A farmer was constructing a wire fence with a hydraulic post driver attached to the back of a tractor using a 3-point linkage. A 3-point linkage is 1 of the main ways farming equipment and implements are attached to a tractor. In this instance the top link of the linkage was replaced with a connection that was integral to the post driver.
It appears that this connection has failed, allowing the post driver to fall away from the tractor and hit the farmer, who was behind the tractor. The farmer was fatally injured.
Many farming implements rely on the tractor’s 3-point linkage for stability or to support the implement’s weight. Because of this, the links in a 3-point linkage are often critical load-bearing components. This is also the case for links replaced by connections integral to an implement, such as hydraulic tilt mechanisms.
If 1 or more of the links fails when carrying such an implement, the implement can fall down or away from the tractor. The falling implement could hit someone nearby or damage the tractor or implement.
A link or other connection in a 3-point linkage could fail because:
- it's worn or damaged and is no longer fit for use
- it has been improperly repaired after damage
- retaining pins have not been inserted into the clevis pins of the links
- there is insufficient thread engagement on threaded connections
These risks are also present with other types of tractor attachments where the attachment points form the critical load path.
Recommended ways to control the risk
- Before each use, inspect 3-point linkages and farming implement attachments for signs of excessive wear or damage (such as bent, corroded or cracked components).
- If a component has excessive wear or damage, don't use the link or implement until it's replaced or repaired.
- Where possible, failed or excessively worn components should be replaced rather than repaired.
- Ensure all maintenance and repairs are carried out by suitably qualified persons in line with manufacturers' specifications, or by the manufacturer or an authorised agent or representative of the manufacturer.
Systems of work
Employers must provide systems of work that are, so far as is reasonably practicable, safe and without risks to health. When working with heavy farm equipment, you should:
- connect and operate the equipment according to the manufacturer’s instructions
- ensure the equipment is maintained according to the manufacturer’s or a competent person's instruction
- ensure all retaining / lynch pins are installed into link clevis pins
- ensure that all guards are in place and operate correctly, according to the manufacturer’s instructions
Access to the work area
- Keep people away from the work area, including other workers, bystanders and children.
If your work involves machinery and equipment (plant), there are duties you need to comply with under the Occupational Health and Safety Act 2004 and Occupational Health and Safety Regulations 2017 (OHS Regulations).
Under the OHS Act, employers must:
- provide and maintain, so far as is reasonably practicable, a working environment for their employees (including independent contractors) that is safe and without risks to health
- provide or maintain plant or systems of work that are, so far as is reasonably practicable, safe and without risks to health
- provide such information, instruction, training or supervision to employees (including independent contractors) as is necessary to enable them to perform their work in a way that is safe and without risks to health.
Under the OHS Regulations, employers have obligations if they use specific risk controls or certain types of plant. See the Plant compliance code for practical guidance on how to comply with those obligations.
A self-employed person must ensure, so far as is reasonably practicable, that persons are not exposed to risks to their health or safety arising from the conduct of the undertaking of the self-employed person.