Ski jumping 101: Aerodynamics key to success
PYEONGCHANG, South Korea (AP) — It’s the Olympic sport famed for its spectacular speed, exhilarating aerodynamics and cringe-worthy crashes. And yet ski jumping , a sport in which athletes hurtle down a ramp at 100 kilometers (60 miles) per hour before jumping the length of a football field, remains relatively obscure outside of Europe and Japan.
Apart from a brief profile boost thanks to “Eddie the Eagle,” the 2016 film about British ski jumper Eddie Edwards’ unlikely bid to become an Olympian, ski jumping is still a bit of a puzzle to much of the public. So what, exactly, goes into ski jumping — and how the heck do the jumpers manage to land without killing themselves? Read on for a primer:
Ski jumping began in Norway in the 1800s and was one of the original Olympic sports. Male ski jumpers have been competing in the Olympics since the very first Winter Games in 1924. Women, however, were not allowed until the 2014 Games in Sochi, following a years-long battle that included a discrimination lawsuit. Though ski jumping has largely been popular with European audiences, it gained some notoriety in the United States in the 1970s, when the horrific wipeout of ski jumper Vinko Bogataj was used in conjunction with the phrase “the agony of defeat” in the opening montage of “ABC’s Wide World of Sports.”
HOW IT’S DONE
Balance, flexibility and an understanding of aerodynamics are crucial. Ski jumpers begin by edging themselves onto a bar at the top of a steep ramp, known as the in-run, before pushing off. They zoom down the ramp with their skis fixed into ice-filled grooves, their bodies tucked into a low crouch and their arms behind them to maximize speed. When they reach the end of the ramp, they have a split second to transition into flight mode, using their legs to launch themselves up and forward. The athletes then lean over so they are nearly parallel to their skis, keeping their bodies still to minimize wind resistance. They fly for a few seconds before landing, ideally, with one foot in front of the other.
HOW HIGH AND HOW FAR
Although jumpers look like they’re soaring terrifyingly high in the air, they follow the curve of the hill and thus are only 3 to 5 meters (10 to 15 feet) above the ground. That’s why jumpers (usually) land without shattering their legs — the impact is not particularly severe. As for distance, the world record is held by Austrian Stefan Kraft, who jumped 253.5 meters (832 feet) at a World Cup ski flying event. Ski flying is an offshoot of ski jumping that involves a larger hill.
ALL ABOUT AERODYNAMICS
In the sport’s early years, jumpers kept their skis parallel while flying. But in 1985, Swedish ski jumper Jan Bokloev began holding his skis in a “V″ shape after realizing he could fly farther that way. Though the V-shape was initially mocked, it is now used by all jumpers because it helps maximize their surface area, keeping them in the air longer. While flying, the forward-leaning position of the body in relation to the skis allows the jumper to function much like an airplane wing, with air moving faster over the top of the jumper’s body than underneath. The difference in air pressure creates lift, which helps keep the athlete in the air. Many ski jumpers work on perfecting their form in wind tunnels, where they can experiment with tiny changes in their posture to find the ideal position that maximizes lift and minimizes resistance.
THE WIND PARADOX
While headwind is a detriment in almost every other sport, it’s the opposite for ski jumpers. Headwind provides lift, while tail wind shortens their flight. Wind direction and velocity is measured during each athlete’s jump. Points are then deducted for headwind and added for tail wind. If there is too much wind, conditions can become dangerous and a race can be postponed.
Ski jumpers are judged on a combination of distance and style. The distance score depends on whether the jumper reaches the K-point, or construction point, of the hill. The K-point is essentially where the steepest part of the hill ends and the ground begins to flatten out. Jumpers who reach this mark earn 60 points. Points are then added or deducted for every meter a jumper lands beyond or short of the K-point. In Pyeongchang, the K-Point is 98 meters (322 feet) for the normal hill and 125 meters (410 feet) for the large hill.
Five judges allocate up to 20 points each for style, with the highest and lowest scores thrown out, for a maximum of 60 style points. Jumpers’ style is rated on their form and balance in the air, the position of their skis during flight and their landing. Points are deducted if jumpers’ hand or backside touches the ground after landing, or if they fail to land with one foot in front of the other.
JUMPSUITS AND WEIGHT
Given how crucial aerodynamics are to a ski jumper’s success and safety, there are strict rules surrounding what the athletes can wear and how little they can weigh. Bigger skis give the jumpers more surface area — which creates more lift — so they are capped at 145 percent of an athlete’s height. The one exception is when a jumper’s body mass index — the ratio of a person’s weight to height — falls below 21; because lighter jumpers can fly farther, they must use smaller skis to compensate.
The spongy jumpsuits the athletes wear are highly regulated. They must fit snugly to the body to prevent extra material acting as a sort of wing. There are also limits to how thick and permeable the suits can be, since a thicker suit helps trap air that gives jumpers more lift.
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