6. Risks associated with mobile crane operations
Mobile crane operations may present a risk of injury to persons from:
- structural failure;
- crane overturning;
- contact or collision with other plant and structures; and
- falling objects.
Structural failure may include the failure of any crane component, such as the boom, jib, hydraulic rams or wire rope. A mobile crane may suffer structural failure if the crane has been overloaded in the structural area of its load chart10. Structural failure may occur without warning.
A mobile crane is likely to overturn if the crane has been overloaded in the stability area of its load chart. This may be influenced by a number of factors including:
- poor ground conditions such as unstable ground;
- failure to use or fully extend outriggers or stabilisers;
- failure to level the crane;
- rapid slewing; and
- high wind conditions.
Contact or collision with other plant and structures may occur where sufficient clearances are not maintained between the mobile crane and other plant and structures, such as other cranes, buildings and overhead powerlines.
Falling objects may result from erecting and dismantling activities, and the way loads are secured during lifting operations. Falling objects may present a risk of injury to workers and members of the public.
10. See appendix 1 for definitions.
Last updated 21 August 2008