A one-inch, 3-leg bridle wire rope sling, rigged at a 45° angle, has a capacity of 18 tons. What happens with the addition of a fourth leg?

When a one-inch, 3-leg bridle wire rope sling is rigged at 45 degrees and rated for a capacity of 18 tons, it means that the sling is designed to lift that specific load under optimal conditions. Adding a fourth leg to the rigging configuration results in an increased distribution of the load among the legs but does not automatically increase the overall capacity of the sling beyond the rated capacity when operating at the same angle.

In this case, since the original capacity was based on the three legs being utilized effectively, introducing a fourth leg could mean that the load supported can be impacted by the angle of rigging or potential loading error. However, if the fourth leg does not share load equally (for example, due to differences in lengths or angles), it may not contribute effectively to increasing the load capacity. If the original arrangement was already utilizing the rated capacity, then the additional leg does not add additional lifting capacity, leading to the conclusion that with the fourth leg, the effective carrying capacity of the rigging remains unchanged depending on load distribution.

In this instance, if the addition of the fourth leg leads to uneven load distribution or complications under the same rigging angles, it can effectively result in an inability to bear the load properly,