decreases as increasing GT, and the fees for the three simulated ships are extrapolated from Table 2.3.2. Figure 2.3.1 illustrates the relation between gross tonnage and tariff rate per GT.The tari11 rate of 50,000 DWT bulker is raised by 10% from the extrapolated value, considering the inferiority of ship performance in comparison with other ships. The escort fee is charged per voyage and regarded as flat rate, thus the frequency of icebreaker escort does not affect it. As the miscellaneous costs, ice pilot costs per day are added when the ships stay within the NSR. One ice pilot is assumed in Regional West routes and two ice pilots are mandate in the other three routes. The working hours of ice pilot is assumed as 12 hours per day.
Port costs
The port costs are needed at each call for port for the use of tag boat, harbor facilities, and loadin/unloading costs. This cost considerably varies with each port and a type of cargoes. As it is explained in 2.3.1, the kind of cargo is assumed as a bulk cargo of grain, plastic and the like. Four ports, Yokohama, Hamburg, Tiksi, Dikson are selected as departure/arrival ports. The port costs at Hamburg and Yokohama are based on the data studied by NYK and those of Tiksi and Dikson were refereed from the WP report.
