Safe Loads on Ice Sheets (Ice Engineering. Number 13)

Abstract : Every winter, ice sheets that grow on lakes and rivers in northern states are used for ice roads, ice bridges, construction platforms, airstrips, and recreational activities, It becomes very important, therefore, to know when the ice is safe to use for these purposes. Figure 1 shows a tow truck and the pickup truck (nearly obscured) it was sent to pull out, both of which fell through lake ice that was not thick enough to support them. Unfortunately, events like this occur every year, sometimes with loss of life. We offer here some guidelines for determining the safety of freshwater ice. Because vehicles, snowmobiles, and people often have fallen through ice, research has been done to determine when an ice sheet is safe for certain loads, Gold (1971) collected a considerable amount of data on the use of ice sheets by aircraft, construction activities, trucks, and tractors in Canada. Using these observations, Gold proposed three plots to represent safe ice thicknesses for various loads (Fig. 2). The upper plot is the most conservative (i.e safest), while the lower plot is Hie least conservative