Cargo Securement: Tiedown Count and Working Load Limit (2026)

How many tiedowns does a load actually need?

Short answer: Two tests must both pass. 49 CFR 393.110 sets a minimum count by article length and weight — one tiedown up to 5 ft and 1,100 lb, two above either threshold, and one more for every additional 10 ft. 49 CFR 393.106(d) sets a minimum strength: the aggregate working load limit of the tiedowns must be at least half the weight of what they secure. Meeting the count while failing the strength test is the most common securement error there is.

Published August 27, 2026

Cargo securement is arithmetic, and the arithmetic is not hard. What makes it go wrong is that the number printed largest on a strap's packaging is almost never the number the regulation uses. This guide walks the calculation with real figures, for fleet managers, owner-operators, warehouse loaders and anyone who has ever counted straps and hoped.

Why this matters.
A load that shifts does not usually fall off. It moves the vehicle's centre of mass mid-corner, and the driver discovers this at the point where nothing can be done about it. The securement rules are written around measured decelerations, not intuition — and the gap between "looks tight" and "meets the aggregate working load limit" is where the failures live.

The two tests, and why both are mandatory

Behind both sits the performance requirement at 393.102: the securement system must withstand 0.8 g deceleration forward, 0.5 g acceleration rearward, and 0.5 g laterally. Forward is the largest figure because hard braking is the most violent thing that routinely happens to a load.

And 393.106(b) states the general duty plainly: cargo must be "firmly immobilized or secured on or within a vehicle by structures of adequate strength, dunnage or dunnage bags, shoring bars, tiedowns or a combination of these." Tiedowns are one tool among several — a load blocked solidly against the headboard is being secured by structure, and the rules recognise that.

Test one: the minimum count

Two things to hold onto. "Or fraction thereof" rounds up, always — a 21-foot article is not 2.1 increments, it is three. And blocking changes the count: an article braced so it cannot move forward needs fewer tiedowns, which is the regulation acknowledging that structure does the same job as tension.

Test two: the aggregate working load limit — and the number that misleads everyone

Here is where most loads fail on paper despite looking secure.

The rule itself is simple once you have the right inputs: add up the marked WLL of every tiedown securing the article, and that total must be at least half the article's weight. A 6,000 lb load needs an aggregate WLL of at least 3,000 lb.

Worked example: where the count passes and the strength fails

An 8-foot crate weighing 4,000 lb, not blocked against forward movement.

1. Count test. Longer than 5 ft, 10 ft or less → 2 tiedowns minimum under 393.110.
2. Strength test. Aggregate WLL must be at least half of 4,000 lb → 2,000 lb.
3. Now check a real strap. A common 1-inch ratchet strap is advertised at "1,823 lb break strength." That is not its WLL. Its marked working load limit will be a fraction of that figure — commonly around a third for web assemblies, but read the label rather than assuming.
4. Do the arithmetic with the marked figure. If the marked WLL is roughly 600 lb, two straps give an aggregate of about 1,200 lb against a 2,000 lb requirement. The count test passes and the strength test fails. You need four of those straps, or two straps of substantially higher rating.
5. Or change the approach. Block the crate against the headboard and the count requirement drops — but 393.106(d) still applies to whatever tiedowns remain, so blocking reduces the number of straps, not the strength duty on them.

That step-three trap is the entire reason this page exists. A driver who counts two straps on an 8-foot crate has satisfied the requirement they can see and missed the one that governs.

Second worked example: a 22-foot article

A 22-foot steel beam weighing 9,000 lb, not blocked against forward movement. This one exercises the part of 393.110 people get wrong.

1. Start with two. Any article longer than 10 ft begins at two tiedowns.
2. Add for length beyond the first 10 feet. There are 12 feet remaining. That is one full 10-foot increment plus a 2-foot fraction — and fraction thereof rounds up, so it counts as two additional tiedowns, not one.
3. Count test: 2 + 2 = 4 tiedowns minimum. Rounding the 2-foot remainder down to zero would give three, and three is a violation.
4. Strength test. Half of 9,000 lb is 4,500 lb of aggregate working load limit.
5. Reconcile. Four tiedowns satisfy the count. Whether they satisfy the strength test depends entirely on their marked WLL — four straps marked 1,000 lb give 4,000 lb and still fail. You would need higher-rated straps or more of them.

The pattern to internalise: the count test and the strength test are independent, and you must pass both. Neither one implies the other, and the strength test is the one that usually bites.

Commodity rules that override the general schedule

Everything above is the general rule. Part 393 Subpart I also contains commodity-specific sections, and where one applies it governs. Checking this list before doing the arithmetic is the difference between a defensible calculation and a wasted one:

Subpart I also addresses roll-on/roll-off containers and large boulders. Metal coils and paper rolls are the two most frequently mis-secured of these, because both concentrate very large mass in a shape that wants to roll — and both have securement geometry that the general schedule does not describe.

Choosing straps you can actually compute with

Prices are as listed at publication and will drift.

• Everest Premium Ratchet Tie Down, 2 in x 27 ft — states a working load limit as well as a break strength, which is exactly what you want on a spec sheet. Two-inch webbing is the practical choice once loads pass a couple of thousand pounds.
• KJE Ratchet Straps, 4-Pack, 2 in x 15 ft — a four-pack is the sensible unit, because the aggregate calculation usually lands on four rather than two.
• Rhino USA Ratchet Straps, 4-Pack, 1 in x 15 ft — 1-inch webbing, appropriate for lighter articles. Note it is marketed on break strength; use the marked WLL for compliance work.
• Stanley S1007, 1.5 in x 16 ft — states a safe working load directly, which removes the guesswork.
• VEVOR E-Track Tie-Down Rail Kit — for enclosed trailers and vans, where anchor points rather than straps are the limiting factor. An anchorage weaker than the strap makes the strap's rating irrelevant.

That last point generalises: the securement system is only as strong as its weakest element, and the regulation's performance test at 393.102 applies to the system, not to the webbing alone.

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Frequently asked questions about cargo securement

How many tiedowns do I need?

Under 49 CFR 393.110: one for an article 5 ft or less and 1,100 lb or less; two if it is 5 ft or less but heavier than 1,100 lb, or longer than 5 ft up to 10 ft; and for articles longer than 10 ft, two plus one more for every additional 10 ft or fraction thereof. The count is a minimum — the aggregate working load limit test at 393.106(d) can require more.

What is the 50 percent rule?

49 CFR 393.106(d) requires that the aggregate working load limit of the tiedowns securing an article or group of articles be at least one-half times the weight of that article or group. A 6,000 lb load therefore needs an aggregate WLL of at least 3,000 lb.

What is the difference between working load limit and break strength?

Break strength is the force at which the assembly fails. Working load limit is the rated capacity marked by the manufacturer and is the only figure the regulation uses. Packaging usually advertises break strength because it is larger. Never use a break-strength number in the aggregate calculation.

Do I have to count both tiedowns and blocking?

Blocking and bracing change the required count. An article prevented from forward movement needs one tiedown for every 10 ft of length or fraction thereof, rather than the unblocked schedule. The aggregate working load limit duty still applies to whatever tiedowns are used.

What forces does a securement system have to withstand?

Under 49 CFR 393.102, the system must withstand 0.8 g deceleration in the forward direction, 0.5 g acceleration rearward, and 0.5 g acceleration laterally. Forward is highest because hard braking is the most severe routine event.

Does "or fraction thereof" round up?

Yes, always. A 21-foot article counts as three 10-foot increments, not 2.1. Rounding down is a compliance error.

Where do I find a strap's working load limit?

Marked on the assembly itself by the manufacturer, typically on a label sewn to the webbing. If a tiedown carries no marked WLL, you cannot compute a compliant aggregate with it.

Does the anchor point matter?

Very much. The securement system is only as strong as its weakest element, and the performance requirement applies to the system as a whole. A high-rated strap fastened to an under-rated anchor is limited by the anchor.

Do these rules apply to a pickup with a trailer?

The cargo securement rules in Part 393 Subpart I apply to commercial motor vehicles as defined in Part 390. Whether a given pickup-and-trailer combination meets that definition depends principally on weight rating and the nature of the operation, and should be confirmed rather than assumed.

Are there special rules for particular commodities?

Yes. Part 393 Subpart I contains commodity-specific rules — logs, dressed lumber, metal coils, paper rolls, concrete pipe, intermodal containers, vehicles, boulders — and where one applies it governs over the general rules. Check whether your commodity has its own section before relying on the general schedule.

Do metal coils and paper rolls have their own rules?

Yes. Metal coils are covered by 49 CFR 393.120 and paper rolls by 393.122, and where a commodity-specific section applies it governs over the general schedule. Both concentrate large mass in a shape that wants to roll, which is why they get dedicated geometry rather than a strap count.

How do I handle a 22-foot article?

Two tiedowns for the first 10 feet, then one more for every additional 10 feet or fraction thereof. A 22-foot article has 12 feet beyond the first 10, which rounds up to two additional tiedowns — four in total as a minimum count, before the aggregate working load limit test is applied.

How often should straps be inspected?

Before every use, and removed from service on cuts, abrasion, chemical damage, heat glazing, a distorted or cracked ratchet, or an illegible WLL label. An unreadable label is a compliance failure as well as a safety one, because the rating can no longer be demonstrated.

Can I use more tiedowns than the minimum?

Yes, and frequently you must — the aggregate working load limit test regularly demands more straps than the count schedule alone. The minimum count is a floor, not a target.

Does the 50 percent rule apply per article or per load?

To the article or group of articles that the tiedowns secure. Where straps secure a group together, the aggregate is measured against the weight of that group.

What is the most common securement mistake?

Satisfying the count and failing the strength test, usually because a break-strength figure was mistaken for a working load limit. The load looks properly strapped and is not compliant.

Further reading on this site

• DOT emergency equipment requirements — the on-board equipment rules and the two 2026 amendments.
• Warning triangles vs LED flares — what actually counts as a warning device.
• Wheel chock selection guide — securing the vehicle while the load goes on.
• How to wrap a pallet — unit-load stability upstream of the tiedowns.
• Floor marking color code standards — marking the dock where the loading happens.
• Vehicle first aid kits — the rest of the vehicle safety kit.