2.2 Vertical, choker and basket

1 The definitions, verbatim

• Vertical hitch — "a method of supporting a load by a single, vertical part or leg of the sling."
• Choker hitch — "a sling configuration with one end of the sling passing under the load and through an end attachment, handle or eye on the other end."
• Basket hitch — "a sling configuration whereby the sling is passed under the load and has both ends, end attachments, eyes or handles on the hook or a single master link."

Those are the only three the standard names. Everything else on a jobsite — double wrap, double basket, bridle, choke with a softener — is a variation whose rating comes from the sling's tag or from the manufacturer, not from arithmetic on one of these three.

2 What each hitch does to the rating

The middle column is a shape, not a number to rig by. What you rig by is the marking, which 1926.251(c)(16) requires to state the rated capacity "for the type(s) of hitch(es) used and the angle upon which it is based." One sling, several numbers, and the largest one is the easiest to read by accident.

3 The choker, and the 120-degree rule

A choker grips. That is the point of it — it is what stops a bundle of pipe from rolling out — and it is also why its rating is below a vertical hitch on the same sling. OSHA's Figure N-184-4 explains the mechanism in the legend itself: the symbol at the choker contact point "represents a load in a choker hitch and illustrates the rotary force on the load and/or the slippage of the rope in contact with the load," and adds that the diameter of curvature of the load surface "shall be at least double the diameter of the rope." The sling is turning hard, sliding against the load, and being crushed against it, all while carrying the weight.

Then comes the rule that catches experienced riggers. The choker column in OSHA's rated-load tables applies only "provided that the angle of the choke is 120 degrees or greater." Cinch a sling hard around a narrow load and you go under that angle immediately.

Read the bottom row against the top of the chapter: a hard choke can cost half of a rating that was already below the vertical figure most people quote. And keep hands clear while it tightens — 1926.251(c)(10) and 1910.184(c)(10) prohibit placing hands or fingers between the sling and the load while the sling is being tightened around it.

4 The basket, and its two conditions

Run the sling under the load and put both eyes on the hook, and two parts of the sling carry the weight instead of one. That is why the vertical basket column in OSHA's published wire rope tables is twice the vertical column. It is the cheapest capacity available on a jobsite, and it is conditional.

1. 1
   The legs must be near vertical. Figure N-184-4's note allows the tolerance and then closes it: "angles 5° or less from the vertical may be considered vertical angles. For slings with legs more than 5° off vertical, the actual angle as shown in Figure N-184-5 must be considered." Spread a basket over a wide load and you are in Part 3's arithmetic.
2. 2
   The bend under the load must be gentle enough. In a basket, the sling body bends, and that is the contact surface Figure N-184-4 marks with its strictest symbol: a diameter of curvature "at least 8 times the diameter of the rope." The published ratings assume far more than the minimum — the general notes on OSHA's wire rope tables read "rated loads based on minimum D/d ratio of 25/1."

And one line from the safe operating practices that belongs here: 1910.184(c)(5) and 1926.251(c)(8) require that slings used in a basket hitch have the loads balanced to prevent slippage. A basket holds by geometry and friction, not by grip. An unbalanced basket does not lean slowly — it dumps.

5 The figure nobody reads: N-184-5

There is a second figure, "Sling Configurations with Angled Legs," and it answers a question crews ask constantly. In its two hitch columns for angled legs, the vertical hitch and the choker hitch are both marked NOT APPLICABLE. Only basket hitches are drawn, with the vertical angle and the horizontal angle marked on the sketch.

That is not an omission. A single leg pulled off vertical is not a vertical hitch any more; it is one leg of a bridle, and its tension follows the sling angle rather than the weight of the load. The same is true of a choker on an angle. If someone asks what the rating is for "a vertical hitch at 45 degrees," the honest answer is that the standard does not recognise the configuration and you are reading the wrong line of the tag.

6 Variations, and where their ratings come from

• Double wrap choker. The sling passes around the load twice before choking. It grips far better, particularly on bundles, and it changes both the bearing and the bend. If a rating for it is not on the tag, it comes from the sling manufacturer.
• Double basket. Two separate baskets under one load, usually to control a long item. Each basket is its own hitch with its own angle; the two do not automatically share equally.
• Basket with the legs choked to the hook. A common improvisation to shorten a leg. It introduces a bend and a bearing point the rating never contemplated.
• Anything with a knot. Prohibited. 1926.251(c)(6) and 1910.184(c)(2) forbid shortening slings with knots or bolts or other makeshift devices, and (c)(3) forbids kinking sling legs.

The pattern is consistent: the further a configuration is from the three named hitches, the more the rating comes from the manufacturer and the less it comes from anything you can work out on the tailgate.