Site Preparation, Crane Siting, Foundation and Erection Interfaces
Crane safety begins before the crane arrives. Siting decisions must consider: the load envelope (radii and heights required), proximity to excavations and underground services, overhead powerlines, neighbouring structures, and the crane's own tail swing and jib oversail. The foundation must be designed for the crane's actual loads - compression, tension, shear and overturning moment - by an engineer, for the specific soil conditions, with drainage and no standing water. Under-slab voids, basements, recently backfilled trenches and buried services are classic causes of foundation failure.
Erection, climbing and dismantling are the highest-risk phases. They require a documented procedure, a competent erection crew, a mobile crane of adequate capacity, exclusion zones, and usually a verification by an engineer or competent person before the crane is placed into service. Interfaces to manage include: the mobile crane's own lift plan and ground bearing; the interaction between the erection crew and any other trades; weather limits during erection; and the handover of documentation - load charts, manuals, inspection and commissioning records.
Traps: assuming the crane's own concrete slab is adequate without design; ignoring the effect of adjacent excavation on foundation stability; forgetting that the crane's working radius and tail swing change site layout and exclusion zones; and treating dismantling as less risky than erection. Another trap is the assumption that a crane can be sited anywhere the jib reaches - the limiting factor is often the foundation and the ground, not the jib.
Rule of thumb: if you can't prove the ground and foundation will carry the loads, the crane doesn't go up.