You've watched horror stories on the news of wrecks involving an unsecure load. You've probably seen trucks and trailers on the road hauling shaky machinery or hay. Purdue University Extension safety specialist Fred Whitford collects these types of stories.
"Recently, a coil of steel fell off a truck, causing an accident that killed three people,” Whitford says. "State police investigators determined that the tie-downs the driver used were not strong enough [they did not have a high enough working load limit] to anchor the cargo. No doubt, this case will be in litigation for years and the driver may lose everything he owns.”
Then there was the poorly secured 2x4 that flew off a vehicle, almost turning the following driver into a human shish kebab. And the drums of cotton defoliant, secured with flimsy plastic wrap, that tumbled off a trailer, leading to $180,000 in medical costs and more than three years of lawsuits.
Stories like these find their way to Whitford because he gives presentations, to Corn College attendees, for example, about how to properly secure cargo. He wants to keep you from having a load fly off your trailer, damaging property or injuring someone, or being pulled over by a highway patrol for not having a load properly secured.
"[The] rules for securing loads are regulations that make sense,” Whitford says. "They tell us how to figure out what we need to do to keep ourselves, our drivers and other people safe on the road.”
The rules are not difficult to follow, he says. "When you anchor cargo in a truck bed or on a trailer, ask yourself these two questions: How many straps or chains do I need to tie it down? What is the working load limit of those straps or chains?”
The U.S. Department of Transportation has set standards for tie-down assemblies, such as chains, cable, webbing and rope, and for the ratchets, binders, bolts and hooks that are used along with them. (See "Working Load Limits” on previous page.) Manufacturers provide information about the strength of these components.
"Your state may have a few rules of its own,” Whitford notes. "But almost all state rules are the same as those issued by the U.S. Department of Transportation.”
Working load limits. Web straps contain a label identifying the working load limit. "If the tag is missing, the Department of Transportation assumes a working load limit based on the width of the strap—1,000 lb. per inch,” Whitford says.
With chains, the working load limit is determined by the diameter of the links and the grade (30 through 100) of the chain. The grade is stamped at least once on every 12 links. If for some reason the grade isn't marked, it's considered to be Grade 30.
The total working load limit for all the tie-downs must equal half the weight of the secured cargo, Whitford explains. So the next step is to determine how many tie-downs you need.
The number of tie-downs may be influenced by the vehicle configuration, placement of cargo, dunnage (anything not permanently mounted to the truck body or the trailer chassis, such as extra chains) and whether the cargo is blocked or positioned to prevent forward movement.
Items that are transported inside enclosed trailers must be secured the same as on open trailers, Whitford notes. And as for shrink-wrapping—forget it; it counts as nothing toward total load securement.
Inspect before each trip. Just because a tie-down was rated for a certain working load limit when you bought it doesn't mean it still retains that strength.
"Tie-downs must be inspected prior to every use and removed from service when you find defects,” Whitford says.
Many factors—such as bent, cracked or broken links, welds and heat damage—reduce the strength of a chain. "Chains may be repaired, but the repair links must be at least as strong as the chain in which they are used,” Whitford says.
Repair links are graded and marked the same as chain. If there is no marking, they are assumed to be Grade 30. Bolts may not be used as an alternative to repair links.
Wear and abrasion weaken web straps, as do cuts, burns, broken stitching, holes and knotting. "Extremely stiff webbing indicates ultraviolet degradation,” Whitford says. "Each of these conditions warrants retirement of the strap. Defective webbing cannot be repaired.”
More safety tips. You can preserve the strength of your chains through proper handling. "If you use a cheater bar to tighten chain, be sure you don't stretch the chain beyond its working capacity,” Whitford says. "It's a good idea to carry spare chains, just in case one of yours fails an inspection by the Department of Transportation.”
The Department of Transportation also requires that any weakened or damaged tie-down assemblies be removed on the spot.
Safety doesn't end with chains and webbing. It doesn't matter how strong a chain or web strap is if it is connected to a weak anchor point, Whitford points out. "Read the owner's manual or contact the manufacturer of your truck or trailer to learn the working load limit of the anchor points,” he adds.
Don't build your own anchor points by welding pieces of steel to the side of a trailer, Whitford says; your home-made anchor point may not meet strength requirements. If possible, always hook tie-downs inside a trailer's rub rail, so they will be protected in case of an accident.
You can find all this information, and much more, in an 88-page publication compiled by Whitford and several colleagues. To download it or order a copy by mail ($5 plus $3.50 shipping and handling), go to www.btny.purdue.edu/ppp/PPP_pubs.html. Scroll down to "Securing the Load: A Guide to Safe and Legal Transportation of Cargo and Equipment” (PPP-75).
You also will find several other resources that can downloaded for free or ordered for a nominal charge: a "Hold It Down!” poster (PPP-76) that contains tie-down information you can hang in your shop; a pocket-size version of the "Hold It Down!” poster (PPP-84) for each vehicle; and a 76-page "Transporting Farm Equipment” booklet (PPP-83).
Consider the books and posters as critical investments in safety and peace of mind.
How Many Tie-Downs?
Follow these guidelines for cargo not blocked or positioned to prevent movement:
- Articles up to 5' long and 1,100 lb. or less: 1 tie-down
- Articles up to 5' long and more than 1,100 lb.: 2 tie-downs
- Articles between 5' and 10': 2 tie-downs
- Articles longer than 10': 1 tie-down for every 10 linear feet or fraction thereof
You can e-mail Darrell Smith at firstname.lastname@example.org.
- March 2010