Submarining
Submarining means that the body slips under the lap belt in a frontal accident with a motor vehicle . This can cause severe or fatal injuries to the stomach, chest or neck.
The problem arose in the 1960s with the introduction of seat belts in formula racing cars, due to the sitting posture leaning far back in a flat seat shell, partly made of bare sheet metal without upholstery or slip-resistant cover. Jochen Rindt died in 1970 of chest and neck injuries after slipping under not fully fastened belts. Since then, two leg straps on the inside of the thighs have been common, which, together with the hip straps, ensure that the pelvis remains fixed. Together with the shoulder straps and a central lock, a 6-point belt system is formed. In addition, the seat surface of a racing bucket seat is typically deepest at the hips and significantly higher at the knees, so that an inclined ramp is formed.
In a car there is a risk that the passenger will dive deep into the seat cushion, especially when the belt tensioner is activated . Some car manufacturers, such as BMW , Mercedes-Benz , Saab , Volvo or Volkswagen , integrate so-called anti-submarining ramps into the front seats . These prevent the body from diving under the hip belt. Renault has also integrated an active anti-submarining element since 2006 . This inflates in the event of an impact and prevents the body from diving under the hip belt.
Bucket seat with 6-point belt in a Porsche 911
