Routes Along Ice-Free Zone on the NSR for Vessels Without Ice Strengthening

Abstract

This chapter describes results of research of ice-free transit zone release from ice cover that is connecting the subsequent NSR seas for the east and west. The first possible route available for vessels with very small draft and separately for larger vessels requiring a minimum sea depth of 14.5 m was taken into consideration. The course of closing of transit ice-free zone during period of ice growth was also made. The only significant difference to these runs was the possibility of passing shallow Laptev Strait or necessity of using more deep Sannikov Strait. For this reason, the archipelago of the New Siberian Islands, where both straits are located, will constitute main restriction for transit shipping of vessels with a deeper draft. Networks of suggested routes for opening and closing transit ice-free zone, including minimum sea depths, have been developed and presented on maps. Each route was assigned the probability of repeatability of their course in future. The decision-maker on board vessel or in the office of the ship’s operator may decide on the selection of the route option based on his own knowledge, experience and knowledge of the hydrometeorological conditions occurring in the current year. Network of suggested routes reduces risk of accidental incorrect route selection. In consequence, it reduces probability of having to change the route option during voyage. Such change would result in higher voyage costs for a vessel and consequently loss of profits. Average length of routes for particular variants and their standard deviation was described and presented by means of graphs. Statistics with average values, standard deviations, medians and quartiles were included in the tables. It was found the routes taking into account minimum depth of sea of 14.5 m significantly delayed opening time for ice-free transit of larger vessels, which was even up to three weeks. Based on results of the studies, the zones with a certain probability of existence of ice-free transit zone at the peak of navigation seasons were developed. Same time, the regions of the most difficult ice navigation conditions during the peak of navigation season were presented. The research established a general rule—the closer the route to the continental coast, the more probably the ice-free zone to occur.