2.3 Attachment Points and Lift Points

Why Attachment Points Belong in "Scope"

Before you select a sling or shackle, you must know where the gear will connect to the load. On the NCCCO Rigger Level I outline, identifying attachment points (also called lift points) sits inside Scope of the Rigging Activity. That placement is deliberate: attachment choice is part of defining whether a lift is a simple, known configuration—or a problem that needs redesign.

An attachment point is any location on the load intended or used to transfer lifting force into the load structure. Good attachment points are:

• Designed for lifting (not merely convenient holes)
• Located so the load is controlled relative to the center of gravity
• Strong enough for the direction of pull that will actually occur
• Compatible with the hardware you will use
• In serviceable condition on the day of the lift

Designed Lift Points vs Improvised Attachments

Designed / manufacturer-rated lift points

Many machines, skids, transformers, and fabricated assemblies ship with dedicated lift features:

Manufacturer drawings, lift diagrams, and nameplates often show which points to use, how many points, and what orientation is allowed (vertical only vs multi-directional). For Level I work, treating manufacturer lift instructions as part of the "known configuration" is exam-sound and job-sound.

Improvised attachments

Improvised attachment means connecting to a member that was not identified as a lift point—examples include random holes in web members, process piping, handrails, electrical conduit, temporary scaffold lugs, or "that stout-looking angle." Improvisation is a major red flag because:

• Capacity and weld design may be unknown
• The member may deform or tear at far less than sling capacity
• Load path through the structure may damage internal components
• CG control may be accidental rather than planned

Level I rule of judgment: if the lift depends on an improvised point without a known rating or qualified approval, do not treat it as a normal simple lift. Escalate to a qualified person / engineer. Exam answers that endorse chaining to unknown structure "because it looks strong" are wrong.

Number of Points and Sharing the Load

Attachment count and layout determine how weight is shared among legs and fittings.

Common patterns

Important: four points do not automatically mean each leg carries 25 percent of the weight. On a rigid load with a four-leg bridle, two legs can carry most of the load if the load is slightly out of level or CG is offset—unless a below-the-hook device or engineered spreader equalizes share. Level I candidates should recognize unequal sharing as a real risk, not assume perfect division by leg count.

Matching points to CG

Recall from the previous section: the load hangs with CG below the resultant of the supports. Therefore:

1. Place attachment points so the resultant can align above the CG for a controlled hang
2. Prefer manufacturer point sets designed around the known CG
3. If only two points are available and CG is far outside the pair, expect severe tilt—stop and reconfigure
4. Never "fix" a bad point layout by standing on the light end or pushing the load with your body

Integrity of Attachment Points

A designed lug that is damaged is no longer a reliable designed point. Inspect before connecting hardware:

Visual / tactile checks (frequent, practical)

• Cracks at welds, holes, or base metal—especially at high-stress corners
• Bent or deformed lugs, elongated holes, or twisted eyes
• Corrosion / section loss that reduces thickness or blurs edges of holes
• Missing or loose fasteners on bolted padeyes or frames
• Undercut, porosity, or obvious poor welds when welds are visible and suspect
• Painted-over damage or fresh grinding that hides defects
• Modifications—flame-cut holes, added plates of unknown origin, re-welded cracks

If integrity is doubtful, stop. Replacing a sling does not fix a bad lug. The weak link may now be the load itself.

Matching Hardware to Attachment Geometry

Even a perfect lug can be used incorrectly if the hardware does not fit the geometry.

Fit and orientation basics

• Shackle pin and bow: pin should seat fully; bow must have room to articulate without side-loading the lug beyond its design
• Hole diameter: too small → force-fit damage; too large → point loading and odd shackle angles
• Thickness of lug: pin must engage properly; washers or spacers only as appropriate—not as improvisation that reduces capacity
• Direction of pull: many eyebolts are rated primarily for vertical loading along the axis; angular pulls can drastically cut capacity or bend the shank
• Shoulder vs non-shoulder eyebolts: angular loading rules differ—follow manufacturer ratings; when angular load is expected, swivel hoist rings are often the correct designed solution
• Multiple legs into one hole: overcrowding changes angles and can side-load fittings; use hardware rated for the connection (for example, a master link or properly sized shackle arrangement)

Geometry mismatches that fail exams and jobs

Attachment Points and the Known Configuration

Level I simple lifts assume a known rigging configuration. Attachment points are part of that configuration:

• Known which points to use
• Known that those points are appropriate for the lift direction
• Known relationship to weight and CG
• Gear selected to match those points

If the only available holes require a nonstandard multi-directional pull, unknown capacity, or complex below-the-hook tooling not provided in the plan, recognize that you may be leaving the "simple known" envelope. Stopping is a competent rigger skill—not a failure.

Worked Scenarios

Scenario A — Four factory lugs

A skid has four factory lifting lugs marked on the drawing for vertical lifts with a four-leg bridle. All lugs are straight, holes true, welds intact. CG mark is centered. Correct approach: use the four designed points with hardware that fits the holes, confirm leg geometry for the known weight, and keep pulls within the lug design (typically in-plane / as drawn).

Scenario B — Convenient process nozzle

A pump has no accessible lugs because of temporary insulation, but a large process flange looks sturdy. A crew member suggests shackling to the flange bolts. Correct approach: treat the flange as not a designed lift point unless documentation says otherwise. Remove insulation or use the manufacturer lift method; do not improvise on process connections.

Scenario C — Damaged padeye

One of two padeyes shows a visible crack at the weld toe. The other is perfect. Someone proposes a single-leg lift from the good eye because "the load is light." Correct approach: reject the damaged system. A two-point design with one failed point is not automatically safe as a single-point lift—CG, stability, and ratings may not support it. Repair/engineering required.

Scenario D — Hardware mismatch

A rated hoist ring is specified for angular loading on a machine tool. The rigger substitutes a standard eyebolt of similar thread size. Correct approach: substitution is not equivalent. Thread size ≠ lift rating or angular capacity. Use the specified swivel hoist ring or another manufacturer-approved fitting.

Integration With Path and Weight

Attachment decisions feed the rest of Scope:

1. Weight/CG determine how many points you need and where they must sit
2. Attachment integrity determines whether those points are usable today
3. Hardware match determines whether the connection will apply force as designed
4. Path must still clear once the load hangs from those points at its true attitude

Exam Traps for Attachment Points

Master attachment-point identification and you close the Scope triangle with path and weight/CG: know where the load will go, know what it weighs and how it balances, and know exactly where—and how—the gear will connect.