Seatbelt use is legal in the United States and many other countries. Studies and crash investigations show that crash survivability dramatically increases with Seatbelt use. Since the use of belts is so ubiquitous, people rarely think about how these lifesaving devices actually work. Understanding seatbelt operation may encourage you to wear the restraint each and every time you get in your vehicle.
Construction
Seatbelts are made from a woven material. This webbing imparts a certain degree of stretch during impact. This reduces kinetic forces on your body as it continues to move forward during a collision. The material and general construction are designed to not only be reasonably comfortable but to give to a certain degree to prevent the belt from snapping under shock.
Moderate stretching also helps reduce the forces exerted on the human body during a sudden stop. Attached to the belt is a series of gears and latching mechanisms, responding to sudden movement or changes in the belt’s position.
Configuration
Most seatbelts are configured in a two-piece manner. The shoulder belt spreads impact forces across your torso, reducing excessive pressures on a small part of your body. The shoulder belt also reduces the overall likelihood that your head will collide with the steering wheel, dashboard or the seat in front of you.
Working in conjunction with the shoulder harness is a lap belt. This keeps you planted in the seat, reducing or eliminating the possibility of ejection from the vehicle during a rollover. Lap belts also work in concert with the shoulder harness, keeping your body from flying into the dash during a crash. Five-point harnesses, used in racing and some off-road vehicles, prevent almost all motion in multiple directions during a rollover or forward impact.
Supplementary Restraint
It has been proven over the decades that seatbelts alone are often insufficient. For this reason, airbags are mandatory in many parts of the world. These powered bags explode forward in a collision, buffering passengers from hitting the hard plastic or internal components of the vehicle.
Seatbelts and airbags are designed to work together. Not wearing a seatbelt while colliding with a deploying airbag is also harmful and, for children and small adults, potentially fatal. Airbags deploy in a manner that distributes contact forces across a wide portion of your body, helping to disperse the impact.
Why It’s Law
Not wearing a seatbelt in nearly all driving scenarios creates unnecessary risk to the driver or passenger. Ejection or collision with the dash is virtual certainties during any collision or rollover event. Kinetic energy keeps unsecured objects inside the vehicle in forwarding motion while the vehicle suddenly stops. If you aren’t wearing a seatbelt, that includes you.
It is impossible to stop the violent motions involved during a collision on your own. An average human weighing 160 pounds imparts 4,800 pounds of force on a seatbelt if you’re wearing one. Without one, massive internal damage and possibly death or incapacitation occurs at as little as 30 miles per hour.
The post How Do Seatbelts Work? Explained In Easy To Understand Details appeared first on A car blog.
