The federal cargo securement rules run from section 393.100 to 393.136 of Title 49. That’s a lot of legal reading for something that comes down to one idea: nothing moves, nothing falls off. Here’s the whole thing spelled out, with real numbers, so you know exactly what an officer at a scale house is checking.
01The goal, in the law’s own words
What the rule says
“Each commercial motor vehicle must, when transporting cargo on public roads, be loaded and equipped, and the cargo secured … to prevent the cargo from leaking, spilling, blowing or falling from the motor vehicle.”
49 CFR 393.100(b)–(c)
What it means for you
Two jobs: the load can’t come off, and it can’t shift enough to make the truck handle badly. Everything else in the rules is the “how”.
02How hard your load pushes in a panic stop
What the rule says
“Tiedown assemblies … must be designed, installed, and maintained to ensure that the maximum forces acting on the devices or systems do not exceed the manufacturer’s breaking strength rating under the following conditions, applied separately: (i) 0.8 g deceleration in the forward direction; (ii) 0.5 g acceleration in the rearward direction; and (iii) 0.5 g acceleration in a lateral direction.”
49 CFR 393.102(a)(1)
What it means for you
“0.8 g forward” means: slam the brakes and the load tries to keep going with a force equal to 80% of its own weight. A 20,000-lb load of steel shoves forward with about 16,000 lb. Sideways in a hard swerve, it’s half its weight.
And if the load sits on the deck rather than inside walls, your tie-downs must press it down with at least 20% of its weight (393.102(b)).
03The “half the weight” rule
What the rule says
“The aggregate working load limit of tiedowns used to secure an article or group of articles against movement must be at least one-half times the weight of the article or group of articles.”
49 CFR 393.106(d)
What it means for you
Add up the working load limit (WLL) of every strap and chain on the load. The total must be at least half the load’s weight.
The catch: how you hook it changes what it counts for. A strap that goes over the load from one side of the trailer to the other counts its full WLL. A chain that goes from the trailer straight to the cargo (a “direct” tie-down) counts only half.
WLL is printed on the strap tag or stamped on the chain links. If it isn’t marked, the rules make you use the lowest value in the table (393.108). Unmarked chain is treated as weak grade 30 proof coil. Some common ratings straight from the federal table:
| Tie-down | WLL |
| 4-inch synthetic strap | 4,000 lb |
| 3-inch synthetic strap | 3,000 lb |
| 2-inch synthetic strap | 2,000 lb |
| 3/8-inch grade 70 transport chain | 6,600 lb |
| 5/16-inch grade 70 transport chain | 4,700 lb |
| 3/8-inch grade 30 proof coil (or unmarked) chain | 2,650 lb |
04How many straps, by length
What the rule says
“(1) One tiedown for articles 5 feet (1.52 meters) or less in length, and 1,100 pounds (500 kg) or less in weight; (2) Two tiedowns if the article is: (i) 5 feet … or less in length and more than 1,100 pounds … or (ii) Longer than 5 feet … but less than or equal to 10 feet … irrespective of the weight. (3) Two tiedowns if the article is longer than 10 feet … and one additional tiedown for every 10 feet … of article length, or fraction thereof, beyond the first 10 feet.”
49 CFR 393.110(b)
What it means for you
This rule is on top of the half-the-weight rule. You need enough WLL and enough straps.
“Or fraction thereof” matters: a 21-foot load isn’t 2 + 1. The extra 11 feet is one full 10 and a fraction, so it’s 2 + 2.
If the front of the load is blocked by a headerboard or bulkhead, the count drops to one tie-down per 10 feet (or fraction) of length (393.110(c)).
| First 10 feet | 2 tie-downs |
| Next 14 feet (one 10 + a fraction) | + 2 tie-downs |
| Minimum by length | 4 tie-downs |
| WLL needed (half of 12,000 lb) | 6,000 lb |
| 4 × 4-inch straps over the top, side to side | 4 × 4,000 = 16,000 lb ✓ |
05Machinery and equipment
What the rule says
“Accessory equipment, such as hydraulic shovels, must be completely lowered and secured to the vehicle. … Articulated vehicles shall be restrained in a manner that prevents articulation while in transit. … heavy equipment or machinery with crawler tracks or wheels must be restrained against movement in the lateral, forward, rearward, and vertical direction using a minimum of four tiedowns.”
49 CFR 393.130
What it means for you
This applies to wheeled or tracked machines that weigh 10,000 lb or more: loaders, dozers, tractors, excavators.
- Bucket, blade or boom down and chained.
- Loaders that bend in the middle get locked so they can’t.
- At least four tie-downs, as close as practical to the front and rear, or on the machine’s marked tie-down points.
- The half-the-weight rule still applies.
| WLL needed (half of 20,000 lb) | 10,000 lb |
| Plus | bucket lowered and chained down |
| 4 × 3/8" grade 70 chains, trailer to machine (direct, so half value each) | 4 × 3,300 = 13,200 lb ✓ |
06The gear itself
What the rule says
“(1) Tiedowns and securing devices must not contain knots. … (3) Each tiedown must be attached and secured in a manner that prevents it from becoming loose, unfastening, opening or releasing while the vehicle is in transit. (4) Edge protection must be used whenever a tiedown would be subject to abrasion or cutting at the point where it touches an article of cargo.”
49 CFR 393.104(f)
What it means for you
A knotted strap, a cut strap or a cracked hook is out of service, even if the rest of the load is perfect (393.104(b)). Put corner protectors anywhere a strap crosses a sharp edge: steel, block, lumber bundles.
07When you have to check it
What the rule says
“Inspect the cargo and the devices used to secure the cargo within the first 50 miles after beginning a trip … Reexamination and any necessary adjustments must be made whenever— (i) The driver makes a change of his/her duty status; or (ii) The commercial motor vehicle has been driven for 3 hours; or (iii) The commercial motor vehicle has been driven for 150 miles, whichever occurs first.”
49 CFR 392.9(b)
What it means for you
Straps settle and loads shift in the first few miles. Pull over within 50 miles and walk the load. After that: every 3 hours or 150 miles, and every time you stop for fuel, a break or the night.
08If you’re the shipper
None of this is your paperwork, but it’s your freight. Ask your carrier two things: how many tie-downs and what kind, and whether they’ll check the load in the first 50 miles. A driver who answers straight away knows the rules. One who says “it’ll be fine” is the one who loses a bundle on US-60.
Bottom line
Enough strap strength for half the weight, enough straps for the length, machinery chained four ways with the bucket down, and a walk-around at 50 miles. That’s 30 pages of federal law in one sentence.
Need flatbed freight moved by people who know these rules cold? See our flatbed trucking or call 434-394-0605.
Sources
- 49 CFR 393 Subpart I: Protection Against Shifting and Falling Cargo (eCFR)
- 49 CFR 392.9: Inspection of cargo (eCFR)
- FMCSA Driver’s Handbook on Cargo Securement (PDF)
Rules quoted from the official text as of 24 October 2026. Rules change: check the source before you rely on it.