Direct vs. Indirect Securement: The Difference That Keeps Your Load on the Trailer

There's a picture every flatbed driver has seen. A coil sitting sideways on a trailer at a rest area. Straps hanging loose. Driver standing there staring at it like the load betrayed him.

It didn't betray him. He didn't know the difference between direct and indirect securement — or he knew the words and skipped the math. Either way, the load told the truth.

Here's the plain version. No textbook talk.

The two ways to hold a load

Direct securement is when one end of your chain or strap hooks to the trailer and the other end hooks directly to the load itself. You're pulling the freight against the direction it wants to move. Direct. Simple.

Indirect securement is when you go over the top of the load — one end hooked to the right side of the trailer, the other end hooked to the left side. The strap or chain never anchors to the freight itself. It holds the load down with pressure and friction.

Both are legal. Both work. But they don't count the same when you add up your holding power, and that's where drivers get hurt:

• A tiedown that runs from the trailer straight to the load itself — direct — counts at half its WLL toward your total.
• A tiedown that passes over, through, or around the load and anchors on the opposite side of the trailer counts at its full WLL.
• A tiedown that goes over the load and comes back to the same side counts at half, same as a direct one.

Direction decides the credit. Remember that and the rest of the math behaves.

The number that matters: WLL

Every strap and chain has a Working Load Limit — the maximum weight it's rated to hold. Not the breaking point. The working limit. You never go above it. Ever.

Now hear this part, because drivers get it wrong: the size alone doesn't set the number. A strap's width or a chain's diameter is not the rating. The rating is what the manufacturer tagged it — and it depends on the chain's grade, the hardware on the ends, and the anchor point it hooks to. Your whole tiedown is only as strong as its lowest-rated piece. A strong chain on a weak anchor is a weak tiedown.

The common gear, by the tags they carry:

• 2-inch strap: 2,000 lbs
• 4-inch strap: 4,000 lbs
• 5/16-inch Grade 70 chain: 4,700 lbs
• 3/8-inch Grade 70 chain: 6,600 lbs
• 1/2-inch Grade 70 chain: 11,300 lbs

And one from my own truck: my 4-inch strap with chain ends — the tag on mine reads 5,400 lbs. That's my strap assembly's manufacturer rating, used in the examples below. It is not a promise that every 4-inch strap on the shelf carries it. Check the tag on yours.

Know your tags the way you know your own phone number.

The math in 30 seconds

Here's the rule that keeps you legal and alive: the total holding power of everything you put on that load — its aggregate WLL — must be at least half the weight of the load. That's the federal floor, §393.106. Not a suggestion — the floor.

Indirect example. A 45,000 lb load needs at least 22,500 lbs of aggregate WLL. Take my 5,400 lb straps, over the top, anchored opposite side to opposite side so each one counts at full value: 5 × 5,400 = 27,000 lbs of aggregate WLL. That clears the aggregate number. Understand what it clears, though — the aggregate math is one requirement, not every requirement. Tiedown count, placement, and the condition of your gear still have to be right before that load is legal, let alone safe.

Direct example. Going direct with 3/8-inch Grade 70 chains on a 47,000 lb load: half the load is 23,500. Each chain is rated 6,600 — but direct counts at half credit, so each one gives you 3,300 toward the total. 23,500 ÷ 3,300 = 7.12. You can't use twelve-hundredths of a chain. Round up. Always round up. Eight chains — giving you 26,400 lbs of aggregate credit — placed to pull against the movement, not just somewhere convenient. And placement is not decoration: which direction each chain restrains, and the other rules that ride along with the count, still matter after the math says yes.

The count has its own rules. Forget the "two in the first ten feet" shortcut — it isn't the law. Under §393.110, for an article that is NOT blocked from moving forward:

• 5 feet or shorter and 1,100 lbs or lighter: at least one tiedown.
• 5 feet or shorter but heavier than 1,100 lbs: two tiedowns.
• Longer than 5 feet, up to and including 10 feet: two tiedowns, whatever it weighs.
• Longer than 10 feet: two, plus one more for every 10 feet — or part of 10 feet — past the first ten.

If the article is blocked from moving forward — headerboard, bulkhead, or other secured cargo up against it — the minimum is different: at least one tiedown for every 10 feet of length, or part of it. Those are federal minimums. Minimums are for passing inspection. Pros do more.

A word on coils, since that's where this started. Metal coils that weigh 5,000 lbs or more — one coil by itself, or a group of them counted together — fall under their own rulebook, §393.120, on top of everything above. Which way the eye faces decides how the coil gets secured, and a coil riding eye-to-the-side needs something under it that keeps it from rolling: timbers, chocks, a cradle. The general math gets you legal on general freight. Coils carry extra law, and they are the last load on earth to freestyle.

What happens when it's wrong

Here's what I won't sugarcoat. A shifted coil doesn't just cost you the load. It costs you the trailer behind you, the car next to you, maybe somebody's life. I've seen what loose freight does at 65 mph. You don't walk away from understanding that unchanged.

Securement failures don't come from one place. They come from wrong WLL math. From not enough tiedowns. From tiedowns placed where they looked good instead of where physics needed them. From worn webbing and tired hardware a driver stopped inspecting. From anchor points that couldn't hold what the strap could. From loads with no blocking, free to walk. From sharp freight cutting an unprotected strap in half. Different causes — one thing in common: every one of them is preventable, and every one of them is free to learn.

That's why the knowledge is free. My WLL reference sheet has every number and both formulas on one page — print it, laminate it, keep it in your door pocket. It costs you nothing, and it's the difference between guessing and knowing.

The sheet tells you what. Doing it right on every load, every time, in the rain, at midnight, when you're tired — that's the system. And the system is coming.

Get the free sheet

Download the free Direct vs. Indirect Securement WLL Reference Sheet here:
https://ghostdog.shop/products/direct-vs-indirect-securement-free-wll-reference-sheet

Get the license. Protect the record. Build the career. — Ghost Dog

Disclaimer

This article is for education only. It explains the federal rules as written in 49 CFR Part 393 at the time of publication. Regulations change, and your carrier's policies may be stricter than the federal minimums. Nothing here replaces the official regulations, formal training, or your own judgment on the road. Always check the current rules and the ratings tagged on your own equipment before you roll.