Ski patrollers go through significant amounts of training and refreshers in their careers, and during the winter season especially they focus on ski and toboggan skills. During this training, they take toboggans down some of the most difficult terrain in their mountains which, due to initial inexperience, has resulted in many crashes and injuries for the patrollers. This project aimed to provide a safer way for patrollers to train on unfamiliar terrain by modifying the toboggan to have an emergency braking system. This braking system utilized a metal edge in the uphill end (angled towards the downhill/front end) that would be inserted into the snow or ice with a hinge if the leading patroller lets go of the handles. A two-way quick release system was designed so that the activator was attached to the patroller's glove and keeps two cables taught. The cables keep the metal edge flush with the bottom of the toboggan, thereby deactivating the system. If the patroller's hand goes outside the range provided by the activator, the cables are released and so is the brake. The edge was able to work on powdered snow by gathering it like a shovel and was able to work on hard pack conditions with the sharp edge.
In training, Ski Patrollers have to lead toboggans down challenging slopes, but due to their initial inexperience they are at risk for losing control of the toboggan and injuring themselves or the person in the sled.
I plan on incorporating an emergency brake into the toboggan that are only activated only when the Patroller leading the sled lets go of the handles. The brake will be at the back of the sled and will act as both a stake and a scoop for powder snow, hard-pack, and ice.
This objective of this project was successfully met – through testing it was found that the braking system effectively stopped the sled in an emergency. By comparing the varying stopping distances and their maximum velocities, the modified sled was shown to have a smaller distance compared to the traditional method and control of stopping manually, although it was not statistically significant. For the goal of the brake only being activated in an emergency, data was found by bringing the sled down with common techniques used in Outdoor Emergency Transportation classes, finding that most did not unintentionally activate the system. This could, however, result in issues for patrollers with longer or shorter arms, as the former could activate the brake unnecessarily and the latter would not activate it soon enough. The “outside the handles left” technique was shown to be more likely to accidentally activate the brake, so this could be solved by lengthening the activation string or switching which hand it is attached to depending on which version of “outside the handles” the patroller intends to use. Some limitations of this testing were due to the location of the tests. They were done on a small hill in my backyard on ungroomed snow. The shorter distance failed to account for the accumulation of velocity a patroller and their sled would get on a steep, long trail. There was also a lack of variability in the snow – conditions vary drastically from day to day, and because testing was done over only one weekend, warmer snow and hard pack conditions were not addressed. The snow conditions on the day of testing included a layer of ice over slight hard pack, but this can be much looser than groomed snow. Because the brake did not completely lie flush with the bottom of the toboggan, some drag was created that slowed the toboggan down. Future prototypes will address this issue. The design does need to be cleaned up, for example the ropes should be secured more firmly rather than with knots. The ropes themselves caused too much friction along the edges of the sled so another type of rope might be considered. Future tests should start having patients sit in the sled and should be done on longer, steeper trails with different conditions. As the objective for this project was to create an emergency braking system, I feel that this conclusion should be short. The braking system was able to effectively stop on icy and looser snow. It was shown to not activate when practicing common toboggan techniques, but this may vary with size of the patroller so the activation rope length may need to be varied. With this toboggan modification, patrollers can more safely practice their skills on unfamiliar advanced terrain without a severe fear of injury. Making the mountain safer for patrollers makes it safer for all skiers.