Every ski area worth its salt has a terrain park nestled somewhere on the mountain. With their jumps, pipes, and rails, these playgrounds for skiers and snowboarders are perfect for practicing flips, spins, and other daredevil moves. As fun as they are, these terrain parks have a significant detractor — they can be dangerous. Balancing the danger of falling with the fun of jumping may become easier thanks to the work of Nicola Petrone at the University of Padova in Italy who has designed a jump that is safe no matter how long you hang in the air.
Rather than focus on ski gear and jumping technique Petrone and his colleagues at the University of Padova focused on the jump itself and developed a new design that reduces the risk of injury to the skier. “There is no question that riders occasionally make mistakes that put them at risk; nevertheless an engineering approach could allow the construction of jumps that reduce the likelihood that a mistake will result in a catastrophic outcome,” Petrone told MIT Technology Review.
To begin designing their safer jump, the team of engineers focused on the equivalent fall height (EFH) of a jump, a value that takes the velocity a person experiences when they make contact with the snow and expresses it as an equivalent height above the snow. People can absorb the impact of a jump with an EFH of 1.5 meters, but they suffer significant injury when the fall height climbs to 10 meters. To reduce the EFH, the team designed a jump that allowed the skier to stay at the same fall height now matter how far they jump
The key to the jump is the contour of both the takeoff portion and the landing slope. The takeoff area was designed to be flat allowing the jumper to take off smoothly and avoid a missed jump that causes them to rotate in mid-air. This flat take-off point helps to ensure the jumper is level during flight. The team then engineered a landing area with a snow surface that was parallel to the jump. This design produces an EFH that remains the same throughout the length of the jump. Unlike traditional jumps where a skier will soar through the air before landing, the jumper using this constant equivalent fall height is never too high above the snow.
Petrone and his team built a 14-meter constant equivalent fall height jump and tested it at the San Vito ski resort in San Vito di Cadore in Italy. Petrone recruited skiers to test the jump and measured their performance using accelerometers and high-speed cameras. After analyzing the data collected from more than 20 jumps, the team discovered that the jumpers consistently maintained the projected 0.5-meter fall height over the entire length of the jump. No matter how far they flew, each skier landed softly and safely on the snow.
Not only is the jump safe for skiers, but it also is easy to make, taking the team only three hours to construct using a Prinoth snow groomer and 100 cubic meters of snow. The University of Padova team hopes the ease of construction and safety offered by this design may inspire ski areas to look more closely at their terrain parks and build them with both fun and safety in mind.
