Ships That Use Weather to Fight the Weather

To cap greenhouse gas emissions, the International Maritime Organization (IMO) has introduced the Energy Efficiency Design Index (EEDI). This index is a measurement of the amount of carbon dioxide that a ship emits in relation to its cargo capacity and speed. The weather conditions affect the emissions. The effect is quantified with a factor (fw) that could affect EEDI by up to around 40%. For seagoing vessels, a significant portion of the weather factor is due to added resistance in waves. This paper includes a unique new technology aiming to reverse the adverse weather effect by converting the wave-induced ship motions directly into a forward ship motion. The technology relies on reaction forces that normally exist when water flows through a pipe bend. An open to the sea ship compartment can be designed to function as a pipe bend. The seawater oscillates inside a specially shaped moon pool due to the relative ship motions in waves. The curved profile of the moon pool deflects the water backward from its natural vertical flow, and the water inertia pushes the vessel forward, according to the momentum conservation law. The new wave-energy drive (WE-Drive) does not have any moving or protruding outside the hull parts. It can efficiently counteract the added resistance in waves. The WE-Drive can reduce the carbon footprint of marine vessels and increase the operability range of battery-powered ships.