Tie-downs must be strong enough to secure cargo. Tie-downs' working load limit must be at least half of the total weight of your cargo if you are using two tie-downs, one on each end. If you are using a direct tie-down, which secures the cargo directly to the trailer versus both sides, then the work load limit must be the total weight that you are carrying.
Tie-downs must be free of knots. Any repairs to tie-downs due to damage must be Department of Transportation-approved. Tie-downs must be protected so that there is no rubbing or abrasion of the edges of the tie-downs. Tie-downs must be adjustable so that they can be tightened if and when the items being transported shift or settle. Tie-downs can be made of steel or chain, webbing, wire or cord.
The size and weight of the cargo being transported will dictate the number of tie-downs you will need. For a cargo load of less than 5 feet, one tie-down is adequate as long as it meets the load weight requirement. For loads between 5 and 10 feet, two tie-downs must be used. For every additional 10 feet of cargo, another tie-down is necessary.
While the requirements that the DOT sets are valid in most situations, there are certain situations that have special requirements. Some of the items that are affected include the transportation of automobiles, logs, paper rolls, pipes and tubing. For example, a minimum of one tie-down at each end and one to three more along the length of a cargo of logs is required based upon the length of the logs and the number of logs. For logs that stack more than 48 inches above the bunks, or walls, of the flatbed, two more tie-downs are required. Exceptions are typically made for items that are oddly shaped, such as logs and pipes.
