Cargo Securement

What it means

In the U.S. the rules are in 49 CFR Part 393, Subpart I, which covers trucks, truck tractors, semitrailers, full trailers and pole trailers.^[1] Cargo must be "firmly immobilized or secured on or within a vehicle by structures of adequate strength, dunnage or dunnage bags, shoring bars, tiedowns or a combination of these."^[2]

The securement system has to withstand 0.8 g deceleration forward and 0.5 g acceleration rearward and sideways without exceeding its breaking strength. Freight in a sided vehicle such as a dry van can meet that through the walls when each article is in contact with, or close to, a wall or other articles.^[3] When tiedowns are used, their aggregate working load limit must be at least half the weight of the cargo they secure.^[2]

The full rule, applied to a trailer of pallets with tiedown counts, is in cargo securement for palletized freight.

Why it matters

A van loaded tight, wall to wall and nose to tail, can satisfy the rule on its own. Gaps at the doors, partial loads and multi-stop loads usually cannot, and those gaps are where most shifts start.

Example

A 53-ft van carries 18 pallets tight against the nose and a separate group of four near the doors for a second stop. The front group is held by the trailer walls and each other; the rear group needs load bars or straps, because nothing in front of it stops it sliding forward.