Ice Model Tests in Compressive Ice

摘要

Dynamic and compressive ice fields cause difficulties for ships operating in ice. Ships might get stuck or even get damaged in a compressive ice field due to the compressive forces. Especially ships with a long parallel midship are vulnerable to compressive ice forces. In the EU FP7 project called SAFEWIN the risks and impacts of compressive ice fields on ships are investigated. Ice model tests are conducted in the ice basin of Aalto University within the project with a tanker model in compressive ice fields. The aim of the tests is to determine the increase of ice resistance resulting from compression in the ice field. In addition, ice loads and ice pressures are measured on the bow shoulder and the parallel midship areas simultaneously with load sensors and tactile pressure sensor sheets. In order to determine the increase of ice resistance and ice loads resulting from different compressive situations, the tests are conducted in compressive level ice fields and in closing channels with different ice thicknesses and different compression levels. The resistance and ice loads are measured with and without compression in the same ice sheet and the measurements are compared between. The compressive force in the ice field and closing channel are created with pushing plates mounted on the testing rig and the compressive force is measured from the plates with load sensors. Test procedures and set-up are described in this paper and the measurements of the rig-imposed ice forces are given. The preliminary assessments of the added resistance and ice loads are presented.