Operating a crane on soft, wet, or unstable ground conditions is dangerous. The crane should always be level and set up on a firm, supporting surface before operations begin. Outriggers provide reliable stability platform only when used on level, solid ground.
Ground Conditions: Before crane setup, ensure that the site is suitable to support the crane and load imposed on the crane. Improper use of supporting materials such as stabilizer pads or cribbing can contribute to having an outrigger pad fail or sink during a lift.
Poor ground conditions and cribbing under the outrigger float.
Span blocking compromises full float contact with ground.
The poor practice of cribbing under the outrigger “beam”.
Outrigger beams on the crane are to be extended to the required lengths or positions in accordance with the crane manufacturer’s recommendations.
Damaged outrigger stabilizer float increases the ground bearing pressure under the float.
The Crane Supervisor and Crane Operator must monitor ground conditions during the course of assembly, operations and disassembly for changes to outrigger and ground conditions.
Unseen ground conditions under the outrigger float.
Stability of Cranes: The suitability of ground conditions is the responsibility of the controlling entity or contractor, who must ensure that all crane supporting surfaces are prepared prior to crane set up.
Hazards: Include but not limited to, underground utilities, tanks, voids, basement or excavations. Site planning must include knowing what underground hazards may be of concern.