THE IMPACT OF A DECADE OF INTENSE RESEARCH ON THE EFFICIENCY OF A TSHD

摘要

"Lower cost per cubic yard dredged", efficiency, is nowadays quickly associated with "Jumbo" hopper dredges, as they have appeared in the market during the last decade. However, it is not only the effect of scale that improved the efficiency of the trailing suction hopper dredges. The replacement market for maintenance dredges initiated its own improvements, while market demands, including environmental ones, triggered other concentrated efforts.The design, construction and operation of the different dredge models surfaced demands that lead to different design features being investigated and improved. The larger vessels invited to look into very deep dredging. The market addressed dredging of more compact materials, while a new target became that with less fuel - and with that propulsion power - higher speeds would be achieved, while reduced wave effects would allow more benefits from that higher speed.During its existence IHC consistently spent substantial amounts for Research. Subjects for this R&D effort are triggered by a hybrid combination of technology-push and market-pull. The past decade the R&D resulted in a large number of useful applications.This paper will address this research and the resulting advances in the areas of. 1. hull shape, resistance and required propulsion power; 2. hopper loading process, improving settling and discharging processes; 3. load line revision for dredging draught;4. excavating technology with innovative excavating drag heads; 5. specific automation; 6. reducing time for ''working up the crew" after delivery of a dredge through trainingIllustrations with the latest generation dredges will document that the application of the recent R&D-results have jolted the efficiency of these dredges forward. Not the efficiency of the Jumbo's only advanced greatly, but also the medium sized hopper dredges in the 5,000 cu yd range, operated throughout the world including North America, profited.The gains that proved to be possible during this decade showed that we have not reached the optimum dredge yet. The paper will conclude with a philosophy of what is expected to be ahead.