Load securement in the United States: what 49 CFR 393 Subpart I and 392.9 say

This page reports what the official source says. It is not legal advice: ask the office named here. The text comes from the Electronic Code of Federal Regulations (eCFR), the Federal Motor Carrier Safety Administration rules in Title 49. It describes what the sections say and does not teach how to load, strap or chain anything. Any state road rules on top of these are on the pages for each state, for example under trucks and trailers for tree work.

Who the rules cover

Section 393.100 says the cargo rules in Subpart I apply to trucks, truck tractors, semitrailers, full trailers and pole trailers. It sets two aims in plain terms. A commercial motor vehicle carrying cargo on public roads must be loaded and equipped, and the cargo secured, so that nothing leaks, spills, blows or falls off. Cargo must also be contained, immobilized or secured so that it does not shift on or within the vehicle to the point that stability or maneuverability suffers. See eCFR 393.100 on applicability and general requirements.

The general rules for any article of cargo

Strength of the devices

Section 393.102 sets the performance test for tiedowns and other fastening devices. The forces on a device may not exceed its breaking strength rating under three conditions applied separately: 0.8 g of forward deceleration, 0.5 g of rearward acceleration and 0.5 g of sideways acceleration. Working load limits are tested at lower figures: 0.435 g forward, 0.5 g rearward and 0.25 g sideways. For an article that is not fully inside the structure of the vehicle, the section also asks for a downward force equal to at least 20 percent of the article's weight.

Tiedowns, working load limit and count

Section 393.104 says damaged or weakened tiedowns, anchor points and vehicle structures may not be used, and it names cracks and cuts as examples that reduce the working load limit.
Section 393.106(d) says the combined working load limit of the tiedowns holding an article or group of articles must be at least one-half times the weight of the cargo. It explains how each tiedown counts toward the total depending on how it runs between anchor points.
Section 393.108 says a tiedown's working load limit is the lowest of its parts, or of the anchor points it hooks to. It also says an unmarked chain is treated as grade 30 proof coil chain, and that unmarked synthetic cordage is treated as polypropylene rope.
Section 393.110 sets a minimum count for an article that is not blocked from moving forward. One tiedown covers an article of 5 feet or less and 1,100 pounds or less. Two cover an article of 5 feet or less over 1,100 pounds, or one longer than 5 feet up to 10 feet. Over 10 feet, it adds one tiedown for every 10 feet of length or fraction beyond the first 10.

The commodity rules in sections 393.116 to 393.136 take precedence over the general rule where they add requirements for a listed commodity, according to 393.106(a). See eCFR Subpart I on protection against shifting and falling cargo.

Commodity sections that touch tree work

Section	Cargo	What it says
393.116(a)(3)	Firewood, stumps, log debris and other short logs	Carried in a vehicle or container enclosed on both sides, front and rear, and strong enough to contain them
393.116(a)(2)	Loads of no more than four processed logs	May follow the general rules in 393.100 to 393.114
393.116(b)(1)	Logs	Carried on a vehicle designed, built or adapted for logs, with bunks, bolsters, stakes or standards that cradle them
393.116(b)(4)	A stack of logs on a frame or flatbed with bunks, bolsters or stakes	Tiedowns with an aggregate working load limit of at least one-sixth of the stack's weight
393.128	Automobiles, light trucks and vans of 10,000 pounds or less each	Restrained at front and rear with at least two tiedowns
393.130	Wheeled or tracked heavy equipment of 10,000 pounds or more each	Accessory equipment fully lowered and secured; restrained in four directions with at least four tiedowns; articulated machines restrained against articulating
393.134	Roll-on/roll-off and hook lift containers	Blocked forward, secured at front and at the rear, with rear fastenings within 2 meters (6 feet 7 inches) of the rear of the container

Section 393.130 names front end loaders, bulldozers, tractors and power shovels as examples of the heavy equipment it covers, and it says lighter machines may follow 393.130, 393.128 or the general rules. See eCFR 393.130 on heavy vehicles, equipment and machinery and eCFR 393.116 on logs.

The driver's duty under 392.9

Section 392.9 is in the driving rules, Part 392. Paragraph (a) says a driver may not operate a commercial motor vehicle, and a motor carrier may not require or permit it, unless the cargo is properly distributed and adequately secured as 393.100 to 393.136 specify. It adds that the tailgate, tailboard, doors, tarpaulins, spare tire and the means of fastening cargo must be secured. It also says cargo or any other object may not block the driver's view ahead or to the sides, get in the way of the driver's arms or legs, block access to emergency accessories or stop anyone leaving the cab.

For trucks and truck tractors, paragraph (b) says the driver must:

assure himself or herself that paragraph (a) has been met before driving;
inspect the cargo and securement devices within the first 50 miles after beginning a trip and make any adjustments the section calls for;
re-examine the cargo and devices during the trip whenever the driver changes duty status, the vehicle has been driven for 3 hours, or it has been driven for 150 miles, whichever comes first.

The section does not apply to the driver of a sealed vehicle ordered not to open it, or to a vehicle loaded so that inspecting the cargo is impracticable. See eCFR 392.9 on inspection of cargo and securement devices.

At a glance

Item	What the sections say
Tiedown strength, general cargo	Aggregate working load limit of at least one-half the cargo weight (393.106)
Tiedown strength, logs on bunks or stakes	Aggregate working load limit of at least one-sixth of the stack weight (393.116)
First re-check	Within the first 50 miles of a trip (392.9)
Later re-checks	Duty status change, 3 hours, or 150 miles, whichever comes first (392.9)
Wheeled or tracked machine of 10,000 pounds or more	At least four tiedowns (393.130)
Firewood and short logs	Enclosed on both sides, front and rear (393.116)

Section 393.100(b) words the duty for each commercial motor vehicle carrying cargo on public roads. Whether a particular truck counts as one is a question for the federal or state office named in the sources.