Car Care: Safety: it’s in the bag

AA Motoring
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Front airbags inflate within 8-40 milliseconds. Photo / Supplied

Front airbags inflate within 8-40 milliseconds. Photo / Supplied

Airbags and recalls are often a hot topic. We all know what airbags are designed to do, but do you know how these critical safety items work?

The concept of the airbag has been around since the 1950s. An American guy called John W. Hetrick came up with the idea after his car almost hit a boulder, forcing him to brake suddenly. His wife threw out her arms to protect their children and the concept was born.

There were two main issues that prevented the concept from taking off. One was the ability for the car to detect a collision and inflate the airbag. Another was the inflation itself.

It wasn’t until a couple of decades later when Ford and General Motors began experimenting with airbags that they were first seen in production cars.

However, commercial issues saw both companies then ditch the concept, and it was left to Mercedes-Benz to re-inflate the idea.

The luxury manufacturer offered airbags as an option on its 1984 models. Two years later, airbags were standard on all their new models, and the rest is history.

MODERN AIRBAGS

Swedish company Autolive, which makes many car safety products, has developed a new airbag fitted in the safety belt that inflates in the event of a collision. This helps to prevent injuries to the rib and chest area. It is the latest in a long line of new airbag technology.

Side impact airbags, curtain airbags, knee and torso airbags are becoming increasingly more common in modern cars, and are reducing deaths and injuries.

THE NEXT GENERATION

With the potential for multiple airbags fitted to vehicles, it’s more important than ever to ensure child seats and restraints are installed appropriately.

The front seat should not be used unless all seating positions in the rear seat are used. A rear-facing child seat should never be placed in the front seat especially one fitted with an airbag.

HOW AIRBAGS WORK

Suddenly stopping your car is unlikely to activate the airbags. It usually takes a collision to do this.

When we’ve spoken to people who have been in a crash, they often express their surprise that airbags haven’t activated but a specific set of requirements need to have been met for them to inflate.

When the car's intelligence system senses a dramatic reduction in speed, it activates the airbags.

There are at least two sensors (arming and impact) that both need to sense enough of an impact in order to activate the airbags, and this ensures that they aren’t set off when the vehicle hits a curb or pothole.

Inflation is caused by a chemical reaction which produces nitrogen gas that deploys the airbags.

For front airbags, this inflation takes place within 8-40 milliseconds. For side impact, they need to inflate in less than 15 milliseconds.

You can’t blink that fast!

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