The safe and stable navigation under circumstances of tumultuous water is a great challenge for medium-sized vessels. Moreover, waves increase fuel consumption and CO2 emissions. The EU-funded SmartWings project has introduced a unique solution for motion damping and fuel saving for medium-size ships. Through the innovative production of the first-ever retractable bow foils, SmartWings aimed to offer a unique fuel saving device contributing to the transition to zero-emission shipping.
Medium-size ships sailing in waves suffer up to 100% higher resistance than in calm water. This added
resistance has several consequences:
• Dramatic speed loss.
• Increase of fuel consumption and CO2 emissions
In addition, vessel motions in waves cause seasickness and decreases crew productivity.
Adding wings or foils to a ship bow utilizes wave energy to propel the ship forward by creating a net forward thrust when the vessel moves up and down in waves. This has been known since the 19th century, but no commercial product has been available with this purpose. Sailing with bow foils is counterproductive in certain situations, where the foils increase the ship resistance, and in extreme weather where so-called slamming loads may break the foils. A retraction and storage mechanism for the foils in these situations is required, but until now no feasible foil retraction mechanism has been available. Wavefoil has developed the first ever retractable bow foils:
• Reduce the energy consumed to propel the ship by 5-15% in waves
• Reduce ship motions, promoting a more comfortable and productive trip
• Can be retracted/deployed to optimize the ship performance for any given situation.
• Delivered as one unit called a foil module containing port and starboard foils and the mechanism to retract/deploy foils that can be installed in in any ship hull.
Our unique foil retraction system allows, for the first time ever, to exploit the full range of benefits of bow foils.
Before SmartWings project was started, Wavefoil had already made a successful retrofit installation in the 45-meter car ferry M/F Teistin that achieved approximately 10% fuel saving in average the first year after installation. The objective of SmartWings was to develop a foil module for vessels in the length range 100-200m that need a significantly larger foil module which could not have been developed without this project grant. The size itself implied several challenges that has been overcome during the project. A significant effort has been paid to keep the production costs as low as possible without compromising the strength necessary to withstand the enormous loads the foil will be exposed to. The project has also covered a thorough design optimization process to maximize the fuel savings. Finally, a decision support system has been developed and verified with acceptable results in simulations. The system gives recommendations on when to retract the foils due to the risk for too high loads without reducing the total fuel saving for a ship operating in a typical route with normal wave conditions. A greater “fuel saving loss” is obtained for very exposed routes where the decision support system recommends retracting the foils more often.
SmartWings intended to produce of a full-scale prototype and testing on a suitable test vessel. Unfortunately, the original ship owner withdrew from the project for reasons outside our control. Despite significant effort and several promising opportunities with alternative test vessels, Wavefoil was not able to carry on the operation of the company long enough to find a test vessel before the company went bankrupt in June 2023. The components of the full-scale prototype were manufactured, but never assembled before the entire project was terminated.
