15 Feb 2022

Vessel Speed Analysis before and after Dredging near Missouri River Mile 282 in November 2020

Abstract: The purpose of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to present information on vessel traffic before, during, and after a dredging event around river mile 282 of the Missouri River in November 2020 along with contextual information about tonnage and commodities that utilize this navigation project.

10 Nov 2021

Houston Ship Channel Expansion Improvement Project – Navigation Channel Improvement Study: Ship Simulation Results

Abstract: In 2020, the US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory, provided technical oversight during a navigation study to assist the Galveston District evaluation of different channel widening alternatives for larger ships transiting the Houston Ship Channel (HSC), Texas. The widening proposals encompassed several areas of the HSC including the Bay Section, the Bayport Ship Channel, Barbours Cut Channel, and the Bayou Section. The study was performed at the San Jacinto College Maritime Technology and Training Center (SJCMTTC) Ship/Tug Simulator (STS) Facility in La Porte, TX. The SJCMTTC STS is a real-time simulator; therefore, events on the simulator happen at the same time rate as real life. A variety of environmental forces act upon the ship during the simulation transit. These include currents, wind, waves, bathymetry, and ship-to-ship interaction. Online simulations of the project were conducted at SJCMTTC over a 3-week period – May through June 2020. Several mariners including Houston Pilots and G&H tugboat Captains participated in the testing and validation exercises. ERDC oversight was performed remotely because of the COVID-19 pandemic. Results in the form of engineering observations, track plots, and pilot interviews were reviewed to develop final conclusions and recommendations regarding the final design.

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.

2 Jun 2021

AIS data case study: quantifying connectivity for six Great Lakes port areas from 2015 through 2018

Abstract: This Coastal and Hydraulics Engineering Technical Note presents results from a preliminary examination of commercial vessel traffic connectivity between six major port areas on the Great Lakes using Automatic Identification System data collected from 2015 to 2018. The six port areas included in this study are Calumet Harbor, IL and IN; Cleveland, OH; Detroit, MI; Duluth-Superior, MN and WI; Indiana Harbor, IN; and Two Harbors, MN. These six locations represent an important subset of the more than 100 federally authorized navigation projects in the Great Lakes maintained by the US Army Corps of Engineers. The results are presented in the context of USACE resilience-related policy initiatives as well as the larger topic of maritime system resilience.

18 May 2021

Suppressing the pressure-source instability in modeling deep-draft vessels with low under-keel clearance in FUNWAVE-TVD

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) documents the development through verification and validation of three instability-suppressing mechanisms in FUNWAVE-TVD, a Boussinesq-type numerical wave model, when modeling deep-draft vessels with a low under-keel clearance (UKC). Many large commercial ports and channels (e.g., Houston Ship Channel, Galveston, US Army Corps of Engineers [USACE]) are traveled and affected by tens of thousands of commercial vessel passages per year. In a series of recent projects undertaken for the Galveston District (USACE), it was discovered that when deep-draft vessels are modeled using pressure-source mechanisms, they can suffer from model instabilities when low UKC is employed (e.g., vessel draft of 12 m¹ in a channel of 15 m or less of depth), rendering a simulation unstable and obsolete. As an increasingly large number of deep-draft vessels are put into service, this problem is becoming more severe. This presents an operational challenge when modeling large container-type vessels in busy shipping channels, as these often will come as close as 1 m to the bottom of the channel, or even touch the bottom. This behavior would subsequently exhibit a numerical discontinuity in a given model and could severely limit the sample size of modeled vessels. This CHETN outlines a robust approach to suppressing such instability without compromising the integrity of the far-field vessel wave/wake solution. The three methods developed in this study aim to suppress high-frequency spikes generated nearfield of a vessel. They are a shock-capturing method, a friction method, and a viscosity method, respectively. The tests show that the combined shock-capturing and friction method is the most effective method to suppress the local high-frequency noises, while not affecting the far-field solution. A strong test, in which the target draft is larger than the channel depth, shows that there are no high-frequency noises generated in the case of ship squat as long as the shock-capturing method is used.

14 May 2021

Brunswick Harbor Numerical Model

Abstract: The Brunswick area consists of many acres of estuarine and marsh environments. The US Army Corps of Engineers District, Savannah, requested that the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, develop a validated Adaptive Hydraulics model and assist in using it to perform hydrodynamic modeling of proposed navigation channel modifications. The modeling results are necessary to provide data for ship simulation. The model setup and validation are presented here.

14 May 2021

Metrics for Assessing Overall Performance of Inland Waterway Ports: A Bayesian Network Based Approach

Abstract: Because ports are considered to be the heart of the maritime transportation system, thereby assessing port performance is necessary for a nation’s development and economic success. This study proposes a novel metric, namely, “port performance index (PPI)”, to determine the overall performance and utilization of inland waterway ports based on six criteria, port facility, port availability, port economics, port service, port connectivity, and port environment. Unlike existing literature, which mainly ranks ports based on quantitative factors, this study utilizes a Bayesian Network (BN) model that focuses on both quantitative and qualitative factors to rank a port. The assessment of inland waterway port performance is further analyzed based on different advanced techniques such as sensitivity analysis and belief propagation. Insights drawn from the study show that all the six criteria are necessary to predict PPI. The study also showed that port service has the highest impact while port economics has the lowest impact among the six criteria on PPI for inland waterway ports.

20 Aug 2020

PUBLICATION NOTICE: Three Rivers, Southeast Arkansas Navigation Study: Ship Simulation Report

Abstract: The McClellan-Kerr Arkansas River System (MKARNS) is a major inland waterway that begins at the Port of Catoosa in Tulsa, OK, and travels to the confluence of the White and Mississippi Rivers. Over the years, many structures have been built to help control overland flow between the White, Arkansas, and Mississippi Rivers. These structures have required a significant amount of rehabilitation, which has resulted in high maintenance costs. The US Army Corps of Engineers and the Arkansas Waterways Commission conducted the Three Rivers Southeast Arkansas Feasibility Study (also known as the Three Rivers Study). The Three Rivers Study focused on providing long-term dependable navigation in the MKARNS. From this study, a proposal was developed that included a 1,000 ft reopening of the Historic Cutoff and a reinforcement of several areas near the White River. In 2019, the US Army Engineer Research and Development Center Ship/Tow Simulator was used to perform a navigation study to ensure the proposed modifications did not negatively impact navigation on the White River section of the MKARNS. Assessment of the proposed modifications was accomplished through analysis of ship simulations completed by experienced pilots, discussions, track plots, run sheets, and final pilot surveys.

11 Aug 2020

PUBLICATION NOTICE: Post-Project Monitoring of a Navigation Solution in a Dynamic Coastal Environment, Smith Island, Maryland: Year One of Post-Project Monitoring

Abstract: In 2018, jetties and a sill were constructed by the US Army Corps of Engineers (USACE) adjacent to the Sheep Pen Gut Federal Channel at Rhodes Point, Smith Island, Maryland. These navigation improvements were constructed under Section 107 of the Continuing Authorities Program. Material dredged for construction of the navigation structures and realignment of the channel were used to restore degraded marsh. Following construction and dredging, 1 year of post-project monitoring was performed to evaluate the performance of navigation improvements with respect to the prevention of shoaling within the Sheep Pen Gut channel, shoreline changes, and impacts to submerged aquatic vegetation (SAV). Given the short period of record after the completion of the navigation improvements, it was difficult to draw conclusions regarding stability of the channel, structures, and shoreline. Therefore, this report documents methodology and baseline conditions for monitoring, except for SAV, which was found to be potentially impacted by construction. A second year of monitoring was funded by the USACE Regional Sediment Management Program for fiscal year 2020. Findings can be used to inform plan formulation and design for USACE navigation projects by illuminating considerations for placement of structures to prevent shoaling and by informing SAV management decisions.