The Nautical Depth Approach, a Review for Implementation
Type:
Presented during:
WODCON XVIII - 2007 Orlando, Florida, USA
Authors:
Fontein
Abstract: A vital element of harbor services is the guarantee of safe passage to and from the port facilities. When high siltation rates persist, adopting the concept of nautical depth may reduce the significant costs associated with maintenance dredging. To implement the nautical depth concept three important prerequisites should be met: 1) Criteria for mud characteristics that can be allowed within the nautical profile should be set. 2) A control system should be implemented to reliably monitor the status of the nautical profile in relation to the set criteria. 3) The participants will have to accept the new approach and be able to gain confidence in the system from both the safety of navigation aspect and as the contractual basis for dredging. All of these prerequisites are best served by a standardized survey method that can be tuned to cope with site-specific variation and variability. This working method requires survey systems with predefined, controllable settings and repeatable results. A survey method that combines acoustics with in-situ rheometric and/or density measurements is outlined below.
Keywords: Hydrographic survey, fluid mud, tuning fork, mud rheology, risk assessment.