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Keywords = floating crane

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34 pages, 20839 KB  
Article
Operation Analysis of the Floating Derrick for Offshore Wind Turbine Installation Based on Machine Learning
by Jia Yu, Honglong Li, Shan Wang and Xinghua Shi
J. Mar. Sci. Eng. 2024, 12(12), 2136; https://doi.org/10.3390/jmse12122136 - 22 Nov 2024
Viewed by 1121
Abstract
To investigate the influencing factors on the operation of an offshore wind turbine installation ship, a neural network, as a machine-learning method, is built to predict and analyze the motion response of a floating derrick in the process of a lifting operation under [...] Read more.
To investigate the influencing factors on the operation of an offshore wind turbine installation ship, a neural network, as a machine-learning method, is built to predict and analyze the motion response of a floating derrick in the process of a lifting operation under an external environmental load. The numerical method for the double floating body, from the software SESAM/SIMA, is validated against the experiments. The numerical method is used to establish the floating derrick-lifting impeller model to obtain the motions of the ship and impeller and the coupling effect. Based on the numerical results, the BP neural network model is built to predict the ship’s operation. The results show that the BP neural network model for the floating derrick and impeller motion prediction is very feasible. Combined with the Rules for Lifting Appliances of Ships and Offshore Installations and the Noble Denton Guidelines for Marine Lifting Operations, the operation of the floating crane system can be determined based on the environmental parameters. Full article
(This article belongs to the Special Issue Impact of Ocean Wave Loads on Marine Structures)
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19 pages, 9532 KB  
Article
Floater Assembly and Turbine Integration Strategy for Floating Offshore Wind Energy: Considerations and Recommendations
by Glib Ivanov and Kai-Tung Ma
Wind 2024, 4(4), 376-394; https://doi.org/10.3390/wind4040019 - 21 Nov 2024
Cited by 4 | Viewed by 2774
Abstract
The increasing demand for cost-effective floating offshore wind turbines (FOWTs) necessitates streamlined mass production and efficient assembly strategies. This research investigates the assembly and integration of 15 MW FOWT floaters, utilising a semi-submersible floater equipped with a 15 MW wind turbine. The infrastructure [...] Read more.
The increasing demand for cost-effective floating offshore wind turbines (FOWTs) necessitates streamlined mass production and efficient assembly strategies. This research investigates the assembly and integration of 15 MW FOWT floaters, utilising a semi-submersible floater equipped with a 15 MW wind turbine. The infrastructure and existing port facilities of Taiwan are used as an example. The effectiveness of various assembly and integration strategies has been evaluated. The study outlines equipment and infrastructure requirements for on-quay floater and turbine assembly, comparing on-quay assembly to construction at remote locations and subsequent towing. Detailed analyses of port operations, crane specifications, and assembly procedures are presented, emphasising the critical role of crane selection and configuration. The findings indicate that on-quay assembly at one major port is feasible and cost-effective, provided that port infrastructure and operational logistics are optimised. This research offers insights and recommendations for implementing large-scale FOWT projects, contributing to advancing offshore wind energy deployment. Full article
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22 pages, 1102 KB  
Article
Improving O&M Simulations by Integrating Vessel Motions for Floating Wind Farms
by Vinit V. Dighe, Lu-Jan Huang, Jaume Hernandez Montfort and Jorrit-Jan Serraris
J. Mar. Sci. Eng. 2024, 12(11), 1948; https://doi.org/10.3390/jmse12111948 - 31 Oct 2024
Cited by 1 | Viewed by 1936
Abstract
This study presents an integrated methodology for evaluating operations and maintenance (O&M) costs for floating offshore wind turbines (FOWTs), incorporating vessel motion dynamics. By combining UWiSE, a discrete-event simulation tool, with SafeTrans, a voyage simulation software, vessel motion effects during offshore operations are [...] Read more.
This study presents an integrated methodology for evaluating operations and maintenance (O&M) costs for floating offshore wind turbines (FOWTs), incorporating vessel motion dynamics. By combining UWiSE, a discrete-event simulation tool, with SafeTrans, a voyage simulation software, vessel motion effects during offshore operations are modeled. The approach is demonstrated in a case study at two wind farm sites, Marram Wind and Celtic Sea C. Three major component replacement (MCR) strategies were assessed: Tow-to-Port (T2P), Floating-to-Floating (FTF), and Self-Hoisting Crane (SHC). The T2P strategy yielded the highest O&M costs—94 kEUR/MW/year at Marram Wind and 97 kEUR/MW/year at Celtic Sea C—due to the extended MCR durations (90–180 days), leading to lower availability (90–94%). In contrast, the FTF and SHC strategies offered significantly lower costs and downtime. The SHC strategy was most cost-effective, reducing costs by up to 64% while achieving 97–98% availability. The integrated approach was found to be either more restrictive or more permissive depending on the specific sea states influencing the motion responses. This variability highlights the critical role of motion-based dynamics in promoting safe and efficient O&M practices, particularly for advancing FOWT operations. Full article
(This article belongs to the Special Issue Modelling Techniques for Floating Offshore Wind Turbines)
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24 pages, 10507 KB  
Article
Dynamic Analysis of Crane Vessel and Floating Wind Turbine during Temporary Berthing for Offshore On-Site Maintenance Operations
by Jinkun Shi, Mingfeng Hu, Yifan Zhang, Xiaodong Chen, Sheng Yang, Thiago S. Hallak and Mingsheng Chen
J. Mar. Sci. Eng. 2024, 12(8), 1393; https://doi.org/10.3390/jmse12081393 - 14 Aug 2024
Cited by 8 | Viewed by 2589
Abstract
With the increased scale and deployment of floating wind turbines in deep sea environments, jack-up installation vessels are unable to conduct maintenance operations due to limitations in water depth. This has led to the recognition of the advantages of floating cranes in offshore [...] Read more.
With the increased scale and deployment of floating wind turbines in deep sea environments, jack-up installation vessels are unable to conduct maintenance operations due to limitations in water depth. This has led to the recognition of the advantages of floating cranes in offshore maintenance activities. However, the dynamic coupling between the crane and the floating wind turbine under wave and wind action can result in complex responses, which also relate to complex mooring configurations. The ability to maintain stability during maintenance operations has become a primary concern. In order to address this issue, a method of connecting a floating crane with a floating wind turbine is proposed, simulating the berthing of a floating offshore wind turbine (FOWT) to a crane. Thus, a systematic comparison was conducted with frequency- and time-domain simulation using ANSYS-AQWA software. The simulation results demonstrated the feasibility and dynamic efficiency of this novel berthing approach. Connecting the crane vessel to a floating wind turbine significantly reduced the crane tip movement. Simulations showed that the crane tip movement in the X-, Y-, and Z-directions was reduced by over 30%, which implies that it may be feasible to conduct offshore on-site maintenance operations for the FOWT by using floating crane vessels if the two bodies were properly constrained. Full article
(This article belongs to the Special Issue Innovative Development of Offshore Wind Technology)
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20 pages, 1217 KB  
Article
Hazard Identification and Risk Assessment for Sustainable Shipyard Floating Dock Operations: An Integrated Spherical Fuzzy Analytical Hierarchy Process and Fuzzy CoCoSo Approach
by Semra Bayhun and Nihan Çetin Demirel
Sustainability 2024, 16(13), 5790; https://doi.org/10.3390/su16135790 - 7 Jul 2024
Cited by 4 | Viewed by 2798
Abstract
Background: This study investigated the process of selecting sustainable safety protocols for floating dock operations in shipyards by identifying potential workplace risks in emergency situations. Thirteen occupational hazards for shipyard floating dock operations were identified through a literature review and expert discussions. Methods: [...] Read more.
Background: This study investigated the process of selecting sustainable safety protocols for floating dock operations in shipyards by identifying potential workplace risks in emergency situations. Thirteen occupational hazards for shipyard floating dock operations were identified through a literature review and expert discussions. Methods: We incorporated four risk elements (consequence: C, frequency: F, probability: P, and number of people at risk: NP) from the Fine–Kinney and Hazard Rating Number System (HRNS) approaches as the risk assessment criteria. We obtained the importance weights of the risk assessment criteria via the Spherical Fuzzy Analytical Hierarchy Process (SF-AHP) and extended the Combined Compromise Solution (CoCoSo) method within the fuzzy framework to prioritize occupational hazards. This study demonstrated the practicality and efficiency of the proposed emergency risk assessment model for shipyard floating dock operations through a case example of occupational risk assessment. Results: The analysis results show that H4 is the occupational hazard with the highest priority, with a score of 3.553. H4 represents the hazard associated with insufficient access to the entire pool area. The second and third most important hazards are the inability of cranes to move freely in and out of the berthing dock and the inability to dispatch emergency teams. These hazards, denoted H1 and H12, follow closely behind with scores of 3.391 and 3.344, respectively. H10 is deemed the least concerning hazard, with a score of 1.802. Conclusions: Professionals can handle complex and uncertain risk assessment data more flexibly using the proposed system, which excels in accurately organizing occupational hazards. Full article
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26 pages, 4810 KB  
Article
Point-to-Point-Based Optimization Method of Ballast Water Allocation for Revolving Floating Cranes with Experimental Verification
by Xiaobang Wang, Yang Yu, Siyu Li, Jie Zhang and Zhijie Liu
J. Mar. Sci. Eng. 2024, 12(3), 437; https://doi.org/10.3390/jmse12030437 - 1 Mar 2024
Cited by 1 | Viewed by 2855
Abstract
The Revolving Floating Crane (RFC) is a specialized engineering vessel crucial for offshore lifting operations, such as offshore platform construction and deep-water salvaging. It boasts impressive lifting capacity, good adaptability to various environmental conditions, and high operational efficiency. Conventionally, the safety and stability [...] Read more.
The Revolving Floating Crane (RFC) is a specialized engineering vessel crucial for offshore lifting operations, such as offshore platform construction and deep-water salvaging. It boasts impressive lifting capacity, good adaptability to various environmental conditions, and high operational efficiency. Conventionally, the safety and stability of RFC operations heavily depend on manual ballast water allocation, which is directly influenced by factors such as personnel status and sea conditions. These manual operations often result in reduced lifting efficiency, higher energy consumption, and compromised operational safety. In response, this paper introduces a ballast water-allocation approach based on the Point-to-Point (PTP) theory for the intelligent operation process of the RFC. The fundamental principles of the PTP theory are analyzed, and a method tailored to optimize ballast water allocation for RFC is proposed. Considering the unique characteristics of the ballast system and the specific requirements of lifting operations, an optimization model for PTP-based ballast water allocation is established. Numerical experiments are conducted to verify the efficacy and reliability of the proposed method. Comparing it to the conventional approaches, the results demonstrate a notable 17.75% reduction in energy consumption and an impressive 73.49% decrease in decision-making time, showcasing the superiority of the proposed approach. Finally, the engineering feasibility of the PTP-based optimization method for ballast water allocation is validated through actual lifting experiments, underscoring its potential to enhance RFC operations. Full article
(This article belongs to the Section Ocean Engineering)
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19 pages, 3995 KB  
Article
Navigation Safety on Shipping Routes during Construction
by Vytautas Paulauskas, Ludmiła Filina-Dawidowicz and Donatas Paulauskas
Appl. Sci. 2023, 13(15), 8593; https://doi.org/10.3390/app13158593 - 26 Jul 2023
Cited by 10 | Viewed by 2165
Abstract
Construction work or other maintenance and repair activities in navigational channels are crucial to ensure and improve ships’ movement on the selected routes. However, during the performance of these works, the ships’ navigation along the construction area becomes more difficult due to the [...] Read more.
Construction work or other maintenance and repair activities in navigational channels are crucial to ensure and improve ships’ movement on the selected routes. However, during the performance of these works, the ships’ navigation along the construction area becomes more difficult due to the decreased parameters of passages for vessels and the operation of specific equipment on the route, e.g., dredgers and floating cranes. During construction work in navigational channels, it is impossible to stop navigation or limit ships’ parameters because there may not be other possibilities for vessels to reach their planned ports or other dedicated areas. The prior determination of ships’ sailing conditions and restrictions is essential to ensure maritime safety in such areas. The aim of this study is to develop a methodology that allows the precise determination of minimum passage parameters for the navigation of ships sailing through the areas in navigational channels where construction or development works are being carried out. The theoretical basis for the minimum passage parameter calculation is presented. The methodology for assessing the conditions and restrictions of navigation during construction work is proposed. The minimum width of the shipping passages in defined navigational, hydro-meteorological, and hydrological conditions and the possible minimum parameters sufficient to guarantee navigational safety are considered in a case study. The research results may be interesting for port authorities, shipping companies, and other entities involved in the organization of ships’ movement during construction work in navigational channels or other areas. Full article
(This article belongs to the Special Issue Advances in Nautical Engineering and Maritime Transport)
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18 pages, 4069 KB  
Article
Predictive Control of a Heaving Compensation System Based on Machine Learning Prediction Algorithm
by Lifen Hu, Ming Zhang, Zhi-Ming Yuan, Hongxia Zheng and Wenbin Lv
J. Mar. Sci. Eng. 2023, 11(4), 821; https://doi.org/10.3390/jmse11040821 - 12 Apr 2023
Cited by 14 | Viewed by 3039
Abstract
Floating structures have become a major part of offshore structure communities as offshore engineering moves from shallow waters to deeper ones. Floating installation ships or platforms are widely used in these engineering operations. Unexpected wave-induced motions affect floating structures, especially in harsh sea [...] Read more.
Floating structures have become a major part of offshore structure communities as offshore engineering moves from shallow waters to deeper ones. Floating installation ships or platforms are widely used in these engineering operations. Unexpected wave-induced motions affect floating structures, especially in harsh sea conditions. Horizontal motions on the sea surface can be offset by a dynamic positioning system, and heave motions can be controlled by a heave compensation system. Active heave compensation (AHC) systems are applied to control vertical heave motions and improve safety and efficiency. Predictive control based on machine learning prediction algorithms further improves the performance of active heave compensation control systems. This study proposes a predictive control strategy for an active heave compensation system with a machine learning prediction algorithm to minimise the heave motion of crane payload. A predictive active compensation model is presented to verify the proposed predictive control strategy, and proportion–integration–differentiation control with predictive control is adopted. The reliability of back propagation neural network (BPNN) and long short-term memory recurrent neural network (LSTM RNN) prediction algorithms is proven. The influence of the predictive error on compensation performance is analysed by comparing predictive feedforward cases with actual-data feedforward cases. Predictive feedforward control with regular and irregular wave conditions is discussed, and the possible strategies are examined. After implementing the proposed predictive control strategy based on a machine learning algorithm in an active heave compensation system, the heave motion of the payload is reduced considerably. This investigation is expected to contribute to the motion control strategy of floating structures. Full article
(This article belongs to the Topic Control and Optimisation for Offshore Renewable Energy)
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29 pages, 7484 KB  
Article
Dynamic Analysis of Full-Circle Swinging Hoisting Operation of a Large Revolving Offshore Crane Vessel under Different Wave Directions
by Dapeng Zhang, Bowen Zhao, Keqiang Zhu and Haoyu Jiang
J. Mar. Sci. Eng. 2023, 11(1), 197; https://doi.org/10.3390/jmse11010197 - 12 Jan 2023
Cited by 6 | Viewed by 2902
Abstract
Waves have an important influence on the motion performances of offshore crane vessels. The floating crane vessel in waves gives rise to the motion of the lifted object which is connected to the hoisting wire. Based on the geometric parameters of a revolving [...] Read more.
Waves have an important influence on the motion performances of offshore crane vessels. The floating crane vessel in waves gives rise to the motion of the lifted object which is connected to the hoisting wire. Based on the geometric parameters of a revolving offshore crane vessel, combined with the specific process of the floating crane vessel at work, a model of the offshore crane vessel under full-circle swing hoisting has been established by OrcaFlex. With the change in wave direction, the dynamic response of the system is made and the impact force between the support vessel and the hanging object and the tension of the crane wire under different wave directions is obtained. At the same time, the minimum impact forces between the support vessel and the hanging object and the tension of the crane wire and their wave directions are obtained. According to the calculated result, the optimal design of the full-circle swing hoisting operation of large revolving offshore crane vessel has been determined. Full article
(This article belongs to the Special Issue Hydrodynamics of Offshore Structures)
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26 pages, 7256 KB  
Article
Dynamic Analysis and Extreme Response Evaluation of Lifting Operation of the Offshore Wind Turbine Jacket Foundation Using a Floating Crane Vessel
by Mingsheng Chen, Guibo Yuan, Chun Bao Li, Xianxiong Zhang and Lin Li
J. Mar. Sci. Eng. 2022, 10(12), 2023; https://doi.org/10.3390/jmse10122023 - 18 Dec 2022
Cited by 21 | Viewed by 4976
Abstract
The jacket is the most widely-used fixed foundation for offshore wind turbines due to its superior strength and low installation cost in relatively deep waters. Floating crane vessels are commonly used to install jacket foundations. However, the dynamic coupling between the jacket and [...] Read more.
The jacket is the most widely-used fixed foundation for offshore wind turbines due to its superior strength and low installation cost in relatively deep waters. Floating crane vessels are commonly used to install jacket foundations. However, the dynamic coupling between the jacket and the floating vessel might generate complex dynamic responses under wave action. The complexity of the multi-body system requires comprehensive time-domain simulations and statistical analysis to obtain reliable results, especially for the evaluation of the operational safety of offshore lift installations of a jacket foundation. In this context, this study performs numerical simulations and statistical analyses to predict the extreme responses and the preliminary allowable sea states for guiding the lowering operation of a jacket using a floating crane vessel. First, ANSYS-AQWA is used to obtain the hydrodynamic coefficients of the vessel in the frequency domain. A nonstationary time-domain simulation of jacket lowering with winches is performed to identify several preliminary critical vertical positions of the jacket from the time series in an irregular wave. The extreme responses of a target probability are evaluated by the extreme distribution model after a large number of steady-state time-domain simulations of the critical vertical positions in irregular waves. The most critical vertical position is determined from three preliminary critical vertical positions by comparing the extreme responses. Eigenvalue analysis and spectrum analysis of the most critical vertical position of the jacket are carried out to find the natural periods of the system and the dynamic coupling characteristics between different components. The influence of wave direction, significant wave height, and spectrum peak period on the dynamic responses are also analyzed in the most critical vertical position. Furthermore, the optimal wave direction is determined as the head sea. Preliminary allowable sea states are derived by comparing the calculated dynamic amplification coefficient with the defined operational criteria. Full article
(This article belongs to the Topic Wind, Wave and Tidal Energy Technologies in China)
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23 pages, 5356 KB  
Article
Ballast Water Dynamic Allocation Optimization for Revolving Floating Cranes Based on a Hybrid Algorithm of Fuzzy-Particle Swarm Optimization with Domain Knowledge
by Qiao Liu, Zhenxing Lu, Zhijie Liu, Peng Lin and Xiaobang Wang
J. Mar. Sci. Eng. 2022, 10(10), 1454; https://doi.org/10.3390/jmse10101454 - 8 Oct 2022
Cited by 8 | Viewed by 3099
Abstract
Ballast systems and ballast water dynamic allocation between ballast tanks are very important for ensuring the offshore operation efficiency and safety of the revolving floating crane (RFC). Its modeling and solving have multiple difficulties such as modeling complexity, solving complexity and engineering practicability. [...] Read more.
Ballast systems and ballast water dynamic allocation between ballast tanks are very important for ensuring the offshore operation efficiency and safety of the revolving floating crane (RFC). Its modeling and solving have multiple difficulties such as modeling complexity, solving complexity and engineering practicability. Early studies showed that domain knowledge is of great significance for the optimization of the design quality and innovation of such complex engineering issues. By analyzing the coupled operation process characteristics among the floating crane, ship hull and ballast system, a ballast water allocation optimization model based on dynamic programming strategy is established. The domain knowledge of ship ballasting is extracted, and a domain knowledge base of expert experience rules for the ballast water allocation is established. A Fuzzy-Particle Swarm Optimization (FPSO) algorithm is given to obtain the optimal allocation scheme, which uses fuzzy logic inference to process domain knowledge and improve the solving quality. Three different cases are given to illustrate the validity of the proposed model and algorithm by comparing it with other algorithms. The analysis results show that the established optimization method can effectively improve the operation efficiency and reduce the calculation time and the number of ballast tanks involved in allocation, which makes the optimal scheme more suitable for engineering applications. Full article
(This article belongs to the Section Ocean Engineering)
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21 pages, 8864 KB  
Article
Position Control of Heave Compensation for Offshore Cranes Based on a Particle Swarm Optimized Model Predictive Trajectory Path Controller
by Hao Chen, Jinke Xie, Jingang Han, Weifeng Shi, Jean-Frédéric Charpentier and Mohamed Benbouzid
J. Mar. Sci. Eng. 2022, 10(10), 1427; https://doi.org/10.3390/jmse10101427 - 4 Oct 2022
Cited by 12 | Viewed by 3806
Abstract
The wave compensation system can be very useful in several naval applications. It can greatly reduce the relative irregular motion between the two ships when replenishment operations are performed, or between the ship and the offshore platform, which is caused by the waves. [...] Read more.
The wave compensation system can be very useful in several naval applications. It can greatly reduce the relative irregular motion between the two ships when replenishment operations are performed, or between the ship and the offshore platform, which is caused by the waves. It is widely used in offshore operations, offshore cargo transfer, oil and gas exploitation, deep-sea mining, the hoisting and recovery of submersibles, etc. However, when a crane is used in a ship or moving platform, due to the influence of the hull, the crane load movement is similar to a space ball pendulum, which causes the heave displacement to show significant nonlinear motion characteristics. Moreover, the time delay of the detection mechanism and control error could result in untimely compensation, which deteriorates the performance. Consequently, this paper proposes one advanced prediction compensation method, namely Particle Swarm Optimized Model Predictive Trajectory Path controller (PSO−MPTP), which can improve the heave compensation performance. This method, which is based on Model Predictive Control (MPC), is firstly applied to the position servo system and takes into account the heave prediction and control effects simultaneously. The heave displacement of the crane load could be predicted in multiple steps in advance and used as the input of the position loop of the compensation machine. The achieved simulations show that the proposed controller has better prediction ability, higher control accuracy, and stronger robustness. Full article
(This article belongs to the Section Ocean Engineering)
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21 pages, 5046 KB  
Article
Safety Assessment for Upper Part of Floating Crane Considering Minimum Luffing Angle
by Min-Woo Lee, Ji-Hyun Lee, Yeon-Seung Lee, Hyun-Jin Park and Tak-Kee Lee
Appl. Sci. 2021, 11(11), 5104; https://doi.org/10.3390/app11115104 - 31 May 2021
Cited by 5 | Viewed by 4983
Abstract
Floating cranes are used for the construction and installation work of harbors, various heavy industries, and offshore structures. In the case of floating cranes that need to move around the work site, their navigation can be constrained due to marine bridges. In some [...] Read more.
Floating cranes are used for the construction and installation work of harbors, various heavy industries, and offshore structures. In the case of floating cranes that need to move around the work site, their navigation can be constrained due to marine bridges. In some cases, the clearance under the bridge between the water surface and the bottom of the marine bridge may be too low, and floating cranes cannot pass under the marine bridge. In this study, the height of the marine bridges and the boom height of the floating cranes considering the minimum luffing angle were investigated. Through minimizing the boom luffing angle of the floating crane by the height of back tower, a floating crane with improved mobility through marine bridges was developed. A structural analysis model was produced to check whether the developed crane design satisfies the design criteria obeying the KR, DNVGL, and ABS rules, including luffing condition as a special consideration. As a result of the structural analyses, structural safety was validated for the service, stowage, and luffing conditions in terms of combined stresses, displacements, and buckling. Full article
(This article belongs to the Topic Industrial Engineering and Management)
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19 pages, 10055 KB  
Technical Note
Experimental Study on Development of Mooring Simulator for Multi Floating Cranes
by Junhyeok Bae, Juhwan Cha, Min-Guk Seo, Kangsu Lee, Jaeyong Lee and Namkug Ku
J. Mar. Sci. Eng. 2021, 9(3), 344; https://doi.org/10.3390/jmse9030344 - 20 Mar 2021
Cited by 5 | Viewed by 3277
Abstract
In this study, the coupled motion of a mooring system and multifloating cranes were analyzed. For the motion analysis, the combined equations of motions of the mooring line and multifloating cranes were introduced. The multibody equations for floating cranes were derived from the [...] Read more.
In this study, the coupled motion of a mooring system and multifloating cranes were analyzed. For the motion analysis, the combined equations of motions of the mooring line and multifloating cranes were introduced. The multibody equations for floating cranes were derived from the equations of motion. The finite element method (FEM) was used to derive equations to solve the stretchable catenary problem of the mooring line. To verify the function of mooring simulator, calculation results were compared with commercial mooring software. To validate the analysis results, we conducted an experimental test for offshore operation using two floating crane models scaled to 1:40. Two floating crane models and a pile model were established for operation of uprighting flare towers. During the model test, the motion of the floating cranes and tensions of the mooring lines were measured. Through the model test, the accuracy of the mooring analysis program developed in this study was verified. Therefore, if this mooring analysis program is used, it will be possible to perform a mooring analysis simulation at the same time as a maritime work simulation. Full article
(This article belongs to the Special Issue Simulation Based Maritime Design)
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13 pages, 7459 KB  
Article
Effects of Topside Structures and Wind Profile on Wind Tunnel Testing of FPSO Vessel Models
by Seungho Lee, Sanghun Lee and Soon-Duck Kwon
J. Mar. Sci. Eng. 2020, 8(6), 422; https://doi.org/10.3390/jmse8060422 - 9 Jun 2020
Cited by 5 | Viewed by 3700
Abstract
This study examined the effects of wind loads on a floating production storage and offloading (FPSO) vessel, focusing in particular on the impact of the turbulent wind profiles, the level of details of the topside structures, and the operation modes of the gantry [...] Read more.
This study examined the effects of wind loads on a floating production storage and offloading (FPSO) vessel, focusing in particular on the impact of the turbulent wind profiles, the level of details of the topside structures, and the operation modes of the gantry cranes. A series of wind tunnel tests were performed on the FPSO vessel model, developed with a scale of 1:200. It was observed that the wind loads measured using a low-detail model were often greater than those measured using a high-detail model. The measured wind loads corresponding to the Norwegian Maritime Directorate (NMD) profile with an exponent of 0.14, were approximately 19% greater than those corresponding to the Frøya profile in the entire range of wind directions, because of the slightly higher mean wind speeds of the NMD profile. The wind forces increased by up to 8.6% when the cranes were at operating mode compared to when they were at parking mode. In view of the observations made regarding the detail level of the tested models, a medium-level detail FPSO model can be considered adequate for the wind tunnel testing if a high-detail model is not available. Full article
(This article belongs to the Special Issue Advances in the Simulation of Wind Conditions)
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