Run-out zone
A run-off zone is an undeveloped area of a racetrack that is next to the actual road. It is intended to enable a racing vehicle that has gotten out of control to be stopped passively or actively before a serious collision occurs - similar to an emergency lane in public traffic. When functioning as planned, these zones, which are usually up to 100 meters wide, protect drivers, track staff and spectators from injuries and prevent major damage to the vehicles. Especially in motorcycle races , a run-off zone is also called a fall area ; There is even a 240-meter-wide area for this on the Indianapolis Motor Speedway .
history
In the original race track construction, run-off zones were not common. Often even the spectators were standing directly on the road, according to today's knowledge and standards absolutely inadequately separated from the racing action only by bales of straw, barricade wires or wooden fences. It was only after the Second World War, and especially after the serious accidents in 1952 on the Grenzlandring (13 or 14 dead) and in 1955 at the Le Mans 24-hour race (84 dead), that safety issues gradually became an issue for motorsport authorities, race organizers and track operators. The possibilities for reducing the risk were limited by spatial and financial restrictions, especially with the temporary city and street courses that were still widespread at the time . On country and national roads, such as those used for the Rouen-les-Essarts race track in France, there was hardly any space to set up run-off zones. Here the carriageway led directly past trees or buildings without any security; particularly noticeable in the original, long track versions from Reims-Gueux in France and Spa-Francorchamps in Belgium. In the long term, therefore, only permanent courses for major security modifications came into question. Often, those responsible were initially too unwilling to make improvements, so that for many years there were numerous accidents with drivers and spectators killed. In the fatal accident of the German Grand Prix driver Wolfgang Graf Berghe von Trips in September 1961 in Monza , 15 racing visitors who were only separated from the track by a low wall and a small wire fence and were hit by the almost unbraked vehicle involved in the accident died.
First run-off zones
However, the growing need for safety from prominent racing drivers such as Jackie Stewart and Jacky Ickx , organizers and spectators, as well as the ever increasing speeds from the 1960s - especially in Formula 1 - increasingly forced race track owners to build run-off zones. The pioneers of this development included the racing drivers Henri Pescarolo and Jean-Pierre Beltoise, who planned the Circuit Paul Ricard in France in 1970, and the Dutch race track designer Hans Hugenholtz with the Nivelles-Baulers plant in Belgium in 1971. Hugenholtz had already in the 1960s, with the designs of the Formula 1 race tracks of Suzuka (Japan), Zolder (Belgium), Jarama (Spain) and the Hockenheimring - new circuit excelled. He also introduced the so-called “safety fences” in motorsport, flexible fence constructions that could brake racing cars that had strayed from the track. These wire fences, some of which were erected in several rows one behind the other, were later no longer sufficient and were supplemented or replaced by wide run-out zones over time. Initially, these areas were almost exclusively covered with lawn , sand or gravel , but from the late 1990s onwards they were increasingly paved and in some cases considerably widened. The Circuit de Dijon-Prenois in France was a pioneer in this area as early as 1975 : During the renovation and extension of the route, large parts of the run-off zones were concreted or paved with asphalt on both sides of the road . However, some route operators are still replacing the zones built according to older methods with asphalt surfaces, such as in Monza in 2007.
The end for older routes
From the 1970s onwards, the increasingly accepted need for exercise zones had a significant impact on the length and design of the older courses; In some cases, it also led to the complete abandonment of routes if conversion appeared to be impossible or profitable . For example, the routes from Spa-Francorchamps in 1979 were halved from over 14 to around 7 kilometers and the Circuit de Charade in 1989 from around 8 to just under 4 kilometers, because only such a drastically shortened route could be made sufficiently safe. The courses that were completely closed included the Solitude race track near Stuttgart in 1966, Reims-Gueux in 1972, the Masaryk-Ring (then Czechoslovakia) in 1986, Rouen-les-Essarts in 1993 and the AVUS in Berlin in 1998.
There are currently only a few permanent race tracks that have no or only insufficient run-off zones, such as the Nordschleife of the Nürburgring . Most of these slopes are now considered too unsafe for modern racing. In May 2006, for example, the French Ministry of the Interior issued a decree to improve the safety of racetracks, which resulted in extensive modifications to the majority of the courses in France. Even the operators of the numerous small, private test tracks had to partially change the routing or clearing up until the start of the 2007 season in order to be able to build the larger run-off zones prescribed by the new legal standards. However, the use of asphalt strips was not prescribed, so that mostly gravel beds remained. Facilities such as the line from Mas du Clos in Auvergne , on which the necessary modifications - estimated at around 2 million euros - had not yet taken place in 2007, lost their operating license and were therefore acutely threatened with closure.
construction
Basic techniques
Run-off zones are sensibly set up on the outside of curves and chicanes and usually connect directly to the curbs at the edge of the route. Ideally, they have a slight camber that increases the braking effect. Modern run-off zones begin with a one to five meter wide “green strip” made of grass, artificial turf , a carpet-like surface or painted concrete. This - not yet officially as a run-off area, but mutatis mutandis as " banquet " (English: verge ) called - strips should, among other things by its low coefficient of friction prevent intentional crossing, as there is a vehicle quickly losing grip and can get out of control. This is followed by an area with around four centimeters thick, “hot-installed” asphalt concrete top layer . With the addition of precisely calculated proportions of lime and sandstone dust as well as chemical additives, a finer micro-roughness is achieved and, due to the increased interlocking effect between tire rubber and asphalt, a higher coefficient of friction than with normal road surfaces. On some stretches, this asphalt surface ends in a gravel bed that is at least four meters wide and around 25 centimeters deep. According to the specifications of the International Automobile Association FIA, this consists of spherical stones with a diameter between 5 and 16 millimeters. At the end of the gravel bed, a stack of two to six rows of car tires screwed together is placed at least one meter high. The front row should be covered with a rubber tarpaulin at least 12 millimeters thick towards the track to prevent the vehicle from breaking through or getting caught in the tire stacks. Structures prepared in this way can absorb up to 80% of the impact energy. Behind it, the run-off zone is delimited by a wall or a guardrail with a protective fence in place to prevent collisions with vehicles on neighboring sections of the route and any danger to spectators and marshals - including from vehicle parts being thrown away.
A further development has been tested since 2006 on very fast stretches or in places where a sufficiently large run-off zone cannot be built : The High Speed Barrier , a three-layer combination of polyethylene foam blocks and multi-layer stacks of tires and a boundary wall or guardrail. This four meter wide construction was used for the first time at the Italian Grand Prix in Monza.
Asphalt preferred
Although there is no explicit regulation, only a recommendation by the FIA, there are only a few places where there are only a few places, especially on Formula 1 racetracks. Due to the high coefficient of friction, these can generally brake a vehicle quickly, but can also lead to digging in and thus to the retirement of the racing car. However, racing cars with little ground clearance (sometimes less than five centimeters) and smooth sub-floors may slide over the pebbles largely unchecked. In the case of gravel run-off zones, therefore, more space must be planned for the next guardrail or wall than for asphalt surfaces. In some cases, gravel beds caused dangerous rollover because one side of the vehicle was buried in the gravel and this resulted in a torque that resulted in the vehicle tipping over. Roll bar of seaters can sink in a rollover in the relatively soft surface and thus ensure not sufficient to protect the driver's head more.
Pure grass run-off zones are no longer built due to their low coefficient of friction (especially when wet), and neither are concrete surfaces, which can still be found on some older routes such as in Dijon-Prenois . In the run-off zones of the Bahrain International Circuit (BIC), which opened in 2004, the initially built-up mixture of compacted sand, cement and water turned out to be insufficiently stable , so that parts of this surface polluted the roadway. In 2007, these zones were replaced by asphalt that was painted sand-colored.
The most modern and largest run-off areas worldwide existed until the completion of the new Formula 1 racetracks in 2005 on the Circuit Paul Ricard, which was modernized between 1999 and 2002. The new owner, Bernie Ecclestone , had a sophisticated system of three consecutive asphalt strips with different, very high friction coefficients built there - achieved, among other things, by the addition of tungsten - that can reliably brake out of control Formula 1 racing cars from high speeds without damaging the vehicle. This saved the teams testing there ( Toyota had a permanent test center there) in costs and time that they would otherwise have to spend on recovering and repairing cars involved in an accident. The FIA “Institute for Motorsport Safety” bestowed the FIA Institute Center of Excellence Award on the Circuit Paul Ricard in 2006, among other things because of this run-off zone concept , and the second track to be awarded this prize was the Bahrain International Circuit 2007.
planning
The former role of Hans Hugenholtz, who died in 1995, in the planning of Formula 1 racetracks and their run-off zones has now been taken on by the industry leader, the German civil engineer Hermann Tilke with his engineering and architecture office in Aachen . When building new racetracks of any kind or when modernizing existing courses, he calculates the dimensions of the run-off zones using a "ray model" on the computer . The assumed maximum speed and the direction of a vehicle when leaving the racetrack in an uncontrolled manner from the braking point for each point of the curve area and the resulting required fall space are calculated. According to the FIA rules, the speeds and weights of Formula 1 vehicles are used as a basis. Despite their relatively low weight, their maximum kinetic energy is usually greater than that of other racing cars at over 36.7 million joules due to the top speeds of up to 350 km / h , which means that the run-off zones calculated for them are often sufficiently large or even oversized for all vehicle classes . The average, maximum deceleration performance of Formula 1 can be used as a guide: from 300 km / h the best possible braking distance to a standstill is around 90 meters, from 200 km / h around 55 meters, from 100 km / h it is around 19 Meter. Ideally, the kinetic energy should be reduced to zero before the impact with a solid obstacle, i.e. the vehicle should have come to a standstill. While the expansion of run-off zones in the 1980s barely reached a lane width (eight to 15 meters), areas up to 80 meters wide are being built in modern courses such as the Istanbul Park Circuit in Turkey, which opened in 2005 . The FIA is currently specifying 30 to 100 meters as a guideline for new racetracks. For existing routes, it has recently made a Circuit Safety Analysis System (CSAS) available, a computer program that uses sensor data from Formula 1 cars in previous races and accidents to gain insight into the dimensions the required run-off zones and safety barriers can be obtained.
When planning run-off zones with large asphalt surfaces, care must be taken to ensure adequate drainage due to the risk of aquaplaning . Since these areas usually have a slight slope towards the route, the surface water flows in the direction of the road. A narrow drainage strip - made of grooved or perforated metal, for example - is therefore installed between the asphalt and the curb in front of it; in some cases a sufficiently water-permeable strip of grass or artificial turf is sufficient. In the case of pure gravel beds, this strip is unnecessary because here the water seeps away before it can flow onto the roadway.
disadvantage
In addition to the high costs for land and construction, extensive run-off zones usually cause long distances between the race track and the spectator areas. The vehicles can therefore only be seen from a great distance on modern tracks such as the Shanghai International Circuit , which greatly reduces the subjective experience of the speeds driven. Large areas of asphalt also reduce this perception of speed; especially in relatively slow racing car classes such as the World Touring Car Championship . For the spectators, for example, parts of the former Formula 1 racetrack in Istanbul with a lane up to 21.5 meters wide and a maximum of 80 meters wide asphalt run-off zone give the visual impression of a parking lot more than 100 meters wide and several 100 meters long. A similar picture has emerged since 2003 after the renovation of the Complexe du Lycée in Magny-Cours , where the route turns into a sharp right-hand bend after a high-speed section and is secured by a generously dimensioned run-off zone with a combined asphalt / gravel surface. The subjective impression of spaciousness there is also given to the racing drivers who may underestimate their speed on such sections of the route or consciously choose a higher speed because a possible “take-off” would not necessarily lead to cancellation. On some routes, asphalt run-off zones are also partially "built into" the ideal line , that is, intentionally used. According to the FIA rules for racetracks, however, the edge of the lane must be marked on both sides with a white strip of non-slip paint that is at least ten centimeters wide. Obviously, deliberately driving over this lane with the entire width of the vehicle is usually punished with penalties, which can range from a warning to disqualification. This is to prevent the misuse of a run-off zone as an additional lane width.
Formula 1 promoter Bernie Ecclestone said at an event in January 2006: “I cannot say whether we have gone over the rails in the run-off zones on some tracks, but with some you can run out of fuel before you hit the tire wall hits " . That is why he has recently been favoring street circuits without run-off zones, as in the early days of racing, since, in his opinion, spectacular sport could be offered here for spectators. Starting in 2008, new Formula 1 city circuits in Valencia , Abu Dhabi , Gwangyang (South Korea), New Delhi , Singapore and the Disneyland Resort Paris were driven, planned or at least considered.
Run-off zones on sections of the route where a vehicle that has got out of control leaves the route at a very acute angle are not considered to be sensible ; for example in straight lines or in very long curves. Here, the FIA prefers a smooth, continuous wall or guardrail after the prescribed shoulder strip, along which the cars can slide and quickly reduce speed. The upper limit for this type of construction will be about 30 degrees angular adopted.
Run-off zones for motorcycle races
In the opinion of the highest motorcycle sport organization FIM , run-off zones are indispensable in road racing for various reasons: They act as a limitation and stabilization of the basic structure of the roadway, they increase safety by improving visibility and the associated possibility of using the entire width of the track, and they serve if dimensioned as a stopping distance for motorcycles that have come off the road.
In the case of routes that are used by both cars and motorcycles, however, the creation of run-off zones leads to a conflict of objectives . Motorcycles are only braked slightly after falling through asphalt zones, as the machines almost never slide over the run-off zone with their tires, but with metal or plastic parts. This results in only a low level of sliding friction , the motorcycle may slide up to the boundaries of the route and can be severely damaged in the process. At high speeds and correspondingly long gliding phases, the risk of injury to the driver increases, especially because of the heavy wear on the protective clothing . This can lead to severe burns and abrasions . Much safer in this case are the gravel beds, which in most automobile racing sports are no longer up-to-date. It must be however taken during preparation to a "smooth" transition from the previous green strip, since this may cause the coefficient of friction by the abrupt change a torque to the rollover leads from the operator and machine. Furrows in the gravel bed drawn across the direction of the fall can also trigger this effect. The FIM regulations therefore require a smooth, non-corrugated surface. In the event of “slipping” from low speeds, asphalt zones have the advantage that after a short gliding phase, the driver and motorcycle can continue the race largely unscathed.
In motorcycle races, the track boundaries after the run-off zones are secured by airfences (German: "Luftzäune") - large, air-cushioned plastic cushions that give way when a rider is impacted and thus gently absorb the kinetic energy. These safety devices are usually only installed for the duration of the racing event and must be homologated by the FIM's Commission de Courses sur Route (CCR) .
The TT Circuit Assen in the Netherlands, the new version of the Misano World Circuit in Italy, the Circuito de Jerez in Spain, the Circuit Bugatti in France, the Phillip Island Circuit in Australia or the Sachsenring in Germany. The MotoGP, the highest class in motorcycle road racing, is a regular guest on these routes , while car races are only of secondary importance. Formula 1 races are not currently taking place there.
The widest run-off zone in the world to date was created when the former Formula 1 infield road circuit in the Indianapolis Motor Speedway was converted into a motorcycle racing track. At the Motorcycle Grand Prix in September 2008, the first four corners after the start and finish straight on the 4.186 km long and anti-clockwise course ran below the first two banked curves of the existing oval and used them as an additional asphalt fall area. The total width of this run-off zone was around 240 meters.
Special forms
On the only traditional Formula 1 city race track that is still driven today, the Circuit de Monaco , plastic tanks filled with water have been used in some places since 1995 to replace the non-existent run-off zones. In addition, there are sometimes short “emergency exits” at bends and chicanes, which can be used as an additional stopping distance, for example after missing the braking point. However, these cannot be viewed as fully fledged run-off areas.
Oval courses have no run-off zones because the elevation of the banked curves and the high speeds driven there make the construction of sufficiently large fall areas unnecessary or impossible. Instead, these routes are limited by high concrete walls and additional fencing structures, which are intended to protect the spectators from vehicles that have gotten out of control and parts flying around. Here are also some of SAFER (Steel and Foam Energy Reduction) barriers used; Polystyrene press plates that are anchored to the concrete wall and can absorb impact energy well without the vehicle being able to get caught like a tire stack.
In rallycross , the run-off zones are still almost exclusively gravel or sand beds. For cost reasons, the prepared trenches are usually filled with the materials available on the site, which means that it is almost always roughly sifted earth or sand instead of washed gravel with a defined grain size. Immediately before the race days, and in the event of strong compaction also during the racing breaks, this bed filling is loosened up using suitable machines and then leveled again.
In acceleration races , hill climbs or automobile slalom , run-off zones are usually not next to the road, but at the end of the route. Here they are used for controlled braking from high speeds and therefore have different properties than run-off zones in circuit races . The dimensions and surface properties are often regulated in detail by the respective motorsport associations.
References and comments
- ↑ The film Grand Prix from 1966 gives an authentic impression of the situation in Spa-Francorchamps up until the renovation at the end of the 1970s
- ↑ Up to 1970, an average of two Formula 1 drivers died in races and test drives per season, see also here
- ↑ Jacky-Ickx-Interview at Bregenznet.at ( Memento from September 28, 2007 in the Internet Archive ) (July 7, 2007)
- ^ "Circuits of the Past: Nivelles-Baulers" (groups.msn.com, Dutch)
- ↑ Racing1 - Internet site: track reconstruction in Monza. Archived from the original on October 7, 2007 ; Retrieved December 7, 2012 .
- ↑ Klaus Wolf: The risk is too high. In: Berliner Zeitung . September 12, 1995, accessed June 9, 2015 .
- ↑ Decree of the French Interior Ministry on road safety (May 18, 2006, French)
- ↑ Legally required renovation of the Anneau du Rhin 2006 (on the route website at Actualités , French)
- ↑ "Pétition contre la fermeture du circuit du Mas du Clos" (on www.pilotedudimanche.net in August 2007, French)
- ↑ According to the FIA rules, asphalted zones may have an elevation of up to 25 percent or a gradient of up to three percent; there are no limits for gravel beds
- ↑ Construction of a race track surface (at motorsport-total.com on October 15, 2004)
- ↑ "track safety" ( Memento of 28 September 2007 at the Internet Archive ) (undated at bmw-motorsport.com found on 17 September 2007)
- ^ Information from Hermann Tilke in Sport auto , issue 6/2007, page 111
- ↑ Aerial photo of the Circuit Paul Ricard with "striped" run-off zones
- ^ "Paul Ricard presented with Center of Excellence award" ( Memento of October 28, 2008 in the Internet Archive ) (f1.automoto365.com on December 11, 2006, English)
- ^ "Bahrain named Center of Excellence by FIA" (official Formula 1 website on April 13, 2007, English)
- ^ "The Lord of the Rings" ( Memento from October 12, 2007 in the Internet Archive ) ( ZDF .de on October 5, 2007)
- ↑ "architect of Schumacher's fast lane" ( World -Online on February 23, 2003)
- ^ Project list of Tilke GmbH ( Memento from September 29, 2007 in the Internet Archive )
- ↑ A current Formula 1 car with the driver and all operating fluids must weigh at least 600 kilograms, a little more than half the weight of an average racing touring car
- ↑ Michael Schmidt: "Course fluctuations" ( sport auto , edition 6/2007, pages 111,112)
- ↑ The vehicles in truck racing with a maximum speed of 160 km / h have up to 64 million joules due to their weight of around five tons
- ↑ Formula 1 "Numbers Games" at sponsoring.allianz.com ( Memento from February 21, 2007 in the Internet Archive ) ( PDF file, 2006; 1.9 MB)
- ↑ Appendix O of the FIA regulations for racetracks ( Memento of November 22, 2007 in the Internet Archive ) (PDF file, English / French)
- ↑ cf. on this: Prof. Dr. Heiner Bubb: "Analysis of speed perception in motor vehicles", Zeitschrift für Arbeitswwissenschaft, 31/1977, pages 103-112.
- ↑ "Hockenheim Ideal Line " (at sport auto -online.de on January 9, 2007)
- ^ "Bernie Ecclestone's view of things" ( Memento from September 29, 2007 in the Internet Archive ) (at formel1.net on January 13, 2006)
- ↑ Regulations for motorcycle racetracks - 2014 ( Memento from May 12, 2014 in the Internet Archive ) ( FIM website, PDF file, English; 2.7 MB) p. 7th
- ↑ David Swarts: "How Airfence works" ( Memento from December 5, 2007 in the Internet Archive ) ( Roadracing World & Motorcycle Technology , April 24, 2002, English)
- ^ FIM website: FIM conference report from March 1999, in French. Archived from the original on September 29, 2004 ; Retrieved December 7, 2012 .
- ↑ "FIM MotoGP (Indianapolis)" (theautochannel.com on July 17, 2007, English)
- ↑ The internationally common English term for sand bed is sand trap , which literally means "sand trap" translated means as defined by the FIA but it is a gravel bed called (dt. Gravel)
literature
- Peter Higham, Bruce Jones (translation: Walther Wuttke): Race tracks of the world . Heel-Verlag, Königswinter 2000, ISBN 3-89365-890-4
- SS Collins (text), Gavin D. Ireland (photos), Helmar Winkel (translation): Forgotten racetracks - traditional courses in Europe . Heel-Verlag, Königswinter 2006, ISBN 3-89880-644-8
- Tim Hill (translation: Nils Günter): The golden age of racing . Parragon Books, Bath 2006, ISBN 1-40547-902-7
Web links
- "Safety factor run-out zone" at credit-suisse.com (August 14, 2006)
- FIA regulations for racetracks (undated, found on September 26, 2007, English)
