Load Securing for Commercial Transport

Cargo that shifts or falls can roll a truck, come through the headache rack into the cab, or land in front of other traffic. Federal rules in 49 CFR Part 393, Subpart I set how cargo must be secured on a commercial vehicle. The driver is responsible for knowing the load is secure, even when someone else loaded it.

This covers the general rules, the equipment, the math and the most common cargo types. Many commodities have their own rules in addition to these. A trailer may also have special rules set by your carrier or the shipper, and those can be stricter than federal law.

What You Will Be Able to Do

• State the forces a securement system must withstand.
• Count the tie-downs a load needs from its length and weight.
• Work out aggregate working load limit, including tie-downs that count at half.
• Inspect tie-downs and pull damaged ones from service.
• Use blocking, bracing, dunnage and friction mats correctly.
• Recheck a load at the required intervals.

What the System Must Withstand

Cargo must stay put under these forces. They are shown as a share of the cargo's weight.

Worked example: a 40,000-pound load must be held against 32,000 pounds of force forward (40,000 x 0.8) and 20,000 pounds to the rear or either side.

Tie-Down Terms

A tie-down is the full assembly of straps, chains or rope and its fittings that holds cargo to the vehicle.

Working load limit (WLL) is the most load a component may carry in normal service. A tie-down's WLL is the lowest rating of any part in it, including the tensioner and the anchor point. A 5,400-pound strap on a 3,000-pound anchor point is a 3,000-pound tie-down.

There are two ways a tie-down can work:

Some people use the words the other way around. The test that matters is the path of the tie-down, because the path decides how much of its WLL counts.

How Many Tie-Downs

The minimum number depends on length, and for short items on weight. This table applies to an article that is not blocked from moving forward by a headerboard, bulkhead or other cargo.

If the article is blocked or braced against forward movement, it needs at least one tie-down for each 10 feet of length, or part of 10 feet.

Worked examples, not blocked:

• A 4-foot crate weighing 900 pounds needs 1 tie-down.
• A 4-foot crate weighing 2,000 pounds needs 2.
• A 15-foot bundle needs 2 for the first 10 feet and 1 for the next 5 feet, so 3.
• A 25-foot bundle needs 2 for the first 10 feet, 1 for the next 10 feet, and 1 for the last 5 feet, so 4.

These are minimums. You also have to meet the WLL rule below, so a heavy article can need more.

Aggregate Working Load Limit

The combined WLL of all tie-downs must be at least half the weight of the article or group of articles. A 10,000-pound machine needs an aggregate WLL of at least 5,000 pounds.

You do not always get to count a tie-down's full rating:

Worked example 1. A 10,000-pound load needs 5,000 pounds aggregate. You run two straps rated 3,300 pounds WLL over the load, from one side of the trailer to the other. Each counts in full: 3,300 + 3,300 = 6,600 pounds. That meets the rule.

Worked example 2. A 20,000-pound machine needs 10,000 pounds aggregate. You use four 3/8-inch Grade 70 chains rated 6,600 pounds, each running from the deck to a tie-down point on the machine. Each counts at half: 4 x 3,300 = 13,200 pounds. That meets the rule. If you had counted them in full, you would not have seen how close the numbers really are.

Tie-Down Equipment

Reading the Rating

Use the rating marked on the tie-down. If it is not marked, federal rules give default values. Two common ones:

Chain with no readable grade counts as Grade 30 proof coil, the weakest default. Marked webbing is treated at its marked value. Using the right rating starts with being able to read it, so keep labels clean, and pull anything you cannot identify from use unless your carrier has approved it.

Straps

Web straps with ratchets are the common choice for general freight. They are light and do not mark the cargo, but they can be cut. Ratchet until snug. Do not over-tighten until the strap or cargo deforms. Tie off the loose tail so it cannot flap.

Chains and Binders

Chain is used on heavy equipment, steel and loads that would cut a strap. Grade 70 transport chain, gold chromate in color, is made for securing loads. It is not for overhead lifting. Lifting calls for alloy chain, such as Grade 80, rated for that purpose.

Steel coils are usually secured with chain because their sharp edges can slice straps. Match the binder and hooks to the chain's size and grade.

Warning: A lever (snap) binder stores a lot of energy. The handle can kick back, or the chain can break and whip with lethal force. Stay out of the snap zone, which is any line the handle or chain could travel. Stand to the side, keep your head out of the path, and push the handle down. Never pull it toward you, and do not use a cheater bar unless the binder maker allows it. Ratchet binders release more slowly and are safer.

Edge Protection

Edge protection is required wherever a tie-down could be cut or worn where it touches the cargo. It must resist abrasion, cutting and crushing. Place it on any sharp corner before you tighten the strap. A cut strap holds nothing.

Inspecting Tie-Downs

Tie-downs and anchor points must be in proper working order, with no damage that weakens them. Knots are not allowed in a tie-down.

Cut a damaged strap in half or tag it so nobody picks it up again. Do not try to repair it unless the maker allows it and it meets the standard.

Blocking, Bracing and Friction

Tie-downs are only part of the system. Cargo must be held by structures of enough strength, dunnage or dunnage bags, shoring bars, tie-downs or a mix of these.

• Blocking is material placed snug against the cargo to stop it sliding, such as timber against a pallet or a wedge at a wheel.
• Bracing uses timber or struts between the cargo and the vehicle to keep it from moving.
• Dunnage is loose material that fills gaps, supports the load and protects surfaces. Dunnage bags are inflated in the gaps between cargo.
• Shoring bars or load bars span the trailer to hold a row in place.
• Friction mats go under cargo to raise friction so it resists sliding. A mat with no rating is assumed to resist movement equal to 50 percent of the weight on it. A mat supplements tie-downs and does not replace them.

Items that can roll must be held by chocks, wedges, a cradle or something equal that cannot come loose in transit. Articles placed side by side and held by tie-downs across the trailer must touch each other or be kept from shifting toward each other.

Headerboards

A headerboard, or headache rack, is the front end structure that protects the driver from forward-moving cargo. It must reach 4 feet above the floor or the height that blocks the cargo, whichever is lower. A structure under 6 feet tall must hold a forward load equal to half the cargo's weight, and one 6 feet or taller must hold 40 percent.

Where the Weight Goes

Put the heaviest items low and centered, slightly forward of the trailer axles. Too much weight at the rear takes weight off the steer axle, can make the trailer sway, and can overload the trailer axles.

Rules for Specific Cargo

Federal rules add specific steps for these loads. Learn the section for what you haul.

Metal Coils

The way you secure a coil depends on which way its eye, the hole through it, is pointing.

Nailed wood blocking alone cannot hold a coil from rolling. Chocks and wedges must be held in place.

Heavy Equipment

• Use at least four tie-downs, placed as close as practical to the front and rear, or at the maker's mounting points.
• Lower and secure all accessories, such as blades and buckets.
• Restrain articulated machines so they cannot bend at the joint.
• Together the tie-downs must stop movement forward, rearward, sideways and up.

Palletized Freight and Vans

In a van, the walls help, but cargo can still shift. Load tight, block or brace the rear of the load, and use load bars or straps to stop a row from sliding. Stretch wrap holds a pallet together. It does not secure the pallet to the trailer. On a reefer, leave airflow channels so the unit can cool the load.

Inspecting the Load on the Road

The rule is in 49 CFR 392.9.

1. Before you leave: Make sure the cargo and all securing devices are in good shape and properly placed.
2. Within the first 50 miles: Stop and inspect the cargo and securing devices. Adjust as needed. Loads settle early, and straps loosen.
3. After that: Recheck whenever you change duty status, or after 3 hours of driving, or after 150 miles, whichever comes first.

If a trailer is sealed and you have been told not to open it, or if it is loaded so that you cannot inspect the cargo, these rechecks do not apply. It still makes sense to look over what you can see, such as the doors and any outside securing devices.

Check again after hard braking or a rough stretch of road. If the truck feels different in the steering or suspension, pull over and look.

Roadside Enforcement

An officer who finds a load not properly secured can write a violation and place the vehicle out of service until it is fixed. Violations go on the driver's and carrier's safety records under FMCSA's Compliance, Safety, Accountability (CSA) program, and fines can follow. The usual violations are too few tie-downs, too little aggregate WLL, damaged equipment, no edge protection, and failure to block the load.

Working Safely on the Load

Securing a load is hard physical work with real injury risks.

• Wear gloves, sturdy boots, eye protection and a high-visibility vest. Add a hard hat where required.
• Use three points of contact on the trailer, and stay away from the deck edge. A flatbed deck is usually more than 4 feet off the ground.
• Throw straps instead of climbing on the load if you can.
• Do not walk on a tarped load, because the tarp hides gaps. Wet or icy decks are very slippery.
• Use fall protection if your carrier or the site requires it.

Tarping

Tarps protect flatbed freight from weather. Lumber tarps are the largest and cover tall loads, steel tarps are shorter for low loads, and smoke tarps cover the front of a load against road grime. Secure the load first, then tarp. Keep lights and reflectors clear, and tie down every edge so nothing can flap. Inspect tarps for holes before use. Tarps are heavy and can catch wind, so practice in good weather with an experienced driver.

Common Mistakes

Check Your Understanding

A 4-foot crate weighs 1,500 pounds and is not blocked. How many tie-downs does it need?

Two. It is 5 feet or less but heavier than 1,100 pounds. It must also meet the rule on aggregate WLL.

You have a 16,000-pound machine and four chains rated 4,700 pounds, each running from the deck straight to a tie-down point on the machine. Is that enough?

Each counts at half, so the aggregate is 4 x 2,350 = 9,400 pounds. The machine needs 8,000 pounds, so that passes on WLL, and four is the minimum count for heavy equipment.

You find a strap with a cut that exposes the inner fibers. It still seems strong. Can you use it?

No. A damaged tie-down must come out of service, because its capacity can no longer be trusted.

You have driven 2 hours and 120 miles since your 50-mile check, and you stop for fuel and log on duty. Do you need to recheck the load?

Yes. A change of duty status triggers a recheck, even though you have not reached 3 hours or 150 miles.

Key Takeaways

• Cargo must withstand 0.8 g forward and 0.5 g rearward and sideways.
• Count tie-downs by length, and for articles 5 feet or under, by weight as well.
• Aggregate WLL must be at least half the cargo weight, and some tie-downs count at half.
• Damaged tie-downs come out of service. Use edge protection wherever a tie-down could be cut.
• Inspect within the first 50 miles, then every 3 hours, 150 miles, or change of duty status.
• Stay out of the snap zone when you use a binder.