Hitch Configurations and Tagged Capacities

Hitch Configurations and Tagged Capacities

Rating source before hitch name

A hitch changes how a sling carries load. Before rigging, identify the sling material and construction, read its tag, and find the rated capacity for the intended hitch and any stated angle. The word “basket” or “choker” is not itself a capacity calculation.

Check the supplied load weight and configuration, then verify every sling and attachment exceeds the required stated load. Level I uses the given rating information. Calculating unknown leg tension or engineering a multi-leg bridle belongs to Level II.

Vertical or straight-line hitch

A vertical hitch supports the load with one straight sling leg between the hook and approved attachment. The load should align with the sling and fittings. Avoid twist, side loading, and tip loading. The attachment must prevent the sling from disengaging and must transmit the force into the load.

The sling's tagged vertical WLL controls. Do not double the rating because the sling has two eyes; only one load path is carrying the load in a single vertical hitch.

In the CCO practical, the straight-line hitch is demonstrated as a complete system using the assigned eyebolt, shackle, and web sling. Follow the test fixture and task instructions rather than substituting hardware.

Choker hitch

A choker passes around the load and through an eye or approved fitting so the body tightens. It provides grip but also bends and compresses the sling where it chokes. The rated choker capacity on the tag is normally lower than the same sling's vertical rating, but the exact relationship is not a universal 75% or 80% for every sling.

Capacity and suitability depend on:

• the tag or manufacturer choker rating;
• angle of choke;
• sling material and construction;
• diameter and shape of the load;
• protection at edges;
• location of the choke; and
• whether the body bears on compatible hardware.

Keep the choke point on the sling body as instructed, not on an eye splice, sleeve, fitting, or tag. Position the tag away from the load. A choker must grip without crushing a fragile load or allowing a loose bundle to telescope.

If a shackle is used to form the choke, orient it as the sling and shackle manufacturers specify so motion does not turn a screw pin and the sling bears on a suitable surface.

Basket hitch

A basket passes under the load with both ends supported. The load must be balanced to prevent slipping. Both parts should bear evenly and have compatible angles and bend diameter. A true, symmetric basket may have a tagged rating greater than the sling's vertical rating, but “basket equals exactly 200%” is unsafe when angle, bending, unequal loading, or tag data changes the result.

Prevent the load from rolling out. Cylinders may need a double-wrap basket or another supplied containment method. Protect the sling at contact points. Make sure both eyes fit the hook or collector hardware without crowding or loading the latch.

A single basket does not positively restrain every long load from sliding lengthwise. Follow the supplied arrangement and use tag lines or additional approved control where required.

Double-wrap configurations

A double-wrap choker or basket wraps farther around a cylindrical load or bundle to improve contact and control. It does not automatically increase WLL. The sling tag and manufacturer instructions still govern.

For the CCO Level I practical, double-wrap choker and basket applications must not overlap or cross at the bottom of the load. An overlap of synthetic web or roundsling inside appropriate hardware can be scored correct, but crossing the wraps under the test load is a deficiency. A tag wrapped against the load is incorrect, and more than a half twist in the sling is a scoring deficiency.

In the field, the approved configuration and product instructions control; practical-exam fixture allowances are not universal engineering rules.

Multi-leg bridles

A bridle joins two or more legs at a master link or subassembly. Verify the assembly tag, number of legs, angle basis, and rating for the supplied configuration. Load sharing can be uneven because of center of gravity, attachment geometry, dimensional tolerance, or load flexibility.

Do not assume four legs each carry exactly one-quarter of a rigid load. Do not turn a rule of thumb about two effective legs into a Level I calculation exercise. Use the rated bridle information and lift plan. If load distribution must be determined, a qualified Level II planner or engineer supplies it.

Collector hardware must fit the hook and legs without crowding. Hooks carry load in the bowl; shackles and links load in their intended directions. Every component must be rated for the force assigned in the plan.

Avoid common hitch errors

Reject these choices:

• tying a knot to shorten a sling;
• placing a load on a hook tip or latch;
• leaving a sling twisted;
• dragging a sling into position under tension;
• using an unprotected damaging edge;
• choking over a tag, splice, sleeve, or fitting;
• allowing a basket load to roll or slide;
• loading a sling above its tagged hitch rating; or
• applying a memorized percentage when the tag says otherwise.

Remove slack slowly and observe how the sling seats. Stop if the load tilts unexpectedly, one leg remains slack contrary to the plan, protection moves, hardware binds, or the hitch begins to slip. Correct the arrangement while the load is supported and stable.