Dalian Shipyard orders rudders for six Asiatic Lloyd container vessels from Damen Marine Components
03 May 2022
Efficient hydrodynamic rudder system for ammonia fueled boxships
Full spade rudders with asymmetric leading edge and bulb in the wake of the propeller to further enhance flow along the rudder and reduce turbulence, will enable considerable fuel savings for the six new 7,100 TEU container vessels that Asiatic Lloyd aims to take in operation from early 2023.
Damen Marine Components (DMC) will provide one Van der Velden® Atlantic Rudder for each vessel. These rudders are known to cause minimal drag thanks to their slim design. For these container vessels, Asymmetric Rudder Technology (ART) will be applied in the design of the leading edge of the rudder. A rudder bulb in the wake of the propeller axis further improves the hydrodynamic properties of the rudder configuration.
The Singaporean shipping arm of AL Group Asiatic Lloyd has ordered the six 7,100 TEU feeders at Dalian Shipbuilding Industry Co, the yard will deliver six vessels during 2023 to 2025. Length between perpendiculars of the four identical vessels is 255 meter, with 42.8 meter breadth, 14.5 meter design load draught and a design speed of 21.4 knots. Damen will provide the tailor designed rudder for each one of the vessels, measuring 61 square meter and generating 3300 Kilonewton meter of torque.
As the propeller in forward thrust has a fixed rotation direction, the asymmetric leading edge will improve the water flow by directing the turbulent water along the rudder blade more efficiently. The propeller wake directs the flow so it does not come in from straight forward. Even more hydrodynamic optimisation is achieved by the bulb. In the wake of the propeller axis, turbulent water can circle and cause vibrations in hull and rudder. The rudder bulb is positioned right behind the center of the propeller and eliminates this turbulence to create a better flow along the rudder blade. This reduces ship’s resistance in the water and it also improves torque of the rudder when it turns. A stable and directional water flow generates more thrust than turbulent water.
The advanced rudder technology adds to the sustainable ambition of the shipowner and charterer to operate vessels that cause minimal emissions. The choice for ammonia as a propulsion fuel expresses this ambition. Reducing drag, exemplified by the application of ART Atlantic Rudders with Bulb allow further fuel and emission savings.
“We will be benefitting from this highly optimised and high efficiency Van der Velden rudder design by DMC in realising our goal of achieving vessel efficiency to the highest possible emission ratings” says Tonci Zdunic, Group Fleet Director, AL Group.
“We are proud to have been selected by Asiatic Lloyd as partner for reaching their targets of improved operational efficiency and reducing the environmental footprint of their fleet” says Wim Knoester, Commercial Director of Damen Marine Components.