When synthetic round slings were introduced, the big concern was how to determine if fibers, hidden by the protective jacket, were broken.
At first, many companies and government agencies banned them because the fibers could not be inspected. However, the jacket around the sling has always been made to fit loose. When it became tight or load baring, most likely internal fibers had broken.
Because of the continued resistance of buyers, manufacturers began installing external indicators of fiber failure. One method uses a large fiber that sticks out through the jacket seam. When the fiber isn’t visible, it indicates that too many fibers have broken. Another method is to include a fiber optic thread among the fibers. If a light beam cannot be seen through the fiber, it indicates that the fiber optic cord as well as other fibers have broken.
Our Rigging Equipment Inspector training program includes inspection of synthetic rope slings.
For more information on inspecting synthetic slings, check out SLINGMAX Rigging Solutions.