Bobsleigh: everything you need to know about this fascinating sport

Often cinema brings sport to the forefront. As was the case for bobsleigh thanks to the film Cool Runnings, which focused on the participation of the Jamaica bobsleigh national team at the 1988 Calgary Olympic Games. Bobsleigh was already a discipline known to the public, in fact, but this film had the merit of bringing it even closer to people, making those ice athletes more human.

Sport was invented in the 1880s in Albany (New York) and then introduced to Switzerland. The first races were held on snow-covered roads and the first competitions took place in Davos in 1883 and St. Moritz in 1884. The first club was formed in 1897 and the first runway specifically built for bobsleigh was opened in 1902. Initially the crews were 5 or 6 people, then they were reduced to 2 or 4 in the 1930s. The bobsleighs were completely made of wood and then the steel skids were introduced.

The Fédération Internationale de Bobsleigh et de Lugeing (FIBT), currently known as the International Bobsleigh & Skeleton Federation (IBSF), was founded in 1923 and sport has been part of the Winter Olympic Games programme since its first edition in 1924. Initially only the bobsleigh competition was played at 4. The bobsleigh 2 was added in 1932, while women's competitions made their Olympic debut in 2002. Germany is the nation that has achieved the most successes in bobsleigh, including the European and World Championships, the World Cup and the Olympics.

The track for international races is at least 1500 m long (1200 m in the case of tracks with artificial refrigeration) and includes at least five curves, whose radius must be greater than 25 m. Each curve is composed of an external elevated surface, connected with the entry and exit straight line by means of an inclined plane called' spoon', which is used to facilitate the transition from horizontal to vertical position. The upper part of the elevated curves is concave so that the bobsleigh, driven by centrifugal force, is not projected out of the track. The bottom of the runway is made with beaten snow and watered at night so that a thick layer of perfectly smooth ice forms. The introduction of artificial cooling systems (the first was built in Königssee in Germany in 1968) represented a revolution in sport, allowing athletes to train in any season.

The starting line consists of a wooden board that marks the entrance to the track. There are three phases in the initial part of the race: a) the first one corresponds to an almost flat section (approximately 1% incline) 15 m long, followed by another one, where the timing starts about 50 m long; along this section the bobsleigh, under the impulses of a coordinated and powerful action, is accelerated; (b) the second shall correspond to an inclined plane, along which the bobsleigh shall accelerate as a result of the component of gravity; (c) the third shall correspond to the section along which the vehicle reaches the maximum possible speed.

A bobsleigh crew at 2 is composed of a pilot and a braking device, to which are added in the bobsleigh at 4 "lateral" which have as their main task to help in the thrust. It is not uncommon that athletes from athletics, especially sprinters, are used as lateral athletes. At the start of the race the crew pushes the bobsleigh for fifteen metres before jumping on board. This sequence is extremely delicate and important both because it has to give positive energy to the medium and not drag the bob back, and because the insertion of the hibernators in the middle has to be carried out very quickly, while respecting the balance of the masses that have to be placed in the vehicle with precision, without negatively affecting the bob trajectory that at that moment is out of the tracks and therefore very sensitive.

At the end of the race, when the bobsleigh has reached maximum speed, the athletes literally jump on the bobsleigh with perfectly coordinated movements and each one glides along the backrest and ends in a sitting position. The rider takes up his position with his hands on the steering handle.

During the descent, the first bobsleigh driver drives the vehicle by controlling the steering with the tie-rods equipped with a handle: he is the head of the crew and requires exceptional coolness, visual perception and reflections. The tail man, the so-called braker, must apply the driver's contribution to the initial thrust in the 15 m of throwing ahead of the start line; he only touches the brakes after the finish line, to facilitate the stopping of the vehicle. In the bobsleigh, the other two crew members cooperate in the initial thrust and try to keep the vehicle along the ideal trajectory during the descent with specific body. movements. For the descent to be valid, the crew must be complete when the bobsleigh crosses the finish line. The races are held exclusively by time trial and involve one crew at a time, according to an order drawn by lot. The rankings are determined by the sum of the downhill times (in hundredth of a second) obtained in two or four races, depending on the weather conditions and the track conditions at the time of the race. Women began participating in this discipline in 2002.

The speed in the thrust phase is around 40 km/h; the maximum speed in a descent is about 135 km/h in some curves the crew is subjected to lateral accelerations equal to five times the acceleration of gravity (5g).

The bobsleigh consists of a metal frame mounted on two pairs of steel skates and covered with a tapered bonnet, equipped with side handles to facilitate the start by pushing. The front pair of brake pads can be swiveled by a system of pulleys and tie rods with handles and allows the vehicle to be driven even at very high speeds ; the rear pair is equipped with lever brakes that act on the ice with a series of metal teeth. Modern bobsleighs combine light metal alloys, steel skids and aerodynamic composite bodies. Competition bobsleighs must have a maximum length of 3.80 metres for the bobsleigh at 4 and 2.70 metres for the bobsleigh at 2. In both cases, the maximum width is 0.67 metres. The maximum weight (including crew) is 630 kg for the bobsleigh at 4 and 390 kg for the bob at 2. Ballast weights can be added to reach the limits, as the greater the weight, the faster the vehicle.

The athletes' clothing is similar to that of the other disciplines previously mentioned. It basically consists of an aerodynamic helmet and an aerodynamic suit made of uncoated technical material. Shoes must have small cleats that are used to grip on the ice during the pushing phase; their maximum diameter must be 1.5 mm and must not be longer than 5 mm.