In June 2019, a crane operator was injured when an overhead travelling crane (also commonly known as a bridge crane) fell to the ground. Early enquiries indicate the anchoring system used to support the rails the crane travels along failed, resulting in the crane falling.
Investigations are continuing.
Preventing a similar incident
Bridge cranes comprise of a bridge beam usually mounted to a pair of elevated runway beams or girders. The bridge beam can travel along the overhead runway and is fitted with one or more hoists (lifting component of the crane) that travel along the bridge beam. Bridge cranes can be operated from within a cabin mounted on the crane or remotely from the ground, for example by a hard-wired pendant or radio control. (Source: Safe Work Australia).
Common risks associated with cranes and lifting equipment include:
- falling objects due to plant or equipment failure or operator error
- operators falling while accessing the crane or performing maintenance
- rollovers or collapse in the event of a structural failure.
Designers have a duty to ensure, so far as is reasonably practicable, the design of plant and structures is free of risk to health and safety. A designer is a person conducting a business or undertaking (PCBU) whose profession, trade or business involves them in:
- preparing sketches, plans or drawings for a structure, including variations to a plan or changes to a structure (this includes but not limited to architects, building designers and engineers)
- making decisions for incorporation into a design that may affect the health or safety of people who construct, use or carry out other activities in relation to the structure.
A PCBU who alters or modifies the design of a structure or item of plant will assume the duties of a designer. The runway and supporting structure (including any supporting columns, brackets or frames) for the bridge crane are critical to its operation. Any modifications or alterations to the runway or supporting structure needs to be assessed and verified by a suitably qualified Professional Engineer (e.g. a structural engineer who is a Registered Professional Engineer Qld).
A systems approach that integrates the risk management process in the design phases and encourages collaboration between a client, designer and constructor is recommended. This process is a systematic way of making a workplace as safe as possible and it should be used as part of the design process. It involves the following steps:
- identify reasonably foreseeable hazards associated with the design of the structure
- if necessary, assess risks arising from hazards
- eliminate or minimise risk by designing control measures
- review control measures.
Ways of controlling risks are ranked from highest level of protection and reliability to the lowest. This is known as the hierarchy of control. The WHS Regulation 2011 requires PCBU's to work through this hierarchy to choose the control that most effectively eliminates or, where that is not reasonably practicable, minimises the risk in the circumstances. Control measures include:
- Elimination - Safe design means the integration of control measures early in the design process to eliminate or, if this is not reasonably practicable, minimise risks to health and safety throughout the life of the structure. For example, incorporating support columns along the runway to provide additional support. If this control measure is not possible, the next steps can be considered.
- Engineering - components attached to the building should be maintained in a safe and structurally stable condition to prevent any unexpected collapse.For example, wherever an anchor system is used to attach runway rail beams to concrete, it is critical the designer selects anchors that will exceed the design life of the crane and are suitable for both the maximum load and type of loading (e.g. cyclic loading). In addition, the designer needs to ensure the anchors can be installed in accordance with the anchor manufacturer's instructions. If the designer finds reinforcing steel in the concrete makes using the anchor system impractical, more traditional types of design such as support columns under the runway rail beams should be considered.
- Administrative controls - Periodic inspection of the crane, runway and supporting structure in line with the manufacturer's recommendations. Displaying warning signs advising where cranes operate and designated exclusion zones.
- Personal protective equipment (PPE) - Any remaining risk must be minimised with suitable PPE, such as hard hats and protective eyewear.
Administrative control measures and PPE rely on human behaviour and supervision, and used on their own, tend to be least effective in minimising risks.
From July 2013 to June 2018, there were 244 accepted workers' compensation claims involving injuries where workers have been struck by moving or falling objects or trapped by moving machinery activities involving cranes. Approximately one third (35%) of these claims were serious (involving five or more workdays absent).
From July 2013 to June 2019, WHSQ was notified of 112 incidents of people sustaining an injury or at risk of a serious injury as a result of the toppling or other failure relating to an overhead or gantry crane, or failure of a load/lift involving an overhead or gantry crane. WHSQ has issued 69 statutory notices across all industries relating to the risk management of such incidents.
Prosecutions and compliance
In 2018, a company was fined $85,000 after a worker was injured when he was struck by a concrete pipe being moved by a crane. The worker was cleaning the end of a concrete pipe in the trench. As the crane was lifting the next pipe into position, it struck the worker resulting in a fractured arm and shoulder blade and lacerations. The company had a safe work method statement, but it was not signed by the workers or implemented. Additionally, the dogman responsible on the day was not suitably qualified.
- How to manage work health and safety risks Code of Practice 2011 (PDF, 1.02 MB)
- Safe design of structures Code of Practice 2013 (PDF, 0.51 MB)
- Bridge and gantry crane information sheet - Safe Work Australia
- Guide to inspecting and maintaining cranes - Safe Work Australia
- Australian Standards: 2550 Cranes, hoists and winches - Safe use Part 3: Bridge, gantry, portal (including container cranes) and jib cranes (subscription required)
- Australian Standards: 1418 Cranes, hoists and winches Part 18: Crane runways and monorails (subscription required)