The Story of the Kappel Propeller tells the story of a remarkable adventure in engineering design innovation. The propeller gives a significant energy saving over conventional designs with consequent economic and environmental benefits. Here, the thirty-year history of the design's development from initial idea to working prototype is told for the first time. Along the way, many difficult hurdles need to be overcome and new understandings of propellers' behaviour requires to be formulated, along with advances in computer software, model testing techniques and propeller manufacture at full-scale. Today, the Kappel propeller is being adopted by many leading shipping lines. Bruce Peter is Reader in Design History at The Glasgow School of Arts and is the author of a number of books about various aspects of modern merchant ship design.