ESD – Energy Saving Devices

The term “Energy Saving Device” (ESD) encompasses the measures and methods for saving energy in ship operation compared to “conventional” ships. ESDs include, among other things, the asymmetric after-body (“stern bulb” form), propeller, nozzles, guide fins, and the rudder, alone and in combination.
The development of ESDs has been worked on already since the 70s. The focus was on the influence of after-body forms and bulges, propulsion and vibration excitation, design and testing of contra-rotating and overlapping propellers, and developing inflow-improving nozzles [1], [2], [3].
Asymmetric after-bodies and guide fins were used in the context of propulsion optimisation of ships for generating a pre-swirl in the propeller inflow to reduce the rotational losses of the propeller. The research and development in this area led to the SVA guide fin systems. Model tests with different types of ships and full-scale measurements show a potential of 2 to 5 % power savings through the use of SVA guide fin systems [4], [5], [6]. Various R & D projects have been processed in order to improve the design of propellers and ESDs. Potential flow methods are used for the design and optimisation of propellers. Viscous calculation methods and experiments are used to verify the design, the prognosis of scale effects and applied to the design and optimisation of propulsion systems such as ducted propellers, thrusters and ESDs. To check the design of the propeller, speed measurements are performed on propeller boss cap fins and rudder. The SVA-developed HVV outlet cover (Hub Vortex Vane), leads to a reduction of the hub vortex and reduces the energy loss of the propeller in the hub area.Systematic CFD calculations are performed for analysis of the effectiveness of Costa Bulb on rudder and to derive design cues [7]. These works were continued in R & D project BossCEff – “Increasing the Effective Degree of Propulsion and Controlling Boss Vortex Cavitation Through Improved Consideration of the Interaction Between Propeller Wash and Boss Cover” [8], [9]. In cooperation with the project partners Technical University of Hamburg-Harburg, The Institute of Fluid Dynamics and Ship Theory (FDS), and the Mecklenburger Metallguss GmbH (MMG), special propeller flow caps were developed and studied for use in rudders with Costa Bulbs and propeller boss covers with fins.

The Mecklenburg Metallguss GmbH developed in the collaborative projects BossCEff a new energy-saving propeller cap, MMG ESCAP®.

The propeller caps improve propulsion characteristics of the vessel on existing propellers and on propeller redesign projects. The ESCAP®, among others, has also been successfully applied in newly designed propellers.

The following maximum power savings were achieved for ships with ESDs by investigations of SVA [11], [12]:

– Twisted Rudder up to 1,4 %
Costa-Bulb with Twisted Rudders up to 3,7 %
Costa-Bulb with Conventional Rudders up to 3,5 %
Boss Cap Fins up to 3,2 %
Propeller Redesign up to 14 %
Wake Equalising Duct up to 4,8 %
Becker Mewis Duct® up to 10 %
Bulbous Bow Retro-fit up to 21 %






Context Related References / Research Projects

[1] Schmidt, D.: Propulsionsuntersuchungen mit Einzelpropeller und Gegenlaufpropeller am Modell eines Containerschiffes, Schiffbauforschung 14 1/2/1975
[2] Schmidt, D.: Der Einfluss der Form des Heckwulstes auf die Schwingungserregung durch den Propeller für ein Containerschiff, Schiffbauforschung 21 1/1982
[3] Schmidt, D.: Die Reduzierung der propellererregten Schwingungen durch nachstrombeeinflussende Änderungen am Hinterschiff,
Schiffbauforschung 23 3/1984
[4] Mewis, F., Peters, H.-E.: Verbesserung der Propulsion durch ein neuartiges Flossensystem Intern. Rostocker Schiffstechnisches Symposium, Schiffbauforschung, Sonderheft, Bd. 1, 1987
[5] Peters, H.-E., Mewis, F.: Das Leitflossensystem der SVA am Containerschiff Typ Saturn, HANSA Nr. 17/18, 1990
[6] Schmidt, D.: Nachrüstung von Motorgüterschiffen ermöglicht Leistungseinsparung, Binnenschiffahrt – ZfB Nr. 9, Sept. 1995
[7] Lübke, L.: Numerical Simulation of the Viscous Flow around Costa Bulbs, NUTTS 2002, Nantes, August 2002
[8] Greitsch, L., Pfannenschmidt, R., Abdel-Maksoud, M., Druckenbrod, M., Heinke, H.-J.: BossCEff – Steigerung des Propulsionswirkungsgrades durch Reduktion von Nabenwirbelverlusten, Statustagung „Maritime Technologien“, BMWE, Rostock, 10.12.2014
[9] Heinke, H.-J., Lübke, L. O., Steinwand, M.: Numerical and experimental investigations for influencing the propulsion efficiency in the hub region of the propeller, STG-Sprechtag “Hydrodynamic Performance of ESDs”, Hamburg, 09.10.2014
[10] Pfannenschmidt, R.; Greitsch, L.: Das MMG Re-Design-Programm, Hanse Sail Business Forum, 07.08.2014
[11] Heinke, H.-J., Lübke, L. O.: Maßnahmen zur Energieeinsparung, Schiff & Hafen, Nr. 10, 2014
[12] Heinke, H.-J., Hellwig-Rieck, K.: Investigation of Scale Effects on Ships with a Wake Equalizing Duct or with Vortex Generator Fins, Second International Symposium on Marine Propulsors, smp’11, Hamburg, Germany, June 2011