ID: 06-001831 child seat cover

ID: nht94-3.51

TYPE: INTERPRETATION-NHTSA

DATE: June 30, 1994

FROM: Trevor Buttle -- McLaren Cars Limited

TO: John Womack -- Acting Chief Council

TITLE: FMVSS 208 -- Seating Reference Points

ATTACHMT: ATTACHED TO LETTER DATED 10/31/94 FROM PHILIP R. RECHT TO TREVOR BUTTLE (A42; STD. 208; REDBOOK 2)

TEXT: My responsibility within McLaren Cars at the moment is for the homologation within Europe of the F1 road car.

I have been asked to generate a programme and budget for a possible Federal version of this vehicle, and in that context, I have a specific query on Standard 208. I have been told by Mr. Taylor Vincent that you are the man to contact for this.

My reading of the standard is that passive restraints are required only for the front outboard designated seating positions, and that the front centre designated seating position is required to be fitted with a type 1 or type 2 (active) seat belt. The c onfiguration of the F1 places the driver exactly on the longitudinal centre line of the vehicle, and two rear seats (each provided with a type 2 belt) either side of this position. I believe therefore, that although the driver's seating position is prov ided with a four point harness (i.e. not a type 1 or type 2 belt) for Europe, compliance with the standard is generally demonstrated.

Could you please process this enquiry.

FAX

To Ms. Mary Versailles

Office of Chief Council

FROM Trevor Buttle

DATE 8/9/94

SUBJECT FMVSS 208-SEATING REFERENCE POINTS

With reference to our discussion just now, I am 'faxing drawing 1P0004 which should help with my enquiry.

To clarify, the driver seating reference (R) point is shown as X2175 and the passenger seating reference points are shown as X2495, being therefore 320 mm rearward of the driver reference point. The driver 'R' point is described as "(rearmost)" because the seat has 100mm forward travel from that point, unlike the passenger seats, which are fixed with no adjustment.

For all type approval purposes, the passenger seating positions have been regarded and certified as rear row seats.

Please let me know if you require any further information or back-up data for the enquiry. As I mentioned, I will be on vacation from August 24 until September 7, and in my absence, you should contact Mr. Barry Lett for any technical data.

Thank you for your help thus far.

Best regards

ENCLOSURE

(DRAWING OMITTED)

ID: 16856-1.pja

Mr. Gerald W. Remillard
President
Best Trailer Corporation
3614 Badger Road
Kewaskum, WI 53040

Dear Mr. Remillard:

This responds to your letter requesting an interpretation of whether two tilt bed trailer designs that your company is considering manufacturing would be excluded from the National Highway Traffic Safety Administration's (NHTSA's) rear impact protection (underride guard) regulations. As explained below, trailer design #1 probably is excluded as a low chassis vehicle, while trailer design #2 is not excluded, and a compliant underride guard would need to be provided.

Although you did not give bed height dimensions, the diagrams on the literature you enclosed with your letter indicate that the bottom of the bed on both vehicles is more than 560 mm above the ground. Design #1 has at the rear of the bed a full width vertical cross member, which you refer to as a rear channel, with the tail lamps set within it. This channel extends below the lower surface of the bed of the trailer and you state that its bottom surface is less than 560 mm above the ground. There are also two flip up approach ramps, which you refer to as "flipper ramps," that bridge the gap between the ground and the bed when the trailer bed is tilted, and flip over and lie on top of the trailer bed during transit. Design # 2 has at the back of the bed a triangular full width "approach ramp" that allows cargo equipment to transition from the ground up onto the bed without encountering the "bump" of the edge of the bed. When the bed is placed into the horizontal position, for transit, the approach ramp is mechanically or pneumatically lowered to hang from the rear of the trailer in a near vertical position in which the lower edge of the plate is less than 560 mm above the ground.

Federal Motor Vehicle Safety Standard No. 224, Rear impact protection, requires most trailers and semitrailers weighing over 10,000 pounds to be fitted at the rear with a rear impact (underride) guard meeting the requirements of Standard No. 223, Rear impact guards (49 CFR 571.223 and 571.224, published on January 24, 1996 at 61 FR 2004). However, certain kinds of vehicles are excluded. The only excluded categories that are relevant for the purposes of this letter are low chassis vehicles and special purpose vehicles.

Low chassis vehicles are defined in S4 of Standard No. 224 as "a trailer or semitrailer having a chassis that extends behind the rearmost point of the rearmost tires and a lower rear surface that meets the configuration requirements of S5.1.1 through 5.1.3 of this section." In other words, the chassis itself must satisfy the configuration requirements applicable to a guard when the vehicle is outfitted for transit. The only part of your vehicles that may meet these configuration requirements is the rear channel of Design #1 and the approach ramp of Design #2, so the question becomes whether these are considered to be part of the "chassis" of the vehicles. Chassis is defined in S4 as "the load supporting frame structure of a motor vehicle." There are two elements to this definition that must be satisfied: "load supporting" and "frame structure."

To be considered "load supporting," the frame structure has to support load when the trailer is performing its function. Generally, this means that the structure would have to contribute to supporting the cargo load when the trailer is in transit.

To be considered part of the frame structure, a structural member must be either an integral part of the overall frame structure, or be connected with other frame structural members in a way that is necessary to the structural integrity of the trailer. One factor the agency considers in deciding whether a structural member is part of the frame is its size and strength. Frame structural components often are the major structures defining the shape of the trailer. Although frame structure is not limited to the largest frame components (i.e., the frame rails for most trailers), generally frame components are substantial and have strength similar to other frame components. Moveable components may "lock" into the frame structure sufficiently that they are integral with other frame members-in this situation NHTSA may consider the combined components to be one frame unit. However, the agency also looks at the purpose and function of the structural member in supporting the trailer and its load.

We conclude that the rear channel of Design #1 is part of the chassis. It directly supports the load of the trailer. The rear channel is an integral part of the overall frame structure of the trailer. It is of similar size and strength to the other structural members such as the side rails, and it helps define the boundary of the trailer bed. Since a chassis member meets the configurational requirements of S5.1.1 through S5.1.3, Design #1 is excluded from the underride guard regulations.

Applying these principles to your Design #2, we find that the approach ramp is not part of the chassis. The approach ramp does not meet the "load supporting" aspect of the chassis definition because the approach ramp does not contribute to supporting cargo load. The ramp is also not part of the frame structure of the trailer. The approach ramp does not define the shape of the trailer. Instead, it hangs down from the rear end of the trailer, forming a protrusion from the outline of the trailer bed. Neither the approach plate nor the steel plate arms attaching the approach plate to the sides of the trailer bed are of a similar size or strength to the other frame components. The approach plate is not locked into another frame structural member in any manner, and is not considered integral with another frame member. In consideration of these factors the approach ramp it is not part of the frame structure, but an attachment. The approach ramp is not part of the chassis, and Design #2 is not a low chassis vehicle.

We turn now to the question of whether Design #2 is excluded as a special purpose vehicle. A special purpose vehicle is defined in S4 of FMVSS No. 224 as "a trailer or semitrailer having work-performing equipment that, while the vehicle is in transit, resides in or moves through the area that could be occupied by the horizontal member of the rear underride guard, as defined by S5.1.1 through S5.1.3."⁽¹⁾ Again, the approach ramp is the only part of your Design #2 trailer that, while the vehicle is in transit, resides in the area that could be occupied be the rear underride guard. Therefore, the approach ramp would have to be considered work-performing equipment for the trailer to be excluded.

There is no definition in the standard for "work-performing equipment." In determining the meaning of regulatory language, the first place the agency looks is the plain meaning of the words. In the context which is relevant to this safety standard, "work" is defined as "the transfer of energy from one physical system to another; especially, the transfer of energy to a body by the application of force . . ." "Perform" is defined as "to begin and carry through to completion; do." American Heritage Dictionary of the English Language, 1971. Taken together, NHTSA interprets the words "work-performing" to mean that the equipment must actively perform its function, and that the function must involve exerting force or moving something else. Approach ramps do not perform work in this sense because they merely form a ramp between the ground and the vehicle driving onto the tilt bed.⁽²⁾ Therefore, the approach ramp is not work-performing equipment, and the vehicle does not meet the definition of a special purpose vehicle.

Since your trailer does not meet the definition of an excluded category, it would have to be equipped with an underride guard meeting our standards. We cannot provide specific guidance on how your Design #2 trailer might be redesigned to accommodate a guard. We note, however, that other manufacturers of tilt bed trailers have told us that they have found engineering solutions that would meet the requirements of the standard without compromising the function of their vehicles. Some of them are using guard designs that deploy when in the flatbed configuration and automatically retract when in the tilted configuration.

Another option to consider is whether your approach ramp could "be" the guard. The approach plate already appears to meet the configurational requirements for an underride guard. If it does not currently meet the strength and energy absorption requirements, you might be able to reinforce or otherwise modify the approach ramp sufficiently so that it would pass these requirements. If you can do this, the approach ramp itself could be labeled and certified as a guard under Standard No. 223, Rear impact guards. Perhaps some of these solutions would work for you, as they have for other manufacturers of tilt bed trailers. We emphasize that you, as the manufacturer of the vehicle, are responsible for the vehicle's compliance.

If you have difficulty redesigning your trailer, the agency would consider a petition for temporary exemption from Standard No. 224. Under one of our regulations (49 CFR Part 555), vehicle manufacturers may apply for a temporary exemption from the Federal motor vehicle safety standards. Under Sec. 555.6(a), a manufacturer whose yearly production is not more than 10,000 units may ask for an exemption of up to three years on the basis that compliance would cause it substantial economic hardship and that it has attempted in good faith to comply with the standard from which it has asked to be excused. We have enclosed a copy of Part 555 for your information. We have also enclosed a copy of our regulations relating to the protection of confidential business information. Most of the trailer manufacturers submitting petitions for temporary exemption have requested that their financial information remain confidential.

Please note Part 555 requires the agency to publish a notice in the Federal Register seeking public comment on each exemption petition before a decision can be made on such a request, and then publish a second notice either granting or denying the petition. This process normally takes three to four months from the date of submittal.

If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992.

Sincerely,
John Womack
Acting Chief Counsel
ref:224
d.5/22/98

1. Note that this definition, as quoted, reflects an amendment made in response to petitions for reconsideration of the final rule. An unnecessary reference to pipe equipment containing hazardous materials was eliminated. See 63 F.R. 3654 (January 26, 1998).

2. To the extent that this interpretation is inconsistent with interpretation letters to Mr. Thomas M. Joyce and Mr. R. H. Anderson of Landoll Corporation, interpreting the frame rails of tilt bed trailers as work-performing equipment, those prior interpretations are superceded. The basic answer in those letters did not depend on this point, and the analysis in this letter is more thorough.

ID: 19596.ogm

Mr. Lance Tunick
Vehicle Services Consulting
P.O. Box 23078
Santa Fe, NM 87502-3078

Re: Seating Positions

Dear Mr. Tunick:

This is in response to your letter requesting information about seating positions. Specifically, you ask several questions regarding a pair of side-facing folding rear seats that appear in photographs enclosed with your letter. The photographs depict what appears to be a sport utility vehicle or a van with bucket seats for the driver and a front seat passenger, forward folding rear split-bench seats for rear seat passengers, and side-facing folding seats in the cargo compartment. The side-facing seats appear to be anchored to the top of each wheelwell with hinges so that when folded, they partially obscure the rearmost set of side windows. When in use, the seat is supported by legs that unfold when it is deployed.

Your letter asks several questions regarding the side-facing rear seats. First, you ask if the side-facing folding seats are "folding jump seats" as that term is used in 49 CFR 571.3. You then ask if the seats would be considered by the agency to be folding jump seats for the purposes of 49 CFR 571.3, and if the seats, and any belts installed with the seats, would have to meet Standard Nos. 207, 208, or 210. (You recognize that any belts incorporated into the vehicle would have to meet Standard No. 209.) If it is the agency's view that the side-facing folding seats in the vehicle are not folding jump seats but are designated seating positions as set forth in 49 CFR 571.3, you ask if Type 1 seat belts can be installed at these seating positions and whether S4.3.2 of Standard No. 207 or an equivalent would apply. Lastly, you ask, regardless of whether the side-facing folding seats are "jump seats" or "designated seating positions," if the seats could be installed as an aftermarket option (after the vehicle is sold at retail) by a repair shop or dealer without having to comply with Standards Nos. 207, 208 or 210?

The term "designated seating position" is defined at 49 CFR 571.3 as:

any plan view location capable of accommodating a person at least as large as a 5th percentile adult female, if the overall seat configuration and design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jump seats. Any bench or split-bench seat in a passenger car, truck or multipurpose passenger vehicle with a GVWR less than 10,000 pounds, having greater than 50 inches of hip room (measured in accordance with SAE Standard J1100(a)) shall have not less than three designated seating positions, unless the seat design or vehicle design is such that the center position cannot be used for seating.

Although your letter did not include any drawings of the vehicle or the seats, it appears from the accompanying photographs that the seats in question are large enough to accommodate a 5^th percentile female. Accordingly, unless these seats are auxiliary seating positions or folding jump seats within the meaning of Section 571.3, they are designated seating positions.

The terms "auxiliary seating," "temporary jump seat" and "folding jump seat" are not defined in the agency's regulations. In an April 28, 1971 letter to Mr. Keitaro Nakajima of Toyota Motor Company, the agency indicated its view that "folding jump seat" as used in Section 571.3 applied "solely to the type of seat that is used from time to time in such vehicles as taxi cabs and limousines to accommodate, for short periods of time, an excess number of passengers." Examination of the photographs depicting the side-facing folding seats in the vehicle that is the subject of your letter indicates that these seats fit within that definition.

Your letter then asks if the side-facing folding seats would have to comply with Standard No. 207, Seating systems, and Standard No. 208, Occupant crash protection. You also ask, if belts were installed for these seats, if the anchorages would have to comply with Standard No. 210, Seat belt assembly anchorages.

Standard No. 207 establishes performance requirements for seats and their attachments to a vehicle. S4.2 of Standard No. 207 provides that each occupant seat shall withstand certain forces when tested in accordance with the procedures of S5. Occupant seat is defined in S3 of Standard No. 207 as "a seat that provides at least one designated seating position." As noted above, the side-facing folding seats depicted in the vehicle in the photographs attached to your letter do not provide a designated seating position. They are not, therefore, occupant seats as defined in S3 of Standard No. 207 and are not subject to the performance requirements of the Standard. Similarly, the seat belt requirements of Standard No. 208 apply only to designated seating positions as that term is defined in Section 571.3. In addition, S4.1.1 of Standard No. 210 provides that seat belt anchorages shall be installed for each designated seating position for which a seat belt assembly is required by Standard No. 208. As the side-facing jump seats described in your letter are not designated seating positions for the purposes of Standard No. 208, seat belt anchorages are not required for these seats by Standard No. 210.

Lastly, you ask if the side-facing folding seats could be sold as an after-market option, after the vehicle's first sale at retail, and installed by a dealer or auto repair facility.

After a vehicle's first purchase for purposes other than resale (i.e., the first retail sale of the vehicle) the only provision in Federal law that affects a vehicle's continuing compliance with an applicable safety standard is set forth in 49 U.S.C. 301222(b)). That section provides that:

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 motor vehicle safety standard.

Any violation of this "make inoperative" prohibition would subject the violator to a potential civil penalty. However, since Standard Nos. 207, 208, and 210 do not apply to these seats, their installation would not affect the vehicle's compliance with Standard Nos. 207, 208 and 210.

We note, however, that this agency strongly advises that all occupants of light vehicles be properly restrained. Therefore, we would strongly recommend that seat belts be provided for any seating accommodation in a light vehicle (one with a gross vehicle weight rating of less than 10,000 pounds) that is likely to be used while the vehicle is in motion. Similarly, we would advise that crashworthiness performance equivalent to that specified by these standards also be provided to occupants of these vehicles.

I hope that this is responsive to your inquiry. If you have any further questions, please contact Otto Matheke of my staff at (202) 366-5263.

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:571
d.3/7/2000

ID: aiam5432

"Dear Mr. Turner: This responds to your letter of May 2, 1994 requesting an interpretation of how the term 'daylight opening,' as used in a recent amendment of Standard No. 217, Bus Emergency Exits and Window Retention and Release, would apply to various exits (57 FR 49413, November 2, 1992, and 57 FR 57020, December 2, 1992). Your letter references a March 24, 1994 interpretation letter to Mr. Bob Carver of Wayne Wheeled Vehicles. That letter discussed the term 'daylight opening' as follows: 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 object 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 letter states that this interpretation represents a drastic change in what we understood from the wording of the final rule ... and what we were told by Rulemaking. We believed and were told that the definition of daylight opening applied to the exit opening itself and did not involve access to the opening. Access to and obstruction of openings are addressed later in the standard in section S5.4.2 School Bus Emergency Exit Extension. Before answering your specific questions, I would like to respond to these statements. You are correct that S5.4.2 includes requirements related to access to, and obstruction of, exits in that it specifies the minimum opening and the minimum amount of access required for various exits. However, the issue of minimum opening is separate from the issue, addressed in S5.2.3, of the maximum amount of area credited for any opening. Section S5.2.3 specifies the number and type of exits required on school buses. This section states: The area in square centimeters of the unobstructed openings for emergency exit shall collectively amount to at least 432 times the number of designated seating positions in the bus. The amount of emergency exit area credited to an emergency exit is based on the daylight opening of the exit opening. Thus, S5.2.3 specifies the maximum amount of area credited for any opening. An interpretation of the term 'daylight opening' that allowed credit for the exit opening, regardless of obstructions, would be contrary to the plain language of the definition of that term. Giving credit for obstructed areas would also be contrary to the intent of the final rule, which is to increase the area on larger buses which is available for exit in an emergency. With respect to your report of receiving an oral interpretation from agency staff, I would also like to emphasize that, to the extent the public has any questions concerning the meaning of any NHTSA standard or regulation, the only agency interpretations which are authoritative and which therefore can be relied upon by members of the public, such as manufacturers, are those issued in writing by the Chief Counsel. We have reminded agency staff not to make formal, or informal, oral statements that might misinterpreted by manufacturers as official agency guidance on which they may safely rely. Your letter states that the March 24 interpretation 'raises other questions regarding the various school bus emergency exits.' Your questions and the response to each follows. By way of background information, NHTSA does not approve motor vehicles or motor vehicle equipment. The following represents our opinion based on the facts provided in your letter. Rear Emergency Exit Door a. Section S5.4.2.1(a)(1) ... requires unobstructed passage of a rectangular parallelepiped 30 centimeters deep. It is our rationale and interpretation that a seat back or other interior component that lies forward of this 30 centimeter deep parallelepiped is not an obstruction to the rear emergency door and would not result in a reduction of the area credited to the rear emergency door. (See figure 1a) Is this interpretation correct? In the case of a rear emergency exit door, the depth requirement in S5.4.2.1(a)(1) reflects a determination that an interior component outside that limit does not render the exit unusable. Therefore, an interior component outside the area bounded by the transverse vertical plane of the exit opening, the two longitudinal vertical planes tangent to the sides of the exit opening, and the transverse vertical plane parallel to and 30 centimeters away from the plane of the exit opening would not be considered an obstruction for determining the area of 'daylight opening.' b. School buses are typically equipped with 39-inch (99 cm) wide seats. At the rear emergency door, one of the rear seats is typically shifted forward to provide the clearance required by S5.4.2.1(a)(1). The other rear seat is typically allowed to be near or against the rear wall of the bus to fully utilize the available seating floor space and to provide maximum knee clearance. When viewed from the rear, this seat protrudes into the door opening, and according to the (March 24) interpretation ..., the area of the obstruction would not be credited to the exit. Following the logic of the interpretation, the area of the seat itself and the area above the seat could not be credited. We disagree with the logic of the interpretation that door exits are only used by movement along the floor. If the bus is on its side or top, the exit must be used from different approaches. It is therefore our logic and interpretation that only the actual area obstructed (i.e. the area of the seat and the area below the seat) cannot be credited to the exit. For the case in question, the area above the seat can be used in many accident scenarios and therefore can be credited as 'daylight opening.' (See figure 1b) Is this interpretation correct? You are correct that emergency doors will be used by people moving along an interior surface other than the floor if the vehicle is on its side or roof following an accident. As stated in the March 24 interpretation, in determining the amount of daylight opening, you should not credit any area which 'cannot be used for exit purposes.' In the case of the seat illustrated in incoming letter from Wayne, the area over the seat is 6.12 inches by 12.5 inches. However, in reviewing that letter in light of your question, we now agree that the area over the seat may be usable in some accident scenarios. For your exit, neither your letter nor figure 1b provide dimensions of the area over the seat. If the area is large enough to be usable in an accident scenario, that area can be credited towards the daylight opening. c. The rear emergency door on Blue Bird school buses is hinged on the outside, and the top portion of the door is angled forward when the door is closed. When the door is opened and held in the open position by the device required by S5.4.2.1(a)(3)(i), the door protrudes into the exit opening when viewed from a direction perpendicular to the plane of the opening. It is our understanding, based on the interpretation of reference 3, that the protrusion of the door now constitutes an obstruction and the area of the obstruction cannot be credited to the exit area. (See figure 1c) Is this understanding correct? This is correct. Emergency Window Exits The seat backs of school bus seats can protrude into the lower region of side window exit openings. Side window exits when the bus is upright may be used by climbing over the seats. If the bus is on its side or top, the side window exits may be used from different approaches. Since areas of sufficient size above, in front of, and behind a protruding seat back could be used for different parts of the body, (i.e. head, knees, legs) when crawling out a side window exit in different vehicle orientations, it is our logic and interpretation that only the actual area of the seat back in the side window exit opening and the smallest area bounded by the seat back, a horizontal plane tangent to the top of the seat back, and the edges of the exit opening constitute obstructions and cannot be credited to the exit. (See figure 2) Is this interpretation correct? In your illustrations, the area obstructed by the seat back protruding into the window opening clearly cannot be credited to the daylight opening. Whether area above or forward or rearward of the seat back can be credited depends on whether the size of the area is sufficient to be used in exiting the vehicle. Any of these areas which permits passage of the ellipsoid proposed in a December 1, 1993 notice of proposed rulemaking indicates that these areas clearly should be credited (58 FR 63321, see proposed S5.4.2.1(c)). NHTSA proposed this because it believed it reflected the minimum size window which could be used as an exit. If not cut off by obstructions from other unobstructed areas of the daylight opening of the window, as viewed in a plan view, it may be possible that smaller areas should also be credited. In all of the illustrations in figure 2, the seat back extends less than halfway up in the opening. Therefore, it appears that the area above the seat would be credited. We also agree that if the seat protrudes near the front or rear edge of the window opening, it is unlikely that the area between the seat back and the nearest edge of the opening would be usable. However, one of your illustrations shows the seat back protruding near the center of the window opening. In such an instance, it may be possible that the area on each side of the seat back is large enough to be usable. For example, a person might use the window by climbing over the seat, with either their legs straddling the seat, or their head and torso over one side of the seat and their legs over the other. Side Emergency Exit Doors Following the logic presented above regarding the use of emergency exits in different vehicle orientations, we disagree with the interpretation that area A2 (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 door opening, and the edge of the door forward of the seat) ... is not usable. In fact even when using the side emergency door when the vehicle is upright, a person would likely lean over the seat back and hold on to the seat, thus using area A2. Figure 3 enclosed is drawn more to scale than the illustration used in (the March 24 interpretation). We suggest the Agency review this illustration, conduct field research by using the exits in real buses, and then reconsider the interpretation ... regarding side emergency doors. We recommend that area A2 be credited as 'daylight opening' for a side emergency door. As explained in our response to question b on rear emergency exit doors, the area above some seats may be large enough to be credited toward the daylight opening. Front Service Door a. The lower portion of the grab handle on many school bus front service doors protrudes into the exit opening when viewed from a direction perpendicular to the plane of the opening. (See figure 4) Based on the (March 24) interpretation ..., we understand that this protrusion now constitutes an obstruction. Is this understanding correct? This is correct. b. The front service door of most school buses leads to a stepwell and steps used to enter the bus. On front engine transit style school buses, the steps are typically angled to the rear and the riser to the first step is just a few inches inboard of the door opening. It is our logic and interpretation that steps in a stepwell do not constitute an obstruction and their presence does not reduce the area credited to the entrance door opening. (See figure 4) Is this interpretation correct? The steps provide the means of using the door, allowing a person to move between the ground and the floor level of the bus. They do not 'block, obscure, or interfere with, in any way, access' of occupants descending to the front service door. Therefore, although they are visible in the doorway when the doorway is viewed in a plan view, the steps are not obstructions within the meaning of the definition of daylight opening. I hope you find this information helpful. If you have any other questions, please contact my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel";

ID: nht78-2.26

DATE: 04/05/78

FROM: AUTHOR UNAVAILABLE; M. M. Finkelstein; NHTSA

TO: C. S. Ullman

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 28, 1978, to Mr. A. P. Uccello, regarding Federal Motor Vehicle Safety Standard No. 202, Head Restraints (copy enclosed).

In this Standard, under section 4(b)(1), the minimum height of the head restraint shall not be less than 27.5 inches above the seating reference point which is determined with a three-dimensional H Point Machine per SAE Standard J826B placed on the seat. Thus, we have specified a minimum dimension that the car builder must comply with, but we have no limit on the maximum dimension of the head restraint. This latter dimension is set by the builder to suit his requirements.

Certainly your height is a problem in this case and for future rulemaking actions along this line we are placing your letter and the Buick reply in the appropriate docket.

SINCERELY,

February 28, 1978

A.P. Uccello Transportation Dept.

Dear Sir:

You are impossible to get on the phone so I will resort to writing.

I have nothing but plaudits for my '77 Buick but I have written to them about the height of the head restraint (head rests). I am 6' 7" tall and the head rest probably would not prevent whip lash in my case. Previously the head rest was made so it could lock in at least three positions-the highest position was correct for me. Now the head rest only tranerses about 1 inch and does not lock so people getting in the back seat could depress the head rest.

Enclosed please find copy of my reply from Buick. I call your attention to the second paragraph. I would like to know what safety standard effects the head rest? If there is such a standard, then it should be corrected.

I welcome your comment and advice.

THANK YOU.

Charles S. Ullmann

BUICK MOTOR DIVISION, GENERAL MOTORS CORPORATION January 31, 1978

S. C. Ullmann Associates, Inc. 94 Highland Road Scarsdale, NY 10583

Att: Mr. Charles S. Ullmann

Dear Mr. Ullmann:

Thank you for your recent note of January 23, 1978 addressed to our Zone Manager, Mr. R. G. Royer, and we appreciate the interest you have shown in bringing to our attention the characteristics of the front seat head rest supports in your 1977 Buick Electra Limited.

As you probably realize, your car was manufactured in compliance with many vehicle safety standards, and one of these considerations is the head rest suitability throughout the range and size of the car occupants.

However, since we welcome comments from all of our owners, it is with this thought that we are forwarding your letter to the attention of those parties responsible for these design caracteristics.

Thank you again for writing, and please be assured of our interest.

K. J. Mariano Manager, Zone Service Operations

ID: Ravens

Mr. Jeff Shahan
Engineering Manager
Ravens, Inc.
1400 Fairchild Avenue
Kent, OH 44240-1818





Dear Mr. Shahan:

This is in response to your letter requesting an interpretation of the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 224, "Rear Impact Protection," as applied to the Ravens Steel Dump trailer with an 18-inch deep spreader pan bolted or welded to the rear of the trailer. As explained below, the Ravens Steel Dump trailer equipped with such a spreader pan will be required to incorporate a rear impact guard that complies with FMVSS No. 223, "Rear Impact Guards."

You provided a drawing of the Steel Dump trailer with an 18-inch deep spreader pan bolted or welded to the rear of the trailer. According to that drawing, the spreader pan extends across the full width of the rear of trailer, and the top rear edge of the spreader pan is 52 and 3/4 inches above the ground.

FMVSS No. 224 requires most trailers and semitrailers with a gross vehicle weight rating of over 10,000 pounds to be fitted at the rear with an underride guard complying with FMVSS No. 223. The standard does not apply to pole trailers, pulpwood trailers, low chassis vehicles, special purpose vehicles, wheels back vehicles, or temporary living quarters. None of these exclusions apply to the Steel Dump trailer depicted in your drawing.

The Steel Dump trailer clearly does not qualify as temporary living quarters or as a pole trailer, pulpwood trailer, or low chassis vehicle. As explained below, it also does not qualify as a special purpose vehicle or a wheels back vehicle.

S4 of FMVSS No. 224 defines a "special purpose vehicle" as "a trailer or semitrailer having work-performing equipment that, while the vehicle is in transit, resides in or moves through the area that could be occupied by the horizontal member of the rear underride guard, as defined by S5.1.1 through S5.1.3." The National Highway Traffic Safety Administration (NHTSA) interprets the words "work-performing" to mean that the equipment must actively perform its function, and that the function must involve exerting force or moving something. A spreader pan does not perform work in this sense. Therefore, we do not consider the spreader pan to be work-performing equipment, and the Steel Dump trailer does not meet the definition of a "special purpose vehicle."

Moreover, according to the drawing you provided, the spreader pan does not, while the vehicle is in transit, reside in or move through the area that could be occupied by the horizontal member of the rear underride guard. In an interpretation letter issued to the National Truck Equipment Association on September 9, 1998, NHTSA stated that the area that could be occupied by the horizontal member of the rear underride guard, or "guard zone," is the cubic area extending (1) vertically from the ground to a horizontal plane tangent to the bottom of the trailer; (2) laterally to the side extremities of the trailer as defined in S4 of FMVSS No. 224; and (3) from the rear extremity of the trailer, as defined in S4 of FMVSS No. 224, to a transverse vertical plane 12 inches forward. The spreader pan does not reside in this zone; thus the Steel Dump trailer does not meet the definition of a "special purpose vehicle."

S4 of FMVSS No. 224 defines a wheels back vehicle as "a trailer or semitrailer whose rearmost axle is permanently fixed and is located such that the rearmost surface of tires . . . is not more than 305 mm [12 inches] forward of the transverse vertical plane tangent to the rear extremity of the vehicle." A vehicle's "rear extremity" is defined as

the rearmost point on a vehicle that is above a horizontal plane located 560 mm [22 inches] above the ground and below a horizontal plane located 1,900 mm [75 inches] above the ground when the vehicle is configured as specified in S5.1 of this section and when the vehicle's cargo doors, tailgate, or other permanent structures are positioned as they normally are when the vehicle is in motion. Nonstructural protrusions such as taillights, rubber bumpers, hinges and latches are excluded from the determination of the rearmost point.

Since the rearmost axle on the Steel Dump trailer is located such that the rearmost surface of the tires is only 3 and 7/8 inches forward of the rear of the tailgate, but 21 and 7/8 inches forward of the rear of the spreader pan, the question becomes whether the spreader pan is structural and, therefore, constitutes the rear extremity of the trailer.

Merely because an object is attached to the vehicle's body does not mean that the object is a nonstructural protrusion. The attributes that the examples of nonstructural protrusions listed in the definition of "rear extremity" have in common are that they are relatively small and localized and would not have a major impact on a colliding passenger vehicle. The spreader pan is 18 inches in depth and extends the full width of the trailer. Consequently, it cannot be considered relatively small or localized. In addition, according to your drawing, the spreader pan is located 52 and 3/4 inches above the ground. At this height, and without a rear underride guard, the spreader pan could penetrate the passenger compartment of a colliding passenger vehicle. For these reasons, we do not consider the spreader pan to be nonstructural. Thus, the Steel Dump trailer equipped with a spreader pan does not meet the definition of a "wheels back vehicle."

Since the Steel Dump trailer equipped with a spreader pan does not qualify for any of the exclusions, it must be equipped with a rear underride guard that complies with FMVSS No. 223.

I hope this letter answers your question. If you have any further questions concerning this matter, please feel free to contact Mr. Dion Casey in the Office of the Chief Counsel at (202) 366-2992.

Sincerely,





John Womack
Acting Chief Counsel

ref:224
d.1/25/01

ID: 77-3.39

TYPE: INTERPRETATION-NHTSA

DATE: 08/01/77

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Collins Industries, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your June 23 and July 8, 1977, letters asking several questions about the effect of Standard No. 222, School Bus Passenger Seating and Crash Protection, on the construction of school buses with gross vehicle weight ratings (GVWR) below 10,000 pounds.

You first ask whether there are any seat performance requirements for the rearmost seat after April 1978. The rear seat has been exempted from the forward and rearward performance requirements of the standard. This exemption was possible since there are no passengers seated behind the rear seat who could impact with it in a crash situation. Therefore, the rear seat may be positioned against the rear panel if it does not protrude into the emergency exit zone.

In a second question, you ask whether the head protection zone requirements (S5.3), as well as the requirements of S5.1.2, S5.1.3, S5.1.4, and S5.1.5, are applicable to buses with GVWRs of 10,000 pounds or less since these buses are required to have seat belts. The answer to your question is yes. Section S5(b) of the standard states that all of the above sections are applicable to buses with GVWRs of 10,000 pounds or less.

In connection with your question concerning the head protection zone requirements, you submitted sketches of the sidewall and roof structure of one of your buses. In that sketch you depict a 50th percentile adult and show the proximity of that adult with the sidewall-roof structure. You question whether a portion of the bus structure above the window is part of the roof structure subject to the head protection zone requirements.

The NHTSA has determined that the portion of the interior skin that is depicted by the diagonal line connecting the horizontal roof line to the vertically contoured line representing the sidewall is part of the roof structure and must comply with the requirements of the standard for head protection.

SINCERELY,

COLLINS INDUSTRIES, INC.

JULY 8, 1977

TIMOTHY A. HOYT SAFETY STANDARDS ENGINEER NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION

THANK YOU FOR YOUR TIME AND ADVICE, JUNE 29, 1977.

ENCLOSED ARE SKETCHES OF THE COLLINS SUPERBUS INTERIOR SKIN IN RELATION TO A 50 PERCENTILE PERSON SEATED NEAR THE WINDOW. SKETCH A SHOWS THE PERSON IN AN UPRIGHT POSITION, SKETCH B SHOWS THIS PERSON IN A MORE NORMAL POSITION WITH THE BUS LOADED. DO YOU FEEL THAT THE INTERIOR SKIN ABOVE THE WINDOWS, AND NEAREST TO THE OCCUPANTS' HEAD, POSES A HAZARD TO THE OCCUPANT IF THE SKIN IS NOT PADDED?

I AM LOOKING FORWARD TO YOUR REPLY.

JAMES M. BEACH DIRECTOR OF ENGINEERING

ID: aiam0973

Dear Mr. Kato: This is in reply to your letter of January 2, 1973, concernin Truck-Camper loading consumer information requirements.; You have asked whether you have correctly indicated the 'rear end o truck bed' in a drawing of the short body pick- up truck that you attached. The answer is yes. As Mr. Vinson of our staff indicated to Mr. Nishibori when he telephoned on January 9, 1973, 'rear end of truck bed' does not refer to a particular point with the tailgate in either a raised or lowered position. It means, in the words of the preamble of the reissued standard (37 F.R. 26605) 'the point where the identified surface of the camper abuts the rearmost edge surface of the cargo area of the truck, presumably the tailgate in most configurations.'; You also ask if you must meet the requirements of S 575.6 on or afte March 1, 1973. As a manufacturer of a truck that is capable of accommodating a slide-in camper, you must pursuant to 575.6(a) furnish consumer information with each truck manufactured on or after March 1, 1973, at the time the vehicle is offered for sale. Material for examination by prospective purchasers, pursuant to 575.6(b) should be made available at dealer showrooms no later than the date that trucks manufactured on or after March 1, 1973, are first offered for sale by such dealers. The NHTSA has been petitioned to delay the effective date by 60 days and this request is under consideration.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: aiam0974

Dear Mr. Kato: This is in reply to your letter of January 2, 1973, concernin Truck-Camper loading consumer information requirements.; You have asked whether you have correctly indicated the 'rear end o truck bed' in a drawing of the short body pick- up truck that you attached. The answer is yes. As Mr. Vinson of our staff indicated to Mr. Nishibori when he telephoned on January 9, 1973, 'rear end of truck bed' does not refer to a particular point with the tailgate in either a raised or lowered position. It means, in the words of the preamble of the reissued standard (37 F.R. 26605) 'the point where the identified surface of the camper abuts the rearmost edge surface of the cargo area of the truck, presumably the tailgate in most configurations.'; You also ask if you must meet the requirements of S 575.6 on or afte March 1, 1973. As a manufacturer of a truck that is capable of accommodating a slide-in camper, you must pursuant to 575.6(a) furnish consumer information with each truck manufactured on or after March 1, 1973, at the time the vehicle is offered for sale. Material for examination by prospective purchasers, pursuant to 575.6(b) should be made available at dealer showrooms no later than the date that trucks manufactured on or after March 1, 1973, are first offered for sale by such dealers. The NHTSA has been petitioned to delay the effective date by 60 days and this request is under consideration.; Yours truly, Richard B. Dyson, Assistant Chief Counsel