The Head and Neck System, HANS for short, is a safety device which became mandatory for the drivers in 2003. The purpose of HANS is to reduce the loads on the driver’s head and neck caused by massive deceleration during an accident. This helps reduce the risk of the driver suffering neck and skull fractures – these are the biggest causes of death in motorsport accidents.
HANS was invented in the mid 1980s by Dr. Robert Hubbard, a professor of biomechanical engineering at Michigan State University. Hubbard and his brother-in-law Jim Downing realised that many racing injuries were due to a lack of head restraint.
When a car makes contact with a wall, it will stop very suddenly. However the laws of physics mean that the head and body will continue to travel towards the wall until they are stopped by their safety restraints. Without head and neck restraints, the head continues forward and hyperextends. The bottom of the rear of the skill can crack from the stress and in doing so, destroy nerve cells that control life functions, cut arteries and cause blood loss.
The HANS device is a semi-hard collar made of carbon fibre and kevlar which weights about 1 pound. It is held onto the upper body by a harness which is worn by the driver. Three flexible tethers on the helmet are connected to the collar. The tethers are loose enough to allow for free movement of the head in ordinary circumstances.
In a crash, the energy absorbed by the neck and skull will be reduced significantly and the force is more directed towards the forehead, which is much better suited to taking the force. Figures suggest that the HANS can reduce head movement in a crash by up to 44%, reduce the force applied to the neck by up to 86% and the acceleration applied to the head by up to 68%.