Analysis of structural safety of ice-going vessels in the Arctic and Antarctic

• Main Author: Kurmiste, Andres
• Other Authors: Suominen, Mikko, Insinööritieteiden korkeakoulu, Kujala, Pentti, Aalto-yliopisto, Aalto University
• Format: Master Thesis
• Language: English
• Published: 2016
• Subjects: Arctic and Antarctic; reliability analysis; ice-induced loads; ice conditions; Antarctic; Arctic; The Antarctic; Antarc*; Antarctica; Northern Sea Route
• Online Access: https://aaltodoc.aalto.fi/handle/123456789/21056

Maritime operations in the Arctic and Antarctic are driven by different causes. In the Arctic the gradual decrease of the ice cover opens up possibilities for new routes for shipping mainly the Northern Sea Route. In addition, Arctic operations are increasing due to the natural resources found in the region. The operations in Antarctic waters are mainly related to ocean research and supplying research bases with goods in the Antarctica. Both regions have severe ice conditions compared to other regions where ice may occur. This is due to these regions having multiyear ice in addition to first year ice. Therefore, to ensure the safety of the ships operating in those regions knowledge is require on loads occurring on the ship. There have been studies on the ice-induced loads based on full-scale measurements in Arctic and Antarctic waters. Though, no research has been made on how the different ice conditions affect the safety of the ships in those regions. The effects of ice conditions on the ice-induced loads have been studied before only in The Baltic Sea. However, only the effects of ice thickness on the loads were studied. Therefore, there are gaps in the knowledge on ice-induced loads and especially on the effects that ice conditions have on the ice-induced loads in polar waters. The thesis aims to analyze the effects of different ice conditions on the structural safety of ice-going vessels operating in polar waters. The ice conditions are categorized based on ice thickness and ice concentration. The structural safety is analyzed for local structures in ice strengthened areas of the hull. The results based on full-scale measurements onboard S.A. Agulhas II in the Antarctic were more reliable than the results measured onboard M/T Uikku in the Arctic. Since, S.A. Agulhas had 6 times more data on ice-induced loads, due to more time spent in ice. Nevertheless, the results were interesting, as generally for the bow both ships showed a decrease in safety indices with the increase of the ice thickness and ice ...