The most common truck accident scenario is where the truck either rolls over or is hit from the front. Volvo’s impact test focuses on simulating the forces that the cab is subjected to under such circumstances.
“It is important that the impact test reflects the sequences and forces to which the truck is subjected in a real-life accident. Our road accident research offers a clear picture of the impact test’s importance. Our investigations of Volvo trucks involved in accidents have shown time and again that a strong cab saves lives,” says Almqvist.
From wood to steel; Volvo test becomes legal standard in Sweden
Once upon a time, all cab trucks had a wooden structure. Volvo Trucks has always focused on safety, and in 1948 the company was the first truck maker to launch series production of steel cabs. The self-supporting steel cab with its three-point suspension system revolutionised both the truck market and on-board safety for truck drivers. In 1959, the first tests were carried out in which a solid pendulum weighing one tonne struck the cab to test its strength. The following year, this impact test was adopted as the legal standard in Sweden, which remained in force until April 2009. It has now been replaced by an EU law (ECR 29). The new law differs from the Swedish impact test both with regard to structure and the forces to which the cab is subjected in the test.
“What was previously a Swedish requirement is now a unique Volvo requirement. As leaders in the field of safety, we don’t want to compromise on our aim of making the toughest cabs on the market. That’s why we’ve decided to maintain our tougher standards in the future too,” explains Almqvist.
Three-stage impact test
Volvo Trucks’ impact test has been developed and refined over the decades. However, the test still consists of three stages as it has done for the past 50 years:
First, the cab’s roof is subjected to a weight of 15 tonnes. After this, a cylindrical pendulum strikes the cab’s front left supporting pillar. Finally, the pendulum strikes the rear wall of the cab. This pendulum weighs one tonne and is released from a height of three metres.
“These three stages correspond to an accident sequence in which the truck drives off the road, rolls over and hits a tree or other hard object. The impact at the rear simulates the truck’s cargo sliding forward and hitting the cab from behind,” says Volvo Trucks’ safety expert Ulf Torgilsman.
In order for the cab to pass the test, the resultant deformation may not compromise the driver’s or other occupants’ survival space. The cab has to retain its original structure, without any large holes or protruding sharp edges. The doors must remain shut, yet must be able to be opened without tools after the impact test.
“The doors must be able to be opened no matter how badly the cab is damaged. Being able to evacuate the driver immediately after an accident is crucial,” explains Torgilsman.
Constant structural improvements
During the impact test’s 50-year history, truck cab structure has been improved in areas such as design, steel strength, attachment security and welding techniques.
Each improvement has been subjected to new impact tests to verify that the new solutions meet Volvo’s stringent demands.
“It’s important to stress that the cab is part of our systematic dedication to protecting the driver and passengers in the event of an accident. This approach also includes features such as the three-point safety belt, airbags and an interior that deforms in accordance with the occupants’ body weight,” says Torgilsman.
“The safety belt is still the truck driver’s best life insurance policy. If you are strapped securely into your seat, you significantly reduce the risk of being injured or killed if the truck crashes or rolls over. Incidentally, the three-point safety belt is a Volvo invention,” he adds.
December 8, 2010
See slow motion images showing how an impact test is conducted. Visit
Volvo Trucks’ YouTube channel.
Volvo Trucks was the first truck maker to introduce series production of steel cabs. The self-supporting steel cab with its three-point suspension system revolutionised both the truck market and on-board safety for truck drivers. In 1959, the first tests were carried out in which a solid pendulum weighing one tonne struck the cab to test its strength.
Volvo Trucks’ impact test has been developed and refined over the decades.
Carl Johan Almqvist, Traffic and Product Safety Director, Volvo Trucks.
Ulf Torgilsman, the person responsible for the many impact tests conducted by Volvo Trucks every year.
For further information, please contact:
Marie Vassiliadis, Media Relations Europe, phone +46 31 322 41 27, e-mail marie.vassiliadis@volvo.com
