School Transportation News November 2009 : Page 52
School Transportation News Magazine | November 2009 Q-U-A-S-I Decoding NHTSA’s new seat testing requirement is easier than it sounds for manufacturers, end-users By Stephane Babcock 52
Q-U-A-S-I SPELL S SAFETY
STEPHANE BABCOCK
Decoding NHTSA's new seat testing requirement is easier than it sounds for manufacturers, end-users
Spells Safety
BEFORE ANY PRODUCT REACHES THE MARKET,
it must go through a gauntlet of testing. Within each industry, there is a set of regulatory agencies that set the standards for this testing, and sometimes changes to the procedures can require companies to alter how their products are certified.
The 2008 NHTSA final rule on school bus seating has done just that, requiring seating manufacturers to begin quasi-static testing, a term that sounds complicated but is actually just the combination of two different tests that companies have already performed in the past.
Quasi-What?
To simplify the term “quasi-static testing,” you must define each part separately: quasi, meaning “almost,” and static meaning “gradually.” The new testing, which will be mandated on school bus seats in November 2011, is a very slow load application. NHTSA developed the quasi-static test to ensure that manufacturers of uni-frame constructed seatbacks did not compromise FMVSS 222.
“I think what the feds were really after, and they talk about this in their final rule, was to make sure if lap/shoulder belts are on school bus seats, that it either compliments or enhances compartmentalization of the seat,” said James Chinni, the director of the Center for Advanced Product Evaluation (CAPE), IMMI’s seat testing facility for SafeGuard, one of the company’s business divisions. “They wanted to make sure that the seats weren’t so flimsy that the seat belts would fold the seat over and reduce compartmentalization protection for any unbelted passengers.”
The new quasi-static test requirement applies existing test capabilities in a new, sequential way.
First, force is applied and held to the rear of the seat using a lower load bar to simulate unrestrained occupants’ knees striking the rear of the seat. Next, force is applied to the torso belt of each seat belt system using semi-circular body blocks. Finally, to simulate unrestrained occupants’ bodies striking the rear of the seat, an upper load is applied to the seat back. The amount of force applied during the test depends on the seat width, capacity and the size of bus in which it will be installed. During the test, the forward movement of the seat back and upper torso belt anchorages are measured.
Working Ahead of the Due Date
Even before NHTSA finalized its 2008 ruling on school bus seats, manufacturers were getting ready for what they knew to be inevitable. CE White started eight years earlier, applying both FMVSS 210 and 222 to its Student Safety Seat, and, according to Executive Vice President Bob Knapp, NHTSA “put their envelope pretty close to the way our seat performed” when it defined the quasi-static test.
“Back in 1999, the talk of the industry was the fact that someday there would be a need for three-point belts in school buses, so we acted on that thought and went ahead and designed the seat,” said Knapp. “At that time, NHTSA had no rules for which that seat was to be built under, so we built it under the rules that we thought would apply, taking into consideration some of the existing rules that NHTSA has for school buses and applying some of the rules the automotive companies have for their three-point belts.”
Other companies worked in the virtual world before performing any actual tests. Syntec Seating Solutions, the manufacturer of the M2K seat, relied on its automotive development tools, such as computer-aided engineering, to develop a seat that would survive the rigors of a school bus.
“Using the lessons learned from our virtual development, we progressed into physical testing shortly before the final rule was published last October,” said Brandon Marriott, general manager of Syntec. “We have run hundreds of actual tests to ensure that our customers, and children, are riding in seats that meet NHTSA performance criteria.”
Unlike IMMI and its CAPE facility, Syntec has performed testing through a third-party company, MGA Research, that is also one of NHTSA’s contract labs for FMVSS 222 testing. Development testing, on the other hand, was done internally at the company’s manufacturing plant in High Point, N.C.
“We wanted an independent, accredited lab to validate our designs without any bias, and we’ve done as much up-front virtual development as possible to keep costs down,” said Marriott.
Testing vs. Certification
In the end, companies understand they must wait until the testing goes into effect to attain certification under the NHTSA rule. Although companies can perform the quasi-static test on their seats, they must also perform the final test on an actual school bus or a section of one.
“Seats do not meet 222, vehicles meet 222,” added IMMI’s James Johnson. “We’ve had our seat tested independently on a hard deck, and it leads me to believe that once it’s installed in the vehicle, the vehicle will very easily pass 222. When you do it outside of the vehicle, it’s practice; then you place it inside the vehicle and the game starts.”
CAPE is currently in the process of updating its testing facility so it can conduct the new quasi-static test in-house.
In the end, all the players in the market have put in the time, money and forethought to assure their seats will meet and exceed any requirements that NHTSA has or will require of school bus seats. It is the thought of all companies that their products, while contributing to the overall success of their balance sheets, must do their job first and foremost, keeping children safe to and from school every day.
“We started this for the safety benefits, not the profit benefits,” added CE White’s Knapp.
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