The United States infrastructure system is deteriorating and in need of improvements in order to maintain competitive within the global economy. The 2017 infrastructure report card from the American Society of Civil Engineers (ASCE) narrowly passed the ports and inland waterways of the U.S, stating the facilities were beyond design life and inadequate for the demands of modern vessels. The U.S. Army Corps of Engineers is tasked with the challenging job of maintaining all U.S. ports and waterways with a limited budget. A large part of improving the waterways of the U.S. includes the work to deepen and widen ship channels and inland waterways. In order to efficiently utilize the limited improvement resources, efficient dredging techniques and dredging vessels are required, therefore this paper focuses on the hydrodynamic aspects of dredger design and operation. Important aspects in the dredgers hydrodynamic design include low operational costs of the high block dredgers, low downtime and comfortable operation in shallow water. Low operational costs can be achieved by an economic design to decreased the fuel consumption which also contributes to the decrease of pollution from exhaust gas which is important for operation in near coast operations. Downtime, due to extreme ship motions, is a function of the combination of environmental conditions, such as wind, wave, bathymetry, the hydrodynamic behavior of the ship, and the downtime criteria such as maximum acceleration, maximum roll and maximum pitch angles. Ships with good hydrodynamic behavior can operate in higher waves and therefore have shorter downtimes resulting in a higher return on investment. Furthermore, an increased crew comfort can be obtained resulting in fitter and more focused crew members who can get a better performance from the equipment and are less prone to cause accidents. Ship motions in shallow water, added resistance in waves and accelerations, which are related to crew comfort, can be analyzed by advanced potential flow panel methods. Although numerical methods have improved significantly over the last years, model scale basin tests will still be needed to check the results of the calculations.
In combination with efficient dredger design, targeted dredging must be employed through the utilization of high fidelity maneuvering models to understand where the critical areas of the waterways are located. The utilization of vessel maneuvering simulations can assist the USACE, and port and terminal designers with operational and engineering design.
This paper focuses on the processes used to analyze the feasibility of new ship channel concepts and identify key areas for dredging. Furthermore, it shown tools which are available to obtain a efficient dredger design.
