- Any interior maintenance access panel or joint which lies forward of the passenger compartment.
- Any interior maintenance access panel within the passenger compartment that does not exceed 305 mm when measured across any two points diametrically on opposite sides of the opening.
- Trim and decorative parts which do not contribute to the strength of the joint, support members such as rub rails which are entirely outside of body panels, doors and windows, ventilation panels, and engine access covers.
- Floor Covering
- Heater Hose Cover
- Cove Molding
- Plastic Light Bar Above the Passenger Window
- Parts Mostly Forward of the Passenger Compartment
Robert L. Douglas
Director of Product Integrity
751 South Harkrider
Conway, AR 72034
Dear Mr. Douglas:
This responds to your October 30, 2002 request for an interpretation of whether seven specified parts in a school bus are excluded from the definition of "body panel joints" as set forth in Federal Motor Vehicle Safety Standard No. 221, School Bus Body Joint Strength. At a meeting of October 24, 2002 with agency staff, you provided samples of sections of some parts.
Standard No. 221 Requirements
Standard No. 221 requires, among other things, that each body panel joint, when tested in accordance with the procedure of S6, shall hold the body panel to the member to which it is joined when subjected to a force of 60 percent of the tensile strength of the weakest joined body panel determined pursuant to S6.2 (S5.1). Standard No. 221 defines "body panel joint" as:
the area of contact or close proximity between the edges of a body panel and another body component, including but not limited to floor panels, and body panels made of composite materials such as plastic or plywood, excluding trim and decorative parts which do not contribute to the strength of the bus body, members such as rub rails which are entirely outside of body panels, ventilation panels, components provided for functional purposes, and engine access covers.
S5.2.1 of the standard excludes the following body panel joints from the requirements of S5.1:
In your letter, you state that "metal trim parts" are used to cover the seams created where the rubber floor mat on the aisle meets the other sections of the school bus floor. You informed us that the metal trim part keeps the school bus floor even. You provided a physical sample of the metal trim part that appears to be made of aluminum and measures 25 millimeters (one inch) in width.
We agree that this part is "trim" which "do[es] not contribute to the strength of the bus body."Thus, it is not a "body panel joint" within the meaning of Standard No. 221.
You also described a metal cover for the heater hose supply and return that is positioned between the bus floor mat and the inside of the school bus wall. ![endif]>![if> The cover protects the rubber hose from damage and in the event of hose failure, protects passengers from being injured by scalding from the hot water or steam escaping from the hose.
We agree that the cover is a "component provided for functional purposes" because of its potential use to shield against hot water or steam escaping from the hose. Thus, it is not a "body panel joint."
You state that your company has installed steel cove molding inside the school bus at the wall-to-floor joint. Used to cover any gaps between the edge of the floor mat and the sidewall of the bus, the cove molding is presently secured to the floor with screws and does not attach to the wall.In the October 24, 2002 meeting, you stated that the purpose of the steel cove molding is to prevent schoolchildren from tampering with (by inserting pencils, fingers, etc.) the gaps created where the school bus wall meets the floor. You assert that the cove molding does not contribute to the strength of the joint.
We agree that the cove molding is a trim part and does not contribute to the strength of the bus body. Thus, it is not a "body panel joint."
You provided the following description:
Above the passenger windows, we are proposing to replace the steel light bars with plastic light bars. The interior roof liner panel behind these light bars extends down to the structure just above the passenger windows and is attached at all joints meeting the joint strength requirements of FMVSS 221. The liner will have small openings to provide wire routing to windows and doors. The plastic light bar will cover the wiring and the small openings. It will be retained by snapping behind the window flange on the lower edge and secured with screws to the interior roof liner on the top edge. The joints and ends of this light bar will be covered with formed plastic parts that will blend into the roof liner or other parts of the body interior, and will be secured with screws. We consider these trim parts compliant to FMVSS 221 and are included in S5.2.1(b).
The interior roof liner panel is a structural joint that must meet the 60 percent joint strength requirement because it "extends down to the structure just above the passenger windows and is attached at all joints meeting the joint strength requirement of FMVSS 221." As such, the interior roof liner panel forms part of the integral inner shell and appears to be a weight bearing structure.
You state that the plastic light bar will be placed in front of the interior roof liner panel (so that the light bar faces the passenger compartment). The light bar will be retained by "snapping behind the window flange on the lower edge and secured with screws to the interior roof liner on the top edge." Because of the way that the plastic light bar will be placed, it does not appear to be a weight bearing structure. Given this, we conclude that the plastic light bar is trim or a decorative part and not load bearing. ![endif]>![if> Thus, the plastic light bar does not have to meet the 60 percent joint strength requirement.
S5.2 of Standard No. 221 excludes from the tensile test requirement any joint that lies forward of the passenger compartment. "Passenger compartment" is defined in S4 as:
space within the school bus interior that is between a vertical transverse plane located 762 mm in front of the forwardmost passenger seating reference point and including a vertical transverse plane tangent to the rear interior wall of the bus at the vehicle centerline.
You have three interior parts that you state are partly forward of the passenger compartment.
Item No. One Interior Liner and Roof Lightbar Above the Drivers Side Window
Your question pertains to an interior body panel ("roof interior liner") that is just above the drivers window. It attaches to a steel trim part ("light bar") which covers a gap between the interior liner and the header of the window to the side of the driver. Some portion of the joint formed by the roof interior liner and the light bar falls within the "passenger compartment," while another portion is forward of the passenger compartment. You state your belief that is acceptable to meet the 60 percent joint strength requirement only for that portion extending into the passenger compartment.
Our answer is the portion of the joint that is within the passenger compartment must meet the 60 percent joint strength requirement of S5.1. Stated differently, the entire joint is not excluded from S5.1 merely because a portion of it lies outside of the passenger compartment. A related question you raise is whether the portion of the joint that is forward of the passenger compartment is excluded from the requirement. The answer is yes. We interpret S5.2.1(a) to exclude the portion of the joint that lies forward of the passenger compartment.
Item No. Two Interior Liner Above the Entrance Door
Your next question is similar to the question above for item one. You describe a joint formed by the interior liner and a "motor structure" used with an optional electric door control. You state that the portion of the joint that is within the passenger compartment will meet the 60 percent joint strength requirement. Your question asks whether the portion of the joint that extends forward of the passenger compartment is excluded from the requirement. The answer is yes. We interpret S5.2.1(a) to exclude the portion of the joint forward of the passenger compartment. However, you are correct that the portion of the joint that lies within the passenger compartment must meet S5.1.
Item No. Three Interior Plastic Trim Box Over Entrance Door
You write that above the entrance door, your company installs a plastic trim box to cover the openings and door-operating devices. This box has a plastic "door" that opens in order to service the controls and/or the motor. The box could intrude about 7 inches into the passenger compartment. You state your belief that the mounting of this plastic trim box does not have to meet the 60 percent joint strength requirement.
We agree that the part is excluded. The plastic trim box extends from the roof interior liner at what appears to be a 90 degree angle. As such, it does not appear to be a weight bearing structure or to be part of the integral inner shell of the school bus. Moreover, you inform us that the plastic trim box serves to cover air and electric door controls. For these reasons, we determine that the interior plastic trim box over the entrance door is "trim" that does not contribute to the strength of the roof interior liner, and thus is not a "body panel joint" that must meet S5.1 of Standard No. 221.
I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or at (202) 366-2992.
![endif]>![if> We agree with your assessment that since the cover has no holes or slots for venting, it cannot be considered a "ventilation panel."
![endif]>![if> We are mindful that the requirement you ask about becomes effective January 1, 2003, and that you will need time in which to acquire supplies of the new light bars to fit the extended roof liner panel that would enable IC Corporation to meet S5.1 of Standard No. 221. Since you have timely asked for clarification from us on the issue, we will not enforce S5.1 with respect to these panels for vehicles manufactured by IC Corporation on or before April 1, 2003.