Limit state identification for ice-strengthened hull structures using measured long-term loads

Safety of ships and economic shipping in ice is becoming more and more important since the traffic in ice-covered waters increases and ice-induced damages requiring repair continue to occur. Consequently, this paper will present the influence of the design load level to the probable repair cost following long-term load. Hence, the aim is to identify optimal scantlings following the chosen design load, which minimize the lifetime costs for ship construction and operation. As a case study MS Kemira's hull structure and therewithmeasured long-term loads are used to evaluate the sensitivity of the load level with varying occurrence frequency to the production and repair cost. As a result, we will be able to identify the optimum structure by means of production and probable repair cost.