tractor forward, left the cab with the engine running, in neutral and did not set the parking brakes.  He walked to the rear of the truck, possibly to close the swing type trailer doors or realized that a tie-down strap was missing.  He stood between the trailer and dock to retrieve the tie-down strap.  The tractor/trailer rolled back and the 53-foot trailer possibly slid over an unlocked rear-sliding axle, pinning him against the loading dock.



 The investigation identified possible factors in the incident:  1) The tractor’s engine was running, the transmission was in neutral with the tractor parking brake not set before the driver exited the cab.  The tractor was rented so it was possible that the driver was unfamiliar with the braking systems of the tractor; 2) It was likely that the trailer trolley valve brake on the steering column (or hand valve or Johnson bar brake) was set but not the parking brake. The trolley valve brake on the steering column is not designed or intended to be used as a parking brake to secure a trailer in a parked position; 3) The locking pin was not in place on adjustable axles and the trailer was capable of sliding 8 feet over the axle; 4) The tractor and trailer wheels were not chocked to protect against a brake or procedural failure while on the 2-degree slope; and 5) Mechanical aspects of the rental tractor were inspected and no deficiencies were found and there were no reported deficiencies on the trailer.


  • Truck operators should fully engage tractor and trailer parking brakes before leaving the cab.  (Products with technology that alarms when a driver leaves his seat without setting the parking brake are available) 
  • Wheel chocks to secure trailers and tractors against inadvertent movement should be used, especially when parked on a slope.
  • Truck operators should confirm that the sliding axle assembly is locked prior to working in or around a trailer
  • Truck operators and workers should not stand in pinch points where vehicles could move or roll.
  • Truck operators should receive training on the controls of rental equipment prior to use, especially key components such as locking mechanisms and brakes.
  • A periodic worker performance monitoring program to ensure that appropriate and adequate safe operating procedures are being used should be implemented.



Oregon Institute of Occupational Health Sciences

Oregon Health & Science University

3181 SW Jackson Park Rd, L606

Portland, OR  97239-9878


Safety Issues is presented by the National Institute for Occupational Safety and Health (NIOSH) in partnership with the National Truckers Association (NTA), with major contributions from State partners funded by NIOSH through the Fatality Assessment and Control Evaluation (FACE) Program.  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. State partners who contribute Safety Issues postings based on recent investigative reports are California, Iowa, Kentucky, Massachusetts, Michigan, New York, Oregon, New Jersey, and Washington.

This month’s Safety Issues is based on an investigative report from the Oregon FACE Program. The complete detailed Oregon FACE INVESTIGATION REPORT:  #OR 2010-6-1 includes additional case information, recommendations and discussion. This report can be found at Additional OR-FACE Investigation Reports, Annual Reports, Hazard Alerts and other publications can be accessed through Oregon Institute of Occupational Health Sciences at

The Safety Issues and Investigation Reports which are the products of NIOSH Cooperative State partners are presented here in their original unedited form from the states. They are intended for educational purposes only. 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.