This alert has been generated to ensure that all sites in Australia are aware of the risks of a recent incident where a Mobile Elevated work Platform was being used for pole maintenance and the operators experienced basket shudder. It was then observed on further inspection of the turret area that the main lift cylinder was not attached to the turret. (See picture on file dowload.)
This placed the operators of the MEWP at severe risk that could have resulted in multiple fatalities from lack of maintenance. This alert has been generated to ensure that the risks associated with Manufactures requirements are managed and to provides guidance on appropriate maintenance intervals and the degree of maintenance required for mobile elevating work platforms (M.M.E.W.P's).
The information applies to all M.M.E.W.P's as defined in Australian Standard AS 2550.10, "Cranes- safe use; elevating work platforms". This definition includes truck mounted units (travel towers or 'cherry pickers'), trailer units, self propelled units (scissor, boom and articulated), and 'push around' type units.
The type of maintenance carried out on M.E.W.P's and the length of time between maintenance should be determined after considering the following factors:
1. Manufacturer's recommendations or the recommendations of a competent person.
2. Recommendations from published technical standards.
3. Number of hours of operation, the type of loading the unit undergoes and the time spent in transit (the oscillating loads applied during transit can reduce the fatigue life of an M.E.W.P).
4. Whether the unit is under the control of the owner or is hired out (units that are hired out generally require higher levels of maintenance due to more severe use).
5. Conditions in which the M.E.W.P operates - in a corrosive or wet environment, or in abrasive conditions (eg open cut coal mine).
6. Age and history of the unit.
7. Special consideration of parts of the M.E.W.P that may be prone to failure or high wear - eg in the case of units with glass reinforced plastic (GRP) boom inserts, the connection between the GRP and the rest of the boom may require special attention (failure of these inserts can be sudden, without warning of yield).
Conclusions regarding the structural and mechanical integrity of a unit should not be based solely on the external visual appearance of the unit nor solely on the hours of operation. In one documented case an eleven year old truck mounted M.E.W.P was stripped down for a detailed inspection. Although the unit had only been operated for 80 hours over that time period, a number of the internal parts of the boom were severely corroded and required replacement. The following points should be noted about this particular boom;
• The unit had only been owned by one owner.
• The external appearance of the M.E.W.P was good at the time of inspection.
• Written records of hours of operation had been maintained and operational systems used by the owner ensured these records were accurate.
An employer should take into account the current state of knowledge in regard to maintenance of M.E.W.P's. It is considered that maintenance should be a major component in any strategy to control the risks (i.e. likelihood) of failure or malfunction of the M.E.W.P.
Published technical standards should be used as a starting point to help control risks. One part of Australian Standard AS 2550, Cranes - Safe use (Section 10 of AS 2550.10) applies to the safe use of M.E.W.P's and provides guidance on maintenance of M.E.W.P's.
AS 2550.10 Guidance
As mentioned in clause 5.1.2 Operating instructions Pre-operational inspections shall be carried out at the beginning of each working shift in accordance with the pre-operational checklist, and the results entered in the logbook and where pre-operational inspections reveal a safety malfunction or potential risk, the MEWP shall not be put in service until the risk has been assessed by a competent person and the appropriate action carried out and recorded.
Inspections shall be carried out at a frequency to enable the MEWP to be kept in a safe and satisfactory condition. Inspections shall be carried out in conformance with this Standard,
AS 2550.1, and instructions written in accordance with this Standard (see Clause 1.4). All
such work shall be noted in the records.
The following inspections are applicable:
(a) Pre-operational inspection—required for all MEWPs.
(b) Routine inspection and maintenance—required for all MEWPs.
(c) Periodic inspections—required for all MEWPs.
(d) Enhanced periodic inspection.
(e) Major inspection—required for those MEWPs not subject to an enhanced periodic inspection regime.
In addition to the above, section 6 of AS 2550.10 specifies three different levels of maintenance to be carried out at time intervals as indicated below (refer to the standard for more detail):
a) Routine Inspections; at intervals not exceeding 3 months - Includes visual inspection, checking that all functions are operable, lubrication check and opening of all covers which would be required for normal service and inspection purposes. A written report shall be furnished on the completion of the inspection. The EWP shall not be returned into service until all safety related malfunctions and problems have been corrected.
b) Periodic inspection; at intervals not exceeding 12 months - Includes all items specified by manufacturer for annual inspection and maintenance, and all routine (ie 3 monthly) maintenance items.
c) Major inspection; after a maximum of 10 years of service and every five years thereafter - This inspection is comprehensive and includes inspecting for wear, fatigue and cracking of all components of the M.E.W.P. According to section 6.4.5 of AS 2550.10, the major inspection includes attention to structural anomalies based on strip-down inspection and non-destructive examination and detailed visual inspection and tolerance checking of all wear components.
When developing a maintenance plan for M.E.W.P's, the principles in this Alert and in other relevant sources, such as AS 2550.10, should be taken into consideration. In some instances it may be necessary to specify a maintenance plan that is more stringent, and that has shorter intervals between maintenance checks, than that required by AS 2550.10.
The guidance given in AS 2550.10 for inspection and maintenance should be followed, unless a verifiable maintenance system and records exist, which demonstrate why compliance with this standard is not necessary.
A supplier of plant who hires or leases plant must ensure that, between any hiring or leasing of the plant, the plant is inspected and maintained to ensure that the risk arising from the use of the plant is eliminated so far as is reasonably practicable or, if it is not reasonably practicable to eliminate the risk, reduced so far as is reasonably practicable. This may involve sending a competent person to inspect the M.E.W.P before it is delivered to the next site, instead of the unit being returned to the hirer's yard for inspection.
Recording of Maintenance
Written maintenance records for each M.E.W.P should be maintained for the life of the unit, and such records should be available on request of an inspector or a Health and safety Representative (HSR). In the case of suppliers who hire or lease M.E.W.P's maintaining such records is a mandatory requirement. One method of recording information is by keeping a maintenance logbook for each M.E.W.P.
It is the recommendation of The ETU that if any of the above steps are not followed the work should cease. Contact your designated Health & Safety Representative, your Manager or your local organiser.