Few people have saved as many lives as Nils Bohlin - the Volvo engineer who in 1959 invented the V-type three-point safety belt. A design as obvious as it was intelligent, it remains as perfectly suited to the seat occupant's body today as it did 50 years ago and still provides the most effective protection in the event of a collision.
Since the 1960s, Bohlin's belt has saved many hundreds of thousands of lives and prevented or reduced the severity of injuries among millions. This makes the three-point safety belt the single most important safety device in the automotive industry's 120-year history.
As confirmation of its effectiveness, Bohlin's invention has been identified by German patent registrars as one of the eight patents to have had the greatest significance for humanity from 1885 to 1985. Bohlin shares this honour with patent-holders such as Benz, Edison and Diesel.
From catapult seats to Volvo vehicles
Engineer Nils Bohlin was born in 1920 in Härnösand, Sweden. He started his career in 1942 at Svenska Aeroplan Aktiebolaget (SAAB) as an aircraft engineer. In 1955 he became responsible for the development of safety systems, including pilot seat ejection systems. Bohlin also expressed interest in the exact opposite phenomenon - keeping the body safe during extreme deceleration.
He soon found the opportunity to develop his ideas. In 1958 Bohlin was recruited to Volvo as a safety engineer by then-president Gunnar Engellau.
Two-point belt not safe enough
During the latter half of the 1950s, Volvo engineers had developed a number of protective systems intended to prevent a vehicle's occupant from hitting interior components or to lessen the severity of such consequences in a collision. These systems included a collapsible steering column, padded dashboard and attachment points for diagonal two-point belts in the front seats.
Volvo had already been equipping its vehicles with anchors for two-point front safety belts since 1957, but early tests of a third "diagonal belt" did not meet the company's safety standards. The inconvenient buckle positioning at the ribcage caused damage to the body's soft organs instead of protecting them.
Volvo president Engellau had a relative die in a road collision, owing partly to the shortcomings of the two-point belt. He therefore gave Bohlin the brief to develop a better alternative.
Bohlin's solution: simple perfection
Bohlin soon realised that both the upper and lower body had to be properly secured in place, with one belt across the chest and another across the hips. His biggest challenge was to create a buckling system that was both effective and simple to use. Bohlin wanted a three-point belt that could be put on using just one hand.
In 1958 his work resulted in a patent application for Bohlin's three-point belt. What Bohlin integrated into his design, and which he regarded as most important for a vehicle's safety belt, involved both a hip or lap belt and also a diagonal belt across the upper body - which was positioned correctly from a physiological viewpoint - and attached at a low anchorage point beside the seat. The belt geometry formed a "V" with the peak pointing down towards the floor. This design allowed the belt to stay in position when it was under load.
The anchorage points was the crucial difference between the effective V-shaped belt according to Bohlin's design and the previous three-point Y-type design. Bohlin's belt was, in fact, an effective demonstration of geometrical perfection rather than a cutting-edge innovation. The solution and the benefits of the three-point design soon spread throughout the world since Volvo immediately made Bohlin's patent available to all automakers.
Volvo first with 3-point belt as standard
In 1959, the patented three-point safety belt was introduced in the Volvo 120 (also known as the Amazon) and PV 544 on the Nordic markets. Volvo thus became the first automaker in the world to equip its vehicles with safety belts as standard equipment.
Despite the two-point belt's relatively poor protective ability, customers initially resisted the Volvo three-point safety belt and perceived it as awkward.
Ahead of the launch of the three-point belt in Volvo's vehicles on markets worldwide, a series of sled tests and trial impacts were first carried out on all the safety belt models available at the time. The results were crystal-clear: Volvo's three-point belt provided by far the best level of protection for the vehicle's occupants. Backed by these results, in 1963 Volvo introduced the three-point safety belt in the USA and on other markets. This meant that all Volvo vehicles leaving the factory were fitted with the three-point safety belt in the front seats.
The belt is equally important in the rear seat
Volvo engineers soon realised the importance of ensuring that all occupants were held securely in their seats, and work on equipping the rear seat with three-point belts began. Volvo vehicles were fitted with attachment points for rear seat belts as early as 1958, but it was not until 1967 that the company succeeded in convincing the public that the rear seat's occupants should also use the belts.
People previously held the belief that just sitting in the rear seat provided protection in a collision - after all, it was in the front that the occupants were in danger. Slowly, the public began to realize that the occupants of the rear seat are hurled forward with a force of 3000-5000 kg in a collision and thus risk seriously injuring both themselves and the occupants of the front seats. Today, wearing seat belts in the rear is required by law and second-nature in many countries.
Safety expert throughout his lifetime
During his time at Volvo, Bohlin came to lead the company's safety drive towards ever-safer occupant protection in Volvo vehicles. He was quick to realise the need for side-impact protection, so in the 1970s he started working on what eventually resulted in the patented Side Impact Protection System (SIPS) of which Volvo was among the world's first automakers to introduce.
After retiring in 1985, Bohlin was consulted by Volvo on a number of occasions regarding particularly complicated safety issues. In 2002, Bohlin succumbed at the age of 82 to complications resulting from a stroke.
One of the auto industry's most important inventors
Bohlin has received many international honours for his work and his development of the three-point safety belt. Many people took the initiative to personally get in touch with Bohlin to thank him when they realised their lives had been saved by his invention.
Both the three-point safety belt and Bohlin received numerous awards, including:
1956 - Grant for continued studies in aviation medicine in the USA, The Swedish Union of Clerical and Technical Employees in Industry
1965 - Award for the best sales-enhancing attribute in 1964 (the Volvo seat), Volvo Dealership Association
1975 - Ralph H. Isbrandt award/medal for best technical report, SAE Society of Automotive Engineers Inc, USA
1977 - Diploma recognising Bohlin's pioneering work in vehicle safety at Volvo, International Association of Accident and Traffic Medicine (6th Int. Conference)
1979 - Safety award for particularly excellent engineering work, NHTSA, USA (ESV conference in Paris)
1985 - Bohlin's safety belt patent listed as one of the eight patents of greatest significance to humanity in the past century (Benz, Edison, Diesel), Germany patent registry, West Germany
1985 - Award for special achievements, NHTSA, USA, (ESV conference in Oxford)
1989 - Nils Bohlin inducted into the International Safety and Health Hall of Fame, USA
1992 - Safety award, Second World Traffic Safety Conference, New York, USA
1995 - Royal Swedish Academy of Engineering Sciences (IVA) gold medal
1999 - Nils Bohlin inducted into the Automotive Hall of Fame
2002 - Nils Bohlin inducted into the National Inventors Hall of Fame