The same sling takes different loads depending on how it is rigged. That is why
the marking states more than one value.
SfS BA’s Løfteveilederen covers this in more depth.
Samarbeid for Sikkerhet i Bygg og Anlegg publishes a guide to slinging, with
references to regulations, standards and industry norms, and its own section on
choking and U-lifts. We do not reproduce it here — it is theirs. Go to the source.
Ulike metoder for anhuking av last — Løfteveilederen (Norwegian)
Straight (direct) hitch
The sling runs straight from hook to attachment point. Simplest, most
predictable, and the configuration capacity is normally quoted for. It requires
the load to have attachment points that take the force from the direction it
arrives.
Choke hitch
The sling passes around the load and back through its own eye. It grips the
load and stops it sliding out — useful on round goods, pipe and bundles.
Choking pinches the sling against itself at the choke point, and the capacity
is lower than for a straight hitch. How much lower is on the sling’s marking — not
here. Note too that choking does not stop individual items in a bundle slipping
out.
Basket hitch
The sling passes under the load with both ends in the hook. It shares the load
between two legs, but only if both stand equally steep — at which point everything
under sling angle and force
applies.
A basket hitch does not hold the load. Smooth goods can roll or slide out of the
basket, particularly if it is rigged too open.
What applies to all three
- Read the WLL for the hitch you are actually using — the values differ
- The sling is not twisted, knotted, or joined with a shackle to make it
longer than it is - It seats in the saddle of the hook, never on the tip
- Several slings in one hook must not pinch each other askew
- Edges need protection whatever the hitch — see
edges and protection
The detail per gear type is in the
lifting gear reference.
The capacity is on the sling, not on this page. This section explains the geometry and the method. It states no working load limits and no reduction factors for hitch types — those differ between slings and belong to the equipment's own marking, its certificate, and the assessment made at sakkyndig kontroll. Calculate the force with the calculator; read what the sling will take off the sling. If the two do not agree, the lift does not happen.