Investigations of ice forces on a conical offshore structure

Conical shapes have been used for a long time to reduce the ice impact forces. For a major Canadian offshore lighthouse in Lake Erie, a nearly conical shape was used as early as 1857. But the actual mode of destruction of an ice sheet colliding with a conical structure is still not fully understood. The measured and theoretical values of the horizontal force calculated by the different methods have been compared. Calculations and field observations suggest that a failure mode transitional between that of crushing and flexure occurs for the steeper cone angles.