August 13, 1959 was a very special day for Volvo and those whose lives would be saved by our invention, the three-point seat belt. After its invention, Volvo opened the patent to anyone who wanted to use this simple device. In 1972, the U.S. Department of Transportation mandated that all cars sold in America would have three-point seat belts for front-seated occupants.
Over one million people are celebrating their birthday this year thanks to a Swedish engineer whose cleverness led to an evolutionary technique to make a simple passenger restraint system: the three-point seat belt; the single most effective life-saving device ever used in road transportation.
In the U.S., the National Highway Traffic Safety Administration estimates that each percentage increase in seat belt usage would save 270 lives a year. Studies by the Global Road Safety Partnership in Europe show that another 7,000 lives would be saved if every European Union country had the same usage statistics as the top-performing countries. The potential is even greater in parts of Africa, Asia and South America where the number of vehicles is increasing very quickly. Think of how many more birthdays could be had with just a simple “click;” more birthday cakes, candles, and happy faces.
“We all know we should buckle up, but very few understand the forces involved in an accident,” states Adam Kopstien, Manager, Product Safety & Compliance at Volvo Cars of North America. “An unbelted 160-pound man, hitting a tree at about 30 miles per hour is subject to approximately 150 Gs (gravity-force) or an impacting force of around 12 tons. To put that into perspective, a jet fighter pilot performing a tight turn is subject to 9-12 Gs. That’s why it is so critical for people to wear their seat belts.”
Seat belts save lives, that’s a given. The reality is some people believe an airbag will save their lives. Airbags are Supplemental Restraint Systems (SRS) and are meant to aid a seat belt, but not act as the primary restraint in a collision. An unbelted occupant increases their risk of impacting the steering wheel or dashboard or being ejected through the windshield. Nothing protects better than a three-point seat belt.
How to calculate impacting body weight:
This example is an approximation of impacting forces transmitted to the human body. In general, this assumes a car hitting a tree at 30 mph with a 160-pound driver:
• Belted with belt webbing that is elastic: 20 Gs, meaning the driver now weighs 1.6 tons
• Belted with belt with no elasticity in the webbing: 30 Gs, which equals 2.4 tons.
• Unbelted: 150 Gs or 12 tons.
DIY calculations: Weight x G force. 160 pounds x 20 Gs = 3,200 pounds (1.6 tons)
“August 13th is our three-point seat belt’s 50th. We are very proud to have added so many birthday candles to so many people’s cakes, even those who have never driven our cars,” comments Kopstein. “We are very proud that there is a little bit of Volvo in all cars.”