A question posed to the Crane and Hoist Professionals group on LinkedIn asked if “Lugs” were required on underhung cranes. Most group members responded, “Yes,” because the ASME B30.11 or MH 27-1 requires it. This is not surprising because the text of many standards make them sound like they set requirements and well intended readers believe it. Let’s get technically correct:
• In the U.S., OSHA enforces the Code of Federal Regulations, for Safety and Health, with fines for non-compliance.
• In order for something to be “required” for safety and health, OSHA has to require it.
• ASME, ANSI, NFPA, NEC and other voluntary standards are only required to be followed if OSHA incorporates it.
• OSHA currently has no regulation covering underhung cranes.
• 29 CFR 1910.179 covers only top running bridge and gantry cranes.
• ASME B30.2, which is incorporated in part, covers top running cranes.
• Cranes only have to meet requirements that existed at the time of manufacture, grandfathering.
• Grandfathering and technical correctness exists until an accident.
• After an accident, OSHA can use the B30.11 lug requirement via the “general duty clause”.
• Lawyers have no rules.
• Lugs are not required on new or existing underhung cranes and employers cannot be required to install them.
• Employers must maintain a safe and healthful working environment.
• Employers can be held liable for not complying with “voluntary” standards.
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Sophisticated tools, including cranes, helped make Astronaut Neil Armstrong’s walk on the moon a reality some 45 years ago. Through hard work, dedication, and ingenuity space flight stepped out of science fiction novels and improved building strategies and equipment for future generations.
The Vehicle Assembly Building (VAB), where the 363 foot tall Saturn rockets were assembled for the Apollo missions, houses 71 cranes and hoists. Two high-bay, 325 ton bridge cranes have the hook height necessary to stack the pieces of the entire Saturn V while sitting on the Mobile Launch Platform. Every section was brought into the building horizontally and was lifted vertically and stacked. One of the benefits of using overhead cranes to do this was that both the main and auxiliary hoists could be used to upright the load.
Another necessary feature, these cranes have the ability to lower loads extremely slowly. Obviously, this was vital in stacking liquid rocket sections. If hard contact were made between sections during assembly there would be damage to one or both sections.
For reliability, redundant systems and components were developed to take over if the primary system on the crane fails, making them fail-safe. Dual load path components are common in high risk applications like nuclear power plants. These cranes go beyond that to redundant controls that take over if the primary controls fail. These advanced features, that we take for granted in today’s cranes and hoist designs, were designed in the 1960s.
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This railroad bridge section would be difficult to replace using a mobile crane on the approaches or in the canyon, but by combining multiple lifting and transporting technologies the job runs smoothly.
A top-running monorail crane is transported on railroad bogies and positioned to span the existing section. It raises on the bridge structure by hydraulic jacks and hoists the old bridge section. The dual top-running trolleys transport the section and lower it onto waiting bogies where it is moved back so the new section can be moved in and lowered into place.