Rutscblock Test A Rutschblock is similar to a compression test in that it uses compression as a force to test how well strong and weak layers are bonded together. The Rutschblock is favored by snow safety professionals because it tests a larger area and it gives you a feel for how sensitive the snowpack is to your weight. To perform a Rutschblock, the slope angle must be at least 20 degrees, but preferably 30 degrees or steeper. First pick the biggest person in your group and make the width of your block one foot wider than their ski. Be careful not to disturb the snow uphill of the front wall of your block. Dig the front wall out at least 1 meter (3 ft) deep or deeper if your shovel shear indicated a deeper weak layer. Either trench or cut the sides with a saw or ski, the sides should be roughly 1.5 meters or a ski pole length uphill. The back of the block must also be cut and you can use a snow saw on a pole, a ski or a piece of cord. Once the block is isolated on all four sides, have the biggest skier in your group, with their pack on, approach the block from the uphill side of the back cut. Now you will load the block in 7 steps and the score (1-7) is the loading step at which the block slides. (See interpreting results table below.) *Rutschblocks for snowmobilers are constructed using these same steps, but are performed on snowshoes. Mark width of pit with your ski and dig front wall about 1 foot longer than your ski. Measure the slope angle of your Rutchsblock. Trench or cut the sides one pole length uphill. You can use a snow saw or ski to cut the sides. Move to the back of the block and cut a straight line between side cuts using a saw or a ski. Back of block should be slightly narrower than front. Step onto upper third of block. Downweight with feet in place. Jump hard once in place. Block fails after single hard jump. This Rutschblock failed on a score of #4.

Interpreting Results Loading Steps That Cause Block to Move #1 The block fails when you are digging or sawing #2The block fails when skier is approaching the block or gently stepping onto the upper third of block. #3 The block fails when skier downweights, or flexes at knees with feet in place. What Do These Scores Mean? Poor Stability - Red Light Similar slopes should be considered very unstable. #4 The block fails when skier does a single vigorous jump in the same spot. #5 The block fails when skier does a second vigorous jump in the same spot. Fair Stability - Yellow Light Similar slopes should be considered "unstable" or "suspicious". Proper route selection and safety measures are essential. #6 The block fails after repeated hard jumps or after jumping onto bottom half of block. #7 No failure after repeated hard jumps or block does not slide cleanly. Good Stability - Green Light Low risk of triggering slabs on similar slopes.

Interpreting snow stability tests takes experience and practice. Take a class and travel with experienced people to learn how to interpret tests correctly. The results of all of these tests will either confirm or challenge the opinion you have developed about the snowpack thus far in your tour. The safest bet is to use snowpit and shear test results to tell you that the snowpack in a given area is unstable, but not to tell you that it is stable, unless these results are well corroborated by other data. A good rule of thumb is that if you are uncertain about stability, choose your terrain accordingly. If you are skilled at recognizing potentially hazardous terrain, you can travel in the backcountry, and have fun, even in times of high hazard. * Remember stability tests are just ONE piece of the puzzle.