A HANS device (Head and Neck Support device), also known as a head restraint, is a safety item compulsory in many car racing sports. It reduces the likelihood of head and/or neck injuries, such as a basilar skull fracture, in the event of a crash.
Primarily made of carbon fiber, the HANS device is shaped like a U, but with the back of that U set behind the nape of the neck and the two arms lying flat along the top of the chest over the pectoral muscles. The device, in general, is supported by the shoulders. It is only attached to the helmet, and not to the belts, the driver's body, or the seat; the helmet is attached to the device with the help of two anchors on each side, much like the Hutchens device but placed slightly back. In a properly installed 5 or 6-point racing harness, the belts that cross the driver's upper body directly pass over the HANS device on the driver's shoulders and they buckle at the center of the driver's abdomen. Therefore, the HANS device is secured with the body of the driver, not the seat.
The purpose of the HANS device is to keep the head from whipping forwards and backwards in a crash, (while also preventing excessive rotational movement, as secondary protection) without otherwise restricting movement of the neck. In other words, it allows the wearer to move their head as normal, but prevents/restricts head movements during a crash that would otherwise exceed the normal articulation range of the skeletal/muscular system and cause severe injury. In any kind of crash, the person's body, which is not protected, is decelerated by the seatbelt with the head maintaining velocity until it is decelerated by the neck. The HANS device maintains the relative position of the head to the body, in addition to transferring energy to the much stronger chest, torso, shoulder, seatbelts, and seat as the head is decelerated.
The device was designed in the early 1980s by Dr. Robert Hubbard, a professor of biomechanical engineering at Michigan State University. After talking to his brother-in-law, road-racer Jim Downing, following the death of one of their mutual friends, Patrick Jacquemart who was killed in an IMSA testing accident at Mid-Ohio, when his Renault Le Car struck a sandbank leaving him dead on arrival with head injuries, it was decided that some sort of protection was required to help prevent injuries from sudden stops, especially during accidents. A major cause of death amongst drivers during races was through violent head movements, where the body remains in place because of the seat belts but the momentum keeps the head moving forwards, causing a basilar skull fracture resulting in serious injury or immediate death.
Notable race car drivers who died from basilar skull fractures include:
Hubbard has had extensive experience as a biomechanical crash engineer, including in General Motors' auto safety program. His first prototype was developed in 1985, and in crash tests in 1989--the first to use crash sleds and crash dummies using race car seat belt harnesses--the energy exerted on the head and neck was lowered by some 80%.
After major racing safety companies declined to produce the product, Hubbard and Downing formed Hubbard Downing Inc, to develop, manufacture, sell and promote the HANS in 1990. However, the product languished until 1994, when Formula One showed interest in the wake of the deaths of Roland Ratzenberger and Ayrton Senna. In 1999, CART driver Gonzalo Rodríguez was killed after suffering a basilar skull fracture in a crash. At the same time, Mercedes was completing research of the HANS on behalf of the FIA for Formula One, finally deciding that it out-performed their airbag project.
On February 18, 2001, Dale Earnhardt was killed on the last lap of the Daytona 500, when his car was touched by Sterling Marlin in turn 4, and collided with the outside retaining wall, collecting Ken Schrader in the process. Earnhardt was the fourth NASCAR driver killed by basilar skull fractures during a 14-month span, following Adam Petty; Kenny Irwin, Jr.; and Tony Roper, who all died the previous year. While it is still debated whether Earnhardt's death was the result of a broken seat belt, or an inadequate head and neck restraint, the fact remained that he died of a basilar skull fracture, which is prevented by the proper use of belts and a head and neck restraint. Hubbard was quoted:
"...(I was) shocked by that. I recorded about 80 entries in my telephone log the first day. And I didn't even write them all down. I was on National television 10 times that Monday. I had been down in Florida and came home on Friday and went cross country skiing in Michigan. So, I didn't know he died until I got home and there was voice mail on my answering machine at 10 o'clock at night. I actually had 2 interviews that night before I went to bed."
Before this point, many drivers, including Earnhardt, resisted the HANS devices or anything that was similar to them, claiming that they were uncomfortable, more restrictive and fearing that it would cause more injuries and problems than it prevented. Some even stated that the positioning of the device made the seat belts feel less secure or rubbed on the shoulders or the collar bone. Earnhardt referred to the device as "that damn noose", claiming the tethers would sooner hang him than save him in the event of a crash. The week after Earnhardt's death, Mark Martin said at Rockingham, "I would not wear one for anything. I'll just keep my fingers crossed and take my chances". However, drivers (all but Jimmy Spencer, who still has a HANS device) were not willing to participate in the process of perfecting the fit and endure the limitations imposed by such devices.
The device was first adopted by the National Hot Rod Association in 1996, following the death of Top Fuel driver Blaine Johnson, but was not a mandatory device until 2004, after the death of 2003 Top Fuel Rookie of the Year Darrell Russell, who was killed during the Sears Craftsman Nationals in Madison, Illinois (Darrell Russell was killed by flying debris). Since that time, all drivers in all categories, either professional, or sportsman, must wear a HANS device, or risk immediate disqualification from the event. Much like NASCAR, the NHRA authorized the use of both the HANS, and the Hutchens device until 2005, when the HANS became the sole head and neck restraint device used. The major difference between the HANS device used in NASCAR, CART, or Formula One, and the one used in the NHRA is that the main part of the device is molded from high strength polymers. The NHRA version is also wrapped with seven layers of Nomex fabric, which is the same material as the seven-layer fire suits that all NHRA drivers must wear. This extra precaution prevents the device from melting should an engine fire occur.
Formula One mandated HANS devices in 2003 after extensive testing by Mercedes from 1996 to 1998, sharing the results with other FIA affiliates. Using that information, CART made the device compulsory for oval tracks in 2001, later requiring the HANS devices for all circuits. Starting in October 2001, NASCAR mandated either the HANS or Hutchens device head and neck restraint be used, going with the HANS device exclusively starting in 2005. ARCA followed suit in the wake of a basal skull fracture crash fatality in an ARCA race at Lowe's in October 2001 which claimed the life of Blaise Alexander. The World Rally Championship and Australian V8 Supercar Series made the device compulsory for drivers in the 2005 season.
Acceptance by drivers was helped by the addition of quick-release shackles developed and implemented by Ashley Tilling. They were sourced from the marine industry, being used on racing sailboat rigging. The shackles allowed the drivers a simple and quick pull to release the HANS device and exit their vehicle. The first driver to utilize them was NASCAR driver Scott Pruett of PPI Motorsports. Shackles were also used on the Hutchens device and others.
Today, most major auto racing sanctioning bodies mandate the use of head and neck restraints; the FIA has made HANS devices use compulsory for all International-level events from the beginning of 2009. Even monster truck drivers use the HANS device in many events. Grassroots Motorsports awarded the HANS device the Editors' Choice award in 2002.
Beginning in July 2007, many sanctioning bodies have approved any head-and-neck restraint that passes the SFI Foundation Specification 38.1 standard. Those would be the HANS device itself, the Moto-R Sport, the R3, the Hutch-II, the Hutchens Hybrid, or the Hybrid X.