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This paper aims to evaluate the applicability of input/output analysis to local content management as a tool to assess the relationship between the Brazilian government’s local content policy and social and economic effects of investment projects in the oil and gas and shipbuilding industry. Wärtsilä plans to develop a harbor tug design to maximize ecological operational sustainability to be used a new port facility being built in the Brazilian city of São Mateus, which will have environmental demands among the most stringent in the world.
Wärtsilä’s integrated infrastructure combines the bridge systems, cloud data management, data services, decision support tools, and access to real-time information for the fleet of tankers managed by Sovcomflot, Russia’s largest shipping company. Wärtsilä plans to develop a harbor tug design to maximize ecological operational sustainability to be used a new port facility being built in the Brazilian city of São Mateus, which will have environmental demands among the most stringent in the world.
The Eni-operated project will be the first FLNG vessel deployed in a deepwater field offshore the African continent upon its projected 2022 startup. Samsung Heavy Industries completed the operation at its shipyard in Geoje, South Korea. Delfin Midstream announced advancements in partnership with Samsung Heavy Industries and Black & Veatch. By re-purposing existing offshore pipelines and building the FLNG vessels at Asian shipyards, the total capital costs are projected to be around $500–550/tpa. The Prelude FLNG begins the 3,600-mile journey from South Korea to northwest Australia; expected to remain at final destination for 20–25 years.
Thompson, Ian (Defence Research and Development Canada, Atlantic Research Centre, Warship Performance, Dartmouth, Nova Scotia, Canada) | Ellis, Bryan E. (Defence Research and Development Canada, Atlantic Research Centre, Warship Performance, Dartmouth, Nova Scotia, Canada)
Ship speed and heading distributions are essential inputs for spectral fatigue analysis, and both may depend on wave conditions. Because rough-weather operational changes are rarely well defined, uncertainties in these distributions can introduce error in fatigue assessments. The influence of speed and relative heading distribution on fatigue estimates has not been thoroughly examined in the existing literature. This study investigates the influence of ship speed and relative heading distributions on fatigue damage accumulation of two sister naval ships. To represent uncertainties, 16 different operating profiles were used, including a baseline profile created from operator surveys and measurements. Fatigue damage estimates are calculated from a spectral analysis of four structural locations near midship. A linear frequency-domain seakeeping code provides the wave loads. The corresponding stresses are calculated using linear finite element analysis. Efforts to maintain seakeeping quality and crew readiness are reflected in the baseline profile with rough-weather speed and course changes. Ignoring these operational changes leads to reductions in estimated fatigue damage of up to 34% relative to the baseline estimate. This nonconservative result emphasizes the importance of understanding how operators manage rough wave conditions.
Dalheim, Øyvind Øksnes (Norwegian University of Science and Technology (NTNU) / Rolls-Royce University Technology Centre Performance in a Seaway) | Steen, Sverre (Norwegian University of Science and Technology (NTNU) / Rolls-Royce University Technology Centre Performance in a Seaway)
Prediction of the added resistance or corresponding speed loss in real sea conditions is essential to evaluate the performance of a ship. Assessment of the environmental impact on vessel performance is essential for route and cargo planning, optimization of fuel consumption and design, and configuration of engines and the main propulsion system. In the present study, added resistance and speed loss in real sea conditions are evaluated from1 year of onboard monitoring data of a platform supply vessel (PSV) operating in the North Sea. The true sea margin is shown on an annual basis. Relative contributions from environmental conditions and vessel operation control are presented. Results are compared with model experiments and existing numerical methods for prediction of added resistance and speed loss in waves. The study shows that added resistance due to waves for this PSV is significantly larger than predicted by conventional frequency-domain calculations or model tests. No reason for the deviation is found, but it is anticipated that a combination of effects of longitudinal mass radius of gyration, differences in wavelength and steepness in model tests and reality, and nonlinear effects (not accounted for in the numerical calculations) is partly responsible for the deviations. For ships having similar main dimensions, the conventional ways of predicting added resistance or speed loss in waves is nonconservative, and improved methods should be sought.
This article introduces the composition and 12 operating conditions of a four-engine two-propeller hybrid power system. Through the combination of gearbox clutch and disconnection, the propulsion system has four single-engine operation modes, two double-engine parallel operation modes, and six PTI operation modes. Because the propulsion system has a variety of operating conditions, each operating condition has a form of energy transfer. As a result, its energy management and control are more complicated. To study the energy management and control strategy of a diesel- electric hybrid propulsion system, this work mainly studies the simulation model and sub-models of a diesel-electric hybrid propulsion system. In this study, MATLAB/ SIMULINK software is used to build the diesel engine model, motor model, and ship engine system mathematical model. The test and analysis were carried out on the test bench of the diesel-electric hybrid power system. By comparing the theoretical value of the SIMULINK simulation model with the test value of the test bench system, the correctness of each sub-model modeling method is verified. On the one hand, research on the text lays a theoretical foundation for the subsequent implementation of the conventional energy management and control strategy based on state identification on the unified management and distribution of the diesel-electric hybrid power system. At the same time, energy management of the diesel-electric hybrid system is also carried out. Optimization research provides theoretical guidance.
Wen, Feng (American Bureau of Shipping) | Gu, Hai (American Bureau of Shipping) | Wang, Bo (American Bureau of Shipping) | Vitali, Tyler (American Bureau of Shipping) | Rasberry, Hunter (American Bureau of Shipping)
Improved remote inspection technologies (such as drones) are enabling safer and more efficient visual inspections of coating conditions in historically hard to reach and dangerous locations on marine and ffshore assets. These technologies may generate a significant amount of data (still images, video) and thus can be challenging for inspectors to identify potential coating failures. This paper presents the development of an Artificial Intelligence (AI) Machine Learning (ML) - based image recognition tool to aid inspectors in the review of data to help make coating condition assessments.
The machine learning algorithm/model development utilizes images taken from different types of maritime assets. These images depict different structural components, coatings, lighting conditions and corrosion. Images were processed and analyzed to create a database for training, validation and testing of the machine-learning model. Multiple machine learning models were developed and then the model with the best performance rate was selected for implementation. Case studies using the tool to process on-site inspection images are presented in this paper. Additionally, a comparison study between the tool performance and human judgment is discussed.
Distribution of the dataset shows that selected images can represent various types of coating failures under different conditions. A recall-oriented metric was selected to evaluate the performance of different machine learning models. Test results of the best performing model show its ability to identify coating failures from field images that have not been previously processed. Comparison studies show the tool can match human accuracy well. These factors support the value of the tool to act as a scanning tool for inspection with remote inspection technologies and as an electronic coating evaluation standard/guideline to aid inspectors.
The study proves the value of using AI technology in the marine and offshore industry. The AI tool supports inspectors with a fast and reliable means to aid them in their decision-making processes during coating assessment tasks, especially when remote inspection technologies are applied. Utilizing more data in the future, the AI tool can be further improved to handle other visual inspection tasks like defect detection, such as cracks and structural deformations.
As part of the Monaco offshore extension project, Bouygues Travaux Publics is in charge of design & build a maritime infrastructure as the first step of the six-hectare expansion of the city into the sea. This maritime infrastructure consists of a fill enclosed by a band of 18 trapezoid reinforced concrete caissons and will serve as base for construction of the new eco-neighborhood in Monaco. The caisson precasting area is located in the port of Marseilles, using a dedicated floating dock.
Morgan, Erin (USCGC MELLON, Seattle) | Bragaw, William (U.S. Coast Guard Academy, New London) | Bruno, Stephen (U.S. Coast Guard Academy, New London) | Schock, James (USCG Sector Guam, Santa Rita, Guam) | Skimmons, Jacob (U.S. Coast Guard Academy, New London) | Wheeler, Judson (U.S. Coast Guard Academy, New London) | Taylor, Todd (U.S. Coast Guard Academy, New London)
A set of five vessel loading conditions was developed for exposed-waters towing vessels in support of compliance with applicable stability regulations invoked under the U.S. Code of Federal Regulations (CFR) Title 46, Subchapter M. These loading conditions are envisioned as a starting framework for the naval architect or third-party organization when pursuing a U.S. Coast Guard stability letter with the fewest operational restrictions. These conditions do not represent required operational scenarios. For each loading condition, variable loads based on both tank location and tank contents were specified with the goal of encouraging conservative stability evaluations, while maintaining a level of realism to the resulting vessel attitude at each condition. Use of these developed loading conditions as a replacement for the nearly forty-year-old McGowan and Meyer conditions is anticipated. Using 3D models and General HydroStatics stability software, three vessels representative of modern exposed-waters towing vessels, but designed before the enactment of Subchapter M, were tested against 46 CFR Subchapter S stability criteria at each loading condition. Results of the analysis are presented for each vessel and for each applicable Subchapter S criterion. As expected, vessels not designed for Subchapter M/Subchapter S stability regulations can have trouble passing using the proposed loading conditions. The authors experimented with simple changes to the tank geometry of these pre-Subchapter M vessels, creating compliance with nearly all stability criteria for all loading conditions. Based on relevant literature and the results of this work, it is recommended that, for conservatism, the free-to-trim method be used for stability analysis—regardless of the loading conditions applied. It is recommended that if an exposed-waters towing vessel passes the applicable Subchapter S stability criteria using the loading conditions developed in this work, then the vessel should be considered for a stability letter with minimal operational restrictions.
Liu, Changhui (Shanghai Jiao Tong University) | Liu, Jianfeng (Shanghai Waigaoqiao Shipbuilding Co. Ltd.) | Zhang, Yansong (Shanghai Jiao Tong University) | Jin, Sun (Shanghai Jiao Tong University) | Wang, Can (Shanghai Jiao Tong University) | Lai, Xinmin (Shanghai Jiao Tong University)
Dimensional accuracy of hull block plays a critical role in guaranteeing the whole ship accuracy and reducing the hull butt-joint cost. The current industry practice of dimensional control in shipbuilding mainly focuses on the prediction of cutting and welding deformation based on engineering experience. Its main limitation is that the propagation and accumulation of deviations in the whole building process are neglected. In this article, cutting errors, assembly deviations, welding shrinkages, turnover distortions, and thermal expansions generated at different stages are analyzed. The propagation and accumulation of deviations and variations in the double-bottom block building process are studied based on the measured data in the whole process. Finally, the correlations of deviations between the adjacent stage are concluded. The conclusions can be used to guide the accuracy control in the hull block building process and reduce dimension trimming.