A characteristic feature of ice-covered waters is the presence of ice ridges. They are formed by compression or shear in the ice cover and are often found in the shear zone between the land fast ice, i.e. frozen to the shore and the drift ice. A high ridging intensity may also be found in straits and sounds with strong currents. Ice ridges are in general long and curvilinear features. Ridges often exist in combination with rafted ice and this combination is named a ridge field. Ice ridges do in many cases give the design loads for such structures as offshore platforms and bridge piers. They may also cause significant impediment to navigation. When drifting into the shallow waters, ice ridges may scour the seabed and create a serious threat to all seabed installations such as pipelines, cables, wellheads etc. The loads from ice ridges on various structures are not clear, and one of the major deficiencies is that the mechanical properties, in time and space, of first-year sea ice ridges are not well known.