Bagiyo Suwasono, I. Putra, T. A. Kristiyono, A. Azhar
Coatings are important instruments in inhibiting the corrosion rate. Field facts in various Indonesian shipping industries show that the choice of organic materials as coating for ship paint uses epoxy, vinyl and polyurethane. Therefore an experimental study is needed on the adhesion ability of paint as a coating for ship armor with these three types of organic materials. The preparation of steel specimens with type ASTM A36 is carried out by blasting, visual inspection standard ISO 8501-1, and roughness test standard ISO 8503-4. Painting of specimens by measuring the thickness of the paint in the wet conditions ASTM D4414 standard and ASTM D4138 standard dry conditions. Treatment of specimens in two conditions, are: tropichal weather condition and salt spray conditon. Observation of specimens by scanning electron microscope and adhesion test standard ASTM D4541-02. The final result shows that the best adhesion ability of the main paint coating in tropical weather conditions was a polyurethane coating with no blister characteristics, but there are fractures on the surface of the material. While the main material for the best coating in salt spray conditions was epoxy coating with characteristics that are resistant to blisters and blends with the surface of the material.
{"title":"ADHESIVE COATING VALUE BASED ON THE MAIN INGREDIENT OF SHIP PAINT","authors":"Bagiyo Suwasono, I. Putra, T. A. Kristiyono, A. Azhar","doi":"10.21278/BROD72202","DOIUrl":"https://doi.org/10.21278/BROD72202","url":null,"abstract":"Coatings are important instruments in inhibiting the corrosion rate. Field facts in various Indonesian shipping industries show that the choice of organic materials as coating for ship paint uses epoxy, vinyl and polyurethane. Therefore an experimental study is needed on the adhesion ability of paint as a coating for ship armor with these three types of organic materials. The preparation of steel specimens with type ASTM A36 is carried out by blasting, visual inspection standard ISO 8501-1, and roughness test standard ISO 8503-4. Painting of specimens by measuring the thickness of the paint in the wet conditions ASTM D4414 standard and ASTM D4138 standard dry conditions. Treatment of specimens in two conditions, are: tropichal weather condition and salt spray conditon. Observation of specimens by scanning electron microscope and adhesion test standard ASTM D4541-02. The final result shows that the best adhesion ability of the main paint coating in tropical weather conditions was a polyurethane coating with no blister characteristics, but there are fractures on the surface of the material. While the main material for the best coating in salt spray conditions was epoxy coating with characteristics that are resistant to blisters and blends with the surface of the material.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43360254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhang Pengfei, Han Bing, Kuang Haibo, Shipping Economics
The increase in risk prevention investments in the port-hinterland service network (PHSN) effectively enhances the network’s ability to resist risks and improve the sustainability and stability of ocean transportation. Based on the construction of the PHSN risk prevention investment utility model, the equilibrium strategy, the related characteristics of each participant in the complementary networks and the complete network are analyzed. Similarly, the subsidy policy of the government under the utility maximization of the whole service network is studied. We further propose new types of subsidy strategies based on the key nodes and key groups given the resources available and the subsidy efficiency constraints imposed, while also validating the advantages of this method based on a case analysis. The results indicate that the (1) equilibrium risk prevention investment is closely related to the Katz-Bonacich centrality, network interaction intensity, cost of unit risk prevention investment and competition intensity; (2) an undifferentiated subsidy strategy cannot improve the risk prevention effectiveness of the whole network; (3) the subsidy strategy based on key nodes and key groups effectively improves the risk prevention efficiency; and (4) the subsidy strategy of key groups is superior to the subsidy strategy of key nodes. Accordingly, the results of this study provide a reference for participants and managers in the PHSN when making risk prevention investment decisions.
{"title":"RISK TRANSMISSION AND CONTROL OF PORT-HINTERLAND SERVICE NETWORK: FROM THE PERSPECTIVE OF PREVENTIVE INVESTMENT AND GOVERNMENT SUBSIDIES","authors":"Zhang Pengfei, Han Bing, Kuang Haibo, Shipping Economics","doi":"10.21278/BROD72103","DOIUrl":"https://doi.org/10.21278/BROD72103","url":null,"abstract":"The increase in risk prevention investments in the port-hinterland service network (PHSN) effectively enhances the network’s ability to resist risks and improve the sustainability and stability of ocean transportation. Based on the construction of the PHSN risk prevention investment utility model, the equilibrium strategy, the related characteristics of each participant in the complementary networks and the complete network are analyzed. Similarly, the subsidy policy of the government under the utility maximization of the whole service network is studied. We further propose new types of subsidy strategies based on the key nodes and key groups given the resources available and the subsidy efficiency constraints imposed, while also validating the advantages of this method based on a case analysis. The results indicate that the (1) equilibrium risk prevention investment is closely related to the Katz-Bonacich centrality, network interaction intensity, cost of unit risk prevention investment and competition intensity; (2) an undifferentiated subsidy strategy cannot improve the risk prevention effectiveness of the whole network; (3) the subsidy strategy based on key nodes and key groups effectively improves the risk prevention efficiency; and (4) the subsidy strategy of key groups is superior to the subsidy strategy of key nodes. Accordingly, the results of this study provide a reference for participants and managers in the PHSN when making risk prevention investment decisions.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42139172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An application method for working ship crossing safely is proposed to determine how to make navigation scheme at a certain time. This method makes it possible for decision makers to make reasonable judgments at different times. In this paper, the position relationship between working ship and navigation vessel in waterway is analysed by considering the ship size, hydrological conditions of waterway, ship arrival model and ship navigation trajectory. Using genetic algorithm, the operation scheme of keeping a safe distance between the working ship and the vessel in the channel is solved by taking the speed and direction of the working ship as genetic factors. By analysing the crossing scheme at each starting time in a given time range, the optimal crossing scheme with the farthest distance between the working ship and the vessels in the channel is obtained. According to the measured data, the simulation is carried out with MATLAB to verify the model of working ship crossing channel. The results show that it is safe and reliable to choose the navigation scheme proposed in this paper, which has strong application value.
{"title":"MODEL OF WORKING SHIP CROSSING CHANNEL","authors":"Zhang He, Hao Yuanyuan, Xu Cheng, Qin Luying","doi":"10.21278/BROD72107","DOIUrl":"https://doi.org/10.21278/BROD72107","url":null,"abstract":"An application method for working ship crossing safely is proposed to determine how to make navigation scheme at a certain time. This method makes it possible for decision makers to make reasonable judgments at different times. In this paper, the position relationship between working ship and navigation vessel in waterway is analysed by considering the ship size, hydrological conditions of waterway, ship arrival model and ship navigation trajectory. Using genetic algorithm, the operation scheme of keeping a safe distance between the working ship and the vessel in the channel is solved by taking the speed and direction of the working ship as genetic factors. By analysing the crossing scheme at each starting time in a given time range, the optimal crossing scheme with the farthest distance between the working ship and the vessels in the channel is obtained. According to the measured data, the simulation is carried out with MATLAB to verify the model of working ship crossing channel. The results show that it is safe and reliable to choose the navigation scheme proposed in this paper, which has strong application value.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":"72 1","pages":"125-143"},"PeriodicalIF":1.8,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47740262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patil Prasad Vinayak, Chelladurai Sree Krishna Prabu, N. Vishwanath, S. Prakash
Recently, several changes have been observed in the Earth’s environment. This is also applicable to the ocean environment. The concept of weather routing has been applied for ship navigation for a long time. Many service providers offer weather routing service with the availability of high-quality satellite data. Unfortunately, not much information is available in the public domain as to how much the recent change in the weather pattern has affected ship navigation. The purpose of this paper is to fill this information gap. We investigate the influence of recent changes in the ocean environment on ship navigation. Weather data from ECMWF, namely ERA-Interim, is used for this purpose. The ECMWF data for the last 27 years is analysed. We compute the statistical characteristics of this data for the first 10 years, last 10 years, and 27 years. The statistical characteristics of the data are determined based on “summer” and “winter” zones as defined by international maritime regulations. Six different worldwide commercial ship routes are selected covering all the ocean regions. Navigation on great ellipse with waypoint is considered. MMG type ship manoeuvring model for 3 different ship types (DTMB 5415, PCC, VLCC) is used. The added resistance due to wave, wind and the effort of keeping the ship on the desired course using autopilot in the rough ocean environment is included in the MMG model. The fuel consumption and the duration of each one of the voyage are computed. Based on the analysis and simulation results it is shown that: (i) The mean wave height, wave period, and wind speed has increased in some ocean zones and decreased in other ocean zones. If any change has occurred, it is uniform for both seasons (summer and winter). (ii) In which ocean regions there is a perceptible change in fuel consumption, average ship speed and voyage time due to the changes in the weather pattern. (iii) The changing weather pattern in different ocean zones affects each ship type differently.
{"title":"NUMERICAL SIMULATION OF SHIP NAVIGATION IN ROUGH SEAS BASED ON ECMWF DATA","authors":"Patil Prasad Vinayak, Chelladurai Sree Krishna Prabu, N. Vishwanath, S. Prakash","doi":"10.21278/BROD72102","DOIUrl":"https://doi.org/10.21278/BROD72102","url":null,"abstract":"Recently, several changes have been observed in the Earth’s environment. This is also applicable to the ocean environment. The concept of weather routing has been applied for ship navigation for a long time. Many service providers offer weather routing service with the availability of high-quality satellite data. Unfortunately, not much information is available in the public domain as to how much the recent change in the weather pattern has affected ship navigation. The purpose of this paper is to fill this information gap. We investigate the influence of recent changes in the ocean environment on ship navigation. Weather data from ECMWF, namely ERA-Interim, is used for this purpose. The ECMWF data for the last 27 years is analysed. We compute the statistical characteristics of this data for the first 10 years, last 10 years, and 27 years. The statistical characteristics of the data are determined based on “summer” and “winter” zones as defined by international maritime regulations. Six different worldwide commercial ship routes are selected covering all the ocean regions. Navigation on great ellipse with waypoint is considered. MMG type ship manoeuvring model for 3 different ship types (DTMB 5415, PCC, VLCC) is used. The added resistance due to wave, wind and the effort of keeping the ship on the desired course using autopilot in the rough ocean environment is included in the MMG model. The fuel consumption and the duration of each one of the voyage are computed. Based on the analysis and simulation results it is shown that: (i) The mean wave height, wave period, and wind speed has increased in some ocean zones and decreased in other ocean zones. If any change has occurred, it is uniform for both seasons (summer and winter). (ii) In which ocean regions there is a perceptible change in fuel consumption, average ship speed and voyage time due to the changes in the weather pattern. (iii) The changing weather pattern in different ocean zones affects each ship type differently.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43351553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most of the offshore wind turbines (OWT) recently installed in Europe, China and North America are in shallow water. However, unlocking the full potential of OWT lies in deeper waters. Jacket substructures have presented themselves as a reliable foundation concept for transitional water depth. This study focuses on the structural static and dynamic analysis of the traditional jacket substructures (with X and K bracing) and the recently patented three-legged twisted jackets (with a twisted angle of 30 and 60 degrees) for deployment in transitional water (beyond 60 m). To facilitate comparison, the dimensions of all the jackets remain the same, while, the geometric configurations are distinct. Static analysis was implemented to better understand the global load bearing behaviour of the jackets. First, the global displacement patterns at the tower top are compared. The individual reactions at mud-line were investigated, followed by the evaluation of the maximum von Mises stress. Subsequently, this research went on to investigate the effect of dynamic loading. In this dynamic analysis, three main critical points were considered, including the wave point (67 m), the platform and the tower top. A modal analysis was performed to compute the mode shapes and natural frequencies for all the jackets. The first five modes of all the jackets were also checked against the results available for the OC4 project. A similar analytical approach was adopted for the structural design of monopile or tripod foundations for offshore wind turbines. The results showed that in the static analysis both the traditional jackets and the twisted jackets were safe under the provided load combination. The twisted jacket proved to possess excellent structural behaviour compared to the traditional four-legged jackets, while maintaining the merits of lower material usage with fewer nodes. Analysing the von Mises stress revealed that the maximum stress occurred at the transition piece and close to the working platform. The modal analysis results of the jackets demonstrated that the twisted jackets (30 and 60 degrees) with the first natural frequency of 0.29 and 0.31 Hz fell under the soft-stiff design category whereas the traditional four-legged jackets were classified as stiff-stiff designs. The discovered structural performance of OWTs equipped with various jacket foundations contributes to the preliminary structural selection and optimal design of foundations of OWTs to be installed in transitional water.
{"title":"STRUCTURAL ANALYSIS OF JACKET FOUNDATIONS FOR OFFSHORE WIND TURBINES IN TRANSITIONAL WATER","authors":"Issa Fowai, Z. Jianhua, K. Sun, Bin Wang","doi":"10.21278/BROD72106","DOIUrl":"https://doi.org/10.21278/BROD72106","url":null,"abstract":"Most of the offshore wind turbines (OWT) recently installed in Europe, China and North America are in shallow water. However, unlocking the full potential of OWT lies in deeper waters. Jacket substructures have presented themselves as a reliable foundation concept for transitional water depth. This study focuses on the structural static and dynamic analysis of the traditional jacket substructures (with X and K bracing) and the recently patented three-legged twisted jackets (with a twisted angle of 30 and 60 degrees) for deployment in transitional water (beyond 60 m). To facilitate comparison, the dimensions of all the jackets remain the same, while, the geometric configurations are distinct. Static analysis was implemented to better understand the global load bearing behaviour of the jackets. First, the global displacement patterns at the tower top are compared. The individual reactions at mud-line were investigated, followed by the evaluation of the maximum von Mises stress. Subsequently, this research went on to investigate the effect of dynamic loading. In this dynamic analysis, three main critical points were considered, including the wave point (67 m), the platform and the tower top. A modal analysis was performed to compute the mode shapes and natural frequencies for all the jackets. The first five modes of all the jackets were also checked against the results available for the OC4 project. A similar analytical approach was adopted for the structural design of monopile or tripod foundations for offshore wind turbines. The results showed that in the static analysis both the traditional jackets and the twisted jackets were safe under the provided load combination. The twisted jacket proved to possess excellent structural behaviour compared to the traditional four-legged jackets, while maintaining the merits of lower material usage with fewer nodes. Analysing the von Mises stress revealed that the maximum stress occurred at the transition piece and close to the working platform. The modal analysis results of the jackets demonstrated that the twisted jackets (30 and 60 degrees) with the first natural frequency of 0.29 and 0.31 Hz fell under the soft-stiff design category whereas the traditional four-legged jackets were classified as stiff-stiff designs. The discovered structural performance of OWTs equipped with various jacket foundations contributes to the preliminary structural selection and optimal design of foundations of OWTs to be installed in transitional water.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47617911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Free running model tests and a system-based method are employed to evaluate maneuvering performance for a Small Waterplane Area Twin Hull (SWATH) ship in this paper. A 3 degrees of freedom Maneuvering Modeling Group (MMG) model is implemented to numerically simulate the maneuvering motions in calm water. Virtual captive model tests are performed by using a Reynolds-averaged Navier-Stokes (RANS) method to acquire hydrodynamic derivatives, after a convergence study to check the numerical accuracy. The turning and zigzag maneuvers are simulated by solving the maneuvering motion model and the predicted results agree well with the experimental data. Moreover, free running model tests are carried out for three lateral separations and the influence of the lateral separations on maneuvering performance is investigated. The research results of this paper will be helpful for the maneuvering prediction of the small waterplane area twin hull ship.
{"title":"EXPERIMENTAL AND NUMERICAL INVESTIGATION ON MANEUVERING PERFORMANCE OF SMALL WATERPLANE AREA TWIN HULL","authors":"K. Dai, Yunbo Li","doi":"10.21278/brod72206","DOIUrl":"https://doi.org/10.21278/brod72206","url":null,"abstract":"Free running model tests and a system-based method are employed to evaluate maneuvering performance for a Small Waterplane Area Twin Hull (SWATH) ship in this paper. A 3 degrees of freedom Maneuvering Modeling Group (MMG) model is implemented to numerically simulate the maneuvering motions in calm water. Virtual captive model tests are performed by using a Reynolds-averaged Navier-Stokes (RANS) method to acquire hydrodynamic derivatives, after a convergence study to check the numerical accuracy. The turning and zigzag maneuvers are simulated by solving the maneuvering motion model and the predicted results agree well with the experimental data. Moreover, free running model tests are carried out for three lateral separations and the influence of the lateral separations on maneuvering performance is investigated. The research results of this paper will be helpful for the maneuvering prediction of the small waterplane area twin hull ship.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67955532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present paper focuses on the numerical investigation of the flow around the fully submerged 2D and 3D hydrofoils operating close to a free surface. Iterative boundary element method is implemented to predict the flow field. This study aims to investigate the aspect ratio effect on the free surface interactions and hydrodynamic performance of the hydrofoils under a free surface by using potential flow theory. Three different submergence depths and aspect ratios are studied in the wide range of Froude Numbers. In 3D cases, spanwise width of the numerical wave tank model is selected both equal and wider to the foil span, to observe the sidewall effects. Wave field seems to be two dimensional at low Froude numbers. On the other hand, signs of three dimensionalities are observed on the free surface structure for higher Fn, even the predicted wave elevations are very close to 2D calculations in the midsection. Increment in the Fn give a rise to the amplitude of the generated waves first, however a further increase in Fn has a lowering effect with the beginning of waves spill in the spanwise direction in the form of Kelvin waves. Free surface proximity and resultant wave field are also seeming to be linked with the lift force on the hydrofoil. As aspect ratio of the foil increase, 3D lift values are getting closer to those of 2D calculations. However, it is seen that, 3D BEM predictions of a hydrofoil under free surface effect cannot be considered two-dimensional even the aspect ratio is equal to 8.
{"title":"WAVE FIELD GENERATED BY FINITE-SPAN HYDROFOILS OPERATING BENEATH A FREE SURFACE","authors":"Y. Ozdemir, Taner Cosgun, B. Barlas","doi":"10.21278/BROD72108","DOIUrl":"https://doi.org/10.21278/BROD72108","url":null,"abstract":"The present paper focuses on the numerical investigation of the flow around the fully submerged 2D and 3D hydrofoils operating close to a free surface. Iterative boundary element method is implemented to predict the flow field. This study aims to investigate the aspect ratio effect on the free surface interactions and hydrodynamic performance of the hydrofoils under a free surface by using potential flow theory. Three different submergence depths and aspect ratios are studied in the wide range of Froude Numbers. In 3D cases, spanwise width of the numerical wave tank model is selected both equal and wider to the foil span, to observe the sidewall effects. Wave field seems to be two dimensional at low Froude numbers. On the other hand, signs of three dimensionalities are observed on the free surface structure for higher Fn, even the predicted wave elevations are very close to 2D calculations in the midsection. Increment in the Fn give a rise to the amplitude of the generated waves first, however a further increase in Fn has a lowering effect with the beginning of waves spill in the spanwise direction in the form of Kelvin waves. Free surface proximity and resultant wave field are also seeming to be linked with the lift force on the hydrofoil. As aspect ratio of the foil increase, 3D lift values are getting closer to those of 2D calculations. However, it is seen that, 3D BEM predictions of a hydrofoil under free surface effect cannot be considered two-dimensional even the aspect ratio is equal to 8.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43672317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Faisal Ikram Abd Samad, Mohd Yuzri Mohd Yusop, N. Shaharuddin, N. Ismail, O. Yaakob
Small high speed passenger crafts (HSC) are commonly known for their poor seakeeping qualities. These crafts are frequently exposed to large slamming impacts and these repetitive shocks may pose danger to passengers’ safety and health. In Malaysia, small high speed passenger crafts having lengths between 7 to 9 meters are mainly used to transport tourists between popular island destinations. Evaluation on impact and vibration for this type of craft was conducted by using accelerometers attached to several locations on craft’s deck. The test was conducted at speeds ranged between 20 to 30 knots and the highest peak accelerations were recorded. The highest acceleration record during the sea trial was recorded at 4.22 g and the average acceleration measure is 2.20 g. Apart from this test, evaluation on effectiveness of the current foam seat typically used in this craft were evaluated using Dynamic Response Index (DRI) and results have shown that the seat is less efficient when impact reaches more than 1g at speeds of more than 20 knots. It is concluded that safety measures such as the use of more efficient suspension seat and limiting the operational speed need to be taken into consideration.
{"title":"SLAMMING IMPACT ACCELERATIONS ANALYSIS ON SMALL HIGH SPEED PASSENGER CRAFTS","authors":"Faisal Ikram Abd Samad, Mohd Yuzri Mohd Yusop, N. Shaharuddin, N. Ismail, O. Yaakob","doi":"10.21278/BROD72104","DOIUrl":"https://doi.org/10.21278/BROD72104","url":null,"abstract":"Small high speed passenger crafts (HSC) are commonly known for their poor seakeeping qualities. These crafts are frequently exposed to large slamming impacts and these repetitive shocks may pose danger to passengers’ safety and health. In Malaysia, small high speed passenger crafts having lengths between 7 to 9 meters are mainly used to transport tourists between popular island destinations. Evaluation on impact and vibration for this type of craft was conducted by using accelerometers attached to several locations on craft’s deck. The test was conducted at speeds ranged between 20 to 30 knots and the highest peak accelerations were recorded. The highest acceleration record during the sea trial was recorded at 4.22 g and the average acceleration measure is 2.20 g. Apart from this test, evaluation on effectiveness of the current foam seat typically used in this craft were evaluated using Dynamic Response Index (DRI) and results have shown that the seat is less efficient when impact reaches more than 1g at speeds of more than 20 knots. It is concluded that safety measures such as the use of more efficient suspension seat and limiting the operational speed need to be taken into consideration.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44968908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper deals with the analysis of development and trends in the field of management of naval shipbuilding projects. The introductory part gives an overview of project management in the defense sector as well as in the naval shipbuilding sector. The analysis of naval shipbuilding project management is done through consideration of four criteria: naval strategy and long-term planning, shipbuilding industrial base, workforce, and project management organization. Due to limited resources, five countries were selected: the United States of America (USA), the United Kingdom (GBR), Australia (AUS), New Zealand (NZL), and Croatia (HRV). After individual countries have been analysed, synthesis and comparison of results were presented in tabular form. The conclusion is based on global trends in this area, how the naval shipbuilding project management in the Republic of Croatia is harmonized with them, and recommendations for improving the process of managing naval projects in the Republic of Croatia. The scientific contribution of the paper is in defining a systematic approach to managing naval shipbuilding projects that could serve as a generic model on which the future organization and management processes of naval shipbuilding projects in the Republic of Croatia and other maritime countries, that are comparable in economic strength and defense needs, may be founded.
{"title":"CURRENT APPROACHES TO THE MANAGEMENT OF NAVAL SHIPBUILDING PROJECTS","authors":"Andrija Ljulj, V. Slapničar, I. Grubišić","doi":"10.21278/BROD72105","DOIUrl":"https://doi.org/10.21278/BROD72105","url":null,"abstract":"The paper deals with the analysis of development and trends in the field of management of naval shipbuilding projects. The introductory part gives an overview of project management in the defense sector as well as in the naval shipbuilding sector. The analysis of naval shipbuilding project management is done through consideration of four criteria: naval strategy and long-term planning, shipbuilding industrial base, workforce, and project management organization. Due to limited resources, five countries were selected: the United States of America (USA), the United Kingdom (GBR), Australia (AUS), New Zealand (NZL), and Croatia (HRV). After individual countries have been analysed, synthesis and comparison of results were presented in tabular form. The conclusion is based on global trends in this area, how the naval shipbuilding project management in the Republic of Croatia is harmonized with them, and recommendations for improving the process of managing naval projects in the Republic of Croatia. The scientific contribution of the paper is in defining a systematic approach to managing naval shipbuilding projects that could serve as a generic model on which the future organization and management processes of naval shipbuilding projects in the Republic of Croatia and other maritime countries, that are comparable in economic strength and defense needs, may be founded.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47778013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article deals with the very topical issues of the use of spot ship’s space booking and the dynamic adjustment of ocean freight, according to the demand and availability of cargo space on container ships. Container lines are facing the challenges of filling the growing container ships, which also raises the difficulty of managing the overbooking. Two research hypothesis; that (H1) freight forwarders have concerns about a new spot booking mode and a dynamic way of formulating ocean rates; and that (H2) freight forwarders feel threatened by Container Lines (CL) to some extent to phase them out from the organization of intermodal transport chains due to the introduction of larger ships and the risk of low space occupation, are followed by the research. A survey between freight forwarders and NVOCCs (Non-Vessel Operating Common Carrier) on a global scale provides guidelines for the further development of CL model for the booking process and the formation of ocean rates because the results expose how new ways of working have a greater impact on the operational and commercial work between CL, freight forwarders and NVOCCs. According to the obtained result, the article proposes a three-step approach to be developed by CL that would bring freight forwarders and NVOCCs closer to a new way of working, reduce business risks, and, as a result, provide leverage to achieve ship space optimization and lower space pressure on container terminals. The study provides new understandings in building new operational models for efficient maritime logistics and brings novelty to the scientific community by defining descriptive gaps in changing strategic and operational approach for ship’s cargo space optimization.
{"title":"INVESTIGATION ON SPOT BOOKING AND DYNAMIC OCEAN FREIGHT MODELLING FOR HIGHER SPACE UTILISATION ON ULTRA LARGE CONTAINER VESSELS","authors":"B. Beškovnik","doi":"10.21278/brod71404","DOIUrl":"https://doi.org/10.21278/brod71404","url":null,"abstract":"The article deals with the very topical issues of the use of spot ship’s space booking and the dynamic adjustment of ocean freight, according to the demand and availability of cargo space on container ships. Container lines are facing the challenges of filling the growing container ships, which also raises the difficulty of managing the overbooking. Two research hypothesis; that (H1) freight forwarders have concerns about a new spot booking mode and a dynamic way of formulating ocean rates; and that (H2) freight forwarders feel threatened by Container Lines (CL) to some extent to phase them out from the organization of intermodal transport chains due to the introduction of larger ships and the risk of low space occupation, are followed by the research. A survey between freight forwarders and NVOCCs (Non-Vessel Operating Common Carrier) on a global scale provides guidelines for the further development of CL model for the booking process and the formation of ocean rates because the results expose how new ways of working have a greater impact on the operational and commercial work between CL, freight forwarders and NVOCCs. According to the obtained result, the article proposes a three-step approach to be developed by CL that would bring freight forwarders and NVOCCs closer to a new way of working, reduce business risks, and, as a result, provide leverage to achieve ship space optimization and lower space pressure on container terminals. The study provides new understandings in building new operational models for efficient maritime logistics and brings novelty to the scientific community by defining descriptive gaps in changing strategic and operational approach for ship’s cargo space optimization.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":"71 1","pages":"53-65"},"PeriodicalIF":1.8,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45952174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：