Automotive safety - Passive safety

You will read in this topic the main passive safety devices that a car has. It could be standard today and normal to see them in cars but it was not the case before. Basically if security has increased (in every vehicules) over the decades it is because of major accidents that has changed designs and laws to reduce wounded people and death. (also a money issue for insurance). You are going to see the two most important passive safety devices in a car.

However, What is active safety? And passive safety?

Active safety in cars = to avoid an accident, it includes all the electronic systems such as A.B.S. (Anti-lock Braking System), E.S.C. (Electronic Stability Control), automated lane keeping system, speed regulator or adaptive cruise control. 

Passive safety in cars = after an accident = crashworthiness, it includes seatbelts, airbags, head restraints, tempered glass or laminated windshield, crumple zones and anti-intrusion bars (when it is a side collison). 

Here let's begin with the three point seatbelt.

It is common to see them in cars because it is mandatory now on new produced cars. In 1959 a Swedish engineer, Nils Bohlin devlopped the three point seatbelt in Volvo's car and Volvo has been pionneers among the automotive industry in security devices. So in 1959, this was patended, but Volvo released it free for the other companies because it was a major found for security and it has protected lots of life. in France, it is mandatory to wear your seatbelt since July 1973. The U.S. follow this mandate a month after France, starting with the 1974 models.

It is preventing the passengers being ejected during a crash or a roll-over. Moreover, the three point seatbelt shape is efficient because it is protecting the shoulders, the pelvis and the chest while moving forward. The material of seatbelts used to be nylon but it was replaced by polyester which is more durable.  

Airbag. 

If you want to know, airbags are not mandatory while producing a car. The only country of where it is mandatory is The United States of America since 1998. Airbags were developed by General Motors and Ford in the 1950's. The process of how an airbag triggers is based on compressed air which blew up a bag in the 45 miliseconds after the impact (which is less than a blinking eye (100 ms)). In fact, it is gaz generated by the combustion of lozenges which blows up the bag. There are different types of airbags in a car now such as side-airbags, side torso airbags or pedestrian airbag.