24 Hours of Le Mans

The 24 Hours of Le Mans is the world's oldest sports car race in endurance racing. Anno since 1923 near the town of Le Mans, France. Commonly known as the Grand Prix of Endurance, it is organised by the Automobile Club de l'Ouest and runs on a circuit containing closed public roads that are meant not only to test a car and driver's ability to be quick, but also to last over a 24 hour period.

Cars

The race field has usually consisted of approximately 50 competitors. Each car is required to have no fewer than two seats, although in recent years only the ability to place a seat in the cockpit has been understood but not enforced. No more than two doors are allowed; open cockpit cars do not require doors.
 
An Aston Martin DBR, entrant in the GT class.

Although all cars compete at the same time, there are separate classes. An overall winner is awarded at the end of the event, while class prizes are given as well.

Classes have varied over the years, but currently there are four. Custom-built Le Mans Prototypes are the top two classes, LMP1 and LMP2, divided by speed, weight, and power output. The next two classes are production-based grand tourer  classes, also divided by speed, weight, and power output as GT1 and GT2. Although the top class is the most likely winner of the event, lower classes have won on occasion due to better reliability.

Drivers

Originally, there were no rules on the number of drivers in a car or how long they can drive. Although almost all teams used two drivers in the early decades, some Le Mans drivers like Pierre Levegh and Eddie Hall attempted to run the race themselves, hoping to save time by not having to change drivers, although this was later banned. Up until the 1980s there were teams where only two drivers competed, but by the end of the decade it was placed into the rules that at least three drivers were necessary.

By the 1990s, due to the speeds of the cars and the strain it put on drivers, further rules were put in place in order to aid in driver safety. Drivers could not drive more than four hours consecutively, and no one driver could run for more than fourteen hours total. This has reduced driver fatigue during the races.

Unique rules and traditions

Although the 24 Hours of Le Mans was part of the World Sportscar Championship for most of its existence, it has regularly had rules which differed from those used in other series, partially due to the length of the event. Some rules are for safety reasons, while others are for the purposes of competition.

For many decades, cars were required to run at least an hour into the race before they were allowed to refill fluids for the car, such as oil or coolant, with the exception of fuel. This was an attempt by the ACO to help increase efficiency and reliability. Cars which could not last the first hour without having to replace lost fluids were disqualified.

Another rule that is unique to Le Mans is a requirement for cars to be shut off while they are being refueled in the pits. Based not only the notion that it is safer and less of a fire hazard to do so, this also allows for another test of reliability, because cars have to test their ability to restart many times under race conditions. Another element of this rule is that mechanics are not allowed to work on the car or its tires while it is being refueled, which has led teams to adapt innovative ways in which to decrease the time of these lengthy pit stops. As an exception to this rule, drivers are allowed to get out of the car and be replaced by another driver during refueling.

At Le Mans there are various traditions that have been seen over the years. One of the longest lasting is the waving of the French tricolor to start the race. This is usually followed by a fly-over featuring jets trailing blue, white and red smoke. A similar flag tradition is the waving of safety flags during the final lap of the race by track marshals, congratulating the winners and other finishers.

The 24 Hours of Le Mans also saw the first known instance at a major race of a winning driver celebrating by spraying champagne instead of drinking it. When Dan Gurney won the 1967 race with co-driver A.J. Foyt, the two drivers mounted the victory stand and Gurney was handed a magnum of champagne. Looking down, he saw Ford CEO Henry Ford II, team owner Carroll Shelby and their wives, as well as several journalists who had predicted disaster for the high-profile duo. Gurney shook the bottle and sprayed everyone nearby, establishing a tradition reenacted in victory celebrations the world over for the next 40 years. Gurney, incidentally, autographed and gave the bottle of champagne to a LIFE magazine photographer, Flip Schulke, who used it as a lamp for many years. He recently returned the bottle to Gurney, who keeps it at his home in California.

source: wikipedia.com