Boom type mobile elevating work platforms (MEWPs), ‘Orchard MEWPs’ and greenhouse trolley scissor MEWPs used within the agricultural industry are not being sufficiently inspected and maintained to ensure the machinery is safe and without risks to health, so far as is reasonably practicable.
MEWPs are increasingly used in the agricultural industry for accessing heights. Tasks at height include picking, pruning, bud removal, and placement and removal of bird netting. In recent years persons operating MEWPs in agriculture have sustained serious injuries due to critical component failure of the plant. Injuries have included serious back and limb injuries requiring extensive rehabilitation.
What are MEWPs?
MEWPs may be identified using their brand names or industry names such as: orchard work baskets; cherry pickers; fruit harvesting boom lifts or platforms; or green-house trolleys. Orchard MEWPs can also be identified by having foot controls only, to travel and move the work platform.
What are the risks?
MEWPs used in the agricultural industry are capable of elevating persons to heights of between 3 to 8 metres, but may be designed to go higher. Failure to implement an adequate inspection and maintenance program for the MEWPs that includes ongoing scheduled inspections and preventative maintenance may lead to malfunction or failure of critical components of the MEWP, placing persons in or around them at risk of serious injury.
The collapse of MEWPs can occur due to excessive structural fatigue cracking, wear, corrosion or damage to components that are critical for supporting persons in an elevated position. Those critical components can catastrophically fail during operation of a MEWP, resulting in collapse of the work platform and injury to the person in the MEWP. In addition, other persons in the immediate vicinity may be struck or crushed by the falling MEWP.
Incorrect or inadequate repair procedures can also result in catastrophic failure of the MEWP. For example, if a component is incorrectly welded during repair, this may result in failure of the component during use and collapse of the MEWP.
Who has duties
Employers must provide and maintain for employees (including contractors and their employees) a working environment that is safe and without risks to health, so far as is reasonably practicable. This includes a duty to provide or maintain plant or systems of work that are, so far as is reasonably practicable, safe and without risks to health.
Specific duties for the use of plant in workplaces are set out in Part 3.5 of the Occupational Health and Safety Regulations 2017 (OHS Regulations), including employer duties to identify hazards and eliminate risks associated with plant, so far as is reasonably practicable. If risks cannot be eliminated, the employer must ensure they are reduced so far as is reasonably practicable.
In addition, under Part 3.5 of the OHS Regulations employers must ensure that plant is inspected to the extent necessary to ensure that any risk associated with the use of the plant is monitored and controlled. Employers must also retain any record of inspection and maintenance for certain plant, including MEWPS, while the employer has management or control of the plant.
Controlling the risks
An employer must ensure that MEWPs are:
- inspected to the extent necessary to ensure they are safe for use
- maintained, and where necessary repaired, to ensure they are safe for use and that risks are controlled, so far as is reasonably practicable.
If a damaged or worn MEWP cannot be repaired to a safe condition, it must not be used. It should be replaced with a MEWP that is safe to use. Risk controls should be put in place to prevent the use of an unsafe MEWP.
General maintenance factors
The type, extent and frequency of maintenance to be carried out on a MEWP should be determined after considering the following factors:
- manufacturer’s recommendations or in their absence, the recommendations of a competent person, such as an engineer
- recommendations from published technical standards relevant to MEWPs, such as Australian Standard AS 1418.10 & AS2550.10
- the age and history of the MEWP including the number of hours of operation and its history of utilisation
- the manner in which the MEWP has been used, transported, and stored that may have increased the likelihood of fatigue or wear on the MEWP
- the conditions in which the MEWP operates and has been operated – for example, in a wet/humid environment that can contribute to corrosion
- whether there are parts on the MEWP that may be prone to failure or high wear - the manufacturer, supplier, authorised repairer, or a suitably competent person may provide information on parts which need to be more frequently monitored and replaced.
Note: The external visual appearance and the hours of operation of a MEWP alone are not always reliable indicators of wear and fatigue. Disassembly of the plant to inspect and assess critical components is often necessary. Environmental considerations and loads experienced by the plant during use and transport may have an impact on component wear and fatigue.
The following Australian Standards contain information about the design, maintenance, inspection and repair of MEWPs:
- AS 2550.10 Cranes, hoists and winches – Safe use - Mobile elevating work platforms,
- AS 2550.1 Cranes, hoists and winches – Safe use - Part 1: General requirements,
- AS/NZS 1418.10 Cranes, hoists and winches – Part 10: Mobile elevating work platforms; and
- AS 1418.1 Cranes, hoists and winches – Part 1: General requirements
Inspection and maintenance of MEWPs should include the following:
- Pre-operation inspection: Before the commencement of each work shift, the MEWP is given a visual inspection and functional test that includes operational and emergency controls. The employer should ensure that the pre-operation inspections and tests have been carried out by the operator.
- Routine inspection and maintenance: These are conducted based upon the working environment, and the frequency and severity of use of the MEWP. They should be carried out at three-monthly intervals or less, unless the MEWP is not in-service (eg seasonal picking where the MEWP has been properly serviced for off-season and is in weather protected storage). This should include functional checks and visual inspection (including critical components).
- Periodic inspection: Safety functions of the MEWP should be assessed by a competent person, and any identified safety-related malfunctions and problems corrected before the MEWP is returned to service/operation.
Upon completion of the inspection a written report should be obtained from the person who conducted the inspection, and the report should be retained by the owner of the MEWP. The report should include an assessment of the practicability of applying the safety measures from the latest edition of the MEWP design standard, AS/NZS 1418.10 Cranes, hoists and winches - Part 10: Mobile elevating work platforms. The report should also contain detail on what was inspected, how it was inspected, the findings and recommendations of the inspection.
For MEWPs that have been in frequent and regular use, the interval for periodic inspections should be 12 months or less.
Note: The employer may consider implementing an enhanced periodic inspection program. Enhanced periodic inspections normally commence after the MEWP has been in service for a period of five years and in addition to the inspection and testing requirements of a periodic inspection have been programed to ensure that all critical components have been properly inspected and tested over a 5 year period.
- Major Inspection: These should be carried out as part of a preventative maintenance program. These inspections should be comprehensive and ensure that all critical components have been properly inspected and tested.
Detailed inspection of all critical components should include checks for wear in comparison to their allowable wear tolerance, checks for corrosion, visual examination of all critical areas and nondestructive testing (as appropriate) for evidence of cracking.
Where necessary the MEWP should be stripped down, and paint and grease removed to allow a complete and thorough inspection of critical components.
Major inspections should be carried out when:
- MEWPs have been in use for a period of ten years and an enhanced periodic inspection regime has not been carried out
- MEWPs are to be re-commissioned or imported (eg the purchase of a second hand MEWP), and their previous working and maintenance records are unavailable, or
- MEWPs have been subjected to a 10 year major inspection and have experienced 5 years subsequent use.
Upon completion of a major inspection, the owner should be provided with a detailed report from the person who conducted or managed the major inspection. The report should include an assessment of the practicability of applying the safety measures from the latest edition of the MEWP design standard, AS/NZS 1418.10: Cranes, hoists and winches - Part 10: Mobile elevating work platforms.
The report of a major inspection should also contain details on:
- the components that were inspected
- what the inspection looked for (corrosion, damage, wear, etc).
- the method of inspection (visual, non-destructive testing, measurement, etc),
- the tolerances used when determining whether a component that is corroded, damaged, or worn is safe or further use, and
- the recommended actions arising out of the inspection.
Note: For greenhouse trolley MEWPs that travel on ground based heating pipes, those pipes need to be inspected and maintained in accordance with specifications of the heating pipe manufacturer and MEWP manufacturer, or from a suitably competent person, as they are a critical component necessary for the stability of the MEWP.