10.5 Rigging Piping, Pipe Spools & Rebar Bundles

10.5 Rigging Piping, Pipe Spools & Rebar Bundles

The NCCER Advanced Rigger written assessment lists "piping materials and rebar" as a Rigging Practices topic, module 38301 Advanced Rigging concludes with "guidance in the rigging and handling of rebar bundles," and module 38102 Rigging Practices expects candidates to "properly attach rigging hardware for routine lifts and pipe lifts."

Pipe and rebar get their own topic because they break the assumptions that work for a machinery skid. They are round, they are smooth, they are flexible, they arrive banded, and their weight is rarely where it looks like it should be.

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Why Round and Bundled Material Is Different

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The Hitch: Two Chokers, Spaced, and Often Double-Wrapped

For bundled pipe, tube, conduit, or rebar the standard arrangement is two choker hitches spaced evenly and set well inboard of the ends, so the bundle cannot see-saw and the hitches cannot slide off. Spacing them too close together makes the bundle unstable; spacing them right at the ends lets material slide out of the middle.

When the material is round, smooth, coated, or free to roll, upgrade to a double-wrap choker: the sling is passed completely around the bundle and then choked. The extra wrap gives full 360-degree circumferential contact, which compresses the bundle and grips it, rather than the single-line contact of a standard choker.

Reminder from Chapter 2: a choker hitch is already limited to about 75% of the sling's vertical rated capacity, and it is further reduced by the choke-angle factor when the angle of choke falls below 120 degrees. A double wrap does not increase capacity — it increases grip.

Never rig to the banding. Shipping bands, strapping, and bundle tie wires are packaging applied to hold material together in transit. They carry no rated load, they are not inspected rigging, and they fail without warning. Slings go around the material itself.

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Weighing a Pipe Spool: A Composite Calculation

A fabricated pipe spool is exactly the kind of composite load Chapter 8 taught you to break into parts:

1. Pipe wall. For standard pipe, use the published weight per linear foot for the nominal size and schedule, multiplied by the length. Wall weight rises steeply with schedule — a Schedule 80 line is far heavier than the same Schedule 40 size.
2. Flanges. Take the catalog weight per flange for the size, class, and facing, and multiply by the count. Class 300 and 600 flanges are dramatically heavier than Class 150.
3. Valves, fittings, and specialties. Use tag or catalog weights. A single large gate valve can outweigh the pipe it sits in.
4. Attachments. Supports, lugs, insulation, cladding, and internal linings.
5. Contents. Water weighs 62.4 lb/ft³, or 8.34 lb per gallon. A large-diameter spool left full after hydrotest can weigh substantially more than the dry steel.

Then find the center of gravity. A valve or a heavy fitting at one end shifts the CG away from the geometric midpoint, so the spool must be rigged with the hook plumb over the CG (Chapter 8) or with a non-symmetrical bridle whose leg tensions are computed by the principle of moments (Section 3.4). Rigging a valved spool as if it were symmetrical is how spools come out of the slings tail-first.

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Rebar Bundles

Rebar bundles behave like a bag of loose sticks that happens to weigh several tons.

• Rig around the bar, not the tie wire. Bundle tie wires exist to keep the bundle together on the truck.
• Two spaced double-wrap chokers are the default. The wrap compresses the bundle so that individual bars cannot slide out of the center as the bundle flexes.
• Control sag. Long bundles deflect under their own weight. Widening the sling spacing helps; a spreader bar or strongback with vertical drops eliminates both the sag and the inward compression a bridle would apply.
• Two taglines, one at each distal end. Long bundles rotate readily and have significant wind sail area.
• Land it flat and land it supported. Set bundles down on dunnage across the full length, never on two point supports that let the bundle bow, and never on top of an existing bundle that can roll.
• Assembled cages and mats need engineered picks. A tied rebar cage has essentially no bending stiffness of its own; it is picked at multiple points from a strongback or spreader system so that it does not fold, and it is often stiffened with temporary bracing before it is lifted.

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Landing, Line of Fire & Edge Protection

• Nobody's hand goes between the bundle and the dunnage. Use push-poles or guide sticks to align a descending bundle (Section 12.3).
• Protect the sling at every edge. A cut pipe end, a raised-face flange, or a rebar bundle corner will cut a synthetic sling through in one lift. Use sleeves, wear pads, corner protectors, or a wire rope or chain sling instead.
• Assume the bundle will roll. Chock or block round material immediately once it is landed, before the slings come off.