westbound direction and a voyage starts at the beginning of a month. Therefore, a voyage starts in Yokohama and terminates in Hamburg on transit voyage, and Dikson and Yokohama are the starting points on regional routes. When navigation days require over one month, the next month data should be used, because the segment data are given on a monthly basis.
However in this simulation, the environmental data for the starting month is maintained to avoid discontinuities between segments as to ice conditions. These one voyage simulations based on monthly environmental data of each year is named as Monthly Voyage Simulation (MVS).
Annual Serial Voyage Simulation (ASVS)
Freight cost is commonly accepted as an index to express the cost efficiently. The freight cost is calculated from the required costs over a specified period by dividing the total transporting cargo capacity and described by $/ton. For this purpose, a serial voyage operation between Yokohama and Hamburg for one year is simulated. A voyage starts on Jan.1st from Yokohama and a number of voyages is calculated. The anchoring days at each port are selected from the actual results. The simulation can also take account of route switching between the NSR and SUEZ route by judging ice conditions. As the results of this simulation, the whole costs and annual amounts of transportation can be calculated. Consequently, they provide us a comparative freight performance by the NSR to year round operation by the SUEZ route. This series of simulation is named as Annual Serial Voyage Simulation (ASVS).
Cost calculation procedure
In the cost calculation, capital cost, escort cost, ship operation cost, fuel cost, and port cost are considered as noted in chapter 2.3. They depend on different units i.e. one-year; one-voyage, escort days, and required power etc. The cost, which depends on the voyage or escort days, can be calculated by multiplying a distribution of days by a unit cost shown in the cost table in chapter 2.3. The fuel cost is one of the costs that depend on the ship performance.
It is obtained by multiplying a distribution of the fuel consumption to one voyage, which is a total of fuel consumption of each segment, by bunker price.
In annual simulation, each voyage cost influenced seasonally is totaled to obtain the total annual cost.
The following shows each of cost calculation ：
Capital cost： Repayment of the loan for new build ship. A fixed amount per year (CCa) would be charged. For one-voyage simulation, multiply CCa by the ratio of voyage-day (Tm) to annual operation days (Ta).
MVS： CCm=CCa×Tm/Ta
ASVS： CCa
Ship operating costs： cost to maintain a cargo ship, which considers a crewing cost, a maintenance cost, and insurance cost in this simulation.
- Crewing cost; cost depends on voyage days, which is calculated by multiplying crew charge for one day (CCRd) by voyage days (Tm).
MVS： CCRm=CCRd×Tm
ASVS： CCRa=ΣjCCRj
where, CCRj is a crewing cost for the j time of voyage.
- Maintenance cost; Cost to maintain a ship for one year (CMa). In one voyage simulation, multiply the maintenance cost per year by the ratio of voyage days(Tm) to operation days per year (Ta).
