OCR Text |
Show It was felt that the combination of these two barriers would divert most of the snow involved in this avalanche, thus giving the highway some protection. During the winter of 1958- 1959, the mountain did not discharge a slide large enough to test the workability of the barriers. The winter of 1959- 1960 did produce snow conditions to produce a large size k avalanche. Normally the debris in the highway would have been 10- 15 ft. deep. The barriers turned most of the snow, but enough ran over them to bury the highway k ft. deep but only in a very short span. ( Photo No. 1) Photo No. 2 was taken from a point about 1500 ft. up the slide path. The highway can be seen below, and the final deposition zone is visible 500 ft. beyond the highway. This was taken at the lower 1/ 3 of the barrier which is covered by slide debris, but the deflection of the slide snow is very apparent. Photo No. 3 is a view taken from the lower end of the barrier. The barrier is approximately 30 ft. high. The lower end, at the observer, shows no indication of being a barrier, but the upper 2/ 3 of the barrier, although half full, would still be partially effective ia turning a second slide should it occur. In Photo No. k, the full length of the slide path can be observed showing the very marked way the barrier turned the majority of the snow away from the highway. Debris can also be seen that did not turn and went on over the barrier toward the highway. |