by Allison Winter
Paul D. Schreiber High School, Port Washington, NY
Third place
Fresh snow whips your face as you zoom back and forth between trees. Skiing down a mountain is perhaps the closest thing to flying. As you zigzag between moguls, you could easily believe that you have wings. You don’t have wings, but what you do have are skis that have evolved over centuries of engineering to become faster, lighter, safer, and as close to man-made wings as possible.
Skis used today for both racing and recreational skiing are vastly different from the first skis used 5000 years ago. These early skis were wooden and were used by hunters and trappers. Over the years, skis have changed based on what they were being used for. Around the 1890s, skis were about 7 feet in length, made of hickory, and were completely straight. Hickory was used because it was a tough wood and enabled the ski to be thinner and more flexible while keeping its strength. These skis were used for recreational skiing, not hunting like they were originally invented for.
As recreational skiing grew in popularity, new innovations began to transform skis. In 1928, an Austrian accountant named Rudolf Lettner introduced a revolutionary innovation to skis. This was the steel edge. While today it is valued for racing, Lettner intended it to save lives. His inspiration came from a near death experience, when the curved hickory edges on his skis were unable to stop him from falling. In order to improve upon the edges he screwed short lengths of steel onto the ski. This gave the edge a better grip, while allowing the ski to flex. However, these screws often came loose. In 1949, Lettner’s technology was built upon by Howard Head. Head created a new type of ski that had a plywood core with a sheet of aluminum on top of and below it. The aluminum sheet on the bottom had a continuous steel edge running along its length. These innovations solved the screw problem and were the first successful skis to be made of different components. The continuous steel edge style was continued in the first successful plastic fiberglass skis. These were invented by Fred Langendorf and Art Molnar in 1959. Fiberglass enabled skis to have less vibration than aluminum skis. Fiberglass was also a much lighter material and therefore easier to turn than aluminum. As the sixties came to an end, fiberglass skis with metal edges had almost completely replaced wood and aluminum skis.
Skiing was transformed by the arrival of “shaped” skis in 1993. Shaped skis aided in creating shorter, cleaner turns. The key feature of shaped skis are their iconic sidecuts. When skis turn they create a semicircle. A sidecut is created by shaping the ski so that the edge curves better around the line of the semicircle created. Sidecuts differ from straight skis because the middle of sidecuts are much thinner, but flow into a wider tip and tail. The radius of the sidecut is the radius of the turn made by the skier using sidecuts. In 1984, Frank Meatto used a deep sidecut of 31 mm and a radius of 8 meters to create a teaching ski. The sidecut made it easier for beginners to turn. However, Meatto’s design had a very wide tip. In order to make it narrower while keeping the deep sidecut he created an asymmetric ski. The outside edge was straight and the inside edge had a radical sidecut. He then engineered an elevated platform for the bindings so they would fit. These became known as “Albert” skis. While they were incredibly useful in helping people learn, it fell out of use due to its asymmetric shape which was considered too radical.
Another design of sidecuts was introduced in 1991, known as the Velocity. The Velocity was a fiberglass ski with a 10mm sidecut. These had more speed through the entire arc of the turn. In the same year the Sidecut Extreme (SCX) came out. It had a 22.25mm sidecut and a sidecut radius of 15 meters. A skier needed less edge on these skis and therefore could keep a straighter leg. The popularity of sidecuts skyrocketed in 1994 when K2 created the K2 Four. The dimensions of the Four were a 14mm sidecut depth and a 22 meter radius. It was essential that all these designs were relatively short skis because otherwise they would become too heavy. This was a problem for sidecuts because to create the sidecut the tip and tail had to be widened and this created extra weight. Therefore, to keep both the sidecut and the lightness of the ski, the ski was shortened. A beneficial effect of this was that it decreased the turn radius. However, another problem faced was that the wider tip would bend upwards in moguls and deep powder. To fix this the ski had to be stronger and stiffer in the center.
Engineering has transformed skiing to what it is today, and will continue to shape skiing in the future. As technology advances, so does our understanding of the physics behind skiing and therefore, so will the engineering of skiing. To create new innovations, it is helpful to understand the mechanisms behind skiing. New technology aids scientists and engineers in accomplishing this. One example is the use of inertial sensor units which measure velocity, orientation and gravitational forces. When applied to skiing it measures the joint angles of the skier. In a 2012 study, Kondo et al. measured the joint angle of skiers’ hips, knees, and ankles while making a turn. They were able to create a motion analysis of the major features of ski turning. Kondo et al. conducted a similar study in 2013, except this time they analyzed the difference between carving and skidding turns. Such technology could help understand the mechanisms behind turning and in turn discover a more ideal turning form.
In the future the need to be environmentally aware will be reflected in technologies. This could include recycled skis. This would reuse the many plastics and metals used to make the skis, including the fiberglass and metal edges. It would also manifest itself in adjustable skis. The design for this features a top plank and two bottom planks. By changing the relationship of the layers the width of the ski can be increased. These would enable beginner skiers to adjust their skis as their skill improves. It would decrease the number of skis used and therefore save materials. It would also be very cost effective because they would last longer as skiers skills evolve. It would also allow skiers to adjust their width for different conditions. This is especially important considering the changing climate and unpredictability of the future.
Skiing has drastically changed from when it was originally being used by hunters nearly 5000 years ago. This occurred thanks to the work of various people over many years. Engineering innovations such as steel edges and sidecuts are examples of innovations that have helped shape skiing into what it is today. They have improved the safety and quality of skiing. Engineers continue to think of new ideas to benefit skiing. New technologies help scientists better understand the physics behind skiing, and will help them create new technologies based on this in the future. Much of the ideas for engineering the future of skiing are inspired by the relationship of skiers to the mountain and their environment. Engineering has and will continue to transform skiing for generations to come.
References:
Evolution of Ski Shape. (n.d.). Retrieved February 17, 2015, from https://www.skiinghistory.org/history/evolution-ski-shape
Fry, John. "History." History. International Skiing History Association, n.d. Web. 17 Feb. 2015.
Kondo, A., Doki, H., & Hirose, K. (n.d.). An attempt of a new motion measurement method for alpine ski turns using inertial sensors. Procedia Engineering, 421-426.
Latest ski innovations. (n.d.). Retrieved February 17, 2015, from http://thomsonreuters.com/articles/2014/latest-ski-innovations
Timeline History. (n.d.). Retrieved February 17, 2015, from https://www.skiinghistory.org/history/timeline