Pre-use inspection of a chain sling focuses on the integrity of all load‑bearing components and the identification marks. The best choice reflects checking every critical part: the chain itself for wear, elongation, corrosion, and any bent or twisted links; the hooks for cracks and openings (and to ensure the latches, if present, function properly); the tags to confirm rated capacity and service information; and pins and other hardware to ensure they’re secure and not loose or damaged. This combination covers structural condition, secure attachment points, and proper documentation, all of which are essential for safe lifting. The other options are incomplete: checking only length misses wear and damage; checking only color doesn’t assess structural integrity; and focusing only on hooks neglects chain condition, tags, and hardware security.

When a non-rotating rope is used in a wedge socket, the key issue to prevent is core slippage. The wedge socket relies on the rope being gripped and the load being transferred through the rope's internal structure. If the rope’s core slides relative to the outer fibers under load, the load path becomes unreliable, reducing strength and risking failure at the socket. To avoid this, ensure proper seating, compatibility between rope construction and the wedge, and correct assembly so the core remains engaged with the outer strands. While surface abrasion, bending fatigue, or pinching can be concerns in other scenarios, they do not address the primary failure mode here.

Fleet angle is the angular relationship you must align as the hoist line enters a guiding sheave. It describes the angle between the rope’s direction entering the sheave and the centerline of the rope path (or crane structure) it follows. Keeping this angle properly aligned ensures the rope sits correctly in the sheave groove, distributes loading evenly, and minimizes side loading, wear, and binding as the rope changes direction. This term is the standard way to describe this specific alignment in rigging and hoisting. Other terms like azimuth refer to broad horizontal direction, while rope angle or radial angle aren’t the conventional terms used for this situation.

When two slings share a load, the vertical components of their tensions must add up to the load weight. If each sling makes an angle θ with the horizontal, and the tension in each sling is T, then the vertical component of each tension is T sin θ, and the total vertical support is 2 T sin θ = W. To have the load in each sling equal to the load’s weight, set the sling tension equal to W (T = W). Plugging in gives W = 2 W sin θ, so sin θ = 1/2, which yields θ = 30 degrees. So at 30 degrees to the horizontal, each sling carries a tension equal to the load’s weight. If the angle is larger, each sling’s tension is less; if smaller, each sling’s tension is greater.