China’s Jiangnan Shipbuilding has become the latest in a series of companies to present designs for wind-assisted propulsion for large ocean-going vessels. The shipyard reports that it developed its smart sail system internally and that it is based on a high-performance computing platform that evaluates the sail's aerodynamic properties and enables the selection of airfoil parameters.
Several companies in Europe have already begun tests on prototype sails designed to reduce fuel consumption and the resulting emissions while well-known corporations including Michelin and Chantiers de l’Atlantique in Europe and Mitsui O.S.K. Lines (MOL) in Japan are also developing concepts for sails. The designs for sails are in addition to the rotor sails which have already been successfully demonstrated to harness wind energy.
Working with Oshima Shipyard, MOL has installed a rigid sail on a bulker that is due to enter service later this year while the companies have placed additional orders for bulkers fitted with their telescoping rigid sail.
Jiangnan’s Intelligent Sail Bost concept is autonomous and controllable by a technology platform that automatically adjusts the sail surface according to the changes in wind speed and wind direction angle on the route. The technology used to rotate the sail ensures that it provides maximum efficiency while the use of the automatic control system equipment reduces the requirements for the crew.
The sail can be automatically lowered in height based on wind conditions and retracts freely according to the requirements of the air draft. In rough sea conditions, the ship can also quickly stow the sail to ensure the safety of the ship.
The surface material of the sail is made of polymer composite materials, and the lightweight design of the entire sail ensures the structural strength of the system under wind pressure. The lightweight and modular designs also mean that the sail can be fitted without a shipyard visit to meet the needs of the shipowner.
Jiangnan reports that its smart sail will produce a four percent saving in consumed energy. The shipyard said it is also working on a modular design of the sail system to accommodate different ship types and sizes.