ID: nht92-2.18

DATE: 11/19/92

FROM: PAUL JACKSON RICE -- CHIEF COUNSEL, NHTSA

TO: PAUL GOULD -- SENIOR ENGINEER - FRICTION MATERIALS, LUCAS HEAVY DUTY BRAKING SYSTEMS

ATTACHMT: ATTACHED TO LETTER FROM PAUL GOULD TO PAUL RICE DATED 9-1-92 (EST.) (OCC 7792)

TEXT: This responds to your letter asking about the dynamometer requirements of Federal Motor Vehicle Safety Standard No. 121, Air Brake Systems (49 CFR 571.121). You requested clarification of the term "average deceleration rate" and its tolerance, particularly with respect to the brake power test (S5.4.2). You stated that you view the specified deceleration rate as "only a target" in order to fade the linings, and believe that it is acceptable to conduct tests at five percent below the specified rate. I am pleased to have this opportunity to explain our regulations to you.

Some background information on Federal motor vehicle safety laws and regulations may be helpful. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. @ 1381 et seq., Safety Act) authorizes this agency to issue safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards.

Manufacturers must have some independent basis for their certification that a product complies with all applicable safety standards. This does not necessarily mean that a manufacturer must conduct the specific tests set forth in an applicable standard. Certifications may be based on, among other things, engineering analyses, actual testing, and computer simulations. Whatever the basis for certification, however, the manufacturer must certify that the product complies with a standard as it is written, i.e., that the vehicle will pass all applicable requirements if it is tested exactly according to the standard's test conditions and other specifications.

Standard No. 121's dynamometer test requirements are set forth in section S5.4. That section specifies that brake assemblies must meet the requirements of S5.4.1 (brake retardation force -- relevant only to towed vehicles), S5.4.2 (brake power), and S5.4.3 (brake recovery), under the conditions of S6.2. The purpose of the dynamometer test requirements is to help ensure that brakes retain adequate stopping capacity during and after exposure to conditions caused by prolonged or severe use, such as long, downhill driving.

With respect to your question about the meaning of "average deceleration rate," that term is used in both S5.4.2 and S5.4.3. Section S5.4.2 specifies, for example, that each brake shall be capable of making 10 consecutive decelerations at an average rate of 9 f.p.s.p.s. from 50 mph to 15 mph, and shall be capable of decelerating to a stop from 20 mph at an average deceleration rate of 14 f.p.s.p.s. after the 10th deceleration. In S5.4, the meaning of average deceleration rate is explained as follows: For purposes of the requirements of S5.4.2 and S5.4.3, an average deceleration rate is the change in velocity divided by the decleration time measured from the onset of deceleration.

We do not agree with your suggestion that the deceleration rates specified in Standard No. 121 are "only a target" in order to fade the linings. As indicated above, manufacturers must certify that each vehicle complies with a standard as it is written, i.e., that the vehicle will pass all applicable requirements if it is tested exactly according to the standard's test conditions and other specifications. Thus, if a vehicle was unable to pass Standard No. 121's test requirements at the specified deceleration rates, it would not comply with the standard, notwithstanding the fact that it might be able to pass the standard's requirements at slightly lower deceleration rates.

We recognize, however, that it may be difficult to achieve any exact deceleration rate in conducting a brake test. For this reason, the agency's Office of Vehicle Safety Compliance (OVSC) specifies tolerances in its Laboratory Test Procedures developed for use by contractors in conducting compliance tests for the agency. For the brake power and brake recovery tests (S5.4.2 and S5.4.3), the agency's current Laboratory Test Procedure specifies the following tolerances on deceleration rates: +0 to -1 ft/s/s, except for 12 ft/s/s: +/-0.5 ft/s/s.

Enclosed for your information is a copy of the agency's Laboratory Test Procedure for Standard No. 121's dynamometer tests. On the issue of tolerances, I call your attention to the following statement at the beginning of the Laboratory Test Procedure:

The OVSC Laboratory Test Procedures, prepared for use by independent laboratories under contract to conduct compliance tests for the OVSC, are not intended to limit the requirements of the applicable FMVSS(s). In some cases, the OVSC Laboratory Test Procedures do not include all of the various FMVSS minimum performance requirements. Sometimes, recognizing applicable test tolerances, the Test Procedures specify test conditions which are less severe than the minimum requirements of the standards themselves. Therefore, compliance of a vehicle or item of motor vehicle equipment is not necessarily guaranteed if the manufacturer limits certification tests to those described in the OVSC Laboratory Test Procedures.

If you have any further questions, please feel free to call Mr. Marvin Shaw of my staff at (202) 366-2992.

ID: nht90-4.65

TYPE: Interpretation-NHTSA

DATE: November 27, 1990

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Cal Karl -- Minnesota State Patrol, District 4700-Commercial Vehicle Section

TITLE: None

ATTACHMT: Attached to letter dated 12-7-82 from F. Berndt to M.B. Mathieson; Also attached to letter dated 1-29-90 from C. Karl to M. Shaw (OCC 4403); Also attached to letter dated 1-18-90 from R.E. Meadows; Also attached to letter dated 1-8-90 from R. Marion to C. Karl; Also attached to letter from C. Karl to All School Bus LCR II's

TEXT:

This is in response to your letter to Marvin Shaw of my staff seeking an interpretation of Standard No. 217, Bus Window Retention and Release (49 CFR S571.217). Specifically, you asked how S5.2.3.2, which applies to school buses, would affect the instal lation of certain designs of "vandal locks" on school buses. I am pleased to have this opportunity to explain this safety standard for you.

Before I address your specific questions, I would like to provide some background information. Throughout this letter, I will use the term "vandal lock" to describe locking systems installed for the doors and emergency exits of school buses intended to prevent unauthorized persons from entering the school bus through those exits when the bus is unoccupied and unattended. S5.2.3.2, the relevant provision of Standard No. 217, reads as follows:

The engine starting system of a school bus shall not operate if any emergency exit is locked from either inside or outside the bus. For purposes of this requirement, "locked" means that the release mechanism cannot be activated by a person at the door w ithout a special device such as a key or special information such as a combination.

Your first question was whether S5.2.3.2 prohibits the use of a vandal lock system that, although it must be unlocked for the bus to start, can be relocked once the bus is started. The answer is that such locks are not prohibited by Standard No. 217. I have enclosed a copy of a December 7, 1982 letter to Mr. M. B. Mathieson in which NHTSA addressed this issue. As stated in that letter, "Nothing in Standard No. 217 prohibits the installation of locking doors (on a school bus) as long as the vehicle can not be started with the (emergency) door in the locked position." In other words, the prohibition in S5.2.3.2 focuses exclusively on whether the vehicle can be started when any emergency exit is locked. If the school bus cannot be started when an emerg ency exit is locked, the bus complies with S5.2.3.2, even if an emergency exit can be locked once the bus is started.

Your second question was whether S5.2.3.2 allows a vandal lock to be relocked after the vehicle is running without the use of a key or special information. The answer to this question is yes. As stated above, the prohibition in S5.2.3.2 focuses exclusi vely on whether the vehicle can be started when any emergency exit is locked. If the school bus cannot be

started when an emergency exit is locked, the bus complies with S5.2.3.2, even if an emergency exit can be locked once the bus is started. Nothing in S5.2.3.2 requires that any locks on emergency exits be relocked only by means of a key or some special information after the vehicle is started.

I appreciate your concern about potential problems that might arise if emergency doors are locked after a school bus is started. Nevertheless, regardless of whether you believe that NHTSA intended to make or should have made some provision to prevent em ergency exits on school buses from being relocked once the bus is started, it is not possible to interpret the language of S5.2.3.2 as including such a provision. Since an interpretation cannot add or delete requirements in the language of a safety stan dard, the only way whereby the standard could include a provision to prevent emergency exits on school buses from being relocked once the bus is started would be for this agency to undertake a rulemaking action to amend the current language of S5.2.3.2.

We are unaware of any safety need to commence such a rulemaking. We do not have any indication that there have been deaths or injuries to school bus occupants as a result of an emergency exit being relocked once the bus was started. Moreover, the poten tial hazards to school bus occupants absent any Standard No. 217 requirements on this subject seem minimal. School bus doors, including emergency doors, should not be locked when the bus is in operation, and we believe that, in practice, they remain unlo cked when the buses are in use. It is also our understanding that the vast majority of school buses with emergency doors that can be locked in this fashion are voluntarily equipped with warning buzzers that alert the driver to the fact that the doors ha ve been relocked.

I hope you find this information helpful. Please do not hesitate to contact David Greenburg of my staff at (202) 366-2992 if you have any further questions or would like some additional information.

ID: nht91-5.18

DATE: August 8, 1991

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA; Signature by Stephen P. Wood

TO: H. George Johannessen, P.E. -- Chairman, Seat Belt Technical Committee, Automotive Occupant Restraints Council

TITLE: None

ATTACHMT: Attached to letter dated 3-22-91 from H. George Johannessen, P.E. to Paul Jackson Rice (OCC 5858)

TEXT:

This responds to your letter seeking an interpretation of Standard No. 209, Seat Belt Assemblies (49 CFR S571.209). More specifically, you asked about the meaning of the requirement in S4.1(b) of Standard No. 209 that "...the pelvic restraint shall be designed to remain on the pelvis under all conditions, including collision or roll-over of a motor vehicle." I am pleased to have this opportunity to explain this provision.

You explained that some have asserted that a safety belt fails to comply with S4.1(b) if it actually moves off an occupant's pelvis during a crash. To reach such a conclusion, one must ignore the words "be designed to" and treat the requirement as though it read "...the pelvic restraint shall remain on the pelvis under all conditions, including collision or roll-over of a motor vehicle." Such a reading is plainly incorrect, because it reads the phrase "be designed to" out of the regulation.

You explained that you believe S4.1(b) of Standard No. 209 is merely a hortatory phrase that is essentially meaningless. According to your letter, this language first appeared in a standard developed by the Society of Automotive Engineers (SAE), and was subsequently adopted verbatim in the safety belt standard issued by the Department of Commerce and in Standard No. 209. You asserted that the SAE committee that developed this language included it as a design goal only, since the committee members "were aware that they had no objective test procedure to confirm compliance with this design goal," and "were aware that the seat belt would not necessarily remain on the pelvis during the entire collision event in all of the varied collisions encountered in the field."

We cannot agree with your suggestion that S4.1(b) of Standard No. 209 is merely a hortatory design goal. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.) requires each safety standard to meet certain requirements, including, among other things, that the standard be practicable, meet the need for motor vehicle safety, and be stated in objective terms. When NHTSA adopted Standard No. 209 as one of the initial Federal motor vehicle safety standards, the agency concluded that Standard No. 209, including S4.1(b), met all applicable statutory criteria.

It is true that there is no compliance test procedure specifically for S4.1(b) of Standard No. 209. However, the meaning of that provision becomes clear when it is viewed in the context of the occupant protection requirements in Standard Nos. 208, Occupant Crash Protection, Standard No.

210 Seat Belt Assembly Anchorages, and the rest of Standard No. 209. Standard No. 208 requires, among other things, that vehicles be equipped with safety belts and that the lap belt portions of those belts adjust to fit persons ranging in size from a 6-year-old child to a 95th percentile adult male (See S7.1.1). Standard No. 209 requires that safety belts meet specified strength, durability, and other performance requirements. Standard No. 210 requires that the anchorage holding the safety belt in the vehicle meet stringent strength requirements, so that the belt will remain attached to the vehicle in a crash, and lap belt location requirements (S4.3.1), including a minimum lap belt mounting angle, to reduce the likelihood of occupant submarining, i.e., having the lap belt move off the pelvis. See the detailed discussion of the minimum lap belt mounting angle at 55 FR 17970, at 17974; April 30, 1990.

Viewed in this context, we believe that the requirement of S4.1(b) of Standard No. 209 means that safety belts must be designed to be capable of being properly adjusted and positioned on the pelvis of occupants ranging from 6-year-old children to 95th percentile adult males. The belts must also be capable of remaining on the pelvis of such occupant during collision or roll-over. A belt system that was not capable of being positioned on the pelvis and remaining there during crashes would not comply with S4.1(b).

Given this meaning and purpose, we offer the following observations. First, the fact that a lap belt moved off the occupant's pelvis during a collision would NOT of itself show that the lap belt failed to comply with S4.1(b) of Standard No. 209. Compliance with S4.1(b) of Standard No. 209 is determined by the design of the safety belt system, not the performance of individual safety belts while in service. Second, the actual performance of a safety belt in a vehicle (e.g., a lap belt moving off the occupant's pelvis during a crash) COULD indicate that the lap belt failed to comply with S4.1(b) of Standard No. 209. If the agency had information indicating that a particular belt design was not capable of being properly positioned on the pelvis or not capable of remaining on the occupant's pelvis when installed in particular vehicles in particular crash modes, the agency might well investigate whether that safety belt design complied with S4.1(b). However, NHTSA has no such information about any safety belt systems at this time.

ID: nht91-7.5

DATE: November 11, 1991

FROM: Richard Gray -- Secretary, Sports Car Club of New Zealand, Inc.

TO: Paul Jackson Rice -- Office of Chief Council, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 1/23/92 from Paul Jackson Rice (by Stephen P. Wood) to Richard Gray (A39; VSA S108(a)(1)(A))

TEXT:

I am writing to in the hope that your Department may be able to assist our Organization in overcoming a couple of vehicle standards problems. The New Zealand Ministry of Transport is introducing new Vehicle Safety Standards similar to those in operation in the USA, United Kingdom, Europe and Australia. Their main thrust is to align the NZ Vehicle Standards with those of USA, Europe and UK. In doing so the cars built by the major manufacturers will require the local importers to ensure that the vehicles they import or assemble locally meet the Vehicle Standards of any of the above named countries.

However, certification of Low volume vehicles (those built in numbers less than 20O per year) is being entrusted to four organizations of which the Sports Car Club of New Zealand is playing a key role in helping to set up the certification system for all low volume vehicles including modified cars.

With the introduction of the Standards we are faced with two major problem areas; glazing and seat-belts. New Zealand has a number of privately imported American built sports cars such as the Montage, GT40, replicas, Cobra replicas, and Cheetahs to name just a few, which are facing the prospect of being legislated off our roads.

GLAZING:

The problem is that many of these cars are fitted with acrylic or polycarbonate side and/or rear glazing. The N.Z. Ministry of Transport is saying that unless we can provide proof from the relevant authorities that such glazing is permissible for use in Low Volume vehicles respective countries of origin, then they will have to have moulds made and new safety glass screens manufactured for fitment. This ruling will apply retrospectively back to 1976.

The cost of such an exercise would be prohibitive and would result in most of these cars being put off the road for good. The introduction of such a regulation would also rule out the possibility of any further low volume cars from being imported into NZ should they also be fitted with such glazing.

The fact that such cars were sold in their countries of origin with acrylic or polycarbonate screens does not help our case. The MOT say that we have no proof that the manufacturers of these cars actually complied with the regulations of their country, or that their countries of origin have any special exemptions in place for low volume vehicles.

To overcome this problem the NZ MOT require us to provide proof from the appropriate authorities in USA and UK to this effect.

A prompt reply from your Department is a matter of urgency as the introduction of the N.Z. Standards governing alternative glazing materials is set for January 1992.

Could you please reply stating if such materials are permissible, and if so, what types are allowed for use (e.g. acrylic, polycarbonate, abrasion resistant films etc), and under what circumstances, placement or conditions they are permitted.

FULL HARNESS SEATBELTS:

The fitment of 3-point dual sensitive seatbelts to the outboard front seating positions on new cars has been mandatory for some time in NZ, but there has been nothing stopping people from fitting full harness seatbelts if they so desired. However, the NZ MOT are about to stop this practice and in fact retrospectively apply the new ruling.

We believe that any person should be allowed to take extra safety precautions to protect themselves over and above those standards set down by the authorities, provided they do not endanger other people. in this regard we have noticed that quite a number of Low Volume American built sports cars come fitted with full harness seatbelts.

Again it would greatly help our case if we could have the official ruling on the provisions for fitment and use of full harness seatbelts in America.

FRONT NUMBER PLATES:

This problem is not quite so urgent, but the NZ MOT have recently decided not to allow the fitment of flexible registration plates to the front of vehicles. This is creating quite a problem with cars such as E type Jaguars, Cobra Replicas and even modern production sports cars like the MX5 to name just a few. The shape of their nose section does not allow for the fitment of rigid metal plates without them either interfering with radiator cooling or becoming a dangerous protrusion.

It would appear that the American regulations allow for the fitment of either alternative flexible registration plates, or none at all. If this is so, a copy of your registrations governing their fitment would be most helpful.

In anticipation of an early reply, I would like to take this opportunity to thank you for your time and assistance.

ID: nht89-3.7

TYPE: INTERPRETATION-NHTSA

DATE: 09/29/89

FROM: STEPHEN P. WOOD -- ACTING CHIEF COUNSEL NHTSA

TO: SHUICHI WATANABE -- MANAGER, AUTOMOTIVE LIGHTING HOMOLOGATION SECT. STANLEY ELECTRIC CO., LTD. JAPAN

TITLE: NONE

ATTACHMT: LETTER DATED 3/27/89 FROM SHUICHI WATANABE OF STANLEY ELECTRIC CO OF JAPAN TO ERIKA JONES OF NHTSA RE: MEASUREMENT OF INCIDENT LIGHT ANGLE

TEXT: Dear Mr. Watanabe:

This is in reply to your letter with respect to measurement of the incident light angle prescribed by Motor Vehicle Safety Standard No. 108 for license plate lamps. You have submitted six Figures for our consideration and reply. I regret the delay in r esponding.

Paragraph 6.5 (not 5.3.3) of SAE Standard J587 OCT81 License Plate Lamps (Rear Registration Plate Lamps) states:

"When a single lamp is used to illuminate the plate, the lamp and license plate holder shall bear such relation to each other that at no point on the plate will the incident light make an angle of less than 8 deg. to the plane of the plate, this angle be ing measured from the edge of the light emitting surface of the device farthest from the surface of the plate (see Fig. 3)."

With respect to your Figure A, you comment that, in order to determine the farthest point on the light emitting surface, "only the distance '1' between license plate and a plane runs parallel to it should be considered and not by distance 'm' nor 'n'".

In examining Figure 3 of SAE J587, you will note that the incident angle is measured by a line that extends from the edge of the light emitting surface of the lamp that is the farthest from the most distant point on the plate that the light can be expect ed to reach, to that point. With respect to your Figure A, the line "n" that extends from the edge of the lamp "p" to the bottom of the plate replicates the line shown in Figure 3, and thus is the correct one, not the perpendicular line "1".

Similarly, with respect to Figure B, a round license plate lamp, a line must be drawn from the bottom of the plate (such as line "n" in Figure A) to the farthest light emitting surface surface of the lamp (as shown in Figure 3, not your Figure B) in orde r to illustrate the farthest point.

With respect to Figures C and D, you have asked: "But if the farthest point can exist so may on a line or a plane . . . how could it be determined? Should it be for instance, left end, right end or center of them?" Figure C appears to depict an elongate d lamp in which "p"s are depicted at the left end, right end, and center. In this instance, "P2" is the edge of the light farthest from the surface of the plate, as represented by corner "Q". Though "Po" represents an edge of the lamp, at no place on t he plate is it the point "farthest from the surface of the plate". Thus, the measurement from "Q" to the tangent of the light emitting surface near "P2" is the line to be used to measure the 8 degree minimum angle.

Figure D appears also to represent an elongated lamp but one in which the lens area is directed more towards the plate. In this Figure, "P" is the edge of the lamp that is farthest from the plate. But because of the configuration of the lamp, light fro m this point is interrupted by a part other than a lens and cannot shine directly upon the plate. Your points "P1", "P0", and "P2" appear to indicate the points on the lamp surface where such interruption ceases and light shines directly upon the plate. Therefore, it is our opinion that in this instance "P2" is the edge of the lamp farthest from the plate, as represented by corner "Q".

You have also asked the same question with respect to Figures E and F. These Figures represent lamp designs with two light sources. However, in Figure E, the two light sources appear incorporated in a single lamp, and the requirements of paragraph 6.5 still apply. Thus, a line from Q, tangent to the light emitting surface of the lens near the point "P3" (and not your line "Q-"P3"), is the correct reference for angle measurement. Figure F, however, depicts the light sources as compartmentalized, and thus may be regarded as a two-lamp device. Paragraph 6.6 of SAE J587 establishes the requirement for two or more license plate lamps. It states:

"When two or more lamps are used to illuminate the plate, the minimum 8 deg incident light angle shall apply only to that portion of the plate which the particular lamp is designed to illuminate. The incident light angle shall be measured in the same wa y as provided in paragraph 6.5."

Under these circumstances the light emitting edge of the lamp farthest from the surface of the plate is the furthest edge of the lamp illuminating that portion of the plate, here represented by "P2". Thus, the angle to be measured would be determined wi th reference to a tangent line to the light emitting surface near "P2", from corner "Q".

I hope that this has answered your questions.

Sincerely,

ID: 08_003235--sa--08 June 24

ID: 11540.JEG

Mr. Robert J. Bishop
Manager--Inflator Engineering
BAICO
1501 Midpark Road
Knoxville, Tennessee 37921

Dear Mr. Bishop:

This responds to your letter asking about Standard No. 208's requirements for pressure vessels that are continuously pressurized. Section S9.1 of the standard incorporates certain provisions of the Hazardous Materials Regulations issued by DOT's Research and Special Programs Administration (RSPA). You noted that you have recently received an exemption from RSPA concerning one of those provisions, 49 CFR 178.65- 11(a). Under RSPA's regulation, you must conduct a pressure test on each cylinder before it is shipped, including holding a specified pressure for 30 seconds. Under the exemption, the hold time for testing each cylinder may be limited to "that which is adequate to show compliance." You asked whether compliance with the provisions of the exemption "satisfies the intent of paragraph S9.1, FMVSS 208."

The answer to your question is that an exemption from RSPA does not change your responsibility under Standard No. 208. However, as discussed below, Standard No. 208 does not incorporate all of the provisions of 49 CFR 178.65-11(a). In particular, Standard No. 208 does not require you to test each cylinder but instead requires you to assure that each cylinder, if tested in accordance with 49 CFR 178.65-11(a), including the 30 second hold time, would meet the specified performance requirements.

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, it is the responsibility of the manufacturer to certify that its vehicles or equipment comply with applicable safety standards.

Section 9.1 of Standard No. 208 states:

A pressure vessel that is continuously pressurized . . . shall not leak or evidence visible distortion when tested in accordance with ' 178.65-11(a) of this title and shall not fail in any of the ways enumerated in ' 178.65-11(b) of this title when hydrostatically tested to destruction.

You noted in your letter that 49 CFR 178.65-11(a) specifies, among other things, that "each cylinder must be tested at an internal pressure of at least the test pressure and must be held at that pressure for at least 30 seconds." Under RSPA's regulation, you must conduct the pressure test on each cylinder before it is shipped, including holding a specified pressure for 30 seconds. However, paragraph 7b(1) of the exemption RSPA granted you (DOT-E 11494) provides that "the hold time at test pressure . . . may be limited to that which is adequate to ensure compliance."

Your letter raises two issues. The first is whether NHTSA requires each cylinder to be tested. The second is whether a 30 second hold time is required to satisfy Standard 208.

Testing.

Unlike RSPA=s requirements, NHTSA does not require each cylinder to be tested. The RSPA requirement to test each cylinder before it is shipped is a quality control provision. When NHTSA added the requirements for pressure vessels to Standard No. 208 (see May 6, 1972 final rule (37 FR 9222), copy enclosed), the agency adopted some, but not all of RSPA's Specification 39 (49 CFR 178.65). Notably, the "quality control" requirements of RSPA were not adopted. NHTSA stated:

A continuously pressurized vessel is required to conform to the requirements of Specification 39 concerning type, size, service pressure, and test pressure of vessels (paragraph 2 of the specification); seams (6(b)); wall thickness (7); openings and attachments (9 (a) and (b)); safety devices (10); pressure tests (11); and flattening tests (12). The reference to the latter two paragraphs are drafted to make it clear that the quality control aspects of those paragraphs are not included in the standard. The remaining portions of Specification 39 . . . are not incorporated. [Emphasis added.]

Thus, while Standard No. 208 incorporated the pressure test performance requirements of that paragraph, it did not adopt the quality control provisions. There is no requirement in the standard that each cylinder must be pressure tested. However, as explained more below, you are responsible for assuring the compliance of each cylinder with the specified performance requirements.

30-Second Hold Time.

Although the RSPA exemption permits you to test your cylinders for less than 30 seconds, an exemption from RSPA does not change your responsibility under Standard No. 208. Under Standard No. 208, you are responsible for assuring that each cylinder, if tested in accordance with 49 CFR 178.65-11(a), including the 30 second specification, would not leak or evidence visible distortion. However, nothing in Standard No. 208 requires you to test each cylinder or to test for a 30 second minimum. You may be able to provide such assurance by a variety of means, included, but not limited to, engineering analyses, computer simulations, testing each cylinder, sample testing, or a combination of these activities.

While your exemption from RSPA does not change your responsibility under Standard No. 208, you may be able to use the testing you conduct to meet RSPA responsibilities to also meet your Standard No. 208 responsibility. That is, you may be able to base your certification of compliance with Standard No. 208 on the data you already have.

If you have any other questions, please feel free to contact Edward Glancy of my staff at this address or by phone at (202) 366-2992.

Sincerely,

Samuel J. Dubbin Chief Counsel

Enclosure ref:208 d:5/9/96

ID: nht94-1.95

TYPE: Interpretation-NHTSA

DATE: March 24, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Bob Carver -- Product Engineering, Wayne Wheeled Vehicles (Marysville, OH)

TITLE: None

ATTACHMT: Attached to letter dated 1/8/94 from Bob Carver to John Womack (OCC 9544)

TEXT:

This responds to your letter of January 8, 1994, asking two questions concerning a recent amendment to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413; November 2, 1992). Your questions and the response to each follow .

1. There's some confusion here in our engineering department regarding the interpretation of the "Daylight Opening" and "Unobstructed Opening" as it applies to the new side emergency door specification in FMVSS 217. Page 2 shows the allowable obstructi on and the context in which "Daylight Opening" and "Unobstructed Opening" are used. Page 3 shows some measurements of our seats placed according to the "30 cm minimum" shown on page 2. Page 4 shows four different interpretations of the "Unobstructed Op ening" area. Depending on the interpretation, between 9 and 15 people may be accommodated by a side emergency door. My question is this: of the four possibilities shown, which definition of the "Unobstructed Opening" area is correct? Mr. Hott indicat ed definition 4.

The term "daylight opening" is defined in the Final Rule as "the maximum unobstructed opening of an emergency exit when viewed from a direction perpendicular to the plane of the opening." An obstruction in this context would include any obstacle or obje ct that would block, obscure, or interfere with, in any way, access to that exit when opened. In determining the "maximum unobstructed opening of an emergency exit," we would subtract, from the total area of the opening, the area of any portions of the opening that cannot be used for exit purposes as a result of the obstruction. The area measurements would be taken when viewed from a direction perpendicular to the plane of the opening.

Your question specifically concerns how the "maximum unobstructed opening" of a side door is measured when the opening is partially obstructed by a seat. In the case of the illustrated door exit, occupants would use the exit by movement along the floor. This would be considered in determining the extent of an obstruction. None of the four examples you enclosed with your letter correctly illustrates the area that would be credited for the illustrated exit. The following regions would not be credited for this exit: (1) the area visually obstructed by the seat; (2) your region A 2, an area bounded by a horizontal line tangent to the top of the seat back, a vertical line tangent to the rearmost portion of the top of the seat, the upper edge of the doo r opening, and the edge of the door forward of the seat; (3) your region A 5, an area bounded by the seat back, a horizontal line tangent to the top of the seat back, and the edge of the door forward of the seat; and (4) your region A 8, an area bounded by the seat leg, the floor, the lower edge of the seat bottom, and the edge of the door forward of the seat. Because the seat would make the last three regions unusable as exit space for a person traveling along the floor of the bus towards the exit, th ey would not be credited for that exit.

You should be aware that the agency published a notice of proposed rulemaking to amend Standard No. 217 on December 1, 1993 (58 FR 63321). The notice proposed two alternate means for determining the maximum amount of area that will be credited for all t ypes of emergency exits on school buses. The agency is currently reviewing the comments received in response to this notice. I am enclosing a copy of this notice.

2. Here is an excerpt from FMVSS 217 S5.5.3(a):

"Each school bus ....shall have the designation "Emergency Door" or "Emergency Exit" as appropriate, .... For emergency exit doors, the designation shall be located at the top of, or directly above, the emergency exit door on both the inside and outside surfaces of the bus.... For emergency window exits, the designation shall be located at the top of, or directly above, or at the bottom of the emergency window exit on both the inside and outside surfaces of the bu s."

I've seen a two-sided sticker used by other bus manufacturers. It is applied on the inside surface of a window and the same image "Emergency Door" or "Emergency Exit" can be read from both inside and outside the bus. Is it permissible for us to use thi s sort of decal, assuming it meets all other (i.e., FMVSS 302)?

The answer to your question is yes. The agency addressed this issue in an October 2, 1978, letter to Mr. E.M. Ryan of Ward Industries, Inc. I am enclosing a copy of this letter.

I hope you find this information helpful. If you have any other questions, please contact Walter Myers of my staff at this address or by phone at (202) 366-2992.

ID: 7742-2

Mr. Paul Gould
Senior Engineer - Friction Materials
Lucas Heavy Duty Braking Systems
Grange Road
Cwmbran, Gwent
South Wales NP44 3XU
Great Britain

Dear Mr. Gould:

This responds to your letter asking about the dynamometer requirements of Federal Motor Vehicle Safety Standard No. 121, Air Brake Systems (49 CFR 571.121). You requested clarification of the term "average deceleration rate" and its tolerance, particularly with respect to the brake power test (S5.4.2). You stated that you view the specified deceleration rate as "only a target" in order to fade the linings, and believe that it is acceptable to conduct tests at five percent below the specified rate. I am pleased to have this opportunity to explain our regulations to you.

Some background information on Federal motor vehicle safety laws and regulations may be helpful. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act) authorizes this agency to issue safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a "self- certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards.

Manufacturers must have some independent basis for their certification that a product complies with all applicable safety standards. This does not necessarily mean that a manufacturer must conduct the specific tests set forth in an applicable standard. Certifications may be based on, among other things, engineering analyses, actual testing, and computer simulations. Whatever the basis for certification, however, the manufacturer must certify that the product complies with a standard as it is written, i.e., that the vehicle will pass all applicable requirements if it is tested exactly according to the standard's test conditions and other specifications.

Standard No. 121's dynamometer test requirements are set forth in section S5.4. That section specifies that brake assemblies must meet the requirements of S5.4.1 (brake retardation force--relevant only to towed vehicles), S5.4.2 (brake power), and S5.4.3 (brake recovery), under the conditions of S6.2. The purpose of the dynamometer test requirements is to help ensure that brakes retain adequate stopping capacity during and after exposure to conditions caused by prolonged or severe use, such as long, downhill driving.

With respect to your question about the meaning of "average deceleration rate," that term is used in both S5.4.2 and S5.4.3. Section S5.4.2 specifies, for example, that each brake shall be capable of making 10 consecutive decelerations at an average rate of 9 f.p.s.p.s. from 50 mph to 15 mph, and shall be capable of decelerating to a stop from 20 mph at an average deceleration rate of 14 f.p.s.p.s. after the 10th deceleration. In S5.4, the meaning of average deceleration rate is explained as follows:

For purposes of the requirements of S5.4.2 and S5.4.3, an average deceleration rate is the change in velocity divided by the decleration time measured from the onset of deceleration.

We do not agree with your suggestion that the deceleration rates specified in Standard No. 121 are "only a target" in order to fade the linings. As indicated above, manufacturers must certify that each vehicle complies with a standard as it is written, i.e., that the vehicle will pass all applicable requirements if it is tested exactly according to the standard's test conditions and other specifications. Thus, if a vehicle was unable to pass Standard No. 121's test requirements at the specified deceleration rates, it would not comply with the standard, notwithstanding the fact that it might be able to pass the standard's requirements at slightly lower deceleration rates.

We recognize, however, that it may be difficult to achieve any exact deceleration rate in conducting a brake test. For this reason, the agency's Office of Vehicle Safety Compliance (OVSC) specifies tolerances in its Laboratory Test Procedures developed for use by contractors in conducting compliance tests for the agency. For the brake power and brake recovery tests (S5.4.2 and S5.4.3), the agency's current Laboratory Test Procedure specifies the following tolerances on deceleration rates: +0 to -1 ft/s/s, except for 12 ft/s/s: +0.5 ft/s/s.

Enclosed for your information is a copy of the agency's Laboratory Test Procedure for Standard No. 121's dynamometer tests. On the issue of tolerances, I call your attention to the following statement at the beginning of the Laboratory Test Procedure:

The OVSC Laboratory Test Procedures, prepared for use by independent laboratories under contract to conduct compliance tests for the OVSC, are not intended to limit the requirements of the applicable FMVSS(s). In some cases, the OVSC Laboratory Test Procedures do not include all of the various FMVSS minimum performance requirements. Sometimes, recognizing applicable test tolerances, the Test Procedures specify test conditions which are less severe than the minimum requirements of the standards themselves. Therefore, compliance of a vehicle or item of motor vehicle equipment is not necessarily guaranteed if the manufacturer limits certification tests to those described in the OVSC Laboratory Test Procedures.

If you have any further questions, please feel free to call Mr. Marvin Shaw of my staff at (202) 366-2992.

Sincerely,

Paul Jackson Rice Chief Counsel

Enclosure

ref:121 d:11/19/92

ID: nht75-4.3

DATE: 08/28/75

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Dennis Replansky

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent request for a discussion of what constitutes the manufacture of a new trailer when used components from an existing trailer are utilized. As you are aware, a newly-manufactured air-braked trailer must, in all but a few cases, be equipped with an air brake system that conforms to Standard No. 121, Air Brake Systems.

The use of new components in combination with used components to assemble a complete vehicle is a common practice in both truck and trailer operations. The National Highway Traffic Safety Administration (NHTSA) has recognized this commercial practice by establishing that the use of a new body on a used "chassis" that has already been certified does not constitute the manufacture of a new vehicle. In contrast, placing a used body on a new chassis that has never been certified as a vehicle has been determined to create a newly-manufactured vehicle that must be certified. This distinction did not present difficulty to trailer manufacturers in the past, when they were only required to meet the lighting requirements of Standard No. 108, Lamps, Reflective Devices, and Associated Equipment.

Since implementation of Standard No. 121, however, manufacturers have had to determine whether the particular assembly they undertake contains a used "chassis" which would not be required to meet the air brake standard. As a general matter, the NHTSA has stated that, as a minimum, the running gear (the axles, wheels, suspension, and related components sometimes known as a bogie) and main frame of the existing vehicle must be used to qualify as a used "chassis". However, the many different types of trailer construction make it difficult to determine what constitutes the main frame of some configurations. The NHTSA has concluded that the load-bearing structural member(s) which run the length of the vehicle and support the trailer will be considered to be the "main frame".

In the case of monocoque van construction, the trailer side walls which constitute the main load-bearing members through the length of the vehicle must be reused as the main frame in addition to the running gear, or else the rebuilding operation will constitute manufacture of a new vehicle.

In the case of container chassis, the box frame that consitutes the main load-bearing member through the length of the vehicle must be reused as the main frame in addition to the running gear, or else the rebuilding operation will constitute manufacture of a new vehicle.

In the case of a platform trailer, the main frame members which run the length of the trailer must be reused in addition to the running gear, or else the rebuilding operation will constitute manufacturer of a new vehicle.

In the case of a platform trailer, the main frame members which run the length of the trailer must be reused in addition to the running gear, or else the rebuilding operation will constitute manufacturer of a new vehicle.

In the case of a tank trailer in which the tank serves the purpose of and replaces frame rails, the tank must be reused as the main frame in addition to the running gear, or else the rebuilding operation will constitute manufacture of a new vehicle. If a separate frame serves as the load-bearing member through the length of the vehicle, the tank could be replaced without the operation constituting the manufacture of a new vehicle. An inner tank may be replaced without certification as a new vehicle if the inner tank does not serve as a main load-bearing member.

Modifications of existing trailers to increase or decrease volumetric capacity or vehicle length are generally permitted without recertification. For example, the barrel of a tank trailer may be lengthened in response to the new weight limits without recertification of the vehicle.

In closing, it should be noted that Bureau of Motor Carrier regulations may differ on modification or rebuilding of vehicles in interstate commerce.

SINCERELY,

BLANK, ROME, KLAUS & COMISKY

July 24, 1975

James C. Schultz, Esquire Chief Counsel U. S. Dept. of Transportation - NHTSA

A number of our clients in the motor vehicle industry have raised questions concerning the applicability to rebuilt trailers of Federal Motor Vehicle Safety Standards, especially Standard #121, Air Brake Systems. Unfortunately, Standard #121 does not define "manufacture" for purposes of determining applicability.

The following factual situation has arisen most often:

A manufacturer's customer presently has trailers, commonly called "chassis", which are used solely for hauling containers. The equipment represents a considerable investment. At present, the customer's trailers are obsolete because they cannot carry the new I.S.O. containers. The customer has asked the manufacturer to modify the old trailers to permit them to use the new I.S.O. containers. The manufacturer will do this by taking the customer's old axle assembly (composed of the axles, brakes, wheels, drums, rims, tires and certain connecting parts) and adding to that a new structural frame, namely a box frame and fittings, to permit each trailer to carry the new I.S.O. containers.

Does Standard #121, Air Brake Systems, apply to such rebuilt trailers?

We would appreciate your guidance.

DENNIS REPLANSKY

CC: TAD HERLIHY