HELSINKI—Despite heavy seas, a joint Norwegian-Dutch salvage operation has managed to get an abandoned Dutch cargo ship under control off the coast of Norway and was towing the ship to port on Thursday. Norwegian officials said the rescue operation of the Eemslift Hendrika, a Netherlands-registered ship designed to carry large boats, was completed early Thursday and the ship is slowly being towed to the western city of Alesund. The ship’s crew of 12 was rescued by helicopter late Monday after a power outage in its main engine. The Norwegian Coastal Administration, based in Alesund, launched a salvage operation late Wednesday as it became clear that churning seas could make the drifting ship crash into the shore. The vessel has substantial quantities of diesel and fuel in its tanks, which could have caused an environmental disaster. Norwegian maritime authorities issued an emergency alert late Wednesday and started preparations in case of …