Comparison of vessel theoretical ice speeds against AIS data in the Baltic sea

The northern Baltic Sea freezes every year, complicating and slowing down ship traffic due to added resistance and from at times having to wait for ice breaker assistance in severe ice conditions. This interferes with optimization of commercial vessel logistics. On-time deliveries are important for industry for countries such as Finland as the industry is mainly shipping its exports by sea. Thus knowledge of how well winter traffic sailing times can be forecasted is paramount for proper logistical planning and cost-effectiveness: better predictability of ship sailing times leads to cost savings due to lower delivery time buffers and overall better utilization of transport capacity. While vessel speed in ice can be theo­retically predicted, another question is how accurately this can be done given the limited availability and resolution of e.g. ice data. For this purpose the performance of an ice breaker and a commercial vessel are analyzed and compared along with discussion on how their design affects their ice-going predictability.