Interpretation ID: 3141o
Specifications Manager
Indiana Mills & Manufacturing, Inc.
18881 U.S. 31 North
Westfield, IN 46074
Dear Mr. Lawler:
This responds to your request for an interpretation of Standard No. 208, Occupant Crash Protection (49 CFR /571.208). Specifically, you noted that a final rule published July 6, 1988 (53 FR 25337) upgrades the safety belt requirements for heavy vehicles manufactured on or after September 1, 1990. One of the new requirements for those safety belts is that, if an automatic locking retractor (ALR) is used, that retractor "shall not retract webbing to the next locking position until at least 3/4 inch of webbing has moved into the retractor." Standard No. 208 sets forth this requirement in section S4.3.2.2 for trucks and multipurpose passenger vehicles with a gross vehicle weight rating of more than 10,000 pounds, and in section S4.4.2.2 for buses. You asked whether an ALR that depended on a mechanism external to the retractor itself to prevent it from retracting webbing to the next locking position would comply with S4.3.2.2 and S4.4.2.2. The answer to your question is no.
The agency explained in detail the reasons why the final rule did not adopt the proposed requirement for all heavy vehicle safety belts to be equipped with emergency locking retractors only; see 53 FR 25338-25340. The proposed prohibition of ALR's in heavy vehicles was based on the tendency of current designs of ALR's to become progressively tighter around an occupant as the vehicle travels over potholes or other jarring surfaces of the road. However, NHTSA acknowledged in the final rule that some newer designs of ALR's do not exhibit this tendency. In response to these newer designs of ALR's, the agency said:
Therefore, this rule has been expanded from the proposal, in order to permit ALR's with anti-cinch capability to be installed in heavy vehicles. For the purposes of this rule, anti-cinch capability is determined by examining the working of the retractor after it has locked after the initial adjustment of the safety belt. 53 FR 25339. This language explicitly states that the "working of the retractor" is what determines whether an ALR on a heavy vehicle belt complies with the requirements of Standard No. 208. Since the focus is exclusively on the "working of the retractor," an ALR must comply with these requirements without depending upon any external mechanisms to assist it. Any ALR that cannot satisfy these requirements without the assistance of external mechanisms would not comply with Standard No. 208's requirements for ALR's on heavy vehicles.
This conclusion is reinforced by the agency's statement that:
"NHTSA believes it is appropriate to measure compliance with this new 3/4 inch minimum webbing travel requirement for ALR's in Standard No. 208 under the same conditions currently specified for determining compliance with the existing 1-inch maximum webbing travel requirement for ALR's in Standard No. 209." 53 FR 25340.
The 1-inch maximum webbing travel requirement for ALR's is set forth in section S4.3(i) of Standard No. 209. Since Standard No. 209 became effective in 1968, the agency has determined whether ALR's comply with this requirement by examining the performance of the retractor itself without any assistance from external mechanisms. As explained in the final rule, the same procedure (examining the performance of the retractor itself without any assistance from external mechanisms) will be used to measure compliance with the minimum webbing travel requirements in Standard No. 208.
In your letter, you requested that we issue an interpretation that any ALR that complies with Standard No. 209 can rely on the use of an external mechanism, such as your company's "Komfort-Lok," to comply with the minimum webbing travel requirements of Standard No. 208 for ALR's on safety belts in heavy vehicles. I cannot do so, for the reasons explained above. Any ALR used on a heavy vehicle safety belt must satisfy the minimum webbing travel requirements in Standard No. 208 by the working of the retractor itself, without the use of any external mechanisms.
Sincerely,
Erika Z. Jones Chief Counsel
ref:208#209 d:ll/l/88