Feds Hesitant To Alter Roof Test

[Infiniti Z350]

Feds hesitant to alter roof test

NHTSA researchers say different angles show little difference in the damage patterns on vehicles.

By Jeff Plungis / Detroit News Washington Bureau


WASHINGTON -- With a long-anticipated revision in roof-strength regulations nearing completion, officials from the National Highway Traffic Safety Administration indicated Tuesday that they were unlikely to pursue a key change to the agency's longtime test.

Safety advocates have been pushing for a stronger roof-strength test, one that more closely resembles what happens in a rollover. Tuesday's comments from NHTSA, delivered during an international safety conference in Washington, are the latest indication that the agency is taking a conservative approach in updating its roof-strength requirements.

The roof-strength test is the main requirement automakers must meet to lessen the likelihood of injury in a rollover crash. The agency applies force to an angled steel plate to the roof of a stationary vehicle. The roof must be able to bear 1.5 times the vehicle's unloaded weight to pass.

In their presentation, NHTSA researchers said their initial examination of different angles showed little difference in the damage patterns on the vehicles they tested. In subsequent phases of research, the agency dropped the idea of changing the test angles.

"The differences produced from the two load plate angle configurations were small, so it could be concluded that both configurations produce equally realistic roof damage," the agency said in a technical report released Tuesday.

NHTSA spokesman Rae Tyson confirmed that research discussed at the safety conference formed the underpinnings of the revised roof-strength regulation. But Tyson cautioned that the regulation was subject to change. The agency sent its proposal to the White House in late April, where it is under review by the Office of Management and Budget.

"Nothing is final until it comes back from OMB," Tyson said.

Previously, NHTSA has indicated that only a tiny fraction of the more than 10,000 rollover deaths in the United States each year would be prevented by stronger roofs. NHTSA is hoping to save additional lives by combining its revised roof-strength requirements with new regulations to make safety belts more effective in keeping passengers in seats during a rollover.

NHTSA is also researching the effectiveness of side air bags in preventing ejections, another leading cause of deaths in rollover crashes.

But consumer and safety advocates charge that the agency is tinkering at the edges of an outdated rule and missing an opportunity to significantly reduce the number of rollover deaths. They want NHTSA to adopt a full-scale rollover crash test, like the one the agency conducts for frontal crashes that helped spur the development of air bags.

NHTSA's latest findings on the roof-strength test angles were challenged by Carl Nash, a former high-ranking NHTSA official. Nash said his own study of 273 in-depth crash investigations showed that the agency's test angles did not match with real-world rollover crashes.

The roof-strength test, known as Safety Standard 216, involves applying force of up to 1.5 times a vehicle's weight to a steel plate on the corner of the roof. The plate is angled at 5 degrees from front to back, known as "pitch," and 25 degrees from side to side, known as "roll."

Nash said his review of real-life crashes showed a substantial number contained damage that indicated a pitch angle of 10 degrees or more. The 5 degree angle used by NHTSA is an easier test for manufacturers to pass, Nash said, since it puts less force on the front pillars and more on the middle pillars. Front pillars, known as "A" pillars, often collapse in crashes, Nash said.

Nash is an adjunct professor at George Washington University and a partner in Xprts LLC, a California research firm that works with trial attorneys in product liability cases.

Automakers have consistently argued that roof strength is a minor factor in rollover injuries. A series of company-financed studies published over the past two decades suggest rollover injuries are due to occupants' flying out of their seats into the roof in the split seconds before a roof collapses during a crash.

NHTSA has ruled out full-scale crash tests. Agency officials say full-scale rollover crash tests do not meet a legal standard known as "repeatability," meaning the tests result in the same kind of damage every time they are conducted.

The Office of Management and Budget is expected to finish its review of NHTSA's roof-strength proposal by July 28. A spokeswoman for OMB said the agency would not comment on the regulation until the agency's review is complete.

Protecting occupants in rollover crashes was a hot topic at the safety conference, known as the 19th International Technical Conference on the Enhanced Safety of Vehicles.

A team of German researchers studying 434 rollovers in Hanover concluded that "stiffer interior structures" to prevent roof collapses of 30 centimeters or more was an important component in preventing injuries in a rollover crash.

Another German team conducted an in-depth analysis of how a new kind of air bag, deployed from the roof, could prevent serious injuries.

Link: http://www.detnews.com/2005/autosins...D01-208278.htm

[turbotoad]

The roof-strength test, known as Safety Standard 216, involves applying force of up to 1.5 times a vehicle's weight to a steel plate on the corner of the roof. The plate is angled at 5 degrees from front to back, known as "pitch," and 25 degrees from side to side, known as "roll."

I sure hope there is more to the test than that!!! 1.5 times the vehicles weight equates to what, 0.5g ? So basically this test is about the same 20 guys lifting a side of the vehicle and quickly rolling it over on to it's roof

What about the tremendous g-forces involved in a high speed crash? There has to be more than 0.5g exerted as a vehicle SLAMS down onto it's roof.

It seems to me that the test should involve an angled plate (equivelant to the vehicles weight) being dropped/swug into the roof structure. Thus more realistically re-creating an actual crash senario. Simply pushing down on the roof structure (1.5g) cannot duplicate an impact or deceleration forces.

[camaro_freak]

I agree... the "safety" standard doesn't sound very standard to me....

[Aerodynamix]

So they use a stationary vehicle to test rollover forces... wouldn't it be more accurate to simply put a brick on the gas pedal, a bunch of dummies in the seats, and have half the vehicle go up a ramp while the other half stays on the ground so a rollover is induced? You guys know what I'm talking about, right? It's the same thing Hollywood uses for rollover stunts.

[zeobandit]

This definitely needs to be done with a heavier load, especially on SUVs.

[asim]

Yea, especially the explorer

[SSrevolution]

Originally Posted by asim

Yea, especially the explorer

Be thankful GM didn't get all the bad press from crap like that. Ford got royaly screwed by the media on that one. But they should have been smarter, served em right.

[SVT2888]

Originally Posted by Aerodynamix

So they use a stationary vehicle to test rollover forces... wouldn't it be more accurate to simply put a brick on the gas pedal, a bunch of dummies in the seats, and have half the vehicle go up a ramp while the other half stays on the ground so a rollover is induced? You guys know what I'm talking about, right? It's the same thing Hollywood uses for rollover stunts.

The problem with that test would be that you wouldn't get the same consistant results.

[RWD60]

can't they pick them up a certain distance and drop them upside down??? based on how fast they want to simulate, they can calcuate how high up to drop... then do a test for a 40mph crash and a 70mph crash, complete with dummies in every seat.

[runningshoes]

how would that be appreciably different?

[LAMRONH]

Funny, they were so hot to trot on air bags, which have killed hundreds of people. No one would be killed by stronger roofs.
That is the highly skilled bureaucratic mind hard at work with our money.

[Aerodynamix]

Originally Posted by Aerodynamix

So they use a stationary vehicle to test rollover forces... wouldn't it be more accurate to simply put a brick on the gas pedal, a bunch of dummies in the seats, and have half the vehicle go up a ramp while the other half stays on the ground so a rollover is induced? You guys know what I'm talking about, right? It's the same thing Hollywood uses for rollover stunts.

The actual test would of course be a little more refined than what I said and results might not be exactly 100% consistant but at least it would better simulate real-world rollovers.

[RWD60]

Originally Posted by runningshoes

how would that be appreciably different?

my idea?? becasue then the 4000lb thing would hit the ground upside down at 70 mph, simulating... the 4000lb thing hitting the ground upside down at 70mph. right now they just push on them with a weight (and not a very big one.

[Aerodynamix]

Originally Posted by RWD60

can't they pick them up a certain distance and drop them upside down??? based on how fast they want to simulate, they can calcuate how high up to drop... then do a test for a 40mph crash and a 70mph crash, complete with dummies in every seat.

I like this idea because it's simple and it would even work to test both vertical and side forces since all you'd need to do is tilt the upside-down vehicle a little bit before they dropped it.

[runningshoes]

oh, right. you propose speeding teh vehicle along upside down on some sort of elevated track, and releasing it. gotcha.

so... how likely is it for a vehicle, of any size, to, while travelling at 70 mph, find itself suddenly upside down and falling towards the earth from some unspecified height? and without having slowed down? (and if it has slowed down to 70 mph, what kind of initial velocity must it have had!?)

also, lets say you mandate that a vehicle must be capable of surviving such an unrealistc crash situation. you have now mandated that vehicles have unreasonably strong roof structures, and, as such, you have ensured that vehicles will have MASSIVE, ungainly, and exceedingly heavy roof structures, which would actually increase the liklihood of a rollover (more mass higher up), and decrease the vehicle's overall crash avoidance capability.

i'm just not so sure its terribly beneficial.

and of course, you then have the problem of being able to repeatably release the vehicle from this test apparatus (explosive bolts, maybe?), that, itself, must be massive and massively expensive, especially in order for it to be reuseable.

alll to replicate a crash scenario that happens, what, once a year on the autobahn?

a car is not designed to survive a 70-mph crash into a brick wall. why should it be required to survive a speeding upside-down drop at 70 mph?

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