Excavators used to lift and suspend loads

Using excavators to safely lift or suspend loads

Excavators are mainly designed for earthmoving activities.

Some excavators are designed to include a secondary function for object handling with the use of an appropriate lifting attachment. This means that the excavator can be used for incidental lifting to lift or suspend loads with lifting equipment or lifting devices attached to a purpose-designed lifting point.

Examples of loads that are lifted or suspended by excavators include:

• trench shields
• pipes
• pits
• excavator accessories
• associated construction equipment, for example, compactors.

Selection of plant to lift and suspend loads

Before using an excavator to lift or suspend loads, a risk control assessment should be done during the planning phase of the job to identify, so far as is reasonably practicable, the hazards associated with the proposed use of the plant for the lifting task.

The assessment may find that an excavator should not be used because of the risks associated with the specific task, and that other types of lifting equipment should be used instead.

If use of an excavator is considered to be the most reasonably practical way to reduce the risk associated with performing the task, then it is important to identify the most appropriate excavator to carry out the work safely, and to implement appropriate risk controls and safe systems of work around its use.

Legal Duties

Under the Occupational Health and Safety Regulations 2017 (OHS Regulations), employers and self-employed persons must, so far as is reasonably practicable, firstly ensure that:

• plant that is used to lift or suspend equipment or materials is specifically designed to lift or suspend the load.

If the plant selected has been designed to lift or suspend equipment or materials, then the lifting and suspending must be done:

• with lifting attachments that are appropriate to the load to be lifted or suspended
• within the safe working limits of the plant.

So far as is reasonably practicable no loads are suspended over, or travel over, a person.

Employers and self-employed persons must also ensure that loads are lifted or suspended in a way that ensures that the load remains under control during the activity.

Safety issues

If excavators are not used in accordance with the duties listed in the Occupational Health and Safety Act 2004 and OHS Regulations, the operator or others near the excavator may be struck by an overturning excavator or falling loads. This can put them at risk of injury due to:

• mechanical, structural or hydraulic failure of the excavator due to inadequate design
• overloading leading to failure of points to which the lifting equipment and load has been connected
• the suspended loads swinging into, or falling onto, the cabin of the excavator
• the excavator exceeding stability load charts or structural capacity of the excavator components.

Recommended ways to control the risks

Ensure the excavator is specifically designed to lift or suspend the load

• Check with the manufacturer or supplier — noted in the specifications or operator’s manual — to confirm if the excavator is designed to lift and move freely suspended loads. Manufacturers may describe the task as a ‘secondary function for object handling’.
• Do not use the excavator to lift and suspend loads if there is no information about whether it can be used for that purpose.

Use an excavator that has an appropriate lifting attachment

Check the operator manual or rated lift capacity chart to ensure the excavator is fitted with an appropriate lifting point. This could be a lifting point that is integrated into the design of the quick hitch. This lifting point should include a fully enclosed eye which has a suitable rated capacity to match the excavator. Australian Standard AS 13031 provides guidance regarding lifting eyes, including lifting eyes that incorporate a latching mechanism.

If a quick hitch is used, ensure that it is appropriately connected to the arm of the excavator because it is a load path. There should be no other attachments connected to the quick hitch when the excavator is used for incidental lifting or suspending loads.

For pin-on attachments, ensure the connection is in accordance with the manufacturer’s specifications. The mounting pins should be the correct diameter and length, securely fastened to the excavator arm and not have excessive wear beyond the manufacturer’s limits.

Ensure that the H-link is well maintained and free from structural damage.

Lift and suspend loads within the safe working limits of the excavator

• Know the weight of the load before lifting.
• Know the rated lift capacity of the excavator for lifting or suspending loads — this should be clearly visible at the lifting point.
  • Excavators designed to lift or suspend loads should display the rated capacity in the operator cabin, this may be a single-rated capacity or a variable-rated lift capacity chart.
• Ensure that those who plan the work, such as supervisors or project managers, understand the rated lift capacity chart so that the correct excavator is selected for the lifting task, based on its size, lifting capacity and configuration.
• Ensure that the ground conditions are appropriate, so that the excavator is always stable.

Single-rated capacity

A single-rated capacity is based on a worst-case scenario or excavator configuration. This is usually based on lifting over the side of the excavator’s undercarriage at full reach. This is acceptable if the weight of the loads, and lifting equipment used, are known and do not exceed the rated capacity. 

If the weight of a load is not known, then it should not be lifted until the weight of the load is known.

An overload alarm can also identify when the excavator is overloaded.

Variable-rated lift capacity chart

A variable-rated lift capacity chart, also known as a rated capacity load chart, should include information about: 

• the appropriate lifting point or attachment
• the safe working limits of the excavator
• any load management systems or configurations for lifting suspended loads
• operator protective guards, top and front
• the controlled lowering devices, for example, hose burst protection
• specify a range of lifting capacities at various positions within the excavator’s range of movement.

If a variable-rated lift capacity chart is provided, additional engineering controls need to be incorporated into the machine that restrict lifting loads beyond safe limits. For example, a Load Management System (LMS) incorporating a rated capacity limiter and a load radius limiter.

Static and dynamic ratings

The static rated capacity is for lifting or suspending loads while stationary, where the excavator is not travelling, only slewing.

When the excavator is used for pick and carry tasks, that is lifting the load and travelling with the load suspended, the rated capacity needs to be reduced to allow for the dynamic effects exerted on the excavator that could cause instability.

The dynamic rated capacity should only be 66% of the static capacity. For example, a rated capacity of 2 t when the excavator is stationary would be reduced to 1.32 t when travelling with the load.

Load management systems should automatically derate the excavator’s rated capacity when it detects the travel system has activated, or prevent the excavator from travelling if the suspended load exceeds the derated capacity.

Ensure that no loads are lifted or suspended over or travel over a person

• Reduce risks of objects falling onto the operator. For example, where a lifted load may fall onto the excavator cabin, a falling object protection structure (FOPS) such as a top guard conforming to AS ISO 10262 should be fitted to the top of the operator station.
• Reduce the risks of the operator being struck by swinging loads. For example, where a lifted or suspended load could swing and strike the operator in the cabin, a device such as a front guard conforming with AS ISO 10262 should also be fitted across the front of the operator station.
• Provide an exclusion zone around the excavator’s working area to help control risks, monitored by a spotter or supervisor.

Ensure that the lifted or suspended load remains under control

If the excavator has been designed to lift and suspend loads, then the excavator should be fitted with controlled lowering devices, such as hose burst protection valves. This ensures the boom, arm and load do not collapse and that they remain under control in the event of a hydraulic failure.

Ensure tag lines are used where required.

Provide information, instruction, and training

You must provide operators with the necessary information, instruction and training in the use of the excavator for lifting and suspending loads so that this task is performed in a way that is safe and without risks to health.

This may include being trained and provided with instruction in the processes used for hazard identification and control of risk, the safety procedures associated with the use of the excavators at the workplace, and the use, fit, testing and storage of personal protective equipment used at the workplace to control risk.

Operators should understand:

• how to interpret the variable rated lift capacity chart, if provided, for lifting loads
• the operation of any safety devices and the impact they may have on operation of the excavator. For example, the rated capacity limiter may prevent the load from being lifted, or the load radius limiter may prevent the load from being extended away from the operator
• signals used by the dogger when providing direction during a lift.

Safe work method statement

You must ensure that excavators are being used safely and that appropriate risk controls are in place.

The use of excavators on a construction site is classed as high-risk construction work. This means you must also complete a safe work method statement (SWMS) before starting work. A SWMS must:

• state the hazards and risks of the work
• sufficiently describe measures to control those risks and
• describe how the risk control measures are to be implemented.

The types of hazards and risks that should be identified, controlled and documented in the SWMS include:

• assessing the load
• selection and inspection of lifting equipment
• application of lifting techniques
• selection of plant to lift the load including consideration of
  • rated lift capacity
  • lifting point radius
• ground conditions
• path of travel if load is being picked and carried
• exclusion zones separating people and other plant from the lifting zone
• placing and alignment of lifted parts with other components
• operator training requirements.

The SWMS must be readily accessible and easy to understand by any persons doing or involved in the work.

High-risk work licenses

An operator of an excavator used for incidental lifting does not need to hold a high-risk work license (HRWL). The employer must, however, ensure that operators are trained and suitably competent.

If a person is undertaking dogging work, they will require a HRWL. This is when the person undertakes one or both of the following:

• The application of slinging techniques, including the selection or inspection of lifting gear, to sling a load.
• The directing of an excavator operator in the movement of the load when the load is out of the operator’s view.

For more information on dogging and slinging techniques, see Dogging and slinging techniques.