As with so many things in life, it’s the little things that make a big difference. The same holds true of overhead lifting equipment and its operation: paying attention to the small details can have a big impact on the safety and productivity of a facility.
That’s why the Crane Manufacturers Association of America (CMAA), an organization dedicated to promoting the standardization of crane design and operation — as well as uniform quality and performance — works hard to meet its mission. That is, to deliver technical specifications and resources that promote safety in the design, operation, and maintenance of overhead cranes.
Even after poring over those specifications, standards, and resources, owners and operators of cranes often still have questions. Many of those questions surround some of the key details that should be taken into consideration when buying, operating, maintaining, and inspecting overhead lifting equipment.
For that reason, CMAA — along with its partners in MHI’s Overhead Alliance, the Hoist Manufacturers Institute (HMI), and the Monorail Manufacturers Association (MMA) —worked together to develop their latest publication, the Overhead Lifting Best Practices Guide. The document was written in collaboration with Occupational Safety and Health Administration (OSHA).
The Overhead Lifting Best Practices Guide gives owners and operators of overhead lifting equipment a comprehensive, single-source reference about some of the key tools and techniques — including the little details — that contribute to a safer operation. As the current President of CMAA and having worked in the industry myself for 20 years, I have seen the operational safety and productivity benefits that result from following these guidelines and standards. The 18 best-practice topics include:
- Qualifications of overhead crane and hoist operator to ensure that personnel have been properly trained to safely use the equipment.
- Fall protection for crane structures, specifically lifelines and harnesses that have been properly designed to prevent or stop the accidental fall of workers and their tools while working at height.
- Capacity markings on cranes, hoists, and monorails to indicate to an operator the maximum rated load the system was designed to handle.
- Safety signs — such as decals, labels, placards, cord tags, or other markings — indicate hazards and the safety precautions that should be taken to avoid them.
- Audible and visible warning alarms that indicate to the operator and other personnel in the area of the crane’s operation that the equipment is in use.
- Load tests to verify that the equipment will perform all functions (lift, lower, travel the length of the bridge and of the runway) while supporting a test load equal to the maximum rated capacity of the equipment. These are performed at commissioning, after any modifications are made, and during certain inspections.
- Conductor bar systems, specifically bare uninsulated copper wire conductors positioned along the length of a runway to supply power to overhead equipment, and a fourth, unpowered bar for grounding the system.
- Conductor bar guards and how to attach and maintain them so that they prevent inadvertent contact of power wires with hoist ropes, block, or load.
- Upper limit switches are designed to cut off the power automatically at (or near) the maximum limit of travel for a crane motion, such as lift/lower, trolley traverse, or bridge traverse. This prevents damage to the overhead equipment that may result in a load drop.
- E-stops and safety disconnects, their location, accessibility, and how they are to be used to cut off the power to the overhead handling equipment outside of the regular operating controls in the event of an emergency or loss of control.
- E-stops for powered, below-the-hook devices that attach a load to the hook, such as vacuum lifters, electro-magnets, and grippers. These E-stops operate independently of the overall crane system, allowing the operator to disengage the power solely for the below-the-hook device if an emergency or malfunction occurs.
- Runway disconnect switches provide a backup to an E-stop as a second means to disconnect power to the crane if a malfunction or emergency happens.
- Rail sweeps, mounted in front of the wheels on bridge and trolley end trucks, ensure that any debris or obstructions in the travel path are bumped off the railway. They prevent damage to crane wheels, axles, and bearings, as well as stop objects from passing between the rail and wheels, which could cause a derailment.
- Trolley and bridge bumpers made of rubber, polyurethane, springs, or a hydraulic device that minimizes the force of an impact when a trolley or bridge reaches the end of its permitted travel or contacts the rail end stops at a high rate of speed. They prevent structural damage to the crane, runway, and building and should be routinely maintained and inspected.
- Bridge and trolley brakes for slowing, stopping, holding, and controlling motion. Operators should be trained in their proper use. They save wear and tear on the bridge and trolley, as well as prevent a load from running into and damaging equipment or injuring personnel. They should be routinely maintained and inspected.
- Guards for couplings and line shafts, whether fixed or removable, serve as a safety barrier that prevents access to dangerous areas. Any moving parts of a crane or hoist that might pose a hazard during normal operation must be guarded to prevent injury.
- End stops limit trolley or crane bridge travel. Typically mounted to a fixed structure, they prevent damage to the equipment and are designed to engage the full surface of a bumper. They should be maintained and inspected regularly.
- Chain containers capture and store slack hoist chains on the no-load side of the load sheave. Their use is recommended when an excess load chain is likely to interfere with the load or to create a hazard to operations or personnel.
Many of the 18 topics discussed are covered by requirements outside of those from CMAA, HMI, MMA, and OSHA. Pertinent standards from the American Society of Mechanical Engineers (ASME), the American National Standards Institute (ANSI), and the National Electrical Code (NEC) are also included. Each topic has a list of best practices for how to interpret those requirements, as well as how to implement or follow their directions, to create the safest overhead lifting environment possible.
Overhead Lifting Best Practices Guide is offered as a free download. I encourage you to add a copy to your library of resources. If you have any questions about the topics it covers — or about any other best practices in the safe operation and maintenance of your overhead handling equipment and its numerous safety features and devices — don’t hesitate to connect with American Crane. Our online Resources Library includes a collection of informative eBooks, videos, CAD drawings, photos, and a crane glossary.
Can’t find what you’re looking for? Contact us. We’re happy to help.