When selecting slings, what criteria must be satisfied beyond the safe working load?

Beyond the safe working load (SWL), which is the maximum load a sling is designed to carry, several other criteria must be satisfied when selecting slings, including the sling's material compatibility with the cargo, the environmental conditions, the lifting configuration, and inspection requirements. The sling's material must be compatible with the cargo to prevent damage or contamination. For example, using a wire rope sling on a highly polished surface could cause scratches, while using a synthetic sling on a cargo with sharp edges could lead to cutting or abrasion. The environmental conditions, such as temperature, humidity, and exposure to chemicals, must also be considered. High temperatures can reduce the strength of synthetic slings, while exposure to certain chemicals can degrade both synthetic and wire rope slings. The lifting configuration, including the sling angle and the number of legs, affects the load distribution on each sling leg. As the sling angle increases, the load on each leg also increases, requiring a sling with a higher SWL. Finally, regular inspection is crucial to identify any damage or wear that could compromise the sling's strength. Slings must be inspected before each use and periodically by a qualified person, and any slings that show signs of damage, such as cuts, abrasions, corrosion, or deformation, must be removed from service. Therefore, proper sling selection involves a comprehensive assessment of the cargo characteristics, environmental factors, lifting configuration, and ongoing inspection requirements to ensure a safe and effective lifting operation.