Fatality: worker struck by excavator

Initial enquiries indicate the excavator was moving backwards to fill a trench when it made contact with the worker.

Investigations are continuing.

Possible control measures to prevent similar incidents

There are significant risks associated with using mobile plant in proximity to workers and other people. Persons conducting a business or undertaking (PCBUs) must eliminate risks arising from mobile plant in the workplace, or if that is not reasonably practicable, minimise the risks. Specific controls are required for mobile plant under the Work Health and Safety Regulation 2011.

Before operating any piece of mobile plant, the person with management or control must ensure:

• A suitable combination of operator protective devices for the plant is provided, maintained and used so far as is reasonably practicable. These can include seatbelts, operator restraining devices, rollover protective structures (ROPS), and falling object protective structures (FOPS).
• The plant, or part of the plant (i.e. attachments) does not collide with pedestrians or other powered mobile plant.
• Where there is a risk of collision, that the plant has a warning device to warn other persons of the risk. These can include:
  • Automatic audible alarms are usually fitted to warn of forward or reversing movement. These alarms emit an intermittent sound which is activated when the gear or drive lever is engaged.
  • Motion sensors that sense the close proximity of a person to the plant are used to activate an integrated or separately located alarm with sound. In some cases, motion sensors also stop the plant. They are sensitive to movement and are activated by motion. These devices may be suitable for a whole range of mobile plant.
  • Lights are usually used to warn of forward and reversing movement. These lights are wired to operate continuously or in hazard mode by flashing, usually when reversing. They generally work when the gear or drive lever is engaged.
  • Rotary flashing lights are coloured revolving lights and are usually mounted in a prominent place such as the top of a vehicle cabin. They can be wired to operate continuously or can be activated by a switch.
  • Radio sensing devices activate when the operator selects reverse. A light and alarm sound inside the cabin to alert the operator if a pedestrian is within a predetermined distance from the rear of the plant.

Developing a safe system of work

A safe system of work should be implemented to manage the risks associated with mobile plant. This could include, but is not limited to:

• Ensuring the plant selected is operated, inspected, maintained and repaired according to the manufacturer’s recommendations and specifications.
• Ensuring the manufacturer's instructions are included in a safe work procedure on how inspection and maintenance should be carried out. For example, checking if the plant or equipment show any signs of excessive wear, damage or cracks to structural components such as excavator boom and dipper arms and plant attachment points.
• Plant operators conducting daily pre-start checks on the general condition and maintenance of the plant.
• Ensuring the operator has received adequate training and instruction in the use of the plant:
  • PCBUs should assess and verify the operator’s knowledge and competence to operate the plant before they commence work.
  • operators should be able to demonstrate they are competent to operate the specific type of plant being used and attachments fitted to the plant.
• In some circumstances, the mobile plant operator may also need to hold the right high-risk work licence.

Pedestrians, powered mobile plant and blind spots

Plant operators and ground workers should be made familiar with the blind spots of the plant being used. Figure 1 shows several blind spots for typical mobile plant.

Figure 1: Mobile plant blind spots
Source: Excavation work Code of Practice 2021 (PDF, 1.9 MB)

Your safe system of work should also consider the following examples regarding mobile plant and blind spots:

• When high risk construction work is to be carried out, the Work Health and Safety Regulation 2011 requires that a safe work method statement (SWMS) is prepared before the proposed work starts. All duty holders involved in a high-risk work activity must make sure the work is carried out in accordance with the SWMS.
• Consult with all relevant parties before work starts. Sometimes a PCBU may share responsibility for a health and safety matter with other PCBU’s who are involved in the same activities or who share the same workplace. In these situations, the PCBUs must exchange information to find out who is doing what and work together in a cooperative and coordinated way so that all risks are eliminated or minimised as far as reasonably practicable.
• Develop induction training programs that emphasise the dangers of people working near mobile plant.
• Ensure all relevant information, training, instruction and supervision is provided before work begins.
• Consider operational exclusion zones:
  • exclusion zones should take into account the type of work being performed and the particular movement of the plant. For example, with excavator slewing, workers are at risk from the dipper arm and the bucket, as well as the counterweight
  • minimise the need for workers to be inside exclusion zones while the plant is operating. Determine if the worker can do their job outside of the exclusion zone, at another time, or when the plant is inactive
  • use physical barriers that prevent workers or plant access to designated areas, such as fencing, para-webbing or water-filled barriers.
• Signage should clearly mark pedestrian walkways, guide traffic, provide warnings and identify exclusion zones. Spotters should also be positioned to ensure pedestrians are notentering exclusion zones.
• Before work starts, develop an effective system of communication (e.g. two-way radios and hand signals) should be established based on two-way acknowledgement between mobile plant operators and ground workers:
  • Workers should also be trained in the safe work procedures involved prior to the work commencing.
  • The system should stop ground workers from approaching mobile plant until the operator has agreed to their request to approach.
  • Similarly, the system should stop operators from moving plant closer than a set distance from ground workers until the operator has been advised by ground workers, they are aware of the proposed movement.
• Before allowing workers to enter a hazardous zone (e.g. within the slew radius of the excavator), the boom and dipper arm should be lowered so that the bucket or other attachment makes contact with the ground. The machine should also be turned off or the controls disengaged to prevent inadvertent activation of the controls.

Any remaining risk must be minimised with suitable personal protective equipment (PPE). For example, use of hard hats, steel cap boots, eye protection, hearing protection and high-visibility vests.

Administrative control measures and PPE rely on human behaviour and supervision. If used on their own, they are least effective in minimising risks. The control measures you put in place should be reviewed regularly to make sure they work as planned.