1983 through a development grant from Mobil Corporation. It was expanded in 1984 through an Army Research Office-URIP, expanded again in 1986 through an Office of Naval Research-URI, and expanded again in 1994 through a second Army Research Office-URIP. The IRL is a materials research facility housed within cold rooms. The laboratory currently consists of ten separate cold rooms, some capable of reaching below -40°C. Situated within are facilities for growing and characterizing ice of different kinds, preparing test specimens, and measuring mechanical and electrical properties.Since icebergs were first proposed as potential aircraft carriers in World War II, Erland M. Schulson research has led to a better understanding of the mechanical behavior of ice. While work remains, especially in relating fracture on the small scale to that on the larger scale and to the appropriate structural features, the groundwork in materials science has been laid. This paper presents an overview of the structure and mechanical behavior of polycrystalline terrestrial ice.