In early 2000s Fortum Shipping, the transportation arm of the Finnish energy company Fortum, started a major fleet renewal program to increase the efficiency and reduce the average age of its vessels. The program also included replacing the company's old tankers, such as the 90,000-ton "Natura", that were used to transport crude oil to the company's oil refineries in the Gulf of Finland. The old ships had traffic restrictions during the worst part of the winter because of their lower ice class of 1C and could not deliver their cargo all the way to the refineries in Porvoo and Naantali because they were denied icebreaker assistance. When this happened, the oil had to be transported to smaller ships of higher ice class at the edge of the ice — a practice that was both uneconomical and hazardous.