Background
In recent years there have been several incidents of fixed cranes running away during windy conditions. During these incidents, there was uncontrolled long-travel movement of the crane to the end of the runway and contact with the long-travel end stops.
The resulting impact with the long-travel end stops damaged the end stops, and caused the crane carriage to dislodge from the runway rails. Further use of the derailed crane could have resulted in a collapse of the crane.
Summary of hazard
During storm wind events fixed cranes and their associated structures are exposed to loading which may not have been considered in the design and construction or during the operation of the crane.
This can lead to overload of parts and loss of control of the crane or load which has the potential to cause injury to those in the vicinity.
Contributory factors
Based on wind runaway incident reports and classified plant registration reviews, inspectors have identified the following.
Design and communication of design specifications
- Crane’s design not addressing all the requirements of Australian and New Zealand Standard AS/NZS 1170.2 Structural design actions – wind actions.
- Inadequate dissemination of design specifications by the designers of the crane, including validation that the manufacturer has understood the designer’s specifications.
Safe systems of work
- The crane’s system of work not addressing the crane’s operating limits (e.g. crane operated in wind conditions exceeding design constraints).
- Crane operators not trained and assessed as competent for the type of crane to be used, including work to be performed and potential hazards of the operating environment.
- The storm-locking arrangement on the crane (where available) not utilised after each use or before a strong wind event.