30-04-2011, 10:29 AM
Submitted by
PARTH UMESH SUROTIA
HANS IN F-1 RACING
HISTORY
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, after the death of one of their mutual friends, Patrick Jacquemart who was killed in IMSA testing accident at Mid-Ohio, when hisRenault Le Car struck a sandbank leaving him dead on arrival with head injuries,[1][2] 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:
Formula 1 driver Roland Ratzenberger[3] in the 1994 San Marino Formula One Grand Prix
Indy 500 drivers Bill Vukovich and Tony Bettenhausen
NASCAR drivers Adam Petty, Tony Roper, Kenny Irwin Jr., Terry Schnoover, Grant Adcox, Neil Bonnett, John Nemechek, Dale Earnhardt, J. D. McDuffie and Clifford AllisonARCA
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 1991. However, the product languished until 1994, when Formula 1 showed interest in the wake of deaths of Roland Ratzenberger and AyrtonSenna.
The device was first adopted by the National Hot Rod Association in 1996, following the death of Top Fuel driver Blaine Johnson, but wasn't a mandatory device until 2004.
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 theHutchens 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 1, and the one used in the NHRA is that the main part of the device is molded from high strength polymers, and custom made to fit the individual driver. 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.
(NASCAR driver Ken Schrader's HANS device)(2005, 2006 and 2007 WTCC ChampionAndy Priaulx with a
HANS device)
Formula One mandated HANS devices in 2003 after extensive testing, 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.
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 use compulsory for all International-level events from the beginning of 2009. Even monster truck drivers use the HANS device in many events.
Starting in July 2007, many sanctioning bodies have approved any head-and-neck restraint which passes the SFI Foundation Specification 38.1 standard. They are the HANS, Moto-R Sport, R3, Hutch-II, Hutchens Hybrid, or Hybrid X.
INTRODUCTION
Simply put, the HANS device is as its initials stand for: Head and Neck Support. It is designed to prevent violent movement of the head and neck, which often has fatal consequences.
HANS was invented by Dr. Robert Hubbard, a Professor of the College of Engineering at Michigan State University, in conjunction with his brother-in-law, racer Jim Downing. Their goal was to reduce the potential of serious and fatal injures resulting from violent movement of the unrestrained head.
The system features a collar and yoke constructed of carbon fibre and Kevlar composites. The device extends from front to rear as it sits on the shoulders and is connected to the helmet by 2-3 flexible tethers which allow the minimum necessary head movement to drive a racing car.
Following comprehensive testing at Wayne State University, the support of General Motors, and race use by Downing, the first unit went on sale in 1991.
In October of 1996, a joint venture comprising of McLaren International, Mercedes-Benz, and the FIA, was created to research a driver restraint system for head-on and oblique frontal impacts, with a crash angle of up to 30°.
DaimlerBenz contracted Hubbard/Downing, Inc. for joint testing and development to make the HANS device suitable for Formula One competition. Initial tests - run in a Formula 3000 monocoque specified to 1998 Formula One cockpit regulations - proved successful, and in April of 2000 at the San Marino Grand Prix in Imola the final reports were released and with the approval of the FIA Safety Committee, HANS was recommended for use.
"This is a major step forward in the search to introduce ever-improved safety standards in Formula One," Max Mosley, president of the FIA, exclaimed. "It is particularly significant that the research has been carried out jointly with one of world's major car manufacturers. This shows how motor sport is a research medium for the motorcar industry not only for performance, but also for safety."
Mosley's words were also echoed by Jurgen Hubbert, Member of the Board of Management of DaimlerChrysler. "We are happy to take up the suggestion from the FIA of bringing our knowledge and our many years of experience of safety engineering for production vehicles to the HANS project and possibly also other further research projects. We consider this to be a significant contribution towards making the fascinating sport of Formula One even more safe."
McLaren-Mercedes's David Coulthard and Ferrari's Rubens Barrichello tested HANS during the Formula One winter testing season. Development will continue with the aid of improving driver comfort. HANS is strongly recommended for the 2001 season and will become requirement for 2002.
The system of collars and tethers is designed to keep the head and neck in plane with the body in violent impacts. Below are average strengths of the head and neck. The force withstood is dependent on location of impact, strike object size, and bone tissue density amongst other factors.
• Frontal bone (forehead): 1,000 to 1,600lbs of force
• Temporal-parietal (sides of head): 700 - 1900lbs of force.
• Rear skull: 1,440
• Facial: 280 - 520
• Neck (under forward movement): 140
In a full human form crash test simulating a 40mph dead stop impact utilising the HANS device, neck loading was kept under 130lbs whilst the unrestrained head endured over 1,000lbs
"As soon as your head - which weighs, with the helmet, 13 or 14 pounds - has a sudden acceleration, it stretches your neck," Downing explains. "If it stretches a little too far, you get a neck fracture or a skull fracture at the base of the skull where your head connects to your spine. With HANS on, the head sort of goes forward then back and looks OK. At the same speed with a fully belted dummy, the head smashes into the steering wheel and it's just appalling. The drivers say, 'Wow. That can't be.' In layman terms, keeping your head close to your body is what it's all about with HANS."
The weight of the head and helmet pulling at the neck can be sufficient to fracture the skull. Known as basal skull fracture (hangman's noose analogy), these injuries can often be fatal. Roland Ratzenberger (F1, 1994); Scott Brayton (IRL, 1996); Adam Petty and Kenny Irwin (NASCAR, 2000) - they all suffered basal skull fractures. Greg Moore's horrific crash in the 1999 CART season finale included basal skull fracture, but other head and neck injuries compounded his incident. There is even speculation by experts that Ayrton Senna would have suffered similar fractures, however the official cause of death was listed as shrapnel penetration of the brain.
BASIC CONCEPT
In a crash without HANS, the shoulder harness and seat restrain the driverâ„¢s torso, but only the neck restrains the head and helmet. The HANS device keeps the driverâ„¢s head from being pulled away from his upper body. With HANS, forces stretching the neck are reduced to less than one-fifth in a frontal collision as slow as 41 mph. The HANS works in a simple and elegant manner.
A CFRP yoke is worn by the driver fitted around his neck and under the shoulder belts. His helmet is loosely connected to this yoke by tethers ensuring free movement of the head. In a frontal crash, these tethers restrain the head with forces that directly counteract the headâ„¢s forward movements while the torso and HANS are restrained by the shoulder harness. By restraining the head to move with the torso in a crash, the head motions and forces in the neck are dramatically reduced. The helmet loading is also transferred from the base of the skull to the forehead- which is far better suited in taking the force.
ABSTRACT
Primarily made of carbon-fiber, the device is something of a U-shape, the back of the U set behind the back of the neck and the two arms laying flat along the top of the chest over the pectoral muscles; the device in general supported by the shoulders. It is attached only to the helmet—and not to the belts, driver's body, or seat -— by two anchors on either side, much like the Hutchens device but placed slightly back. The seat belts that cross the driver's upper-body are properly installed so that the belts go right over the HANS device, on the driver's shoulder, and buckle into the center of the driver's stomach. Therefore, the HANS device is secured with the body of the driver, not the seat.
The purpose of the device is to stop the head from "whipping forward" in a crash, without otherwise restricting movement of the neck. In a crash, an unprotected body 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, with the device transferring energy to the much stronger chest, torso, shoulder, seatbelts and seat as the head is decelerated.
