Zero-fuel open ocean-going tugs, and applications for the large scale collection of ocean plastics

This paper presents analysis of an innovative new zero fuel propulsion technology developed for open ocean transportation, and discusses near term applications in the mitigation of ocean plastic pollution. The Wave Tug is an innovation in propulsion technology evolved from decades of research and testing in ocean powered systems, and delivers commercially useful towing forces through harnessing the energy dense orbital motion of open ocean wave streams. The Wave Tug requires zero-fuel inputs, has zero carbon emissions and delivers towing forces comparable with existing ocean-going tugs. The development of the Wave Tug technology is here discussed with its first application in the collection of ocean plastics, and in combination with a proposed ocean waste concentration technology. The problem of ocean plastic waste is well understood, and the need to remove in the near-term the plastics currently in the oceans to avoid further food-chain and environmental contamination is critical. The key requirements of a realistic technology to remove plastics from the open ocean are identified as; (1) The ability to reliably track specified navigation routes identified through live weather and shipping data and the identification of high densities of plastics; (2) To continuously sweep large areas of ocean with minimal intervention and no crew requirements; (3) To securely store collected waste; (4) To concentrate the waste collected; (5) Minimise negative impacts on marine ecology. An array of ten harvesting devices is calculated to be capable of sweeping the area of the North Pacific Garbage Patch in less than ten years, and to provide an economically and technical viable solution to the existing environmental crisis. The paper discusses the development timeline of the Wave Tug and Waste Concentration technology, and the key steps in achieving open ocean deployment of an effective and reliable plastic harvesting device. The research and development to date is discussed, and opportunities for optimisation identified.