14 Sep 2023

Surge Analysis in Mobile Harbor, Alabama: Ship-Simulation Report

Abstract: A navigation channel improvement study for Mobile Harbor was conducted by the US Army Corps of Engineers, Mobile District (CESAM), and the Alabama State Port Authority. The US Army Engineer Research and Development Center (ERDC) assisted CESAM in assessing channel modifications using ERDC’s Ship/Tow Simulator through a Feasibility Level Screening Simulation study in 2017 and through a more comprehensive ship-simulation study in 2020. During the 2020 study, a safety concern was identified related to vessel interactions between a transiting vessel passing docked vessels at the McDuffie Coal Terminal located along the main federal channel. In the previous ship-simulation studies, the docked vessels were represented as targets, which means the ships are visually represented but no hydrodynamic interaction is captured. To fully assess this interaction, a surge-analysis study was completed in 2022 that used hydrodynamic models to represent docked vessels with representative mooring conditions. This study assessed several proposed navigation channel expansions across from the McDuffie Coal Terminal over the course of six testing days with four pilots. Assessment of the proposed modifications was accomplished through analysis of ship simulations completed by experienced local pilots, track plots, run sheets, and final pilot questionnaires.

29 Oct 2021

Mobile Harbor, Alabama Navigation Study: Ship Simulation Report

Abstract: Mobile Bay is a large estuary located in the southwest corner of Alabama, which connects to the Gulf of Mexico. Mobile Harbor contains the only port in the state that supports ocean-going vessels. Some of the larger vessels calling on the port experience transit delays and limited cargo capacity, so a study was conducted by the US Army Corps of Engineers, Mobile District (CESAM), and the Alabama State Port Authority to investigate channel improvements. In 2017, the US Army Engineer Research and Development Center (ERDC) assisted CESAM in screening proposed deepening and widening alternatives in Mobile Bay by completing a Feasibility Level Ship Simulation (FLSS) study using the ERDC Ship/Tow Simulator. These lower-resolution databases from the FLSS study were used as a foundation to complete a more robust navigation study in 2020 to test the proposed modifications to Mobile Harbor. During this study, three main areas were focused on: a bend easing, a passing lane, and a turning basin. Testing of the proposed design was evaluated over the course of 2 weeks with eight pilots. Assessment of the proposed modifications was accomplished through analysis of ship simulations completed by experienced local pilots, discussions, track plots, run sheets, and final pilot surveys.