4.1.2 Simulation for transit route operation
The monthly voyage simulation (MVS) linking Yokohama and Hamburg was executed in order to investigate the trends for transit voyages. 40BC and 50BC were used for N-route voyage, 25BC was used for S-route voyage. The simulation series was executed using the environment data from 1957 to 1990, however, those years in which the data did not satisfy the fulfillment of 50% were excluded from our database as noted in chapter 2.2.
Figure 4.1.1 to 4.1.3 show the voyage-days and Figure 4.1.4 to 4.1.6 indicate the escorted days by icebreaker by month for 25BC, 40BC and 50BC in both 1979 and 1980 as one of the results. The notations, 1% max. in the figures means the value corresponding the probability of occurrence at 99%. Another notation, 1% min. means the value under which the probability at 1%. However the difference between 1% and 99% is small, and that demonstrates that the ice index is reasonable. Figures 4.1.7 to 4.1.9 show the components of one-voyage cost. The results in the other years are summarized in the Appendix C.
Table 4.1.4 to 4.1.6 and Figure 4.1.10 to 4.1.12 show the monthly tendency of the voyage-days and the escort days for 25BC, 40BC and 50BC respectively. Each data of them represents the average of 1957 to 1990. The monthly tendency indicates that the voyage-days decrease from June to October. The ratio of escort-days to the voyage-days in the NSR tends to exceed over 50% from February to June. As for a comparison between the cargo ships, the ratio of 50BC is greater than the other ships. These results for the escort-days are reasonable.
50BC needs longer escort-days than 40BC in the N-route, since 50BC is inferior in the icebreaking capability. 40BC in the N-route, where the ice condition is more severe, needs longer escort-days than 25BC in the S-route as both 40BC and 25BC has the same icebreaking capability.
Figure 4.1.13 to 4.1.15 show the monthly tendency of the average navigation speed by Sea area. On the whole, the navigation speed ranges between 4 to 7knots in the winter from December to May. In the summer season from August to October it ranges between 9 to 13knots for 25BC and 40BC, between 9 to 14knots for 50BC. The tendency indicates that the speed of 40BC and 50BC in the winter season is slightly greater at the Laptev Sea than the other area, but in summer season one at the Chukchi Sea is greater. On the other hand, as for 25BC in the summer season, the superiority at the Chukchi Sea is not recognized. As a whole, the speed in the East Siberian Sea is relatively slower than other areas.
Table 4.1.7 to 4.1.9 and Figure 4.1.16 to 4.1.18 show the monthly tendency of the cost components, as the average of 1957 to 1990. The operating and fuel costs slightly vary although the capital cost greatly changes in season. The escort days increase from January to July, and decreased from August to December nevertheless the icebreaker fee is almost constant because the flat rate charge is adopted. The difference among ship types is that 50BC requires more expenses on icebreaker fee, fuel fee and port fee than that of 40BC and 25BC but capital cost for 50BC is relatively low. As the results, the total costs for 50BC is less than those of other two ships. The detailed data are listed in Appendix C.
