In September 2018, a truck driver suffered severe abdominal injuries when a chain failed during a semi-trailer recovery operation. The chain was being used with other heavy vehicle recovery equipment including a pulley (snatch block), winch rope and hook to move the jack-knifed semi-trailer.
The winch rope from the tow truck passed through a snatch block and then to the semi-trailer, so that it formed a 'V' when viewed from above. The snatch block was attached to a tree trunk using a chain. As tension was applied to the winch rope, the chain broke and the winch rope and snatch block recoiled towards the tow truck, striking the semi-trailer driver. Investigations are continuing.
Preventing a similar incident
Vehicle recovery, especially recovery of trucks and semi-trailers, can be high risk due to the varying work tasks, environmental conditions, equipment requirements, time constraints and location of the immobilised vehicle.
The tow truck operator, workers or others in the immediate vicinity are at risk of being hit by moving parts of the vehicle and recovery equipment.
PCBUs should conduct a risk assessment of work practices, develop appropriate safe work systems, conduct appropriate training and ensure the system is enforced at the workplace.
In the case of winching systems used for vehicle recovery, all parts of the system are to be able to safely withstand the stalling capacity of the winch with a suitable factor of safety. In the case of snatch blocks used to divert the winch rope, an additional load factor of 2:1 should be applied to the snatch block, its connections and anchorage point. For example, if the winch has a stalling capacity of 5 tonnes, connectors on the rope should have a minimum failure capacity of 10 tonnes (i.e. 2:1 factor of safety). However, the components connecting the snatch block to its anchor point should have a minimum failure capacity of 20 tonnes.
Note1: The factor of safety on the wire rope, connectors and rope terminations for recovery winches usually range between 1.6:1 and 2:1 based on the maximum line pull of the winch, depending on the make and model of winch. All connectors that are used with a specific winch should have a factor of safety on failure equivalent to or exceeding that specified by the winch manufacturer. In a practical sense a factor of safety of 2:1 on all connectors is reasonable. It should be noted that winches intended for lifting have higher factors of safety than winches used solely for vehicle recovery (i.e. winching a vehicle across the ground).
Attachment hardware and the different rigging configurations used for vehicle recovery should be specified by a competent person who has a high risk work licence in rigging or who is a suitably qualified professional engineer. All attachment hardware should be load rated by the manufacturer and comply with the relevant Australian Standard. A regular inspection program should be implemented for both the recovery winches and any attachment hardware.
Before commencing work, identify hazards and assess risks associated with recovering or working around heavy vehicles or trailers as part of the risk management process. Risk assessments should be documented. Where appropriate:
- establish an exclusion zone that is clearly marked and enforced. Exclusion zones should be established around the vehicles being recovered and adjoining areas to prevent people from entering the area. The size of the exclusion zone should be based on a written risk assessment
- use safe work procedures for vehicle recovery and ensure that workers are trained in these procedures
- ensure worker training, experience and competency is appropriate for the nature and complexity of the tasks to be carried out.
Since 1 July 2013, there have been 75 work-related incidents involving people being injured by chains, wires, cables and ropes. One of these was fatal and 22 involved a serious injury.
Prosecutions and compliance
In March 2018, a business was fined $104,000 after a farm owner was severely injured. The farm owner was assisting a contractor on his property to recovery a bogged piece of machinery. After an unsuccessful attempt using a chain, a snatch strap was used to try to recover the machine. The contractor attached one end of the snatch strap to the tractor and the other to the tow hitch on the machinery. While the tow was underway, the tow hitch connection to the machinery failed, causing the snatch strap to recoil with the tow hitch attached. The tow hitch was catapulted approximately 15 metres and through the rear window of the tractor cabin, striking the farm owner through the back of his seat.
In January 2014, a local government office entered into an enforceable undertaking with a cost of $120,000, after a worker was injured during a training exercise to recover a bogged vehicle using a snatch strap. The connection point on the bogged vehicle broke and the snatch strap and connection point recoiled through the rear window of the recovery vehicle, striking the driver.
- How to manage work health and safety risks code of practice 2021 (PDF, 0.65 MB)
- Managing risks of plant in the workplace code of practice 2021 (PDF, 1.57 MB)