The Federal Department of Transportation oversees interstate shipping and trucking and sets safety standards for commercial trucking. Among these standards are requirements for loads on flatbed trucks that require tie-downs, with the DOT mandating the type of tie-down and manner of securing cargo. Inspectors perform checks at weigh stations to ensure that drivers are meeting these standards.
Federal Motor Carrier Safety Administration Rule 393.106(d) requires that tie-downs be of sufficient strength to secure cargo. When using indirect tie-downs, or tie-downs secured on both ends to the trailer, the tie-downs’ working load limit must be half of the total weight of your cargo. When using direct tie-downs, which secure the cargo to the trailer, the strap's working load limit must be equal to the load you carry.
According to Rule 393.104(f), tie-downs must be free from knots; repaired in DOT approved manner for the type of tie-down; and protected from rubbing or abrasion through the use of edge protection. Each tie-down must be secured in a method that keeps it from coming undone or loosening while in transit. Tie-downs must be adjustable so drivers can tighten them if items settle in transit, as required by Rule 393.112. Tie-downs can be made of steel, chain, webbing, wire rope or cord, as per Rule 393.104(e).
Minimum Number of Tie-Downs
The size and weight of your cargo determines how many tie-downs are required, as defined by Rule 393.110. If your cargo is less than 5 feet long and weighs less than 1,100 pounds, one tie-down is adequate. You must use two tie-downs if you transport an item that’s less than 5 feet long but weighs more than 1,100 pounds or on any item between the length of 5 and 10 feet, regardless of weight. For each additional 10 feet in cargo length, you must use one more tie-down. Thus, a 12-foot load requires three tie-downs and a 22-foot load needs four.
Specific to Cargo
Although the Department of Transportation requirements on securing loads is broad enough to cover most cargo, detailed requirements for special situations including transporting logs, automobiles, rolls of paper, pipe and tubing, boulders, lumber and metal bands.