The research and development project DYPIC (Dynamic Positioning in Ice) focuses on the challenges related to DP operations in Arctic environment. At the HSVA (Hamburg Ship Model Basin, Germany), model tests in ice were carried out using two configurations; one where the model was fixed to the towing carriage, and a free floating configuration, where the model ship was controlled by a DP system scaled to model parameters.
During the model tests a number of parameters were systematically varied. Model ship velocity and yaw angle were the parameters related to the controlling of the model. In addition, the ice field characteristics were varied by applying two variations in ice floe size and two variations in concentration, resulting in four different ice field descriptions. The ice thickness was remained constant for all test implementations. Every test run with a particular controlling (velocity and heading) profile was executed in each of the four ice fields.
In order to develop a DP controller which is optimally adjusted to the environment in which the system operates, it is important to find relations between the characteristics of the ice field and the forces they apply on the hull of the vessel or construction. An assessment of the measurements and observations during the testing is the basis of a study which has the objective to find how the ice field appearance and the ice loads on a structure relate to each other.