In bobsledding, a two- or four-person crew in a steerable sled races through a twisting, sloping halfpipe course made of ice, trying to achieve the fastest possible time without crashing. The official rules of bobsledding are governed by the Federation Internationale de Bobsleigh et de Tobogganing (FIBT).
FIBT-sanctioned bobsled courses are up to 1,600 metres long, with a gradient of between 8 and 15%. At least 1,200 metres of the course must slope downhill. The course must include one straightaway and one labyrinth. The most technically demanding parts of the courts must be located in the first two-thirds of the track.
The first fifty metres of the course are close to level, with grooves for the bobsled’s runners. The maximum gradient of the last 100 metres may not exceed 12%. This part of the course may even slope uphill, but it must have bends.
Because heavier sleds have an advantage, the weights for the sled plus its crew have been standardized. The maximum weight for a four-man bobsled is 630 kilograms, 390 kilograms for a two-man bobsled, and 340 for a two-woman bobsled. Crews which are underweight may use ballast to add extra weight up to the limit.
Other components of the sled have also been standardized, from the steel frame to the steel runners. The rules governing sled construction are extensive and detailed. Most of them are aimed at not giving any team a technological edge, but many are also based on safety. For example, the fibreglass of the body must be strong enough to protect the crew in case of a crash.
The runners are the most important part of the sled, so they are governed by the most rules. Runners must be made from a single solid piece of homogenous steel. As of 2006, all bobsled runners must be made from the same type of unplated, uncoated, unlubricated steel. Runners cannot be too thin or too narrow. They may not be heated. Runners that are more than four degrees warmer than a reference runner exposed to air disqualify the sled.
Races begin from a standing start, with the crew standing beside the bobsled. During the first forty or fifty metres of the course, the crew pushes the bobsled forward as fast as they can, jumping into the sled at the last moment. The pilot jumps in first, followed by the brakeman, and the two pushers are last. Two-person teams jump in nearly at the same time.
The bobsled crew makes four runs. Timing is by electronic sensor, accurate to the nearest hundredth of a second, and is based on when the front of the bobsled crossed the start and finish lines. Obviously all four runs must be completed successfully to remain in contention, although the Jamaican national bobsled team won our hearts in 1988 when they got up after their crash and walked with their sled to the finish line.
The next bobsled does not begin the course until the previous one has cleared it. Only one bobsled is permitted on the course at a time.
The times for the runs are added together, and the team with the lowest aggregate time wins. In case of a tie, the tiebreaker is the fastest heat.