Abstract: There are distinctions between the analyses of ice forces on wide and narrow cone structures. The effect of rubble ice on the total ice loads must be considered in the former case. Professor Maattanen presented a finite element model for analysis of ice forces on a large cone structure on the basis of field experience of the Kemi-I lighthouse in the Gulf of Bothnia. The height of the rubble ice, however, was not clearly defined in the presentation. In this paper, the rubble height is determined from a reasonable derivation, and this model was used in the analysis of loads on the JZ9-3 artifical island. The results were accepted by designer.