Nebraska Administrative Code
Topic - EDUCATION, DEPARTMENT OF
Title 92 - NEBRASKA DEPARTMENT OF EDUCATION
Chapter 92 - REGULATIONS GOVERNING THE MINIMUM EQUIPMENT STANDARDS AND SAFETY INSPECTION CRITERIA FOR PUPIL TRANSPORTATION VEHICLES
Appendix D - SCHOOL BUS SEAT UPHOLSTERY FIRE BLOCK TEST
A. TEST CHAMBER
Cross Section
The suggested test chamber is same cross section as bus body in which seats are used with rear section on each end. If bus section is not used, cross section to be 91" ± 1" in width x 75" ± 3" in height. There shall be a door, which does not provide ventilation, in the center of each end of the test chamber. The doors shall be 38" ± 3" in width and 53" ± 3" in height and include a latch to keep the doors closed during the test. See Figure 1.
Length
Length of chamber shall allow 3 rows of seats at the minimum spacing recommended by the installer or required by Federal Motor Vehicle Safety Standards. See Figure 1, Detail A.
In order that different types of seats may be tested in the same chamber, a length tolerance of plus 45" is allowed.
Ventilation
One ventilation opening shall be in each end of the test chamber and shall be 325 square inches ± 25 square inches. The bottom of the opening shall be 30" ± 3" above the chamber floor. Ventilation openings shall be on the same side of the test chamber. See Figure 1.
There shall be no ventilation openings along the length of the test chamber.
A forced air ventilation system may not be used.
Baffles shall be used to prevent wind from blowing directly into the ventilation openings.
Camera View Area
An opening covered with glass shall be provided at the midpoint of the chamber length for camera viewing. The opening shall allow the camera to view the seat parallel to the seat width. See Figure 1.
B. TEST SAMPLE
Sample shall be fully-assembled seat.
Record the weight of all padding upholstery prior to assembly. Record the weight of the fully assembled seat.
IGNITION
A paper grocery bag whose dimensions are approximately 7" x 11" x 18" is used to contain double sheets of newsprint (black print only, approximately 22" x 28"). The total combined weight of bag and newspaper shall be 7 oz. + .5 oz.
TEST PROCEDURE
1. Install three (3) seats in test chamber at minimum spacing per installer recommendation of FMVSS requirement. Seats shall be perpendicular to the dimension indicated as "length" in Figure 1 Detail A. Install so that seat frames will not fall during test. Seat width shall be determined so that maximum passenger capacity per row (2 seats) for the seat style shall be tested.
2. For each test, position ignition source in the following positions outlined. Widest seat in the center row shall be tested.
Position A
Position ignition source with 18" dimension in contact with seat cushion and touching seat back. Center bag on top of cushion. See Figure 2.
Position B
Position ignition source on floor behind seat with 18" dimension on floor and parallel to seat width centered on width so that rear of bag does not extend rear of seat back. See Figure 3.
Position C
Position ignition source on floor on aisle side of seat with 18" dimension on floor and perpendicular to seat width touching seat leg with centerline of bag at center of seat back. See Figure 4
3. A wooden match shall be used to light the ignition source. Time the test beginning where the ignition source is on fire until all flame is out.
4. After each ignition source position test, weigh seat assembly including loose materials on the seat. Do not include loose material which has fallen off the seat onto the floor.
C. PERFORMANCE CRITERIA
For each ignition source position test, the seat tested must meet all of the following criteria. A new seat specimen may be used for each ignition source position test.
1. Maximum time from ignition to flameout shall be 8 minutes.
2. Flame shall not spread to any other seat with ignition source in Position A and Position C.
3. Weight loss may not exceed 10% of pretest weight of padding and upholstery.
