Maritime transportation is extremely important for the development of the world economy as it is still the main means of transporting goods with approximately 90% of the world trade [1]. In Finland, more than 80% of foreign trade is transported by sea and the amount is gradually increasing every year [2]. The Baltic Sea and particularly the Gulf of Finland had been recognized as one of the busiest vessel traffic areas in the world [3]. In the Gulf of Finland, maritime traffic has been continuously growing due to the constant increase of the transportation of various cargoes to Russia and the transport of oil from Russia [4]. This increment of traffic has been reflected even during winter periods when sea waters are frozen and the sea ice extent gradually covers several areas within the Baltic.

Winter ice navigation in Finland has been practiced for almost 400 years. It started with boats delivering the post from Turku in Finland to Stockholm in Sweden during the years 1636 – 1898 and the first icebreaker Express II started to operate on 1877 [5]. The winter ice navigation season at the northern Baltic commonly begins in late November on the Bay of Bothnia and between mid-December and early January on Gulf of Finland and Sea of Bothnia. The ice conditions commonly remain until early May in the Bay of Bothnia and until mid-April in the Gulf of Finland and Sea of Bothnia.

The ice class rules together with traffic restrictions will guarantee the safe operations

The ice class rules specify the structural characteristics, machinery and equipment of vessels which can navigate under specific ice conditions. There are six different ice classes (III, II, IC, IB, IA and IA super). Classes II and III are basically open water vessels which are only capable of operating independently in very light ice conditions, classes IC and IB are vessels designed for early winter and late spring ice navigation, class IA vessels can operate during all winter but they may be restricted when ice conditions are severe, and class IA super vessels are able to operate in heavy ice conditions also without icebreaker assistance [6,7].

Every winter, traffic restrictions for vessels entering to the Baltic Sea are designated based on the sea ice conditions surrounding the winter operational ports of the zone. The restrictions specify the type of ice class vessels which are allowed to navigate under certain ice conditions and also the ones eligible for receiving icebreaker assistance. In general, traffic restrictions aim at ensuring the integrity and operational safety of vessels, protecting the natural environment in the area, and reducing the time vessels have to wait for icebreaker assistance [7,8].

 A view from the aft deck of IB Kontio in the Bay of Bothnia: Towage and the towing wires of the icebreaker are not always needed, if the assisted cargo ship can maintain steady speed behind the icebreaker. Photo: Risto Jalonen.

Winter navigation system will not function without powerful ice-breaker fleet

Icebreakers play an elemental role within the winter ice navigation system. The assistance operations by icebreakers may cover from a simple provision of instructions for guiding a vessel in its journey, to the actual implementation of a rescue operation. The opening of channels in the ice for a subsequent escorting of one or more vessels, the releasing of vessels stuck in ice, and the towing of a vessel under certain ice conditions are the most common rescue operations performed by icebreakers.

Daily ice charts will reveal ice conditions

Ice services provided the required input of information for activating the winter ice navigation system. The services encompass a monitoring of ice conditions and ice developments on a daily basis. The services basically provide processed meteorological information which is presented as ice charts and reports describing the ice conditions in different zones of the Baltic. The services include satellite images, ice charts, positions and destinations of the vessels navigating in the area, ice forecasts, weather forecasts and weather observations for supporting vessels routing and assistance decisions for icebreakers [9].

High level of safety is based on good co-operation between various players

The application of the Finnish-Swedish winter ice navigation system enables a systematic controlling and managing of the operations performed by vessels during winter ice navigation in the Baltic Sea. Therefore, winter ice navigation is currently perceived to be effectively controlled and managed in terms of safety. The system is positively accepted and utilized by the maritime community established in the zone. As a result, accidents that have occurred during winter ice navigation have mostly been reported as accidents with no severe consequences in recent years. However, the aim is to constantly seek for means to improve the safety performance of winter navigation operations. And in order to keep this proactive safety approach, the maritime community is permanently working to reduce the risks of accidents and to create appropriate responses for facing emergency situations which may rise from the development of vessel operations under ice conditions.

Penguins seemed to be interested in the icebreaking polar supply and research ship S.A. Agulhas II and the researchers conducting experimental work. Photo: Pentti Kujala.

Aalto University aims to build reliable and systematic models to analyse the safety elements

Department of Applied Mechanics in Aalto University has a number of ongoing projects to study the safety of shipping in ice covered waters. The most important project is the new centre of excellence for Arctic shipping and operations for which Aalto University, together with three other universities, received significant funding from Lloyd’s Register Foundation (LRF). The other partners in the centre are Helsinki University, the Norwegian University of Science and Technology NTNU (Trondheim) and Memorial University of Newfoundland (St. John's, Canada). The Centre will support eight doctoral dissertations on risk management in Arctic operations over a period of five years.

Another project focuses on two main issues: 1) to update and develop the pollution combating contingency plans of Russia and Finland related to Gulf of Finland waters, and 2) to carry out risk assessment of winter navigation with the understanding of proper risk control options. In addition, Aalto researchers have taken part in the full scale measurement voyages onboard SA Agulhass both in the Baltic Se and in Antractica [10]. The aim of these measurements has been to gather full scale data of ice induced loads on the ship hull and propulsion system.