Effective December 26, 2002, the U.S. Department of Transportation's Federal Motor Carrier Safety Administration (FMCSA) has issued a final tie-down rule affecting concrete producers who deliver their product. While it specifically exempts ready mixed concrete, the latest ruling contains a new section for concrete pipe, allowing motor carriers until January 1, 2004, to comply with the new requirements.

The FMCSA bases these rules upon the North American Cargo Securement Standard Model Regulations. The changes comprise replacement of section 392.9, concerning driver inspection of cargo and cargo securement, and 393.100 through 393.106 relating to cargo securement methods. New definitions are also adopted in 393.5 to clarify aggregate working load limit, working load limit, and other terms.

Key definitions in the latest version of the tie-down regulations include:

• Aggregate working load limit: The summation of the working load limits or restraining capacity of all devices used to secure an article of cargo on a vehicle
• Blocking: May be one or more pieces placed symmetrically about the center of a pipe
• Tiedown: A combination of securing devices attached to anchor points that forms an assembly to attach articles of cargo to or restrain articles of cargo on a vehicle or trailer
• Working load limit (WLL): The maximum load that may be applied to a component of a cargo securement system during normal service, usually assigned by the components manufacturer

Section 392.9 includes a change requiring drivers to inspect the cargo and tie-down equipment within the first 50 miles rather than the first 25 miles. To meet the requirements, therefore, a road inspection need not be performed for cargo delivered within 50 miles. For cargo delivered beyond 50 miles, the driver must conduct an inspection between 25 and 50 miles. A second inspection remains at three hours of travel or 150 miles, whichever comes first.

According to new performance criteria for tiedown equipment, cargo securement systems must be capable of withstanding the following three forces applied separately:

.8 g deceleration in the forward direction

.5 g deceleration in the rearward direction

.5 g acceleration in a lateral direction

“Structural integrity of tiedown equipment” is reworded to specify that all tiedown equipment and tie-down points must be in proper working order with no damaged or weakened components that could adversely affect their performance. Included is an update of the reference to the National Association of Chain Manufacturers (NACM) Welded Steel Chain Specifications from June 15, 1990, to the November 15, 1999 version. Some working load limits vary slightly, although working load limits are now included for a new grade of alloy chain, grade 100.

Section 393.106 still requires the same header-board strength requirements, although the revised rule addresses header boards that have the cargo in contact with the header board during transport.

Section 393.124. What are the rules for securing concrete pipe? Noteworthy is the fact that the new tiedown regulation is almost identical to that recommended in Concrete Products some five years ago. The provision does not require the de-icing of concrete pipe for delivery during icy weather. A summary of the new section follows:

(a) Applicability: This section applies to the delivery of concrete pipe “on flatbed trailers, vehicles, and lowboys.” The tiedown requirements for pipe must meet the provisions of 393.100 through 393.114.

(b) General specifications for tiedowns: The aggregate working load limit of all tiedowns must be at least half the total weight of load. A load of pipe is considered a group of pipe when individual members are secured together by means of a transverse tiedown through a pipe or an upper tier or over longitudinal tiedowns.

(c) Blocking: One block must extend at least half the distance from the center to each end of the pipe; and two blocks must be placed on the opposite side, one at each end of the pipe, and secured from movement. Timber blocking must be at least 4 ∞ 6 inches.

(d) Arranging the load: Pipe of different diameter must be secured in separate groups of like diameter. The bottom tier of a load must extend the full length of the vehicle, or as a partial tier in one group or two groups. Each successive tier of pipe must extend the full length of the wells created by the lower pipe before an upper tier may be started.

Bell pipe must be loaded on at least two longitudinal spacers of sufficient height to ensure that the bell is clear of the deck. Bell pipe loaded in one tier must have the bells alternating on opposite sides of the vehicle. The ends of consecutive pipe must be staggered, if possible, within the allowable width, or they must be aligned. Bell pipe loaded in more than one tier must have the bottom tier bells all on the same side of the vehicle. Each successive tier must have the bells on the alternate side of the bells on the lower tier. If the second tier is not complete, the lower pipe that do not support an upper pipe must have the bells alternating as in a single tier.

(e) Securing pipe less than 45 inches in diameter: The bottom tier of pipe must be blocked at each end, and in between if preferred, to stabilize against movement. With tiedowns, each pipe must be held firmly in contact with the adjacent pipe to maximize frictional forces between them. At least one tiedown must be secured through the front pipe and angled not more than 45 degrees back to the trailer. At least one must also go through the rear pipe and be angled forward not more than 45 degrees to the deck.

Securing the load then requires either a tiedown through each pipe or a longitudinal tiedown over the whole load. Longitudinal tiedown must be provided by either a ½-in.-diameter chain or wire rope or two ⅜-in.-diameter chains or ropes.

A transverse tiedown is required for every 10 feet of load length. If the first pipe in a group in the top tier is not placed in the first well formed by pipes at the front of the tier, it must be secured with an additional tiedown. The same applies to the last pipe in the top tier.

(f) Securing pipe more than 45 inches in diameter: In addition to the previously stated rules, the front and rear pipe must be immobilized by blocking, wedges, “vehicle end structures,” stakes, locked pipe unloader or other equivalent means. (Pipe placed against the header board must be equipped with blocking to reduce the forward load on the header board during braking.) Each end pipe must have at least one tiedown through the pipe and angled as previously described, “which includes the middle one if there is an odd number, and must run rearward at an angle of not more than 45 degrees with the horizontal, whenever practicable…” At least one tiedown is required through each pipe in the rear half of the load and must run forward as described, especially if the front or rear pipe is not also in contact with vehicle end structure. Each pipe must be blocked or braced as previously described. If only one pipe is transported, it must be tied down and blocked or braced in both directions.

Additionally, unmarked tiedown equipment may continue to be used, despite numerous comments in support of marking all tiedown equipment during the rule-making review period. Unmarked steel chain must be considered to have a working load limit equal to that of grade 30 proof coil. Likewise, other types of unmarked tiedowns must be considered to have a working load limit equal to the lowest rating for that type according to the table of working load limits included in the new rule.

FMCSA promises to make training materials available to the public before the January 1, 2004, compliance deadline.