Navigating icy waterways
Backed with EU funding, the 'Safety of winter navigation in dynamic ice' (SAFEWIN) project is dedicated to developing an efficient ice compression and ice dynamics forecasting system that will be particularly appropriate for conditions in the Baltic Sea, the Okhotsk Sea and the western Russian Arctic. The biggest damage to ship structure occurs in moving ice cover, where large compressive forces can act on the ship hull and possibly even lead to hull rupture. As such, a better understanding of the behaviour of ships in this kind of ice is required, and ships are in need of a warning for nearby compressive regions. Project work commenced with intensive observations initially focused on the Gulf of Finland, and then the Bothnian Bay. To date, observations have also been carried out in the Gulf of Riga. Visual observations of sea ice compression were made on board icebreakers and merchant vessels, and ice cover movements were studied with drift buoys, satellite images and captured radar images. SAFEWIN partners conducted two winter field campaigns, producing measurements such as ice motion detection, ice thickness and ice pressure. These were very successful in terms of outlining severe compression events that can seriously disrupt shipping operations. Other actions have succeeded in improving on ice models - ice compression has been added to these as a new prognostic variable. In addition, first hind cast simulations, including ice stresses, have been performed. SAFEWIN efforts allowed development of an operative forecasting system for dynamic and especially compressive ice. The forecasting system includes a description of the compression (magnitude and direction) in terms of quantities that can be applied in ship operations. The system is integrated into the existing IBnet system, a distributed traffic information system for icebreakers and will operate as a decision support tool for ice navigation. This may have a large impact on the probability of ships getting stuck in ice and thus decrease the risks remarkably. The use of such forecasts and systems will help merchant vessels better plan their routes for maximum safety, and assisting icebreakers will be able to determine waypoints for merchant ship routes on the basis of the safest and most efficient passage of ships.
Keywords
Dynamic ice, compressive ice, forecasting, route planning, ship safety, winter navigation, ice sheet, ship design, sea ice modelling, operative forecast
