The strength of a heavily loaded propeller for a high arctic class ship-more than class 7- has been studied. At first, ice impact and ice milling model test have been carried out. Sequentially, statical loading test also has been conducted, and the measurement results have been analysed by FEM technique. In impact and milling test, 320 mm dia. NiA1Br 4-bladed model propellers have been used. Ice blocks for test have been specially prepared, saline ice and paraffin wax blocks. This 1st report mainly describes details of the model tests of impact and milling tests. From this study, the authors have made clear an interactive behavior of propeller blades and ice blocks, namely bending moment, thrust, and torque of propeller blades and shafts during impact and milling condition.