Ocean-Going Tug

Long-endurance tug used for ocean towage of barges, mobile offshore units, and disabled ships. Typical bollard pull is 100–200 t and the tug carries fuel, stores, and accommodation for voyages of weeks. Ocean tugs are usually conventional twin-screw or ASD with high free-running efficiency and a stern winch carrying long towline lengths to set up the catenary needed for stability in seaway. Salvage variants additionally carry firefighting (Fi-Fi notation), pumping, and damage-control equipment under Lloyd's Open Form contracts.