ID: aiam2189

Dear Mr. Coffey: This is in response to your request for information concerning method of ensuring the compliance of school buses with the barrier crash test requirements of Federal Motor Vehicle Safety Standard No. 301-75, *Fuel System Integrity*.; Standard No. 301-75, while establishing minimum performance levels does not specify any particular design requirements for school bus fuel systems. A manufacturer is free to design his vehicles in the manner that he believes most appropriate to ensure compliance. To this end, you may find helpful information in a study by Dynamic Science entitled *School Bus Safety Improvement Program*. The NHTSA cannot assure you, however, that following the suggestions contained in the study will guarantee that your school buses will comply with the standard.; The study is filed in the NHTSA's public docket as document numbe 75-03-GR1. Copies may be obtained by writing to:>>>Technical Reference Branch, National Highway Traffic Safety Administration, Room 5108, 400 Seventh Street, S.W., Washington D.C. 20590<<<; You should refer to the following publication numbers: HS 801-615 -616, and -617.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: aiam1409

Dear Mr. Eckhold: This is in reply to your letter of January 24, 1974, asking for a interpretation as to whether a rear lamp assembly design that Ford demonstrated to NHTSA representatives conforms to the location requirements of Standard No. 108. The assembly consists of three units which, from outboard to inboard, as a rear lighting assembly, comprise the tail lamp/stop lamp, backup lamp, and turn signal lamp.; Standard No. 108 specifies that stop lamps, tail lamps, and turn signa lamps be 'as far apart as practicable.' The standard does not specify a minimum separation distance of lamps, a maximum permissible location inboard, or location of one system relative to another. The determination of practicability in lamp spacing is to be made by the vehicle manufacturer, and the agency has generally afforded manufacturers some latitude in this interpretation.; Therefore, the configuration you have described and demonstrated woul not violate Standard No. 108. It should be noted, however, that it would be in conflict with the requirements for rear turn signals and stop lamps as proposed in Docket 69-19, Notice 3.; Sincerely, James B. Gregory, Administrator

ID: aiam0097

Dear Mr. Yamada: Thank you for your letter of July 23, 1968, to Mr. George C. Nield Acting Director, Motor Vehicle Safety Performance Service, concerning the requirements for turn signal and hazard warning signal flashers as specified by Motor Vehicle Safety Standard No. 108.; With certain exceptions, paragraph S3.3 of Standard No. 108 permits th use of combination lamps, reflective devices and items of associated equipment, provided the requirements for each lamp, reflective device and item of associated equipment are met. Therefore, a combination turn signal and hazard warning signal flasher may be used, provided the requirements for each signal (turn and hazard warning) are met.; You are correct in your understanding that Standard No. 108 an basically referenced SAE Standards J590 and J945 do not require operation of the flasher unit with only one signal bulb in the test circuit. The standard test circuit shown in Figure I of SAE Standard J823 indicates a minimum of two signal lamps and one pilot indicator lamp as the lamp load.; Thank you for writing. Sincerely, David A. Fay, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service;

ID: aiam3649

Dear Mr. Miyazawa: This is in reply to your letter of November 23, 1982, to Mr. Elliott o this agency asking whether you may distinguish between U.S. and Japanese-manufactured lighting equipment subject to Federal Standard No. 108 by marking the lenses 'U.S.A. DOT' and 'JAPAN DOT', rspectively (sic).; As you know, the National Highway Traffic Safety Administration has no adopted the SAE standard on equipment marking, J759c. This means that the only marking subject to Standard No. 108 is that which certifies compliance to all applicable Federal motor vehicle safety standards, the DOT symbol. We believe that the intended proximity of the words 'Japan DOT' in your Japanese- manufactured equipment might create the impression that Stanley was certifying compliance to the requirements of the Japanese Ministry of Transport, rather than to those of the U.S. Department of Transportation. Therefore, we suggest that you place the word 'Japan' at the end of the line rather than adjacent to the 'DOT' symbol.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam0315

Dear Mr. Barnett: This is in reply to your letter of February 23, 1971, requesting advic on the acceptability of your regrooving pattern for regrooved tires.; Enclosed is a copy of the Rules and Regulations on regrooved an regroovable tires as it appears in the *Federal Register* published January 24, 1969, under Section 369.7(a)(3) Requirements, 'After regrooving, the new grooves generated into the tread material and any residual original molded tread groove which is at or below the new regrooved groove depth, shall have a minimum of 90 linear inches of tread edges per linear foot of tire circumference.'; There are no measurements on your drawings to assist us in determinin if your zig-zag grooves and the three circumferencial grooves measure 90 linear inches. Three *straight* circumferential grooves would only provide approximately 72 linear inches.; The use of lateral cuts should substantially increase the tread edg measurements, providing the lateral cuts are from shoulder to shoulder to allow unobstructed fluid escape passages as required in Section 369.7(a)(5); Thank you for your interest in tire safety. Francis Armstrong, Director, Office of Standards Enforcement, Moto Vehicle Programs;

ID: aiam1928

Dear Mr. Jones: This is in response to your letter of May 2, 1975, inquiring about th existence of regulations governing the manufacture, design, and on-the-road operation of trailers used to transport fertilizer while hitched to a pickup truck.; The National Highway Traffic Safety Administration has th responsibility of promulgating safety standards that set minimum performance requirements for vehicles manufactured and/or sold in the United States. There are five motor vehicle safety standards that apply to trailers. These standards relate to trailer lighting, tires, and braking systems (Standard No. 106-74, *Brake Hoses* (49 CFR Part 571.106), Standard No. 108, *Lamps, Reflective Devices and Associated Equipment* (49 CFR Part 571.108), Standard No. 116, *Motor Vehicle Brake Fluids* (49 CFR Part 571.116), Standard No. 119, *New Pneumatic Tires for Vehicles Other Than Passenger Cars* (49 CFR Part 571.119), Standard No. 121, *Air Brake Systems* (49 CFR Part 571.121)).; There is no safety standard that applies to the towing of a trailer The use of a safety chain to guard against release of the trailer may, however, be mandated by state law.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: aiam0163

Dear Mr. Hilgendorf: Mr. Frank Coy, Special Assistant to the Under Secretary o Transportation, has asked that I respond to your letter of April 16, 1969, in which you ask whether a station wagon purchased in March of 1968, equipped with two ply tires, violates Federal Motor Vehicle Safety Standard No. 109.; The vehicle you purchased was apparently manufactured prior to April 1 1968, and therefore, it was not required to be equipped with tires conforming to Standard No. 109. However, even if the standard were applicable, because a tire is labeled '2-ply' it is not necessarily a non-conforming tire. Standard No. 109 does not specifically require tires to have a given number of plies. It does require that irrespective of any ply rating tires pass minimum performance tests. As to passenger cars, Standard No. 110 requires that passenger car manufactured after April 1, 1968, (1) must be equipped with tires that comply with Standard No. 109, and (2) the vehicle must not place a load on any of the tires greater than the load capacity of the tire specified in Standard No. 109.; Very truly yours, Howard A. Heffron, Chief Counsel

ID: aiam0620

Dear Mr. Danker: This is in reply to your letter of February 23, 1972, in which you lis information you wish to label on child seats you will manufacture, and ask whether the information as presented will comply with Motor Vehicle Safety Standard No. 213. You state that a label containing the model number, date of manufacture, and the company's name and place of business will be permanently affixed to the product, while a separate legend, containing other information, will be molded on the bottom of the seat in raised letters at least 3/32 inches high.; The labeling scheme you with to use would conform to paragraph S4. ('Labeling') of Standard No. 213, providing, of course, the blank spaces for model number and date of manufacture are appropriately filled in. We would suggest, however, that that part of the molded legend beginning '. . . and there is a minimum of 19 inches vertical clearance between this seating . . .', to the end of that provision be simplified to be more understandable to an ordinary consumer.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: nht88-2.63

TYPE: INTERPRETATION-NHTSA

DATE: 07/08/88 EST

FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA

TO: DONALD FRIEDMAN -- PRESIDENT-LIABILITY RESEARCH, INC.

TITLE: NONE

TEXT: This is a response to your letter dated November 17, 1987, asking whether two child restraint systems you have designed comply with certain requirements of Federal motor vehicle safety standard 213, Child Restraint Systems. You call one system "Cradle S afe," and describe it as an inclined, rear-facing, deformable, vinyl-covered woodfiber board carrier designed to restrain new-born infants from 4.5 to 14 lbs. The second system you call "Premie Cradle," and describe it as a recumbent, rear-facing, defor mable, vinyl-covered woodfiber board carrier designed for premature infants from 4 to 6 lbs.

Your letter assesses the performance attributes of these systems as follows:

"In an accident the baby is oriented and cushioned to avoid injury and ejection by a deformable, energy absorbing 'bed' and 'shell' without harnessing the infant.

The bed and its crushable extensions (wings) cause the infant to rotate and take acceleration forces through its back and limit those applied to the head. After rotation, the infant is cushioned by the collapsing bed."

You state your belief that both systems comply with applicable provisions of Standard 213, but ask for our comment because "the designs are innovative and make the applicability and interpretation of certain paragraphs of the standard not entirely obviou s." To help the agency better understand your products and the methods you used to test performance, you requested that agency staff meet with you, and your colleague, Mr. David Shinn.

On April 12, 1988, a meeting was held with you, Mr. Shinn, and agency staff from the following offices: Chief Counsel, Enforcement, Plans and Policy, Research and Development, Rulemaking, and Traffic Safety

Programs. At that meeting, you and Mr. Shinn presented a video-film showing two sled-tests of your cradle-safe restraint system, one with a NHTSA-specified, 17 pound dummy, and one with an EEC eight pound dummy. In the video film, your child restraint system broke apart in the 30 mph test with the 17 pound dummy, but appeared to maintain its structural integrity when tested with the eight pound dummy. You did not show a sled-test with your "Premie Cradle" product.

By a letter dated June 8, 1988, you informed this agency that you had performed tests of a "modified" Cradle-Safe restraint system, and that this system will contain the NHTSA-specified 17 pound dummy in simulated barrier-impact testing under Standard 21 3. You state further that a restraint system you call "One-ride" also will contain a 17 pound dummy in Standard 213 testing. (You did not address the "One-ride" restraint in your November 17, 1987, correspondence, nor did you present it during the Apri l 12, 1988 meeting.) Your June 8 letter also references a letter of July 22, 1987, addressed to Mr. Val Radovich of this agency; a June 3, 1988 video tape showing a simulated barrier impact test of your Cradle-Safe seat with a 17 pound dummy; and submiss ions of patent documents in support of a patent application for your products.

As NHTSA staff understood from your November 17, 1987 letter, and the April 12, 1988 meeting, your principal question was whether you could test a Standard 213 child restraint system with an eight or 14 pound dummy (rather than the specified 17 pound dum my), if you intended to label the restraint as appropriate for children from 4.5 to 10 pounds. You briefly addressed the other matters raised in your November 17, letter, clarifying a reference to an "unspecified belt provided for use outside the vehicl e and not required in (Standard 213) testing." You explained that the "belt" to which you refer is a two-piece, cloth wrap that anchors at either side of the restraint, and fastens over the child with a velcro attachment.

I shall respond to your comments in the order that you present them in your letter, also discussing new matters raised in the meeting, in the June 8, 1988 letter, and in your other submissions where appropriate. I will not discuss the patent materials b ecause they are not relevant to a determination of whether your restraint systems comply with Standard 213. In responding to your comments, I assume that we are discussing only those child restraint systems designed for children weighing less than 20 po unds (infant restraints).

Your First Comment. Paragraph 5.1.1.a dealing with Child Restraint System Integrity specifies "no complete . . . and no partial separation" of surfaces. Our design is deformable and involves materials of 1/4" thickness which in deforming, tear slight ly. However when torn these materials are not lacerating and not likely to come into contact with the infant.

Response. Paragraph S5.1.1(a) states that when a child restraint is tested as specified in the Standard, the system shall:

Exhibit no complete separation of any load bearing structural element and no partial separation exposing either surfaces with a radius of

less than 1/4 inch or surfaces with protrusions greater than 3/8 inch above the immediate adjacent surrounding contactable surface of any structural element of the system.

If the system failure you describe as tearing of materials at the system surface does not result in a failure of the load-bearing structure of the system, then paragraph S5.1.1(a) is inapplicable. In 1978, NHTSA proposed adding this language to 213 as o ne of a number of amendments to the Standard that would upgrade performance requirements, improve performance criteria, and require dynamic testing of child restraint systems using anthropomorphic test dummies. (43 FR 21470, 21473, May 18, 1978.) In the preamble of that document, we stated that our objectives in promulgating the system integrity requirements were to prevent a child's excessive excursion or ejection from the system, and to ensure that the system does not fracture or separate in such a wa y as to harm the child. (43 FR 21470, 21473.) To accomplish this objective, Standard 213 requires that in dynamic testing, any load-bearing, structural element of a child restraint system must not separate completely; and that any partial separation must not expose surfaces with sharp edges that may contact the child. Id. Your letter states that some materials at the surface of your system may tear during an impact. In promulgating S5.1.1(a), the agency intended to minimize dangers resulting from failures in the structural integrity of the syste m, rather than failures in the materials. The agency did not intend to preclude a manufacturer from designing some deformation into a child restraint system to improve the system's energy absorption performance.

Your Second Comment. Paragraph 5.2.3.2.b The system surface in contact with the infant's head shall be covered with slow recovery, energy absorbing material. Although our system surfaces are not covered, they are fabricated out of such material. Th e system surface in contact with the infants head (the bed) is 3/16" woodfiber separated by air from a similar material in the shell. The system complies with the requirement and when dynamically tested exhibits deformation much better than a 25% compre ssion-deflection, but there is no appropriate ASTM Test Standard such as for open or closed cell foam.

Response. As I read your comment, you raise three issues which I shall address separately. The first is whether the material from which you fabricate your system can meet the S5.2.3.2(b) requirement that a child restraint system must be "covered" with slow recovery, energy absorbing material. The agency's long-standing position is that a given type of surface material is an acceptable "covering" if it is a flexible material that would meet the thickness and performance requirements for energy-absorbi ng padding set out in paragraphs (a) and (b) of S5.2.3.2. The surface needn't have a separate layer of energy-absorbing padding.

The second issue is whether 3/16 inch woodfiber is a sufficient thickness for a system surface. This thickness would not comply with S5.2.3.2(b) of Standard 213. That subparagraph requires thicknesses of at least 1/2 or 3/4 inch, depending on the mater ial's compression-deflection

performance as measured in the static testing specified in S6.3 of Standard 213.

You assert that the 3/16 inch thickness material used in your systems exceeds a 25% compression-deflection measurement in dynamic testing. In the preamble to the final rule amending Standard 213, NHTSA responded to commenters who suggested that specifyi ng a minimum thickness for the infant restraint surface was design-restrictive. (44 FR 72131, 72135, December 13, 1979.) We explained in that document that we set these minimum thickness requirements because there was no available test device to measure the energy absorption properties of either the surface or underlying structure of an infant restraint in dynamic testing. Consequently, the agency specified "long-established static tests" of the surface material, and established minimum thickness requ irements based on the results of those static tests. Therefore, a compression-deflection measurement derived from dynamic testing is not an acceptable test of compliance with paragraph S5.2.3.2.

The third issue is whether the compression-deflection measurement for this system must be derived from tests under one of the ASTM standards in S6.3, even though none of the ASTM titles expressly states that the test is for woodfiber, and all three proce dures are for static tests. Paragraph S5.2.3.2(b) requires that when one tests the energy absorption properties of child restraint materials, those tests must be conducted under one of three ASTM static test procedures set out in paragraph S6.3 of Stand ard 213.

Your restraint systems are made of woodfiber. Woodfiber - or any material that meets the Standard's requirements - can be an acceptable substance out of which to fabricate a child restraint. As NHTSA stated in the final rule preamble cited earlier, the agency wishes to allow restraint manufacturers to use a wide range of materials, provided that the material exhibits acceptable energy absorption properties. You may use any ASTM title specified in paragraph S6.3 to test your surface material, and the material is acceptable if it displays the required energy absorption properties when tested under one of those titles.

Your Third Comment. Paragraph 5.4.3.1 "Each belt that is part of a child restraint system and that is designed to restrain a child using the system..." is interpreted to mean that a soft unspecified belt provided for use outside the vehicle and not r equired in testing, need not conform to this paragraph.

Response. As you explained in the April 12, meeting, the "belt" to which you refer is the cloth device described in the beginning of this letter. By its express terms, paragraph S5.4.3.1 is inapplicable to belts that are (1) not part of the child re straint system and (2) not designed to restrain a child using the system. On the other hand, I note that in the June 8, video tape, the narrative refers to a belt within the Cradle-Safe system as a belt for restraining the child. If you do intend any b elt in the system to be used for restraining the child, then various provisions of paragraph S5.4.3, Belt Restraint, will apply, depending on the design configuration of the belt assembly.

In the preamble to the May 1978 proposal cited earlier in this letter, the agency expressed its continuing concern that child restraint system designs minimize the prospect of system misuse. (43 FR 21470, 21471.) If there are belts in any of your child restraint systems that you do not intend as restraints for the child, then I hope you will consider whether these additional belts unreasonably increase the risk that some users will mistake the additional belt assembly as a Standard 213 belt intended fo r use in restraining a child.

Your Fourth Comment. Paragraph 6. This paragraph requires the CRADLE SAFE to be tested with a paragraph 7 dummy (17 lb.) for which it was not designed and which cannot be physically accommodated. We would prefer to use available 7.8 lb. and/or 14 l b. non-specified dummies. The PREMIE CRADLE falls in the car bed "travel crib" category and does not require dynamic testing.

Response. Paragraph S7.1 of Standard 213 requires testing an infant restraint system with the 6-month-old dummy specified in 49 CFR @ 572.25. (An infant restraint system is one that is recommended "for use by children in a weight range that includes ch ildren weighing not more than 20 pounds.") That test device is 17.4 pounds. Because your child safety system meets the definition of infant restraint, it must be capable of meeting Standard 213 performance requirements when tested with the specified 17. 4 pound dummy. If an infant restraint can not accommodate this test device, then it can not be certified as complying with Standard 213. I understand from your June 8, 1988, letter that the Cradle-Safe and One-Ride systems will accommodate the specifie d 17.4 pound dummy in Standard 213 testing. Further, your restraint systems must meet head excursions limits with the 17.4 pound dummy under paragraph S5.1.3.2, Rear-facing Child Restraint Systems.

The dummy specified in Part 572 is based on a simple design that represents a 6-month-old infant in dimensional, mass distribution, and dynamic response characteristics. NHTSA chose to use this test dummy after conducting extensive testing and evaluatio n of the dummy's responses. The testing, conducted by NHTSA and the Federal Aviation Administration (FAA), showed that the specified dummy provided a consistent and repeatable measure of the structural integrity and confinement properties of a child res traint system, and was superior to a previous test version. (43 FR 21490, May 18, 1978; 44 FR 76527, December 27, 1979.) Before we can sanction use of another device to test an infant restraint system, the agency would have to determine that the dummy i s a reliable surrogate for measuring a system's performance in an actual crash. NHTSA can not now make that statement with respect to any unspecified dummy, instrumented or non-instrumented. The agency can make this kind of finding only through a rulem aking process.

Further, contrary to what you believe, infant car beds are subject to dynamic testing to ensure that the test dummy stays within the confines of the restraint system during impact. (Standard 213, S6.1.2.3.3.)

While you believe you have identified some potential problems with Standard 213, I am sure that you can appreciate the need to follow established procedures when considering any change to a safety standard.

Following established practices helps ensure that child restraint systems which comply with Federal standards continue to offer satisfactory crash protection for children. The agency has scheduled two public meetings this summer in order to explore the need for changes to Standard 213. I enclose a copy of the notice announcing these meetings, and invite you to participate in the forum.

Based on the information you provided, it appears that you would have to modify your systems, or the agency would have to amend Standard 213 in order for you to be able to certify your child restraint system as satisfying all the applicable requirements of that Standard. Title 49 CFR Part 552, Petitions for Rulemaking, Defect, and Noncompliance Orders (copy enclosed) sets out a procedure for petitioning the agency to amend a safety standard, and you have a right to file such a petition. If NHTSA grant s your petition, the agency would follow its normal rulemaking procedures to amend Standard 213.

If you have some further questions or need further information on this subject, please contact Joan Tilghman of my staff at our address, or telephone (202) 366-2992. ENCLOSURES

ID: ACSBcmc

[ ]

Dear [ ]:

This responds to your letter in which you asked about the applicability of Federal motor vehicle safety standards (FMVSSs) to an auxiliary child shoulder belt system (ACSB) for use with belt positioning boosters. Specifically, you ask whether the ACSB would be regulated as a Type 2a shoulder belt or as a child restraint system. As explained below, the ACSB would be regulated as a Type 2a shoulder belt.

Background

Your letter states that the ACSB would be an add-on shoulder belt that would allow the use of belt positioning boosters at seating positions equipped with lap belts only. You state that:

The add-on shoulder belt would be equipped with a standard buckle and length adjustment. It would easily attach to the lap belt buckle, and hook onto the standard top tether anchor for the rear outboard seating position using a standard tether hook.

You also state that the add-on shoulder belt would be recommended for children between 50 and 80 pounds. The add-on shoulder belt would not be originally installed in vehicles but would be provided as an aftermarket product.

By way of background, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under 49 U.S.C. Chapter 301, manufacturers are required to ensure that their vehicles and equipment meet applicable requirements. The following represents our opinion based on the facts you provided in your letter, and addresses some or all of the specific issues you raised. If we have not addressed an issue, you should not assume that we have concurred with a position you have expressed on that issue.

Your letter asks about the applicability of four standards; FMVSS No. 208, Occupant crash protection, FMVSS No. 209, Seat belt assemblies, FMVSS No. 210, Seat belt assembly anchorages, and FMVSS No. 213, Child restraint systems. I have addressed each standard below.

FMVSS Nos. 208 and 210

Your assertion that FMVSS Nos. 208 and 210 would not apply to the ACSB is correct. FMVSS Nos. 208 and 210 apply, with certain exceptions that are not relevant to this product, to vehicles and not directly to items of equipment. Because the ACSB would not be part of the vehicle as manufactured or sold, FMVSS Nos. 208 and 210 would not be applicable. However, please note that any commercial business that would install this product would be subject to the provisions of 49 U.S.C. 30122(b), which provides that:

No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly make inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard.

None of the above named businesses would be able to install this product if installation would cause the vehicle to no longer comply with an FMVSS.[1]

FMVSS No. 209

Under FMVSS No. 209, the add-on shoulder belt would be classified as a Type 2a shoulder belt. Unlike FMVSS Nos. 208 and 210, FMVSS No. 209 is an equipment standard and applies to all seat belt assemblies regardless of whether the seat belts are originally installed in a vehicle or installed after the vehicle has been purchased.

FMVSS No. 209 defines a Type 2a shoulder belt as an "upper torso restraint for use only in conjunction with a lap belt as a Type 2 seat belt assembly."[2] As you state in your letter, this product would provide upper torso restraint and would be intended for use in conjunction with a lap belt only, making it a Type 2a shoulder belt. Type 2a shoulder belts are generally not permitted as original equipment under FMVSS No. 208.[3] However, this general prohibition under FMVSS No. 208 is a vehicle standard and does not prohibit the sale of Type 2a shoulder belts as aftermarket equipment.

You would be required to certify that the ACSB complies with the applicable sections of FMVSS No. 209. Under S4.1(c) of FMVSS No. 209, a Type 2a shoulder belt is required to "comply with applicable requirements for a Type 2 seat belt assembly in S4.1 to S4.4, inclusive." While only those requirements raised by your letter are discussed below, keep in mind that the ACSB would be required to comply with all of the applicable requirements in S4.1 through S4.4.

S4.1 Requirements

S4.1(f) Attachment hardware

Type 2a seat belt assemblies have specific hardware requirements under FMVSS No. 209. However, because of the design and the intended manner of use of the ACSB, it would not be required to provide the attachment hardware specified under S4.1(f) of FMVSS No. 209. S4.1(f) requires that a seat belt assembly must include:

all hardware necessary for installation in a motor vehicle in accordance with Society of Automotive Engineers Recommended Practice J800c, "Motor Vehicle Seat Belt Installation," November 1973. However, seat belt assemblies designed for installation in motor vehicles equipped with seat belt assembly anchorages that do not require anchorage nuts, plates, or washers, need not have such hardware, but shall have 7/16-20 UNF-2A or 1/2-13UNC-2A attachment bolts or equivalent metric hardware.

Because the attachment hardware required under S4.1(f) is needed for permanent installation of the seat belt assembly in a motor vehicle, we interpret S4.1(f) to apply only to seat belt assemblies designed for permanent installation. In this instance, the ACSB is designed to attach to a vehicles existing tether anchorage with the tether hook supplied with the ACSB, allowing for installation when a belt-positioning booster is placed in a seating position that has a lap belt. (The requirements for the tether hook are discussed later in this letter regarding S4.3.) Additionally, in the past we have not required seat belt buckles to comply with requirements that are obviously inapplicable.[4] Because the ACSB is not designed for permanent installation, it would not have to comply with the hardware requirements of S4.1(f) of FMVSS No. 209.

S4.1(g) Adjustment

The add-on system would not have to be certified as complying with the adjustment requirements of S4.1(g) of FMVSS No. 209, which requires Type 2a seat belt assemblies to be capable of fitting up to the dimensions of a 95^th percentile adult male. S4.1(g) contemplates seat belt assemblies that would be permanently installed in motor vehicles. Permanently installed belts need to fit a wide range of occupants. Conversely, the ACSB would be recommended for use only with a booster seat and only for children weighing between 50 and 80 lb. Because of this limited and specific recommended use, the ACSB would not be required to comply with the adjustment requirements of S4.1(g) of FMVSS No. 209. However, as discussed below, the ACSB must be labeled with information about the size of the occupants for whom it is intended.

S4.1(k) Installation instructions and S4.1(l) Usage and maintenance instructions

S4.1(k) and S4.1(l) of FMVSS No. 209 require appropriate installation and use instructions to be provided with the add-on shoulder belt. S4.1(k) requires the ACSB to be accompanied by an instruction sheet providing sufficient information for its proper installation. As such, in this case these instructions would have to including a statement that the assembly is for installation only in motor vehicles with an upper tether attachment point that meets the applicable requirements of FMVSS No. 225. S4.1(l) requires that written instructions on proper use accompany the assembly. Because proper use of the ACSB would only be with a booster seat and only for children up to 80 lb, the instructions would be required to specify as such. Also under S4.1(l), a warning would have to be provided stating that the system is not to be used without a lap belt or by occupants weighing over 80 pounds. In addition, we suggest that you consider placing warning labels on the belt to inform occupants of the weight and use restrictions.

S4.2 Requirements for Webbing

FMVSS No. 209 establishes several requirements for the webbing used in a Type 2a shoulder belt. These include width, strength and elongation requirements.

S4.2(a) Width

S4.2(a) establishes a minimum width for specific portions of webbing in a seat belt assembly, including a Type 2a belt. Seat belt assembly webbing must be a minimum of 46 mm in width, except for portions that do not touch a 95^th percentile adult male. S4.2(a) ensures that belt webbing coming into contact with an occupant spreads the load imposed by the belt in a crash. By requiring webbing to spread rather than concentrate the load, the belt width requirement helps minimize the possibility of webbing-caused injury. The shoulder belt portion of the add-on belt meets the minimum width, but the attachment webbing for the add-on buckle is of narrower width.

You state that the narrower webbing is not intended to apply restraint force to the occupant and is of a short, non-adjustable length. If the narrower webbing would not apply restraint force to the occupant, then the webbing need not meet the minimum width requirement.

S4.2(b) Breaking strength and S4.2(c) Elongation

You state that the ACSB buckle is attached to the lap belt with a short loop of 25 mm wide webbing. You concluded that because the ACSB buckle webbing would be used solely as a loop in the assembly, the strength and elongation requirements should be applied to the webbing as a loop and not to a single piece of webbing. We disagree. After the ACSB buckle is attached to the vehicles lap belt, it would be possible for the ACSB buckle attachment to experience a substantial portion of the loading along a single piece of webbing, not the loop. If the webbing were to break at a point on a single strap, the anchoring could fail. In addition, the load may not be distributed equally across both sections of the loop. One section could experience a higher load than the other. Because of these potential consequences, the strength and elongation requirements of S4.2(b) and S4.2(c) would be applied to a single piece of the ACSB buckle webbing and not to the webbing as a loop.

S4.3 Requirements for Hardware

S4.3(c) Attachment hardware

The tether hook used to anchor the add-on shoulder belt to the tether anchorage at an adjacent seating position would be considered a "quick-disconnect" type of attachment hook under FMVSS No. 209 and would be required to meet certain strength requirements. The tether hook is a single hook and would be capable of quickly connecting to, and disconnecting from, the tether anchorage, which acts as an eye bolt. Under S4.3(c)(3) of FMVSS No. 209, seat belt assemblies having single attachment hooks of the quick-disconnect type for connecting webbing to an eye bolt shall be provided with a retaining latch or keeper ("keeper"). "Keepers" must be certified as not moving more than 2 millimeters (mm) in either the vertical or horizontal position when force is applied as specified in S5.2(c)(3). The "keeper" requirements ensure that the attachment hardware does not disconnect when loaded. Because the tether hook used with the add-on belt would function as a quick-disconnect type of attachment hook for a Type 2a seat belt, the tether hook spring clip would be required to comply with the "keeper" strength requirements under FMVSS No. 209.

FMVSS No. 213

In your letter, you ask if the add-on shoulder belt would be defined as a child restraint system (CRS) under FMVSS No. 213 if it were recommended for children between 40 and 80 lb. Because this assembly would be a Type 2a assembly, it would be excluded from the definition of a CRS. S4 of FMVSS No. 213 defines a CRS as any device, except a Type 1 or Type 2 seat belt, designed for use in a motor vehicle or aircraft to restrain, seat or position children who weigh 50 lb or less.[5] (Emphasis added.) The add-on shoulder belt is intended for use in conjunction with a lap belt. Under the intended use, the entire assembly would provide pelvic and upper torso restraint and function as a Type 2 seat belt assembly. As a component of a Type 2 assembly, this product would not be a CRS under FMVSS No. 213. We note that while the ACSB is currently excluded from the definition of a CRS, Antons Law (Pub. L. No. 107-318; 2002) requires NHTSA to consider whether to include injury performance criteria for booster seats "and other products for use in motor vehicles for the restraint of children weighing more than 50 pounds" under FMVSS No. 213.

In closing, the agency encourages approaches that may increase the use of child restraint systems, provided that the approaches comply with all applicable Federal motor vehicle safety standards and do not compromise the safety of motor vehicle occupants. As with any product that is designed to attach to an existing device on a vehicle, we urge you to consider ways to reduce the likelihood of misuse of the product. Further, the use of an additional buckle on a product used to restrain children could increase the difficulty in releasing the child in an emergency situation. We appreciate your concern in thoroughly considering these and all other safety issues.

If you have any other questions please contact Chris Calamita of my staff at this address or at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

ref:209#213
d.4/8/03





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[1] It is unclear whether additional loading from the ACSB would adversely impact the vehicles existing belt and anchorage systems. You should determine if the ACSB would negatively impact compliance with FMVSS Nos. 208, 210, or 225, Child restraint anchorage systems.

[2] Under FMVSS No. 209 S3, a Type 2 seat belt assembly is a combination of pelvic and upper torso restraints.

[3] The agency determined that the integrated assemblies of Type 2 seat belts are safer than the Type 2a shoulder belts. Original equipment Type 2a shoulder belts may only be used at the driver seating position of vehicles intended to accommodate a wheel chair (58 FR 11975; March 2, 1993).

[4] See letter from Frank Berndt to Donald J. Gobeille, dated April 4, 1976, in which the agency states that buckles that are unlikely to contact the steering wheel in a crash situation do not have to meet the crush requirements of S4.3(d)(3) of FMVSS No. 209.

[5] The agency is considering amending the definition to include devices recommended for use by children 65 lb or less. (67 FR 21836.)