Bypassing and Backpassing at Harbors, Navigation Channels, and Tidal Entrances: Use of Shallow Water Draft Hopper Dredgers with Pump-Out Capabilities

Abstract

A port's success often depends upon maintenance of depths they provide. Major ports are located in rivers, estuaries, bays or lagoons, but a fair, and still increasing number of ports or terminals have been established on open, often exposed, shores where the requirement for natural depths are more easily met. The increasing size and drafts of vessels raises questions of maintenance depths. On the open sea coast, entrances to harbors and tidal inlets on littoral drift shores present major obstacles to natural longshore drift of sand causing extensive accumulations updrift and in navigation channels and heavy erosion downdrift. This paper first briefly reviews existing methods of maintenance and then concentrates on new procedures for bypassing of materials, combinations of bypassing and backpassing and the associated economics.