3.1 Slings, Rigging Hardware, and Inspection Criteria

The domain in one sentence

Domain 2, Rigging and Mobile Equipment, contributes 9 of 115 items and draws on core module 00106 Basic Rigging, 32111 Material Handling and Hand Rigging, and 32112 Mobile and Support Equipment. Nine items is small, but rigging is heavily standardized, so it is the cheapest domain on the exam to convert into points.

Sling types and where each belongs

Inspection: the rule that generates the items

29 CFR 1910.184(d) requires that each day before being used, the sling and all fastenings and attachments be inspected for damage or defects by a competent person designated by the employer, and that damaged or defective slings be immediately removed from service. Additional periodic inspections are required where service conditions warrant, and a record of the most recent thorough inspection is required for alloy steel chain slings.

The removal criteria worth memorizing exactly:

• Wire rope slings — remove for ten randomly distributed broken wires in one rope lay, or five broken wires in one strand in one rope lay. Also remove for kinking, crushing, birdcaging, heat damage, severe corrosion, or end-attachment damage.
• Synthetic web slings — remove for acid or caustic burns, melting or charring of any part of the sling, snags, punctures, tears or cuts, broken or worn stitches, and distortion of fittings.
• Alloy steel chain slings — remove for cracked, bent, gouged, stretched, or twisted links, and whenever the manufacturer's allowable wear is exceeded.
• Every sling must carry the manufacturer's identification and its rated capacity. A sling with an unreadable tag has no rated capacity and comes out of service.

A "rope lay" is the distance along the rope in which one strand makes a complete revolution around the core. Counting broken wires over a longer distance understates the damage.

Rigging hardware

Shackles. Anchor (bow) shackles handle multi-leg loads and side-pull better than chain (D) shackles, which are meant for straight in-line pull. Three rules cover most assessment items:

1. Never side-load a shackle beyond its rating; capacity falls sharply as the pull angle moves off the shackle's axis.
2. Never replace a shackle pin with a bolt. A bolt is not rated, is not the correct diameter, and will bend.
3. Seat a screw-pin shackle fully, then back it off a quarter turn only if the manufacturer instructs; on long-term or vibrating lifts, use a bolt-type shackle with a nut and cotter pin.

Hooks. Every hook used for personnel-adjacent lifting should have a functioning safety latch. Under ASME B30.10 practice, a hook is removed when the throat opening has increased by more than 15% of the original dimension or the hook is twisted more than 10 degrees from the plane of the unbent hook, and for any crack, gouge, or wear exceeding 10% of the original section.

Eyebolts. A plain (non-shouldered) eyebolt is rated for vertical, in-line pull only. A shouldered eyebolt can take an angular pull, but its capacity drops dramatically as the angle increases, and the shoulder must be seated flush against the load. Never rig two legs to a single eyebolt in a way that pulls it sideways.

Turnbuckles, wire rope clips, thimbles. Wire rope clips are installed with the saddle on the live (load) side and the U-bolt on the dead end — "never saddle a dead horse." Thimbles preserve the eye radius and prevent crushing.

Protecting the sling and the load

Sharp corners cut synthetic slings and crush wire rope. Use softeners, corner protectors, or wear pads at every edge. Keep slings off the floor when not in use, store them out of sunlight, and never shorten a sling by knotting it, bolting it, or wrapping it around the hook.