Author(s): Junji Sawamura
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Keywords: No Keywords
Abstract: Japanese Antarctic Research Expedition (JARE) begun in 1956. Japanese Antarctic research icebreaker Shirase engages in the transportation of the cargoes and scientists in order to maintain the Japanese Antarctic research station Showa since 2009. Antarctic sea close to the Showa Station is covered with a multi-year ice with extremely thick ice and snow. The icebreaker Shirase has to encounter such severe ice conditions during her voyages. In the 55th Japanese Antarctic Research Expedition (JARE 55) from 2013 to 2014, the ice conditions and icebreaking performance of the Shirase were measured during the JARE 55. In this paper, the measured ice thickness distributions and ice breaking along the ship route are presented. The great variety of ice conditions such as a pack ice, hummock ice, level ice and multi-year ice are distributed. The maximum ice thickness including the snow was around 7 m in the multi-year ice, in which the icebreaker Shirase advanced by a ramming. Ramming performance is important to keep the voyage schedule and safe navigation in the Antarctic sea as well as continuous icebreaking. The icebreaking cups when the Shirase was advancing into the first year ice by the continuous icebreaking were measured using the 3D measurement system. The numerical model calculates the icebreaking cusp when the icebreaker advances into the first year ice. The calculated icebreaking cusps show agreement with the measured ones. The continuous icebreaking in level ice are investigated experimentally and numerically. The measured and numerical results of the ice breaking can be used in the future work for the safe navigation of the Japanese icebreaker Shirase in the Antarctic sea.
Year: 2016