Are airbags linked to seatbelts?

[Packard]

I read this from the Insurance Institute of Highway Safety (IIHS).  It sounds like the seatbelt use triggers a different response from the airbags:

For unbelted occupants, a front airbag will typically deploy when the crash is the equivalent of an impact into a rigid wall at 10-12 mph. For belted occupants, most airbags will deploy at a higher threshold — about 16 mph — because the belts alone are likely to provide adequate protection up to these moderate speeds.

The full quote is located here: https://www.iihs.org/topics/airbags#

 

[Mini Me]

Air bags are different in the pressure they inflate at in markets that do not have mandatory seat belt requirements, the US was one such market but that may have changed now.

 

[AstroKeith]

Yes, in most modern cars they are. The same sensor that reminds you to fasten the belt tells the airbag controller.

Also, the seat belts often have tensioners that at the same time as the air-bags deploy, the belt tightens.

 

[montyss]

The Seat Belt tensioners go off milli seconds before the Steering wheel Airbag or Passenger dash air bag so that the charge in the seat belt Tensioner will pull you back into your seat away from the inflating Air Bags.

 

[Packard]

So, if you are driving along at 16 mph, and you get in a fender bender, you would expect at that low speed that no one would get hurt.

But if your front seat passenger is using a tablet, the airbag would launch into that passenger’s face.  If the screen glass shatters, that would be bad.

Or, I see teenage girls riding with one or more feet up on the dash.  The airbag could do horrible things to her back.

In fact the only thing that passenger should have is a paper magazine or newspaper.

And Starbucks still sells drink cups with rigid plastic straws.  An airbag could drive that spike right through the soft palette of the mouth into the brain stem.  (Though these seem safer than the stainless steel straws).

My problem is that I have been burdened with a too active imagination.

 

[Mini Me]

Legs on the dashboard guarantees smashed knees and a smashed face and most probably spinal injuries. Having the seat reclined usually means submarining out of the belt as the bag goes off above you.

 

[kevinculle]

...if you are driving along at 16 mph, and you get in a fender bender, you would expect at that low speed that no one would get hurt.

The specs discussed above are based on the energy equivalent to a crash into a rigid structure (like the barriers used to develop and certify ACRS) at 16MPH, which is very, very different from a vehicle-to-vehicle impact where energy absorbent structures in both vehicles act to ease deceleration rates.  Take it from a guy who was hit head-on by a drunk 50 years ago driving a vehicle twice the mass of mine, with both of us travelling about 35MPH, airbags are your best friend when they deploy.  Are they perfect?  No, nothing is but I would have gladly traded the 140 stitches in my face for a bit of airbag rash.  When I looked in the mirror the morning after it looked like I had gone 15 rounds with Muhammed Ali...with my hands tied behind my back.

 

[Crazyraceguy]

There is some kind of sorcery involved with seatbelt tensioners. They are electronically controlled, somewhat tied to the airbag system, and they can lock by rapid movement. There is a counterweight in the mechanism that stops the travel if is too quick.
Of course, all of this is dependent on the age of the vehicle. I have owned/driven a whole lot of them that were made way before this technology existed, even a couple that didn't have seatbelts.

 

[Ron B]

Of course, all of this is dependent on the age of the vehicle. I have owned/driven a whole lot of them that were made way before this technology existed, even a couple that didn't have seatbelts.

Seatbelts were optional at one time in the US.  I think Tucker Automobile (the car with a middle headlight that pivoted with the steering) was the first. My Dad had a 1966 Chevy Impala with seatbelts-I think that was the first year they were required.  I later owned a 1964 Studebaker Champ pickup and it did not have seatbelts. 

 

[Crazyraceguy]

Yes [member=72457]Yardbird[/member] I think you are correct. Tucker had several innovations that were way ahead of its time.
The Federal mandate for seatbelt installation was 1968, though many vehicles had them before that.
The really crazy part is that there was no legal enforcement for actually using them.
Those original units were just lap-belts too. The cars that did have shoulder straps, it was an additional unit that clicked into the main buckle. Many of them clipped into a hook in the headliner above the side window.

 

[Packard]

My dad had an early 1960s Saab that came with shoulder harnesses and a built in roll bar.  I rolled the car, so I know both worked.

It also had a 3 cylinder, 2 cycle engine and he had to add oil to the gas each time you filled up.  And “free wheeling”, which meant you could shift gears (a manual transmission) as long as you were not accelerating, without using the clutch.

He later got the “sports” edition (1963 Monte Carlo edition)which was supposedly identical to the model that Erik Carlsson drove to win the European rally that year.  It had 3 Weber carburetors, one sitting on each of the 3 cylinders. It was also one of the earliest passenger cars with disc brakes.  But seriously uncool to me as a teen.

But the shoulder harness is almost certainly the reason I’m here to type this post today.  So, thanks, Saab.
https://en.wikipedia.org/wiki/Erik_Carlsson

 

[AstroKeith]

So, if you are driving along at 16 mph, and you get in a fender bender, you would expect at that low speed that no one would get hurt.

But if your front seat passenger is using a tablet, the airbag would launch into that passenger’s face.  If the screen glass shatters, that would be bad.

Or, I see teenage girls riding with one or more feet up on the dash.  The airbag could do horrible things to her back.

In fact the only thing that passenger should have is a paper magazine or newspaper.

And Starbucks still sells drink cups with rigid plastic straws.  An airbag could drive that spike right through the soft palette of the mouth into the brain stem.  (Though these seem safer than the stainless steel straws).

My problem is that I have been burdened with a too active imagination.

The crash sensor is set to trigger airbag deployment above the 'fender bender' threshold.

 

[Packard]

Still, even if you hit a brick wall at 16 mph, you would not expect to have any injuries.

But depending on what the front passenger is holding in his hands, it could kill them.  A shattered glass tablet screen could leave a scar that resembled a spiderweb.  I met a girl that had that injury.  The surgeon did an excellent job.  The pattern of the scar only showed when she laughed, smiled or cried.  But still, an avoidable injury.  Front seat passengers have to be aware that the airbags can turn a “nothing” accident into a serious one.