WorkSafe Victoria recently issued a safety alert after an employee was fatally injured when a critical component of a concrete-placing boom failed, causing the boom to collapse and strike the employee.
The alert said employees in the immediate vicinity of a raised concrete-placing boom are at risk of death or serious injury in the event of a structural or mechanical failure of the boom or stabilising outriggers.
Inadequate inspection and maintenance of critical components (such as the slew ring assembly, boom pins, bushes, welds, king post) increase the risk of catastrophic structural or mechanical failures.
The alert said employers must provide and maintain plant (concrete-placing booms) so that they are, so far as is reasonably practicable, safe and without risks to health.
To reduce the risk of structural or mechanical failure of concrete-placing booms, employers need to ensure:
Employers should keep a record of all details of persons engaged to undertake the work, including the competent person undertaking or supervising the assessment for continued safe operation, and any persons or contractors undertaking parts of the work.
Employers need to ensure that employees do not enter the area beneath a raised boom. Where line-hands cannot avoid working under a raised boom, the time spent under the raised boom can often be reduced by manoeuvring the hose from the side to avoid working directly under a raised boom.
The alert said periodic inspections are part of the preventative maintenance program outlined in AS 2550.15:2019 and should be conducted in addition to other inspections (eg pre-operational and routine inspections). Periodic inspections of concrete-placing booms should only be undertaken by a competent person(s).
Furthermore, critical components, including structural welds, need to be inspected. If a critical component cannot be adequately inspected or tested (for example, by NDT) due to other components or sections of the plant partly or fully obstructing the critical component, then the obstructing item(s) need to be removed to facilitate adequate inspection or testing.
If the competent person determines that removal of the obstructing component(s) to facilitate inspection is not required, the periodic inspection report needs to include identification of the components not inspected and the rationale for the decision.
The alert also noted all reports provided in regard to the inspection activity should be signed and authorised appropriately.