QLD: safety alert issued after two workers injured by tractor slasher

Workplace Health and Safety Queensland (WHSQ) recently issued a safety alert following a September 2020 incident in which two workers were injured, one seriously, when a tractor slasher lowered unexpectedly.

Early investigations indicate the two workers were removing barbed wire wrapped around the vertical shaft underneath the slasher at the time.

The slasher was the type that “floats” and kicks up when the tractor drives over a culvert or similar (i.e. the rear of the support frame consisted of chains and was not rigid).

While investigations are continuing into the exact cause of the incident, the safety alert noted that when performing maintenance or other tasks on tractor attachments, workers and other people can be exposed to risk of death or serious injury associated with unexpected or uncontrolled movements.

Attachments raised and lowered by hydraulics are a potential hazard to workers when the hydraulics either creep or inadvertently lower.

Attachments, including slashers, can drop because there are no props, or the props fall over due to the type of loading applied (i.e. the load on the props isn’t simply a vertical load downwards, but also includes horizontal loading).

The person conducting the business or undertaking (PCBU) must manage risks associated with the provision and maintenance of safe plant.

“Effective risk management starts with a commitment to health and safety from those who manage the business,” said the alert, which observed that managing work health and safety risks is an ongoing process and involves four steps, including: identifying hazards, assessing risks, controlling risks, and reviewing control measures to ensure they are effective.

PCBUs must work through this hierarchy to choose the controls that most effectively eliminates or, where that is not reasonably practicable, minimises the risks. PCBUs must first consider controls that most effectively eliminate the risk or, where not reasonably practicable, that minimise the risks.

“You must always aim to eliminate a hazard causing the risk with something of a lesser risk,” said the alert, which noted that if these controls are not reasonably practicable, you must minimise the risk by one or a combination of the following:

Engineering controls

This involves changing the physical characteristics of the plant or work area to remove or reduce the risk. Examples include:

• using components to support tractor attachments, such as a suitable propping system and lifting devices according to the tractor attachment’s manufacturer specifications and instructions. In the case of a propping system for slashers, the system must not be able to collapse or fall over as the slasher lowers
• the propping system and lifting devices should also only be used and maintained according to the manufacturer’s specifications and instructions
• using a flat even surface that can bear the general load of the tractor and/or attachment and the point load of any equipment such as props and lifting equipment
• if a safety system is not provided on the plant, make sure you use another system that is specified by the manufacturer and is load rated and has adequate strength to safely withstand any loads that could be applied to it

Administrative controls

If risk remains, it must be minimised by implementing administrative controls, so far as is reasonably practicable. Consider developing and implementing a safe system of work that can include:

• developing safe work procedures for;
  • maintenance and repair tasks in line with the manufacturer’s recommendations
  • use of props, jacks, or other systems in line with the manufacturer’s recommendations
  • a lock and tag out process
  • in the case of working underneath slashers or on other powered attachments, the procedures need to ensure that the engine has been shut off, the power take-off disengaged and the tractor key removed
• providing workers with instruction, training and supervision on safe work procedures
• ensuing worker training, experience and competency aligns with the requirements and complexity of the task
• ensure only those workers who have received training and instruction are authorised to carry out the work
• sufficiently monitor all work to ensure safe work practices are being adhered to, including the use of all safety procedures and systems and personal protective equipment
• exclusion zones around the plant (ensuring they are clearly marked and enforced)
• considering whether repair of plant can be carried out back at the workshop or depot where a greater range of tools and equipment can be used to safely perform the work.

“Administrative control measures rely on human behaviour and supervision, and used on their own, tend to be least effective in minimising risks. The control measures you put in place should be reviewed regularly to make sure they work as planned,” said the alert.