Mitsui O.S.K. Lines (MOL)

Mitsui O.S.K. Lines (MOL) is a major Japanese shipping group headquartered in Tokyo. In propulsion it is best known as the developer and owner-operator of Wind Challenger, a wind-assisted propulsion system using telescopic rigid sails, developed with Oshima Shipbuilding. MOL markets the technology through its MOL Marine & Engineering service platform.

Wind Challenger sails are made of glass-fibre reinforced plastic. They extend, retract and rotate automatically based on sensor readings of wind speed and direction, and can be lowered in bad weather. The first unit was fitted on the 100,000-dwt coal carrier Shofu Maru in 2022, which recorded fuel savings of 5% on Japan–Australia voyages and 8% on the Japan–North America West Coast route. MOL says daily reductions reached up to 17%.

Later vessels include the bulk carrier Green Winds (2024) and the LNG carrier Fujin Sailor (2026). The coal carrier Kurotakisan Maru III, owned by J-Power, received the first retrofit of the system on a ship in service in 2026. MOL has also obtained approvals for an LNG carrier with four sails and a liquefied CO2 carrier with three sails. It targets 25 vessels with Wind Challenger by 2030 and 80 by 2035.