First Year Hull-Ice Interaction Loads Measured on the Louis S. St-Laurent During the 1995 Gulf of St. Lawrence Trials

During March of 1995, hull-ice interaction loads were measured on the hull of the Louis S. St-Laurent (LSSL) in the Gulf of St. Lawrence. The programme made use of strain gages placed on the bow and shoulder areas of the hull for the LSSL 1994 North Pole voyage. An additional measurement area in the stern was added. The winter of 1995 was a mild winter. Ice thickness during the trials was in the range of 0.4m to 0.5m and air temperatures were generally above zero during the day and -5°C at night. There was marked deterioration of the ice strength over the duration of the trials. The trials were conducted on a non-interference basis. Only very limited dedicated trials were conducted. The data was collected using transient recorders with user-defined threshold triggers. Two video systems were installed, one to document the view looking forward of the vessel and a second looking vertically downwards along the side to record the ice thickness of ice piece broken by the bow and turned on edge. This paper documents the measurement program conducted, including a description of the measurement systems and data processing methods. The final results of measured forces/pressures and their distributions are presented and comparisons made to the 1994 LSSL voyage and several other ships.