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International Windship Association | June 16, 2024

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Siegfried Wagner – IWSA Supporter

RMI Design 3d Model

Grown up in the southern parts of Germany I enjoyed sailing since my early youth. Later I began working as a professional Skipper for adventure and educational sailing with school classes on board of yacht style sailing vessels in the Mediterranean Sea. During that time, I began to interest myself for the design and construction of these wonderful vehicles that are able to cover immensely large distances without the need for permanent fuel consumption.

Many years later in 2015 I finally finalized my master’s degree for Naval Architecture and Ocean Engineering at the Technical University of Hamburg-Harburg (TUHH). During my studies I developed a strong interest in the topic of Wind assisted propulsion for commercially operated vessels, which eventually led to different study research projects and thesis works including wind-tunnel testing series of sails, academic research concerning the vortices effects of traditional centerkeel concepts as well as a study on shape variations for possible bilge-keel configurations for large commercial sailing vessels using CFD-RANSE calculation concepts.

After my studies, I further pursued the topic of wind propulsion for commercial applications. In 2016 I started a cooperation with a like-minded industrial designer. We developed different vessel concepts ideas for future wind shipping solutions. During this cooperation the Cargo-Sail-Concept ( was developed. Basically the Cargo-Sail Concept is a vision for future Zero-Emission large scale maritime cargo transportation and could be the basis for various research projects focusing on different aspects that are required to make this vision a reality.

In 2018 I joined the research team from Prof. Capt. Michael Vahs at University Emden Leer (HEL) for the project ‘Transitioning to Low Carbon Sea Transport’ (TLCSeaT). The project is a GIZ funded initiative in cooperation with the Republic of the Marshall Islands (RMI). The Marshall Islands, being seriously affected by climate change already, have declared to decarbonize their domestic shipping fleet until 2050. Together with my team from the University and the naval architects from SDC (Ship Design & Consult) we developed a ‘wind assisted island supply vessel’ utilizing the INDOSAIL sailing system. This new-build 50m vessel represents a milestone for commercial application of modern sail systems. The concept incorporates many technological aspects for low or zero emission transport that are also needed for large scale applications. The vessel is currently constructed at a shipyard in South Korea and will be delivered to RMI by the end of 2023 followed by extensive testing as well as training for RMI seafarers.

My core competencies, developed during my involvement with wind propulsion technologies, focus on the aero- and hydrodynamics of commercially operated wind ships. In-depth knowledge of various types of sail systems. Conceptual design of wind-powered, commercially operated vessels incorporating aero- and hydrodynamic aspects into a reasonable overall design suitable for commercial applications. Speed and power predictions to evaluate the overall performance of a design and optimizing based on specific design goals.

Please feel free to contact me if you have any questions about these specific wind propulsion topics.

IWSA Supporter


AddressSiegfried Wagner
Kuckucksleegde 2
26629 Großefehn
Phone0049 (0) 179 6254434