Working load limit, tiedowns, and the math
Federal cargo securement rules under 49 CFR Part 393 require that the total working load limit (WLL) of all tiedowns securing an article of cargo be at least one-half the weight of the article. WLL is a property of each individual tiedown, marked on the tag, and represents the manufacturer's rated capacity for normal use — not the breaking strength.
The minimum number of tiedowns required scales with cargo length and weight: one tiedown for articles five feet or shorter weighing one thousand one hundred pounds or less; two tiedowns for articles longer than five feet or heavier than one thousand one hundred pounds; and an additional tiedown for every ten feet of length beyond ten feet.
Special cargo categories
Logs, dressed lumber, metal coils, paper rolls, concrete pipes, intermodal containers, automobiles, large boulders, and flattened or crushed vehicles each have their own dedicated securement subpart in Part 393. Test questions often hinge on whether you remember that, for example, metal coils transported with eyes vertical require chocks or wedges in addition to tiedowns, or that concrete pipes must be loaded with their lengths perpendicular to the centerline of the vehicle.
Inspection cadence
You must inspect your cargo and securement devices within the first fifty miles of a trip and then at every change of duty status, every three hours, or every one hundred fifty miles, whichever comes first. The CDL exam will test whether you know this cadence — and whether you understand the exception that applies to sealed loads and certain placarded hazmat shipments.
For drivers preparing for Cargo Securement Fundamentals, additional context — including federal manual excerpts, employer hiring practices, and DOT medical guidance — is widely available from industry resources. Continue reading on a recommended industry resource for further detail. Always cross-check anything you read with the current edition of your state CDL manual, since enforcement guidance is updated periodically.