China Merchants Group has recently signed a contract with China Shipbuilding for two Very Large Crude Carriers (VLCCs) that will sail, powered, in part, by the wind while gliding on a cushion of air bubbles.

The two 300,000 DWT tankers will feature four rigid wing sails to provide wind-assisted propulsion. These ships will not be the first VLCCs with wing sails. In November 2018, China Merchants took delivery of New Vitality, a 300,000 DWT tanker with two rigid wing sails. The sail-assist provided on the New Vitality must have been successful, as the new ships will have double the number of wing sails of their near sister vessel.

The new tankers will also incorporate an air lubrication system. While the technology has been employed on a range of vessels, according to China Shipbuilding it will be the first time it has been installed on a VLCC.

The air lubrication system reduces the resistance between the ship’s hull and seawater by using air bubbles.  The air bubbles distributed across the hull surface reduce the boundary layer skin friction of the ship’s hull. With the right ship hull design, the air lubrication system can potentially result in substantial reductions of both fuel and CO2 emissions.