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ge and understanding of A/D procedures. This supervisor must ensure that the A/D crew members understand their individual tasks and the associated hazards before allowing assembly or disassembly to begin. Further, the A/D director is required to consider specific hazards, determine the appropriate means for addressing them, and oversee implementation.

Hazards to be addressed by the A/D director are site and ground bearing conditions; blocking material and proper location of blocking; assist crane loading, boom and jib pick points, and center of gravity; stability upon pin removal, snagging of suspension ropes and pendants; struck by counterweights; boom hoist brake failure; loss of backward stability; and wind speed and weather.

Many of these potential hazards are not obvious to those with limited expertise in assembly/disassembly. There are numerous scenarios in which there is stored kinetic energy in the equipment’s component parts, and the installation or removal of components in the wrong order, or using the wrong procedure, can release the energy in ways that would be unexpected to those with little knowledge of the process.

Take the example of blocking under boom sections during disassembly. Failure to place blocking in the correct position under the boom can lead to unexpected movement or collapse when a pin that is in tension is removed. Workers unfamiliar with the concept of pins in tension may not recognize the dangers of removing such a pin in that circumstance, which could result in serious injury and/or damage to the equipment.

Inspections (Sections 1926.1404, 1412, 1435, 1436)

Coupled with the A/D director’s obligation are new requirements for post-assembly inspections. For example, Paragraphs 1926.1404(m) (2) and 1926.1412(c)(1) mandate that the equipment be inspected by a qualified person upon completion of assembly to ensure that the proper components were utilized and that the equipment is configured correctly. Even though this type of inspection was not required under the old OSHA code, its addition addresses the dangers associated with incorrectly assembled equipment.

For example, if the applicable load chart is based on a certain amount of counterweight and not all of the required counterweight is present, then the load chart will not accurately reflect the machine’s capacity, which could easily result in the equipment toppling over. For tower cranes, post-assembly inspection requirements are expanded to include a load test using certified weights or weights that have been measured using a certified scale. [See Paragraph 1926.1435(f)(3). Similar load tests are also required for derricks under Paragraph 1926.1436(g)(3)]. The new standard also includes a special pre-erection inspection requirement for tower cranes. Under Paragraph 1926.1435(f)(2), a qualified person must inspect the crane’s components for damage or excessive wear before they are erected, paying particular attention to components that will be difficult to inspect during shift inspections.

Ground conditions (Section 1926.1402)

Recent crane incident studies also indicate that improper ground conditions are one of the top four contributors to crane accidents, accounting for 11 percent of fatalities during crane use. Subpart R was cognizant of this fact years before C-DAC was even convened, requiring the controlling contactor to ensure th