How Many Ratchet Straps Do You Need?
To determine how many ratchet straps you need, you must know some key information about what you are trying to secure. Weight and length of the cargo are crucial in determining the number of straps needed. Also critical is the working load limit of your strap assembly.
Working Load Limit (WLL) is the maximum load a component or assembly should be subjected to during routine use. These values apply to new products in normal working conditions and are marked by the manufacturer on the synthetic web tie down assembly or other cargo securement system.
U.S. Department of Transportation regulations subchapter B-Motor Carrier Safety Regulations, 49 CFR, Part 393, Paragraph 393.102(b) requires that: "The aggregate working load limit of the tie down assemblies used to secure an article against movement in any direction must be at least 1/2 times the weight of that article."
Example of Working Load Limit and Determining Tie Downs Needed
In the above example only the weight of the object is in consideration. Other factors also determine the number and location of tie downs.
Blocked or Not
If an article of cargo is not blocked:
If an article of cargo is blocked or positioned to prevent forward movement: