Control of Snow and Ice on Missile Fields

The effect of snow and ice on the operation and maintenance of a subsurface missile system was investigated during the construction stage of the Grand Forks safeguard system site. Meteorological observations were made daily from 1 November to the following 30 April for the two winters 1971-72 and 1972- 73, and compared with observations made at the 1st order stations of Minot and Grand Forks, North Dakota, west and east respectively of the Safeguard site. Though differences occurred, the climatic patterns at the 1st order stations were similar, and indicate that 25-40 snowstorms can be expected each winter, snowfall in a single storm may reach 11 in. each year, and 20 in. 1 year in 30. A full-scale model of a portion of the Spartan missile mound was constructed, as well as part of the double chain link security fence and plywood models of six cell covers, and snow accumulation was observed during one winter. It was concluded that accumulation would never exceed the height of a cell cover, nor would snow completely bridge the pavement between cells. However, snow could accumulate to depths approaching 5-6 ft around the security fence under extreme conditions. When a hydraulic flume for conducting model tests for snowdrift potential became available late in the investigation, major structures at two of the radar installations were investigated, and a problem identified at one location. Performance tests were conducted on 12 models of 7-8 hp walk-behind snowblowers to evaluate the three tasks of lane, obstacle, and drift clearing which could be expected on the missile field. An analysis was made of the equipment requirements for snow clearance based on an estimate of accumulation on the site.