Safety Alert - Stockpile dozer rollover fatal incident

Background

In January 2026, a plant operator was fatally injured when the dozer he was operating, rolled at a bulk material storage facility.

Initial investigations indicate he was operating the dozer on a stockpile when the dozer rolled over down the side of the stockpile. During the rollover the operator was ejected from the dozer’s cabin, sustaining fatal injuries.

Investigations into the cause of this incident are continuing.

In addition to this incident, there is a continuing pattern of dozer rollover and loss of control incidents across Queensland mine and quarry operations, including repeat scenarios involving reversing, cross grade work and operation near unprotected edges.

Contributing factors

Dozers can roll for a number of reasons.

Dozers are often operated in environments where there is a higher risk of rollover. For example, a dozer being operated on a large material or soil stockpile or a dozer being used to cut a road in hilly terrain.

Dozer rollovers on stockpiles can occur for many complex reasons including the following:

• Inadequate pre‑task planning and work area preparation.
• Allowing work to proceed in the absence of effective edge protection or defined work limits.
• The dozer rolling as it is reversed near drop offs or voids.
• The dozer rolling backwards as it initially climbs the stockpile – this is exacerbated if the material density of the stockpile is too low.
• The sloping sides of the stockpile can collapse as the dozer attempts to climb the stockpile, due to low material density, causing the dozer to lose control and/or be engulfed.
• The dozer can roll sideways if the side slope exceeds the capability of the machine in that operating environment. It is important to note that the allowable side angle before a dozer loses traction, is much less than the angle that a dozer can drive up or down. As such, operating a dozer on a side slope is especially hazardous.
• The dozer can roll when it is driven too close to an edge (i.e. a face) causing the dozer to drop off the edge. In the case of a near vertical edge, the material next to the edge can collapse due to the weight of the dozer and cause the dozer to drop. This can also occur when a berm is too small. The density of the stockpile material will be less near the edge than in the middle, where dozer movement has compacted the material.
• The operator cannot see where the edge of the stockpile is due to blind spots on the dozer and/or glare from the stockpile material in certain lighting conditions (this may be worse depending on the colour and reflectivity of the product).
• The risk of rollover can be impacted by the stability at the face of the stockpile. That stability can be adversely affected by steepness, moisture, and reclamation activities below (e.g. by loaders removing material) among other factors.

Action required

Nearly all dozer rollover incidents are preventable. Persons conducting a business or undertaking (PCBUs) should:

• review current and planned dozer tasks
• verify that work areas are adequately prepared and controls are in place
• actively confirm that identified controls remain effective throughout the task, rather than relying solely on pre‑start discussions.

Work activity specifically relating to spreading material stockpiles

Spreading a stockpile with a dozer on top of the stockpile can be one of the most hazardous activities involving a dozer. Before selecting a dozer to carry out this task, the PCBU should be able to demonstrate that the activity can be undertaken safely based on the size of the stockpile, type of stockpile material and model of dozer to be used.

Only dozer operators with demonstrable experience on the make and model of the dozer should be permitted to carry out this task. The stockpile should also be constructed so that the risk to a dozer operator is minimised so far as is reasonably practical. Considerations should include:

• the height of the stockpile and if it could be reduced to decrease the height at which the dozer will operate
• the stockpile base dimensions and spread of material and if it could be increased by altering the discharge position of the conveyor or by progressively spreading the material more frequently.

Where a dozer has been selected to spread a material stockpile, a safe system of work needs to be developed that:

• minimises the risk of the dozer rolling either end on end or sideways
• provides a step-by-step procedure that addresses the safe operation of the dozer and the sequence of material removal by other plant at ground level (e.g. if a loader removes too much material from a batter close to where a dozer is operating above, this could cause the dozer to roll)
• includes the dozer pushing material towards the stockpile perimeter and avoids the dozer having to drive along, and close to, an edge
• limits the time the dozer operator is required to operate the dozer at height on the stockpile to avoid operator fatigue (for example the dozer operator could rotate with operating a loader on level ground or operate the dozer for other activities of lower risk)
• addresses visibility issues for operators by providing suitable safety eyewear that minimises glare and closed-circuit television (CCTV)cameras for rear vision and blind spots on the dozer
• establishes and enforces minimum set-back distances from stockpile edges
• considers ways of helping to prevent the dozer from approaching an open edge, such as by constructing a berm of at least one metre height that runs for the length of the open edge
• ensures appropriate safeguards on the dozer are provided including:
  • dozer has an enclosed rollover protective structure (ROPS), and
  • an appropriate seatbelt is fitted and worn at all times during operation.

Seatbelts and operator presence sensing systems

While a dozer needs to be used in such a way to minimise the risk of overturning, risk control measures need to be implemented to reduce the likelihood of serious or fatal injury if the dozer overturns. This includes the need for the dozer operator to wear a seat belt at all times while operating the dozer.

• The safety features on modern dozers (e.g. operator presence system including seat belt and/or seat pressure sensors) should be designed to reduce the likelihood of the operator failing to wear a seatbelt without causing the dozer’s operation to become potentially unsafe.
• On older dozers these safety systems will be limited. However, consideration should be given to the fitting of warning lights on the exterior of the cabin that notify site supervisors of when the seat belt is disconnected. If an operator is found not to be wearing a seatbelt after being provided with written instructions to do so, a procedure could be followed where the operator receives documented warnings that will result in the operator not being permitted to operate a dozer.
• Where the dozer is in use and the activity could increase the likelihood of an operator getting out of their seat (e.g. ripper attachment engaged and the operator needs to look rearwards) the dozer should be fitted with additional operator aids so that this becomes unnecessary (e.g. external camera and on-board display in the cabin).

General

• While wearing a seatbelt remains a critical control, injury can still occur when a dozer rolls and the operator is wearing a seatbelt. The cabin should be designed and laid out so that in the event of a rollover the operator cannot hit their head on an obstruction (e.g. fire extinguisher mounted inside the cabin, additional displays and controls placed inside the operator envelope). Consideration should also be given to the design of the seat and seatbelt to minimise potential injury to workers if a dozer rolls, especially where a dozer rolls down a steep, long slope.
• Dozers need to be fitted with a rollover protection system (ROPS) complying with Australian Standard AS ISO 3471.
• Dozer operator skill levels need to be high so that the operator holds a comprehensive knowledge of both dozer operation and the safest method of carrying out the specific work activity. These skills will take time to develop. To confirm competency PCBU’s should ensure that new workers complete a verification of competency or on-the-job assessment to verify their skills. Additional guidance on machine operation can typically also be obtained from the equipment manufacturer or supplier.
• Newly trained operators should initially only work on lower risk dozer activities until their increased skill levels are confirmed by the PCBU. Only then should a worker progress to dozer operation in more hazardous terrain or for more hazardous activities.
• In addition to general training on safe dozer operation, documented familiarisation training, on the specific make and model of dozer, should be provided for operators. As part of the operator familiarisation training, it is advisable to include information regarding the characteristics (e.g. density, moisture content etc.) of the stockpile(s) on site and how this affects stockpile stability.
• Training should include a review of all safety features on the plant (e.g. ROPS structures, seat belts, operator presence systems etc.), along with emergency procedures that include steps to be taken if the operator believes that rollover is imminent.
• Seatbelts and ROPS are means of reducing the risk of a serious or fatal injury. It is best to implement work systems that will prevent the occurrence of a rollover in the first place.
• Where practical, consideration should be given to the use of systems such as remote-control dozer operation to remove operators from higher risk work.