Originally published by the Australian Institute of Health & Safety
WorkSafe Victoria recently issued a safety alert about the risks associated with operating mobile plant on batters and slopes following an incident in which an operator was injured when an eight-tonne excavator overturned while moving felled trees.
A contract arborist was using an excavator with a log grab attachment to move felled trees down a batter, and while slewing the excavator down slope, a log slipped through the ‘log grabber’ attachment pulling on the excavator’s boom.
The combination of slewing while tracking and the unexpected slip of the log caused the excavator’s centre of gravity to suddenly move, rolling onto its side.
The operator was wearing a seatbelt and received facial injuries and was admitted to a local hospital for treatment.
The alert said hazards that may pose a risk to employee health and safety when operating excavators on batters and/or slopes include:
- Traversing across a slope or turning on a slope can reduce the excavator’s stability, causing it to overturn.
- Carrying an elevated load while working on a slope can raise the centre of gravity of the plant, increasing the likelihood of the plant overturning.
- Slippery or low traction surfaces can cause the excavator to skid, lose control or run away.
- Uneven, soft or unconsolidated ground can cause the excavator to rock, lose control or overturn.
The risks associated with operating mobile plant on slopes including batters can be eliminated by moving the plant off the slope using an alternative system of work, for example:
- using a haul rope or winch cable fitted to mobile plant that is positioned on the flat level ground at the bottom of the slope to drag the felled trees down the batter/slope
- If it is not reasonably practicable to eliminate the use of mobile plant on a batter/slope, employers can reduce the risk of mobile plant overturning by:
- assessing the angle of the batter/slope to ensure that the excavator can safely ascend and descend without overturning. If limitations are not provided by the manufacturer, operators should approach the slope from the bottom to confirm the mobile plant’s capability of ascending the slope without overturning and/or running away down a slope
- ensuring plant, including excavators, only ascend and descend the slope with the arm of the excavator extended up the slope
- ensuring that any load carried by the attachment is placed as low to the ground as possible
- ensuring that rollover protection structures (ROPS) are installed on mobile plant and that operators wear a seatbelt
- using handheld tools to reduce the size of items being moved on the slope
