Rigging Fundamentals: Hardware, Terminology, and Standards

Why Rigging Knowledge Matters for Lineworkers

Every time a crew sets a pole, strings a conductor, or lifts a transformer, rigging hardware stands between a controlled lift and a catastrophic drop. Electrical lineworkers work around energized equipment, uneven terrain, and changing weather—conditions that magnify every rigging error. Learning the names, ratings, and governing standards for rigging hardware is not optional background knowledge; it is a core safety competency required on every job site.

Governing Standards

Two parallel sets of rules govern rigging in construction and utility work.

ASME B30 is a family of safety standards published by the American Society of Mechanical Engineers. Each volume—called a subpart—covers a specific category of lifting hardware or equipment. The volumes most relevant to line construction are:

• B30.9 – Slings (wire rope, chain, synthetic web, and round slings)
• B30.10 – Hooks
• B30.26 – Rigging hardware (shackles, eye bolts, swivels, links)

ASME B30 standards define design factors, inspection intervals, removal-from-service criteria, and marking requirements. Employers and equipment manufacturers reference these volumes to set rated capacities.

OSHA 1926 covers construction safety. Subpart H addresses materials handling, storage, use, and disposal, including rigging hardware requirements for construction work. Subpart CC governs cranes and derricks in construction and includes detailed rigging inspection and use requirements that apply when a crane is part of the lift. Always check both the equipment standard and the OSHA construction standard—they work together.

Wire Rope

Wire rope is the most common rigging medium in line construction. It is made of individual steel wires twisted into strands, which are then twisted around a core. The designation (for example, 6×19) tells you the number of strands and the approximate number of wires per strand. Rated capacity depends on rope diameter, construction, and grade. Wire rope must be inspected before each use for broken wires, kinking, bird-caging, corrosion, and damage to the core. A rope showing the removal-from-service criteria in ASME B30.9 must be taken out of service immediately—never use damaged wire rope.

Chain Slings

Alloy steel chain slings handle high-temperature environments and rough, abrasive loads better than synthetic slings. They must be marked with the manufacturer's grade, size, rated capacity, and reach. Only alloy steel chain is approved for overhead lifting—proof-coil or hardware-store chain is never acceptable. Inspect each link for wear, stretch, cracks, and distortion before each use.

Synthetic Web and Round Slings

Synthetic web slings are flat nylon or polyester webbing; round slings enclose polyester yarns in a protective sleeve. Both are lightweight, grip loads without marring surfaces, and conform to irregular shapes. Color-coding systems indicate rated capacity. Synthetic slings must never contact sharp edges without padding, and they must be kept away from heat, chemicals, and ultraviolet exposure. Check tags—if the tag is missing or unreadable, remove the sling from service.

Shackles

Shackles connect sling ends to load attachment points or to each other. Two types appear constantly in line work:

• Screw-pin shackle – the bow or dee is closed with a threaded pin. Quick to rig but the pin can back out under side loading; the pin must be moused (secured with wire) when side loading is possible.
• Bolt-type (safety) shackle – the pin is secured with a nut and cotter pin. Preferred for permanent or semi-permanent rigging where the shackle may rotate.

The rated working load limit (WLL) is stamped or forged on every shackle. Never exceed it.

Hooks

Hooks used in construction lifting must have a functional safety latch unless a latch would create a greater hazard. Swivel hooks allow the load to rotate without twisting the sling. Inspect hooks for cracks, deformation, and throat opening—if the throat has opened more than 15% of its original dimension, remove the hook from service (ASME B30.10).

Eye Bolts and Swivels

Eye bolts are threaded into load attachment points. Shoulder-type eye bolts can accept angular loading; plain shank (no shoulder) eye bolts are rated for straight vertical pull only—angular loading drastically reduces their capacity. Swivels allow the rigging to rotate freely and prevent torque buildup in wire rope. Like all hardware, both must carry legible WLL markings.

Rigging Blocks

A snatch block is a pulley that can be opened on one side so the rope can be inserted without threading an end. It changes the direction of pull and, in a mechanical-advantage system, can reduce the force required. Come-alongs (ratchet lever hoists) are hand-operated chain or wire-rope devices used for tensioning and short-distance pulling—not for sustained overhead lifting of personnel loads. Load binders secure loads on flatbed trailers and are not lifting devices.

Pre-Use Inspection: The Non-Negotiable Step

Before every lift, conduct a documented inspection of all rigging hardware:

1. Check every piece for its legible WLL/rated capacity marking.

2. Inspect for physical damage, deformation, corrosion, or missing components.

3. Verify that the hardware is appropriate for the load weight, lift angle, and environmental conditions.

4. Remove any item that fails inspection and tag it out of service.

Never rely on memory for rated capacities—read the marking on the hardware itself.

NCCER Connection

The NCCER Power Line Worker curriculum includes a dedicated rigging module that reinforces these standards in the context of utility construction. The skills and knowledge you build here map directly to NCCER performance profiles and are verified through the NCCER Registry when you complete your assessment.