Design Optimization of Trailing Suction Hopper Dredgers How to achieve the maximum result with your investment

摘要

The dredging market is constantly changing. Therefore it is very important for dredging companies to anticipate rapidly with dredging equipment and techniques. New techniques can also create new markets. For example the ability to dredge on very large dredging depths or the new generation very large hopper dredgers have created new markets. To be able to anticipate it is very important to invest in modem equipment which is state of me art Abo the delivery time and the possibility to adapt the design during the building is vesy importantIn the last decade the West European dredge contractors have focused on some specialisation for different market segments. The Chinese dredging companies have been focusing on flexibility and have chosen for multipurpose hopper dredgers. When the flexibility of the dredger is high, the weight and the investment of the dredger are relatively high too. This means higher exploitation costs and lower transport capacity. On the other hand a high level of flexibility results in a high degree of capacity utilisation which can reduce the exploitation costs drastically.When an investment is done, it is always important to optimise on exploitation costs. If some design aspects like shallow draught or trailing speed are too strict, this can lead to a less economic design. By varying the functional requirement and making exploitation calculations the impact of the design aspects can become clearer.Before a design can be made, the functional requirements must be defined. These requirements are made on the basis of the kind of work the dredger most probably will meet in its lifetime.With the help of an extensive research program and the development of new design tools it is nowadays possible to find the most favourable solutions for a certain design opportunity.As an example of design optimisation the effect of our latest insight in hopper design based on our research on the hopper loading process may be mentioned. It has become clear that there must be a balance between hopper size and dredging installation.Other examples are the insight in hull optimisation and propulsion efficiency improvement New techniques are used to predict wave patterns and the flow round the aft ship.With the help of some typical designs is shown what the effect is of a variation of mam particulars, installed power, dredging installation and other starting points on the exploitation performance of the shown examples.