ANNUAL OF NAVIGATION 26/2019 DOI: 10.1515/aon-2019-0012 SCHEDULING TRANSIT VOYAGES OF VESSELS OF VARIOUS ICE CLASSES ACROSS THE NORTHERN SEA ROUTE Tadeusz Pastusiak Gdynia Maritime University ABSTRACT Main problem for scheduling vessel transit voyages through the Northern Sea Route is the difficulty in predicting distribution of ice boundaries in regions that cannot be overcome by individual ice classes of vessels. Scheduling of voyage is related to speed that vessels can develop and moment of time when vessels will be able to commence and complete passage safely through areas that are main obstacle and are blocking longest transit passage through the Northern Sea Route. This applies to voyages carried out by vessels navigating on their own and with support of icebreakers. Additional problem is lack of consistency of content of maps of ice cover, which can be used for vessels voyage planning through areas where ice cover occurs. Results of this research on influence of uncertain information related with time window of conditions favorable for navigation of vessels of different ice classes on schedule of theirs voyage on example of summer navigation season 2017 are presented in this work. Keywords— Northern Sea Route, ship’s ice class, ship voyage schedule INTRODUCTION A significant acceleration in reduction of ice in the Russian Arctic resulted in interest of international maritime carriers. The reason is significant shortening of voyage route between European ports and the Far East compared to traditional route through the Suez Canal. The leading route seems to be attractive but the carriers take into account costs of icebreaking, pilotage, additional insurance and potential unexpected shipping difficulties related to ice conditions occurring on the Northern Sea Route (hereinafter NSR). Sea transport on the NSR in 2015 was estimated at 4 million tones. In contrast, potential transport capacity on this route until 2030 is estimated at 80 million tones. Thus, a 20-fold increase in freight transport is possible (https://vz.ru/economy/2015/6/9/749791.html, date accessed 17.09.2017). In connection with expected climate changes, the need to increase number of icebreakers in relation to the currently operated and with more drive power than icebreakers currently in use has been noticed [4]. The government of the Russian Federation has secured in state budget expenditure on new-generation nuclear and diesel-powered icebreakers to secure sea transport on the NSR [7]. The will of government of the Russian Federation was upheld in subsequent documents in 2017. The state budget provides for construction of high- power new generation Arctic icebreakers [6]. Results of previous work of the Author [25, 26] indicate systematic extension of time period of occurrence of lighter ice conditions on the NSR, including period favorable to ice-free navigation. It was determined [1, 114 ANNUAL OF NAVIGATION 26/2019 2, 11, 15], that during spring and summer period, when ice melts, vessels should set voyage route in zones with low ice concentration (40-60%), and if possible - in regions with very low ice concentration (10-30%) [21, 24]. Regions with 70-100% concentration were classified as difficult for ice navigation. For this reason, they should be avoided by vessels. In legal regulations of the Russian Maritime Register of Shipping [29] requirements for ships with different ice and polar classes of vessels are specified. However, the NSR Administration issues special permits also for vessels whose steel hulls do not have ice strengthening. Maritime transport by vessels without ice strengthening is allowed only in ice-free waters [16]. General rule of navigating vessels is practiced by the lightest ice conditions, especially in ice-free or almost ice-free waters, regardless of whether it concerns a low ice-class vessel or icebreaker. Taking above into account, there is a need to examine ice conditions in the recent past, i.e. in 2017 on the Northern Sea Route and their impact on transit shipping of vessels with different ice classes and in particular vessels that do not have ice reinforcements. Important role for scheduling voyage (determination date of beginning, date of end of acceptable for vessel’s passage ice conditions and also ice conditions along vessel’s route) plays proper designation of ice maps used. Actually available ice maps are made using mostly data from remote sensing methods. Discrepancy in between processed and interpreted satellite image and real ice conditions plays key role in economically scheduled voyage [27]. For this reason more than two sources of ice information should be cross checked during research. PURPOSE AND SCOPE OF THE WORK Purpose of the work is to collect information on ice conditions occurring in 2017 at the NSR and to determine impact of these conditions on possibility of carrying out scheduling transit voyages of vessels with different ice-breaking capabilities. Specific objectives will be: - determination of boundaries of areas along the vessel's transit route through the NSR, which have at the very least been free of ice and have been closed for ice-free navigation at the earliest, - determining time course of changes in ice concentration in navigation season, - determination of time frame in navigation season in which it will be possible to transit through the NSR on vessels with specific ice-breaking capabilities, referred to as ice classes. Main criterion for ability to pass ice in summer navigation season is concentration of ice [23, 24]. For this reason, selected sources of information on ice concentration will be analyzed. Three groups of sources of information will be selected for analysis in order to verify information content presented on individual maps. DATA SOURCES Among the sources of information on the state of ice cover available on the Internet, there are those that are published by countries with high research activity in the Arctic. These are: 1. Ice concentration analysis maps in simplified Marginal Ice Zone in the Arctic Ocean published by the NIC in georeferenced ERSI Shapefile vector format [3]. These files are available on the NATICE web site (http://www.natice.noaa.gov/products/daily_products.html, date accessed 25.02.2016). They are compiled from various sources of information with a better resolution than 50 meters per pixel. These sources of information include, among others ENVISAT, OLS DMSP, AVHRR i RADARSAT. Analysts carry out necessary interpretation of images. It increases value of these sources for correct identification of ice edge range. Information content is in line with the ice ellipse standard [31, 32], but it has significantly reduced range of information. Total ice concentration scale includes clean water (range 0 to 17%), Marginal Ice Zone (range from 18 to 80%) and compact ice (range from 81 to 100%). Maps are published every 24 hours. 115 ANNUAL OF NAVIGATION 26/2019 2. Maps of the analysis of ice concentration, ice thickness, ice floe size published by the NIC for selected regions of the Arctic Ocean according to the S-411 standard in geo-referenced vector GML format (http://www.bsis-ice.de/IcePortal/ILP_S411.shtml, date accessed 25.02.2016). Previously published NIC maps were based on analysis and integration of all available data on ice conditions, including weather and oceanographic information and visual observations from shore, ships and planes, aerial radar, satellite images (RADARSAT, ENVISAT, MODIS, GMM) and climate data. Total ice concentration scale includes discrete values 2, 13, 24, 46, 68, 81 i 92 %. These maps are published every 7 days (168 hours). The specification of the S-411 standard is described in the IHO document [9], 3. Maps of analysis of ice concentration, ice thickness, ice floe size for selected regions of the Arctic Ocean from the PLANETA project in raster JPG format according to the Russian standard for map description [5] convergent with ice ellipses description standard [31, 32] in GIF raster format. In summer season, content of map applies only to concentration of ice. (http://nsra.ru/ru/navigatsionnaya_i_gidrometinformatsiya/icecharts.html, date accessed 25.02.2016). Automatic classification of objects (clusters analysis) from multispectral satellite data using SAR images based on satellite Severyanin is used to develop these maps. Scale of total ice concentration includes discrete values in form of clean water (no ice), 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 %. These maps are published every 4 days (96 hours). Content of maps published by the PLANETA service includes the most discreet concentration limits. Content of maps in the S-411 standard provided by the NIC includes reduced scope of concentration scale. It seems, however, that it is directly related to operational capability of particular groups of vessels and thus meets the needs of economic activity of vessels in the Arctic. However, content of MIZ type maps published by NIC is significantly reduced. Nevertheless, it meets the needs of vessels that do not have ice strengthening of hull (concentration from 0% to 17%), medium and high ice class vessels without distinction (concentration from 18% to 80%), icebreakers and vessels with the highest ice classes with the support of icebreakers (concentration from 81% to 100%). An important factor indicating timeliness of information content is period of time between consecutive editions of maps [20, 22, 23]. The MIZ type maps are issued by the NIC in the shortest time intervals every 24 hours. The PLANETA project maps are published every 96 hours. Maps in the S-411 standard are issued by the NIC every 168 hours only. From point of view of the use of ice map files in decision support systems [21, 23, 25] both vector georeferenced files issued by the NIC (type MIZ and S-411 standard) seem to be the most useful due to possibility of direct implementation in computer software like GPS one [10].