2. Decision Support System for Initial Planning of a Voyage on the NSR

This chapter discusses system of initial transit voyage planning and scheduling of vessels that do not have ice strengthening of the hull through the Northern Sea Route developed by the author. Assumed that vessel should make voyage on the “there and back” way, that is, the first part of the voyage to the East and the second part of the  voyage to the West, or vice versa. Planning process concerns 2–5 months advance in time relative to date of planned beginning of voyage. General scheme of the system was presented. The system consists of numerous partial procedures, which allows to achieve information necessary to make decisions. Large number of decisive criteria and input data with uncertain values for vessel’s voyage planning decision-making model required to develop the algorithm that binds components of model and also supports the analysis on computer data processing. The qualitative and quantitative indicators were included in the system. The criteria for route selection in summer navigation season were based on ice concentration using probabilistic methods. Average values of opening and closing dates of ice-free transit zone and their standard deviations were used. Trend lines of opening and closing of the NSR seas for ice-free navigation were approximated using polynomial function of second degree obtained on basis of historical data. The diagram of speed determination of PANAMAX-type vessel was implemented in the model. Duration of ice-free navigation period for vessels without ice strengthening and limited by their draft in the shallow NSR regions is relatively short. In order to plan two consecutive voyages through the NSR on a “there and back” basis, it must be assumed that first voyage will use a network of suggested routes for opening period and will use network of suggested routes for closing the NSR for ice-free navigation. Route determination procedure that uses network of suggested transit routes for opening and closing periods of the NSR regions for ice-free navigation in the east and west directions was described in one of chapters. Principle of avoiding, as much as possible, regions of probable occurrence of extreme ice drift phenomenon was described in other chapter. Designated nets of suggested routes include statistical location of ice massifs and ice cover extent. Criterion of safe depths has already been met at the stage of determining network of suggested routes. Procedure for determining beginning date of voyage on the NSR is based on statistical data described in one of chapters. Duration of ice-free navigation for vessels without ice strengthening and limited by their draft in the shallow NSR regions is relatively short. Procedure for assessing quality of designated route variant covers length of route and probability of availability this route for ice-free navigation. Voyage cost calculation procedure uses an algorithm that takes into account fuel costs and charter costs. Decision-making module makes performance evaluation of designed route option. It determines whether received results of route plan option meet initial assumptions and whether it is possible or desirable to carry out new voyage plan next time. At this stage, human intervention is necessary, that is, decision-maker.