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