TOWARDS SUSTAINABLE DESIGN OF DREDGING EQUIPMENT

摘要

Sustainability of dredging is generally understood to strike a balance between environmental, economic, social and technical aspects while complying with legal requirements. For IHC Merwede, equipment supplier's point of view, the actual challenge is to translate the requirements imposed by environmental and social conditions into paradigm shifting improvements to our equipment. These improvements should not only meet these requirements, but also lead to improved economics of our equipment. To do so, we specified research programs aiming at the design and supply of sustainable equipment to the market. In this paper, the understanding and principles of sustainability in dredging is addressed. Our focal research topics are mainly introduced which will contribute to Chinese dredging market to tackle the energy crises, global warming and other environmental problems, within the always present economic constraints. Our first focal topic is energy. Traditionally efforts to improve on energy efficiency are driven from an economic perspective; by improving energy efficiency one lowers the fuel cost. Now today additional driving forces to reduce fuel consumption are the depletion of natural resources and need to reduce emissions. The reduction of emissions is our second focus point of high importance. Technical innovations on emission control (or pollution control through the exhaust gasses) are needed to meet upcoming international legislation that severely limits NOx and SOx emissions. Two other topics are relatively new: turbidity and underwater noise. Turbidity plumes caused by cutterhead, overflow, drag head, propeller wash, etc., can have a negative impact on the health of certain ecosystems adjacent to the dredging field. These environmental concerns frequently lead to delay or even cancellation of dredging projects. In other cases dredging is obliged to stop when the measured turbidity exceeds the limits. Underwater noise, both continuous sounds caused by the propeller, pumps, and generator and repetitive sounds caused by particular dredging events are considered to affect the marine life and ecosystems. At this moment no legislation on underwater noise is available, although legislation is expected in the medium long term. If we do not react in time to adopt our equipment this legislation could lead to restrictions in dredging operations. The overall goal of these topics is to improve equipment economics by optimization of design and operation. By sharing the major findings and progress on sustainability and sustainable dredging equipment design, more opportunities and technical alternatives are expected to be created to execute dredging projects in an improved way.