ID: 12654.ztv

Mr. Ernst Waldeck
Vice President
FER North America, Inc.
P.O. Box 2229
Birmingham, MI 48012-2229

Dear Mr. Waldeck:

This is in reply to your FAX of October 15, 1996, to Rich Van Iderstine of this agency requesting approval of a design proposal to place a combination front side marker lamp and reflector behind the front wheel house.

As you noted, Table IV of Motor Vehicle Safety Standard No. 108 requires front side marker lamps and reflectors to be located "as far to the front as practicable." The center of the combination device shown on the drawing you enclosed is 1222.6 mm from the front of the vehicle. In this location, it is behind the front wheel house. We surmise that this location is otherwise used for a turn signal repeater lamp in markets other than the United States.

As a general rule, it is initially the vehicle manufacturer that determines whether a specific location is "practicable" for its vehicle design. The agency will not contest that determination unless it is clearly erroneous. In this instance, we believe that it would be clearly erroneous to place the combination device at the location indicated. In that location, the combination device would not fulfill its intended function of indicating the forward edge of the vehicle. There appears to be ample room in front of the wheel house for location of the combination device so that it might more nearly fulfill that function. Unless the manufacturer can demonstrate convincingly that a location in front of the wheel house is not practicable, we would regard a location behind the wheel house as noncompliant with the requirements of Standard No. 108.

If you have any questions, you may refer them to Taylor Vinson of this Office (202-366-5263).

Sincerely,

John Womack

Acting Chief Counsel

ref:108

d:11/14/96

ID: 12666.ztv

Mr. Charles H. Fuller
President
Graphiclite Systems Inc.
P.O. Box 437
Tallmadge, Ohio 44278

Dear Mr. Fuller:

This is in reply to your letter of October 24, 1996, asking several questions about the relationship of your product, the Graphiclite, to Federal Motor Vehicle Safety Standard No. 108.

You have told us that the Graphiclite, a 20 watt halogen light, "is being designed to be mounted on the sides, near the bottom, of trailers and trucks to illuminate the advertising graphics which are becoming more and more popular." You also enclosed a copy of an interpretative letter of this Office, dated August 19, 1988, on an earlier version of the product.

There are no affirmative requirements of Standard No. 108 with which additional and optional motor vehicle lighting equipment must comply. This equipment, if offered as original equipment, is subject only to the prohibition of paragraph S5.1.3 that it must not impair the effectiveness of the lighting equipment that the standard requires to be installed. This means that the answer to your questions 1,2,4, and 5 is no. Your question 3 is whether a demonstration of Graphiclite will be required in accordance with S5.1.3. The answer again is no. It is the responsibility of the truck or trailer manufacturer in certifying that its vehicles comply with all applicable Federal motor vehicle safety standards to make the impairment determination. Unless that determination is clearly erroneous, the agency will not question it. In directing the light from the lamp toward the vehicle side, we would caution against placement of the lamp so that the beam falls upon any intermediate side marker lamp and reflector (required on vehicles whose overall length is 30 feet or greater).

The fact that original auxiliary lighting equipment may be acceptable under S5.1.3 does not preempt a state from prohibiting it under its own lighting regulations. We are unable to advise you on state laws, and suggest that you contact the Department of Motor Vehicles in those states where you anticipate marketing Graphiclite.

If you have any further questions, please telephone Taylor Vinson (202-366-5263).

Sincerely,

John Womack

Acting Chief Counsel

ref:108

d:12/11/96

ID: 12669.ztv

The Honorable Bill Baker
U.S. House of Representatives
1801 N. California Boulevard
Suite 103
Walnut Creek, CA 94956

Dear Mr. Baker:

I am replying to your letter of October 22, 1996, addressed to Marilynne Jacobs, Director, Office of Vehicle Safety Compliance, on behalf of your constituent, Duane Doyle of San Leandro. You have asked for our views on his letter to you of October 17, 1996, a copy of which you enclosed.

Mr. Doyle bought a 1996 Rover Mini Cooper in Switzerland, and when he attempted to import it, he was informed by the U.S. Customs Service at the Port of Oakland that the vehicle would have to be brought into compliance with the Federal Motor Vehicle Safety Standards which this agency (NHTSA) administers, as well as Federal emissions requirements that are administered by the Environmental Protection Agency. Mr. Doyle offered to retrofit the car with a roll bar and racing safety harness and was told by this agency that this was insufficient to fulfil the requirements of this agency. He then offered to store the car on his property and not drive it on the public roads, and was informed that this, also, was not acceptable. He now seeks to import it under 49 U.S.C. 30112(b), which he interprets as follows: "the prohibitions on importing noncomplying motor vehicles and equipment do not apply to a person that had no reason to know, despite exercising reasonable care that a motor vehicle did not comply with applicable motor vehicle safety standards." The tone of his letter indicates that he feels he is being singled out unfairly by NHTSA.

Although the legal background may have been discussed in other correspondence between Mr. Doyle and this agency, this is the first time that the Office of Chief Counsel has been afforded an opportunity to discuss this matter. There are several provisions of law applicable to Mr. Doyle's situation. First, there has been a prohibition in effect for almost 29 years, since January 1, 1968 (15 U.S.C. 1397(a)(1)(A), recodified as 49 U.S.C. 30112(a)), against importing motor vehicles into the United States unless they conform, or are brought into conformance, with all applicable Federal motor vehicle safety standards. Furthermore, under the Imported Vehicle Safety Compliance Act of 1988 (codified as 49 U.S.C. 30141 et seq.), since January 31, 1990, for almost 7 years it has not been possible to import a noncomplying motor vehicle unless this agency has determined that the vehicle is capable of being converted to comply with all applicable Federal motor vehicle safety standards. The agency has not made such a determination with respect to the 1996 Rover Mini Cooper.

Under 49 U.S.C. 30142, Mr. Doyle may import the Mini Cooper after demonstrating that he has a contract with a "registered importer" to bring the Mini Cooper into full compliance with the Federal safety standards, and that the agency has made a determination under section 30141(a)(1) (B) that "the safety features of the vehicle comply with or are capable of being altered to comply with those standards based on destructive test information or other evidence [NHTSA] decides is adequate." NHTSA makes the determination after the public has commented upon an application filed by the "registered importer", which is an entity that NHTSA has recognized as capable of performing standards compliance work. If Mr. Doyle is interested in pursuing this avenue of approach, the Office of Vehicle Safety Compliance will provide him, upon his request, with a list of "registered importers" in his area. This is the procedure that must be followed by persons seeking permanent importation of vehicles for their own use. The fact that the Mini meets the safety standards of other countries is an argument that may be made in the application.

The modifications which Mr. Doyle offered to make, while addressing some aspects of occupant protection, were insufficient to demonstrate that the Mini would comply afterwards with all the safety standards that apply to it. We note also Mr. Doyle's offer to restrict the Mini's use to private property. The problem with this offer is that it is not binding on a subsequent purchaser of the car, and we have no authority to require a person other than the importer to bring a car into compliance. Thus, an importer must bring into compliance a motor vehicle that was originally manufactured for on-road use even if (s)he intends to use it on private property.

As noted above, Mr. Doyle seeks an exemption based upon his interpretation of Section. 30112(b). Section 30112(a) contains the basic prohibition against, among other things, importing a motor vehicle unless it complies with the Federal motor vehicle safety standards and bears the manufacturer's certification of compliance. Section 30112(b) sets forth nine circumstances in which section 30112(a) does not apply, that is to say, under which a violation will be considered not to have occurred (and for which a civil penalty may not be imposed). One of these exceptions is if a person can establish "that the person had no reason to know, despite exercising reasonable care, that a motor vehicle . . . does not comply with applicable [U.S. Federal] motor vehicle safety standards. . . ."

Mr. Doyle has not violated Section 30112(a). He has not completed importation of the Mini into the United States; indeed, he was prevented from doing so by the U.S. Customs Service because it did not comply with the standards. Since he has not imported a noncomplying vehicle, he has not violated Section 30112(a) and therefore Section 30112(b)(2) does not apply. He cannot now import the Mini using Section 30112(b)(2) as a defense because he now knows that the Mini fails to comply. The exception that applies to Mr. Doyle is that set out by Section 30112(b)(5) -- "a motor vehicle imported for personal use by an individual who receives an exemption under section 30142 of this title", that is, importation of the Mini through the auspices of a "registered importer" who will conform the vehicle.

Taylor Vinson of this Office will be pleased to answer such further questions as may occur (202-366-5263).

Sincerely,

John Womack

Acting Chief Counsel

ref:591

d:11/15/96

ID: 12730a.jeg

Mr. Chet K. Wilson
Executive Consultant
AEI Consulting
38345 Ten Mile Road
Suite 230
Farmington Hills, MI 48335

Dear Mr. Wilson:

This responds to your letter concerning regulations issued under the American Automobile Labeling Act. I apologize for the delay in our response. You ask about the following factual situation:

An outside supplier, in preparing a response to a request from an unrelated motor vehicle manufacturer, pursuant to 49 CFR 583.10, determined the following percentages of foreign and domestic content contained in the equipment (which is not an engine or transmission) supplied directly to the manufacturer:

You ask three questions under these facts, which are addressed below.

Question 1. Because the combined U.S./Canadian content is less than 70% in the equipment, the supplier must determine and report the country of origin. In determining the country of origin, are the Canadian and U.S. content percentages to be combined or treated separately?

The Canadian and U.S. content percentages are combined. Section 583.10(a)(5) specifies that, for equipment which has less than 70 percent of its value added in the United States and Canada, an outside supplier is to provide "the country of origin of the equipment, determined under 583.7(c)." Section 583.7(c) specifies that the U.S. and Canada are treated together in making this determination.

Question 2. If Canadian and U.S. are to be combined, how is the supplier to report the country of origin?

The supplier should specify the country of origin as U.S./Canada, but must do so in a manner that makes it clear this determination is being made pursuant to 583.10(a)(5), and not 583.10(a)(4). The country of origin would not be "U.S./Canada" under the latter section because 70 percent of more of its value was not added in the U.S. and/or Canada.

Question 3. Does the supplier have to report the percentage of content or just the name of the country of origin?

Section 583.10(a)(5) only requires the supplier to report the name of the country of origin.

I hope this information is helpful. If you have further questions, please feel free to call Edward Glancy of my staff at (202) 366-2992.

Sincerely,
John Womack
Acting Chief Counsel
ref:583
d.7/25/97

ID: 12975-1.pja

Dana Schuman
1443 Revelation Road
Meadowbrook, PA 19046

e-mail: CloonCraze@aol.com

Via e-mail and mail

Dear Dana Schuman:

This responds to your October 27, 1996 e-mail to President Clinton enquiring about where you could get information about writing a bill to require seat belts on school buses. Your inquiry was referred to the National Highway Traffic Safety Administration (NHTSA) because this agency is authorized to develop motor vehicle safety standards applicable to all new motor vehicles, including school buses.

Before referring you to sources of information on school bus seat belt legislation, I will briefly review this agency's existing belt installation requirements for school buses and the rationale behind them. Small school buses, those with a gross vehicle weight rating under 10,000 pounds, must be equipped with lap or lap/shoulder belts at all designated seating positions. For larger school buses, our requirements only specify that a safety belt must be installed for the bus driver. Note that NHTSA regulates only belt installation. Belt use regulation is left to the States.

We have not required large school buses to have safety belts for passengers because we have not found sufficient justification for such a requirement, given that these buses have excellent safety records. This safety record arises in part from the fact that, in crashes with other vehicles, buses tend to be substantially heavier than the other vehicle. As a result, the crash forces experienced by bus occupants tend to be less than those experienced by car occupants. Also, because of the elevated seating positions in large buses, bus occupants sit above the area typically damaged in a collision with another vehicle. Since the size and weight of small school buses are closer to those of passenger cars and trucks, the agency believes seat belts in those vehicles are necessary to provide occupant protection.

Larger school buses have a protection system so that children are protected without the need to buckle-up. Our regulations require large school buses to use a concept called "compartmentalization," which protects occupants by a protective envelope consisting of strong, closely-spaced seats that have energy-absorbing seat backs. The effectiveness of compartmentalization has been confirmed in studies by the National Transportation Safety Board and the National Academy of Sciences (NAS).

Although large school buses are not required by Federal law to have passenger safety belts, NHTSA does not prevent States and local jurisdictions from requiring safety belts on their own large buses. If you are considering drafting such legislation, we urge you to include provisions designed to promote proper belt use. The NAS report states that if seat belts are to be beneficial, "states and local school districts that require seat belts on school buses must ensure not only that all school bus passengers wear the belts, but that they wear them correctly."

Since no Federal legislation requiring seat belts on school buses has been introduced, the best sources of information are in the two States that have such requirements, New York and New Jersey. We suggest you contact one of the following people:

I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Paul Atelsek of my staff at (202) 366-2992.

Sincerely,

John Womack

Acting Chief Counsel

ref:208

d:12/4/96

ID: 13104.jeg

S. G. Hong
V-Car Safety Team
Daewoo Motor Co., Ltd.
KOREA
FAX: 82-32-520-2837

Dear Sir or Madam:

This responds to your faxed letter asking about Standard No. 208, Occupant Crash Protection. I apologize for the delay in our response.

You noted that passenger cars are required to meet Standard No. 208's occupant injury criteria using the air bag only, and also using the air bag plus the manual seat belt. You asked whether passenger cars are also required to meet the standard's injury criteria using the manual seat belt only. The answer to this question is no.

You also cited the possibility of people being killed in a crash in which the air bag does not deploy, and where the passenger car does not meet Standard No. 208's occupant injury criteria using the manual seat belt only. You asked who would be "responsible" for the deaths.

I note that liability issues are a matter of State law rather than Federal law. We therefore cannot provide an opinion concerning this question.

I hope this information is helpful. If you have any further questions, please feel free to contact Edward Glancy of my staff at (202) 366-2992.

Sincerely,
John Womack
Acting Chief Counsel
ref:208
d.6/16/97

ID: 13171.jeg

Mr. Dietmar K. Haenchen
Process Leader
Safety Affairs and Vehicle Testing
Volkswagen
Mail Code 4F02
3800 Hamlin Road
Auburn Hills, MI 48326

Dear Mr. Haenchen:

This responds to your letter concerning the recent air bag warning label rule (Docket 74-14; Notice 103). You asked whether it is permissible to place a reference to the owner's manual, such as "See owner's manual for further important safety information," on the side of the sun visor bearing the air bag alert label. As discussed below, the answer is no.

Section S4.5.1(b)(3) of Standard No. 208 sets forth the following limitation on providing additional information, beyond what is required by the standard, on the sun visor:

Except for the information on an air bag maintenance label placed on the visor pursuant to S4.5.1(a) of this standard, no other information shall appear on the same side of the sun visor to which the sun visor warning label is affixed. Except for the information in an air bag alert label placed on the visor pursuant to S4.5.1(c) of this standard, or in a utility vehicle label that contains the language required by 49 CFR 575.105(c)(1), no other information about air bags or the need to wear seat belts shall appear anywhere on the sun visor.

Thus, on the warning label side of the visor, the only information, of any sort, that may appear is that specified for the warning label and for the air bag maintenance label. On the alert label side, the only information about air bags or the need to wear seat belts that may appear is that specified for the alert label.

We interpret the term "information" broadly and consider a reference statement such as "See owner's manual for further important safety information" or similar language, added to the alert label side of the visor, to be information about air bags or the need to wear seat belts and therefore precluded by section S4.5.1(b)(3). This conclusion follows from both the context in which this statement would be provided, and the purposes for providing the statement. We also note that the statement is essentially taken from the previous air bag warning label specified by Standard No. 208, which the agency expressly decided to eliminate.

I hope this information is helpful. If you have further questions, please feel free to call Edward Glancy of my staff at (202) 366-2992.

Sincerely,

John Womack
Acting Chief Counsel

ref:
1/31/97

ID: 13193.drn

Mr. Jir Misk
Chief, Type Approval Tests and Technical Regulations
SKODA, automobilov a.s.
Vslava Klementa 869
293 60 Mlad Boleslav
Cesk republika (Czech Republic)

Dear Mr. Misk:

This responds to your request for an interpretation of Area "A" to be wiped on motor vehicle windshields, as specified in Federal Motor Vehicle Safety Standards (FMVSS) 103, Windshield defrosting and defogging systems, and 104, Windshield wiping and washing systems. Your question is answered below.

Your letter states your understanding of two ways in which Area A is to be measured, and asks which of the two is correct:

1. Area 'A' as described in SAE J903 and MVSS 104, may enter into the windshield perimeter zone of 25 mm from the edge of daylight opening in which case the area "A" may be reduced to keep the 25 mm perimeter zone intact for the purpose of calculating the performance of wipers or,
2. Area 'A' as described in SAE J903 and MVSS 104, must always meet both of these requirements at the same time--
   
   1. specific angles 16 to 18
   2. remain (on the windshield) bounded by the perimeter zone of 25 mm from the edge of daylight opening (it can not intervene into the perimeter zone of 25 mm). Area 'A' can not be reduced.

Statement One is correct. Area A is that portion of the total area bounded by the angles in Tables I through IV of Standard No. 104 that is also within a perimeter 25 mm within the daylight opening of the windshield frame. It is not necessary that the windshield be large enough to contain the whole area bounded by the angles (of which 16 to 18 is the left border) as indicated by Statement Two.

S.4.1.2 of Standard No. 104 states the following:

Wiped area. When tested wet in accordance with SAE Recommended Practice J903a, May 1966, each passenger car windshield wiping system shall wipe the percentage of Areas A, B, and C of the windshield (established in accordance with S4.1.2.1) that (1) is specified in column 2 of the applicable table following subparagraph S4.1.2.1 and (2) is within the area bounded by a perimeter line on the glazing surface 25 millimeters from the edge of the daylight opening.

Area A of the windshield is described at S3.1 of SAE Standard J903a. S3.1 states:

[Area A] ... has been established using the angles of Table 1 applied as shown in Figs. 1 and 2. Fig. 1 (side view), the upper and lower boundary of the area is established by the intersection of two planes, tangent to the upper and lower sides of the eye range contour, with the windshield glazing surface. The planes are fixed by angles above and below the glazing surface reference line. Fig. 2 (plan view), the left and right boundaries of the area are established by the intersection of two planes tangent to the left and right sides of the eye range contour. The planes are fixed by angles to the left and right of the plan view reference line.

S3.1's description means that Area A is not a fixed, predetermined area for all windshields, but is an area that varies from windshield to windshield. The variables are the angle of measurement and the width of the car. S4.1.2 of Standard No. 104 adds another variable by describing Area A as within the area bounded by a perimeter line on the glazing surface 25 millimeters from the edge of the daylight opening.

Furthermore, not all of Area A must be wiped. In Standard No. 104, Tables I, II, III, and IV all specify that after the test is conducted, a minimum of 80% of Area A must be wiped.

Please note that since Standard No. 103 references Standard No. 104 in specifying Area A as the applicable cleared area, the above description of Area A also applies to Standard No. 103.

I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Our FAX number is (202) 366-3820.

Sincerely,
John Womack
Acting Chief Counsel
ref:103#104
d:5/6/97

ID: 13208.ztv

Mr. Robert M. Currie
President
Fiber Light Concepts, Ltd.
1102 East Railroad Street
Long Beach, MS 39560

Dear Mr. Currie:

This responds to your letter of December 3, 1996, asking for "an interpretation of NHTSA statutes, regulations, and standards" that apply to your "new after market accessory lighting for all road motor vehicles." We are pleased to assist you.

The product folder you enclosed depicts the "lightrail", described as a "side light fiber optic cable, locked into a full length, heavy duty, aluminum extruded rail." It is intended "for pickup trucks, trailers, emergency, utility and commercial vehicles." It illuminates the side of vehicles at night. Its operation is described as follows: "LIGHTRAIL can be connected for yellow normally on, flash with your directionals, and turn red with your brake lights - or - red normally on and flash yellow/red with your directionals."

First of all, as an accessory for a motor vehicle, "LIGHTRAIL" is "motor vehicle equipment" as defined by 49 U.S.C. 30102(a)(7)(B). This means that its manufacturer must notify purchasers and remedy any safety related defect that may occur in its construction or performance.

NHTSA's Federal motor vehicle safety standard on motor vehicle and motor vehicle equipment lighting, Standard No. 108, establishes after market specifications only for lighting equipment manufactured to replace original lighting equipment required by Standard No. 108. Thus, Standard No. 108 does not regulate "LIGHTRAIL" since this device is not required as original equipment on any motor vehicle.

The sole provision in Federal law that relates to "LIGHTRAIL" as an after market product is a prohibition contained in 49 U.S.C. 30122 against making safety devices and elements inoperative. Under this section, "a manufacturer, distributor, dealer, or motor vehicle repair business may not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable [Federal] motor vehicle safety standard. . ." In applying this prohibition to specific products, we first determine whether the product will prevent the regulated elevemnts of the vehicle from operating. Since "LIGHTRAIL" does not involve disconnection of lighting items, we next examine the effect of its performance on the performance of lighting equipment that Standard No. 108 requires as original equipment on motor vehicles. If the auxiliary lighting device is likely to detract from the purpose of a required lighting device, or create confusion, we regard that effect also as a "making inoperative" within the meaning of the prohibition.

According to the product sheet, LIGHTRAIL has three modes of operation, steady-burning yellow or red in normal operation, steady-burning red when the stop lamps are applied, and flashing yellow/red when the turn signals are activated. The product literature you enclosed shows LIGHTRAIL installed and lit on the sides of two self-propelled vehicles (a pickup truck and a wrecker), and a trailer. Standard No. 108 requires that motor vehicles have side marker lamps at the front and rear. Because your device illuminates the sides of the vehicles, we consider it to be a supplementary side marker lamp. Side marker lamps are permitted to flash with the turn signal lamps and the operation of the device causes us no concern.

What does concern us, however, is LIGHTRAIL's color. The side marker lamps required for motor vehicles must be amber at the front (and midpoint if the overall length of the vehicle is at least 30 feet) and red at the rear. Thus, LIGHTRAILs installed on the side of the box of pickup trucks should be red, to harmonize with the color of the rear side marker, not amber, where they will conflict with the color of the rear side marker. For the same reason, LIGHTRAILs installed on trailers must be amber up to the midpoint of the trailer, and red to the rear of the midpoint.

The legality of the use of supplementary lighting devices such as LIGHTRAIL is, at bottom, a question of the laws of the individual states. We are unable to provide you with interpretations of these laws, and suggest that you contact the Department of Motor Vehicles in each state in which it is likely that LIGHTRAIL will be used.

If you have any questions, you may refer them to Taylor Vinson of this Office 9202-366-5263).

Sincerely,

John Womack
Acting Chief Counsel

ref:108
d:1/31/97

ID: 13241-2.pja

Mr. Frank Smidler
Director of Engineering
Wabash National Corporation
P.O. Box 6129
Lafayette, IN 47903

Dear Mr. Smidler:

This letter responds to your December 11, 1996, letter asking several questions about the National Highway Traffic Safety Administration's January 24, 1996, (61 FR 2004) rear impact protection (underride guard) standards. You asked about using an elastomeric bumper facade to meet the energy absorption requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 223, Rear impact protection. The short answer to your questions is that the elastomeric material, by itself, cannot be used to meet the energy absorption requirements because the requirements call for plastic, not elastic, deformation of the guard. Your specific questions are answered below, in the order that you posed them.

Question 1: S5.2.2 Guard energy absorption states ". . . shall absorb by plastic deformation within the first 125 mm of deflection at least 5,650 J of energy . . .". Is energy absorption through elastic deformation acceptable? (Emphasis in original).

You urge us to interpret the standard to allow for elastic deformation for two reasons. First, you believe that a guard designed to absorb energy by "simple plastic deformation of steel" is more likely to be damaged by repetitive normal impacts of a vehicle with a Gross Vehicle Weight Rating of 80,000 lb with loading docks, thus rendering it useless for the intended purpose of protecting colliding vehicles. Second, you state that elastomeric material would be easier to apply to trailers with low floor heights and other special applications where it is not possible to mount a bumper that hangs down and can pivot back on a long arm during impact.

The standard's required energy absorption cannot be met by elastic deformation of the guard. We interpret the language "by plastic deformation" in S5.2.2 to mean that the required energy absorption will be provided exclusively by plastic deformation. In other words, any energy that the guard returns to the force application device when the load is removed (i.e., the elastic component of the deformation) is subtracted from the total energy absorption for purposes of meeting the requirement. The typical energy absorption curve in Figure 2 (61 FR 2034) shows that the area under the force-deflection curve where the guard rebounds elastically from 125 mm of deflection to about 90 mm of deflection is not included in the shaded area (the shaded area represents the amount of energy absorption counted against the requirement in the standard). There is a discussion in the preamble to the final rule (61 FR 2011) of NHTSA's reasons for requiring plastic deformation.

Please note that the standard does not prohibit the use of elastomeric material as supplemental shock absorbers. The material might be useful in preventing shock-induced metal fatigue for certain guard designs. However, NHTSA believes that the strength requirements of the standard are sufficiently high that most guard designs would stand up to the stresses of normal use without significant degradation in performance.

Please also note that the standard is not prescriptive about guard design, as your letter implied. There is no requirement that "[s]imple plastic deformation of steel" provide the energy absorption. Other materials may provide the deformation, and the deformation may be as complex as desired. There is also no requirement that trailers with low floor heights or any other trailers have a "bumper that hangs down and can pivot back on a long arm during impact to absorb energy." The final rule specifically mentioned that vertical supports were not required (61 FR 2013). Even if the conventional vertical strut guard design would not work well for certain vehicles, other designs could be engineered for these vehicles without resorting to elastic materials.

Question 2: S6.6(c) states that when testing for energy absorption ". . . apply the force to the guard until displacement of the force application device has reached 125 mm." S5.2.2 states ". . . shall absorb by plastic deformation within the first 125 mm of deflection . . .". If our test bumper absorbs the required amount of energy at less than 125 mm of deflection (i.e., ". . . within the first 125 mm . . .") do we have to continue to test load to the full 125 mm of deflection? (Emphasis in original)

No. The test procedures in the standard describe how NHTSA will test guards for compliance with the standard's requirements, and are not binding upon guard manufacturers. They may certify their guards based on other kinds of testing or even engineering analysis, if these provide a reasonable basis for certification. If a guard can pass NHTSA's test after less than 125 mm of displacement, it would be reasonable to assume that it will pass the test if displacement was continued to the full 125 mm, because more displacement will only result in more energy absorption, up to a certain point.

Even if the guard appears to have absorbed the required amount of energy before the displacement has reached 125 mm, NHTSA will continue the test because S6.6(c) states "[i]f conducting a test . . . for . . . energy absorption . . . apply the force . . . until displacement . . . has reached 125 mm." NHTSA does this because it does not know how much elastic rebound the guard will exhibit once the load is removed, and the energy returned during the rebound will have to be subtracted when calculating the total energy absorbed.

Question 3: S6.6(b) states that "If conducting a strength test . . . the force is applied until the forces specified . . . has been exceeded, or until the displacement of the force application device has reached at least 125 mm, whichever occurs first." Is it correct to take this to mean that the strength requirements must be met at or before 125 mm of deflection? The ". . . at least. . . " is slightly confusing.

Your assumption is correct. The words "at least" do not imply that NHTSA will continue to displace the guards beyond 125 mm. If the required level of strength has not been achieved by 125 mm, the guards will have failed the test. The test procedures are based on demonstrating compliance with the requirements, and the relevant requirement, S5.2.1, states "[t]he guard must resist the force levels specified . . . without deflecting by more than 125 mm."

Question 4: Hydraulic guards that are velocity sensitive have been excluded from the energy absorption test with the statement in the January 24, 1996 Federal Register that the NHTSA is unaware of any nonhydraulic guards that are velocity sensitive. We are looking at the contribution of energy absorption of air escaping from an elastomeric bumper facade as it is compressed under load and at high velocity. What must be done to allow the energy absorption of a pneumatic chamber deflating?

Hydraulic guards are defined in S4 as ". . . a guard designed to use fluid properties to provide resistance force to deformation." (emphasis added). Pneumatic guards use the fluid properties of air to provide resistance to deformation. However, the word "hydraulic" is defined as "operated by, moved by, or employing water or other liquids in motion."⁽¹⁾ Therefore, the word "hydraulic" limits the meaning of the word "fluid" to liquids. This is also the common sense meaning of the word "hydraulic."

Like hydraulic guards, guards based on pneumatic resistance of escaping air might not provide sufficient resistance to the slow application of force in Standard No. 223's quasi-static test. Therefore, the quasi-static test is inappropriate for testing guard designs based on the principle of pneumatic resistance of escaping air. Only a change in the standard will allow relying on such a chamber to provide energy absorption.

Question 5: Will we be allowed to use a full width elastomeric bumper facade that does not meet the quasi-static test using an 8" x 8" input plate but that in total provides more energy absorbing potential that a structure utilizing plastic deformation of steel supports that does meet the quasi-static test using an 8" x 8" plate?

No. The requirements are not based on the total energy absorbing potential of the entire structure, but on the energy absorbing potential at the P3 test points using an 8" by 8" plate. Writing a standard based on calculating the "total energy absorbing potential" would be impractical due to the many possible guard designs. In addition, that is not an appropriate measure for guard performance, because the force of an underriding vehicle will normally be concentrated in a certain area, rather than distributed along the entire surface of a bumper facade.

We note that NHTSA has received petitions for reconsideration on certain aspects of the energy absorption requirements, although their resolution probably will not affect our answers to your questions. If you have any further questions, please feel free to contact Paul Atelsek of my staff at (202) 366-2992.

Sincerely,

John Womack

Acting Chief Counsel

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1. Random House Dictionary of the English Language, unabridged edition, 1966.