An existing tug of Multraship (the ‘Multratug12’) was retrofitted with the Carrousel technology and put into regular harbour tug service with Multraship starting late 2002. Specific tests were also undertaken to measure performance and efficiency. Experience and tests with the prototype proved the enormous potential of the Carrousel technology: The Carrousel raises the dynamic braking and steering forces of the Multratug 12 to some 6 times its capability based on static bollard pull, and all that perfectly safely. In ‘Carrousel mode’ the Multratug 12 realised considerable fuel savings of some 30% overall, as compared to the Multratug 12 without using the Carrousel and on identical jobs.
This is particularly impressive given that the Multratug 12 (1) already has a slender hull and (2) has limited capability in ‘normal mode’ (static BP of just 20t), meaning that these comparisons had to be done on (the same) jobs whereby the ‘Carrousel mode’ was hardly challenged. The ‘Carrousel effect’ rises steeply when more performance is required. The tests were validated in the context of various Dutch innovation and cleantech subsidies awarded to the Carrousel towing system by the innovation agency of the Dutch government. These subsidies were for research aimed at cleantech solutions to help save fuel and emissions in general as well as in the maritime industry in particular. Academic institutions involved include TNO and the Delft University of Technology.