Avalanche Safety Device tested
Hello All, newbies here.
Last Sunday Feb 5 through Friday the 10th we conducted testing of an avalanche safety device in the Selkirk Mountains near Revelstoke, British Columbia. The device we were testing was a 3 cubic foot inflated nylon bladder attached to a crash test dummy by a chest harness. Last year in three separate class 2 avalanche tests we found our dummy partially buried on the surface of the avalanche debris field with the nylon lift bag completely exposed on the surface. This year’s test results were quite different.
In the first avalanche the two dummies (one dummy with an attached lift bag, and a control dummy with no lift bag) were placed on the top of the mountain, just beneath a rather large cornice. We bombed the cornice and dropped the snow just uphill of the dummies. Unfortunately the result was a rather large class 3 avalanche. The dummy with the lift bag attached (Adam) traveled approximately 3000 feet downhill at approximately 110 miles per hour. He slammed into a 4 foot diameter pine tree, wedged against it and was buried by 2 meters of very heavy snow. It took several hours to extract him. His head was completely torn off, his legs were both missing from the knees down, and both arms were torn off. The lift bag was still attached and torn open. The speed and the size of the avalanche were estimated by the avalanche control people we hired for the bombing, so we feel those estimates are good. The dummies we use are the same ones used by Fire Departments for training purposes, so they are quite durable.
Eve, the dummy without the lift bag attached, was found 100 meters straight uphill from Adam. She was face down, head uphill, and completely buried under one foot of snow. Both of Eve’s legs were torn off, as well as both her arms. The avalanche snapped off several 40 foot pine trees, and everyone agreed it was not a survivable avalanche for a human. The debris field was about 400 meters across down in the valley.
We can only surmise that the lift bag carried Adam further down the hill before he slammed into the tree and stopped.
The second avalanche test produced another class 3 slide where the dummies took another 3000 foot ride while dropping down a 100 meter rock chute before launching off a 100 meter cliff. The dummies were found 50 meters apart with Adam uphill from Eve, and both dummies buried under 2 meters of snow. The lift bag was missing from Adam, and his torso was retired from service.
The third and final avalanche test produced a class three avalanche with a 4000 foot runout. Unfortunately, after several failed attempts to bring down the mountain, the 50 pound bomb punched through the cornice, landed right next to Eve and blew her to kingdom come. A team will be flying into the area this spring before the grizzly bears emerge to locate and remove the various arms, legs, torsos and heads. We spotted Eve’s airborne torso in one frame of film, so we do think she will be recovered.
We dropped our lift bag strength from 420 denier nylon (420 cross stitches per square inch) to 200 denier this year in order to conserve weight, and we put our dummies in unsurvivable locations. The plan is to return to 420 denier nylon, and to place our dummies lower on the slopes, rather than at the tops of the mountains. Although skier and snowmobile triggered avalanches often place the victim at the very top of the avalanche as it starts, we start our slides by dumping cornices, and we just don’t feel that dropping tons of snow onto test dummies is realistic.
Any comments would be appreciated.
