OCR Text |
Show 8 tested in the climate of the Northern Rockies. Also, the dynamics of airflow through them had not been analyzed. We concur that jet roofs are effective in preventing cornices. To date, ten of these have been built on Bridger Ridge incorporating various designs, inclinations, and materials. Some general conclusions are as follows: ( 1) If single jet roof panels are to be erected, an efficient arrangement is to use solid 8 x 10 ft. ( 2.4 x 3 m) frames mounted on two upright posts by means of pivot bolts. These structures are guyed to the ground using no. 9 gauge wire and 4 ft. ( 1 m) cement rebar anchor pins. No holes need to be dug, and the structure is stable on solid rock provided both uprights and panel ends are guyed. One of these can be assembled and erected by two men in approximately four hours. Present cost of materials ( Bozeman, Montana) is about $ 25.00 per unit. ( 2) Jet roofs of the above dimension can be effectively mounted on four posts but assembly and erection are much more difficult than in the case of the two posted model. ( 3) If multiple jet roofs are to be erected along a ridge, the space between them should be no wider than the width of the panel ( also noted by Hopf and Bernard, 1963)- ( 4) Jet roofs consisting of panels with open slats have proved slightly less effective than the solid type. The former have the advantage of preventing buildup of snow on the panel, and naturally less material is involved. Although such snow accumulation was not found to be a problem in the Bridger Range |