11.5 Cranes, Rigging, Signal Persons & Power-Line Safety

11.5 Cranes, Rigging, Signal Persons & Power-Line Safety

Cranes amplify planning errors. Before setup, identify the load, center of gravity, rigging, pick and set points, travel path, operating radius, crane configuration, ground support, underground hazards, obstructions, weather, personnel, and energized power lines. Use the manufacturer load chart for the exact machine and configuration.

Capacity and setup

Crane capacity falls as operating radius increases. The radius is measured from the axis of rotation to the load's center of gravity, not to the boom tip. Determine gross load by including the object, hook block or ball, slings, shackles, spreader beams, lifting devices, and other chart deductions. Use the chart quadrant, boom length, angle, parts of line, counterweight, outrigger position, and configuration that actually exist.

The controlling entity must provide ground conditions that are firm, drained, and graded sufficiently, with supporting materials when needed. The operator or competent setup personnel verify outriggers, cribbing, level, clearance, and manufacturer limits. Barricade the swing radius where employees could be struck or crushed by the rotating superstructure.

Assembly and disassembly follow manufacturer procedures or employer procedures developed by a qualified person. A competent and qualified assembly/disassembly director controls the operation. Do not release pins, pendants, or sections until their movement and load are understood and supported.

People and communication

Operators must satisfy OSHA Subpart CC training, certification or licensing, and evaluation requirements. Certification can be by crane type or by type and capacity under the standard; do not assume every credential must state capacity. The employer also evaluates the operator for the equipment and work assigned.

A signal person is required when the point of operation is not in full view, the operator's travel view is obstructed, site-specific safety concerns require one, or the operator or load handler requests one. The signal person must be qualified through an employer or third-party evaluator and demonstrate knowledge of signals, equipment limitations relevant to signaling, and the standard. Qualification is not synonymous with a mandatory third-party certification card.

A qualified rigger is required for specified assembly/disassembly and other covered work. OSHA defines qualification by recognized degree, certificate, professional standing, or extensive knowledge, training, and experience with demonstrated ability. There is no universal rule that every rigger hold an accredited certification. Qualification must fit the rigging and load.

Use one designated signal person at a time except that anyone may give a stop or emergency-stop signal. Agree on hand, radio, or other signals before the lift. The operator obeys a stop signal and halts when communication is lost.

Rigging and load control

Inspect slings and rigging before use as the applicable standard requires. Verify identification, rated capacity for hitch and angle, edge protection, hardware compatibility, center of gravity, and load control. Sling tension rises as the angle from horizontal becomes smaller. Never use an unverified shortcut in place of the manufacturer table or engineered calculation. Remove damaged rigging under the applicable discard criteria; criteria differ for alloy-chain, wire-rope, synthetic-web, round, and metal-mesh slings.

Keep employees out of the fall zone except as allowed for essential hooking, guiding, or receiving work. Use tag lines when needed without placing employees in a pinch point. A critical-lift plan should define the organization's chosen threshold, approvals, redundancy, communications, weather limits, and stop-work authority; OSHA does not impose one universal percentage definition for every project.

Power-line safety and Table A

First determine whether equipment, load line, or load could come within 20 feet of a power line. Deenergization and visible grounding, with utility confirmation, is preferred. If operating under the clearance option, identify voltage and use OSHA Table A:

Table A does not use the older 10-feet-plus-0.4-inches-per-kV formula. Implement the required planning meeting, encroachment prevention, warning line or barricade, dedicated spotter or permitted device, and operator warning. Treat lines as energized unless the utility owner confirms deenergization and grounding.

Stop-work rule

Stop when voltage is unknown, setup changes, ground settles, wind exceeds the governing limit, communication fails, the load chart does not match configuration, or load weight and center of gravity are uncertain. Resolve the condition before resuming.