Site support, wind, interference and environmental hazards
Review the whole operating envelope
A tower crane interacts with ground, foundation, nearby buildings, other cranes, power lines, public areas and changing construction work. Assess pickup, travel, counter-jib sweep, landing and the out-of-service envelope rather than draw only the hook path. Excavation, stored materials, water and settlement can alter support conditions after erection. The operator must report and escalate changes through the actual plan rather than assume an earlier approval covers every later condition.
Treat wind as a load and control problem
Wind effects depend on actual speed, gusts, direction, exposed area, shape and crane configuration. A light broad panel can create a substantial lateral effect even while its mass is below chart capacity. In a supplied aerodynamic model, force is pressure times projected area times the stated coefficient, and pressure can vary with speed squared under the defined assumptions. A universal operating wind speed cannot safely cover every crane and load. Use the actual manufacturer and site limits, sensing arrangements and preplanned actions.
Plan conflicts and communication
Overlapping cranes and new obstructions require coordinated actual operating and out-of-service envelopes. An anti-collision system can support the design but does not prove that every sensor, coordinate or new structure is correct. Establish controlled areas and clear communication for the task. Overhead electrical lines require the actual voltage, jurisdictional rules, isolation or protection plan and competent coordination; foreign clearance numbers are not transferred as French law. A signalperson cannot simply make an unknown electrical separation safe.
Prepare before conditions deteriorate
Severe weather, poor visibility or unreliable communication can require a controlled stop before the task becomes unmanageable. Follow the actual emergency and out-of-service method rather than improvise hook, trolley, brake or access actions during a storm. Weather-vaning is a specified machine state where applicable, not permission to release every crane’s slewing brake in all configurations. Check the required clear envelope and responsibilities in advance. This chapter gives no geotechnical distance rule, universal storm threshold or actual crane-erection approval. Real site assessment, manufacturer instructions, current French requirements and practical competence remain essential.