Thread: Hit large Roo...

He was a big roo, I've hit plenty in my work ute but this one takes it, I did some research as well. If this was a full grown alpha male could weigh 80kgs. The assessor said the same thing as well about the airbags going off. I asked is it by impact or deceleration that causes them to deploy, he said impact. To my understanding the bull bar does not have any sensors mounted on them?

Originally Posted by Canaussie

He was a big roo, I've hit plenty in my work ute but this one takes it, I did some research as well. If this was a full grown alpha male could weigh 80kgs. The assessor said the same thing as well about the airbags going off. I asked is it by impact or deceleration that causes them to deploy, he said impact. To my understanding the bull bar does not have any sensors mounted on them?

I don't think the bar has sensors in it, but I think the assessor may be wrong, again my understanding is all Internet based and may be dodgy, but I think deceleration is the main trigger and then the ECU'S use other data as confirmation.

Originally Posted by Canaussie

............I asked is it by impact or deceleration that causes them to deploy, he said impact. To my understanding the bull bar does not have any sensors mounted on them?

There are sensors at the front of the chassis rails. The impact would have gone through the bar and set off the sensor.

Everything did it's job just right, and everyone, except the roo, came out in one piece.

Billy, also glad to hear you are all ok.
thanks for the photos.
Another tick in the box for Bar work, and more importantly, Airbag compatible barwork. If big mate came for a visit to your wife, I am sure the bag would have helped significantly!
Cheers, Dave.

Originally Posted by Blknight.aus

the powder in the bag is either cornstarch or talc

Didn't used to be Dave .It used to be something else I cannot remember the name (something oxide).It knocked over an accident investigator in Canada.That's why it was changed.
John.

Originally Posted by AnD3rew

Very pleased you are all ok.

I am a bit surprised the airbags went off. As I understand it (and my understanding is pretty limited) it requires a very significant deceleration to set off an airbag (as well as other corroborating data sensed by the ECU's.). I wouldn't have thought even a decent sized roo could cause that much deceleration.

Seems odd to me also. If there was very little deformation and if you didn't hit the bags they were not required in that scenario... Wonder if that is simply an accident not foreseen by the programmers. I would have air bag deployment in that scenario might have caused an accident. Glad you're all ok.
Cheers

Originally Posted by ozscott

Seems odd to me also. If there was very little deformation and if you didn't hit the bags they were not required in that scenario... Wonder if that is simply an accident not foreseen by the programmers. I would have air bag deployment in that scenario might have caused an accident. Glad you're all ok.
Cheers

I agree, I guess it is impossible or at least extremely difficult to set it up so that the airbags will go off correctly in every situation where they are needed and never when they are not and when you have only a few milliseconds to make that decision, but in this situation they were definitely not needed and are likely to do more harm than good, with a very good chance of causing a fatality if the deployment resulted in the driver losing control of the car at speed.

It definitely should have been conceived as a possibility hitting an 80kg non fixed weight at speed as animal strikes like deer are common in many places in the world including Europe and North America. I wonder if the bar actually contributes to this as it will likely distribute the impact and tell t sensors you have hit something across the full width of the car rather than a single point?

The substance used in airbags is "Sodium Azide" which is used to deploy the airbag,ie. when the sensors activate it, an electrical signal ignites the Sodium Azide which burns (for want of a better word) producing an inert gas which is not detrimental to our health. The white powder is like a talc and is there simply to lubricate the bag as it unfolds when deploying. It is not detrimental to our health as such, however it can be an irritant to the respiratory system particularly for asthmatics etc. I'm not completely sure on this next point but I believe the sensors pickup the amount of deformation that occurs at the crush cans that are located within the mounts of he Bull bar or the intrusion beam behind the bumper cover (when no bull bar is fitted), therefore I believe it activates on impact. Some vehicles also have sensors that trigger on deceleration as well.

I may be wrong, this is just my understanding.

Murray