Assessing the WLL of a Cargo Restraint Device

The 2-Minute Test

If you have any questions on the legitimacy of a working load limit (WLL) rating on your restraint net or traditional tie-down, put it to this simple test.

Take the advertised WLL and multiply by a safety factor of 3 to get the weakest link tensile

(Product WLL) X (Safety Factor of 3) = (Minimum Tensile of Weakest Component)

Look at the assembly, components and product literature. Would each critical component obviously meet this tensile? A critical component is any part of the net whereby failure would cause your load to shift or spill in part or completely.

Critical components might be hooks, webbing, or buckles. Keep in mind: if webbing has been altered in any way (i.e. the inclusion of grommets) the strength of the webbing will be reduced significantly from the reported webbing tensile.

To conclude, if the weakest critical component is not obviously 3 times higher than the advertised product WLL, start asking questions.

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This post was originally published on Feb. 3, 2014, and has since been updated.