New Building Research Articles

The effect of main dimensions on the preliminary design of motor yachts

The design process of motor yachts mainly relies on the experience of designers, who have confidence in the knowledge acquired from designing units with similar hull-form characteristics. However, once a new concept needs to be developed, the acquired experience on a standard platform is no longer sufficient to achieve in a short time a successful design. The design of a motor yacht implies considering multiple aspects of ship hydrodynamics: resistance, propulsion, seakeeping, and manoeuvring. Such factors have been widely discussed individually on different kinds of ships, but an appropriate joint investigation of hulls like motor yachts is missing in the open literature. Therefore, the present paper intends to cover this gap, providing guidelines for the design of motor yachts in a length range between 20 and 40 meters. As a preliminary study, a series of 15 yacht hulls has been developed, starting from a reference hull form. Seakeeping, manoeuvring, and propulsive performances have been evaluated at a reference environmental condition and speeds according to the ISO 22834:2022 guidelines. Such calculations allow for developing response surfaces of the hydrodynamic properties for the series of yachts as a function of the hull's main dimensions. As a final result, the obtained responses allow for identifying the best compromise solutions for the main dimension selection of a new motor yacht in the length range of 20-40 meters.

Asbestos history and use

All six fiber types called asbestos can cause all the diseases related to exposure, including lung cancer. Known to the ancients, the modern history of asbestos hazards started in the 1890s with more and more data accumulating over time. Use increased exponentially in the middle of the 20th century with major use coming in construction and ship building. The recognition of asbestos as causing lung cancer dates to the early 1940s.

The impact of hydro generation on board large sailing yachts

In response to the leading narrative of increasing sustainability in the yachting sector, a research collaboration is started between the Delft University of Technology and Dykstra Naval Architects (DNA) to examine the potential use of hydro generation on board large sailing yachts. By harvesting energy from the water flow when a yacht is sailing, diesel generator use can be limited, reducing overall emissions. However, it is a challenge to quickly identify the impact of a chosen hydro generation system on the overall design during the early stages of yacht design. A design method, with a primary focus on the propeller, is therefore developed to quantify this impact. This allows the designer to explore various hydro generation systems in an early design stage. This paper describes the developed method and presents results from a case study to provide insight into the applicability of the method.

Non-Flammable Epoxy Composition Based on Epoxy Resin DER-331 and 4-(β-Carboxyethenyl)phenoxy-phenoxycyclotriphosphazenes with Increased Adhesion to Metals

Functional cyclophosphazenes have proven to be effective modifiers of polymer materials, significantly improving their performance properties, such as adhesive characteristics, mechanical strength, thermal stability, fire resistance, etc. In this study, 4-(β-carboxyethenyl)phenoxy-phenoxycyclotriphosphazenes (CPPP) were obtained by the condensation of 4-formylphenoxy-phenoxycyclotriphosphazene with malonic acid. Its structure was studied using 31P, 1H, and 13C NMR spectroscopy and MALDI-TOF mass spectrometry, and the thermal properties were determined by DSC and TGA methods. Molecular modeling using the MM2 method showed that CPPPs are nanosized with diameters of spheres described around the molecules in the range of 1.34–1.93 nm, which allows them to be classified as nanosized structures. The epoxy resin DER-331 was cured with CPPP, and the conversion of epoxy groups was assessed using IR spectroscopy. Using optical interferometry, it was shown that CPPPs are well compatible with epoxy resin in the temperature range from 80 to 130 °C. It was established that the cured epoxy composition was fire resistant, as it successfully passed the UL-94 vertical combustion test due to the formation of porous coke during the combustion process and also had high heat resistance and thermal stability (decomposition onset temperature about 300 °C, glass transition temperature 230 °C). The composition has low water absorption, high resistance to fresh and salt water, fire resistance, and adhesive strength to steel and aluminum (11 ± 0.2 MPa), which makes it promising for use as an adhesive composition for gluing parts in the shipbuilding and automotive industries, the aviation industry, and radio electronics.

Practical implementation of configuration management in the context of concept ship design – first lessons

The implementation of configuration management (CM) in support of concept design activities at the Products and Proposals department of Damen Naval has put forward a number of challenges that seem to be unique to the shipbuilding industry and the process of concept development therein, that traditional enterprise-level product lifecycle management software and processes are unable to tackle. Information fluidity, an uneven and fast evolving tooling landscape and limited team sizes have driven us to pursue dedicated software implementations in support of CM during concept design. From the first attempts of doing so, we have seen that a number of performance requirements for the software that were completely under the radar are now driving factors for further selection (mostly related to speed and agility of the tool), while some others even impact our way of working and organizational structure as a whole, requiring us to carry system responsibility per discipline, instead of only functional responsibility.

Layout Characteristics and Design Principles of Atrium Integrated Space

With the development of China's cruise tourism industry, it is necessary to study the design and construction of cruise ships, especially the central atrium, which is an important part of public area design and represents the quality and characteristics of the entire ship's design. However, compared with Europe, China's research foundation for large-scale cruise ship design is still lacking. Therefore, studying the spatial layout characteristics of the central atrium is of great significance for improving China's cruise industry. This article focuses on the design principles and characteristics of integrated space layout in the central atrium of cruise ships. By applying basic theories from architecture, shipbuilding engineering, aesthetics, international maritime safety conventions and technology to analyzing representative central atria from 25 typical domestic and foreign cruise brands through data collection and research methods including mathematical statistics methodology, clustering methodology and cases research methodology. Through comparison and generalization of the cases, the study eventually summarizes six overall principles and four structural principles for designing integrated space in the central atrium of a cruise ship. The six overall principles include safety, rationality, applicability, artistry, coordination and technique-economics. The four structural principles include clear space circulation, natural spatial connection, theme coordination & unification and prominent key levels. This study provides insights into designing integrated space in the central atriums of cruise ships that hopefully can be applied in improving China's cruise design work while also supporting guidance for future related fields. Keywords: central atrium of cruise ship, integrated space, design principles, functional layout, decoration style

Digital Shipbuilding – Needs, challenges, and opportunities

Ship design firms, shipyards, and ship equipment manufacturers – the shipbuilding industry or just shipbuilding, must adapt their products and services' deliverables to the steadily evolving expectations of the stakeholders in the market. Digitalization and the use of computational tools have been suggested as the effective means to meet such challenges. However, many anecdotal statements and industry recognitions have expressed concern that such efforts have proven less effective than should be expected and promised, and opposite to what many application suppliers advertise. It is argued by this paper that such a situation is experienced because of, among other explanatory factors, incompatibility, lack of proper protocols for information sharing and isolated implementation efforts in single departments rather than a holistic organizational approach. The lack of full understanding of the ship designer's role and responsibility as the main facilitator of such a change process is also recognized as a clear weakness in the effort of successful digitalization of shipbuilding. It is argued that such a vital transformation process cannot be left alone to the software application providers, despite their size and dominance. This paper explains and discusses why this situation is experienced and indicates what improvement measures could be introduced to counteract the opportunity loss. The article addresses five potential digital service deliverables that could complement the existing service delivery of shipbuilding operations and thereby increase competitiveness and market attractiveness. These services include a) vessel support and control centres, b) performance monitoring, c) maintenance management, d) spare part handling, and e) life cycle assessment (LCA). The article also reflects on what implications and consequences this development has on the ship designers' work and their firm's adaptation to new services' demand in the shipbuilding market. The paper concludes with some reflections on the actual implementation of these services, highlighting challenges and further opportunities.

A Service Blueprint Approach in Ship Building Activity Mapping

In the evolving landscape of shipbuilding, the confluence of innovative methodologies and advanced technologies is reshaping paradigms in ship design and production. The industry's quest for multidisciplinary methods that elaborate representing diverse ship building activities and boost efficiency in managing these activities has unveiled the potential of the service blueprint, a tool used in service design, which addresses design of activities and determining who does what activities when in collaboration with whom. Our proposition centres on the structured activity mapping representation, a novel activity map that utilizes service blueprint with detailed description of activities with rich and structured representation of context. The framework offers a comprehensive perspective, illuminating intricate processes such as concept design, detailed design and production stages as well as service and operation stages. This mapping would ensure alignment of each activity with overarching project objectives, encapsulating values, interactions, collaborations. This paper illustrates the approach of service blueprint in representing ship building activities with discussion on improvement potential of current activity mapping through the service blueprint approach as being conducted in the SEUS EU Horizon project.

Performances of the sandwich panel structures under fire accident due to hydrogen leaks: Consideration of structural design and environment factor using FE analysis

Abstract This study presents a comprehensive analysis using the finite element method (FEM) to examine and evaluate the behavior of fuel carrier ship structure. Sandwich panels are effective structures for use in ship structures due to their lightweight yet robust nature. Sandwich panels used in ship structures have various core shapes, such as hexagonal, circular, and square, as needed. The sandwich panel structure can be widely implemented in ship construction, for example, on the deck, hull, and bulkhead of the ship’s cabin. Hydrogen is an alternative fuel that can replace fossil fuels. In this modern era, hydrogen is high valuable energy commodity, so accidents involving carrier ships could have significant consequences. Hydrogen is produced from liquefied natural gas (LNG), so if a leak occurs, for instance, in a storage tank or fuel tank, it has the potential to lead to accidents such as fires. Corrosion is a significant concern for the maritime industry, as it can jeopardize the structural integrity of these vessels and pose substantial safety and environmental risks. In this research, FEM was utilized to model and simulate the effects of corrosion on hydrogen carrier ships when exposed to fire, considering various environmental and operational factors. Through a systematic investigation, it is aimed to gain insights into the impact of corrosion on ship structural components during fires, such as hulls and storage tanks. The result of this study will contribute to improving corrosion and fire mitigation strategies, ensuring the safety and longevity of hydrogen and LNG carrier ships, and supporting the sustainable transportation of hydrogen to meet global energy demands. No research has been conducted on the structural behavior resulting from hydrogen fires and corrosion simultaneously. To achieve this, it is assumed to use the corrosion properties of steel in heavily traveled ship routes such as the Panama Canal Zone, Barent Sea, North Sea, and Suez Canal Zone. This study utilized an approach by modeling corrosion using shell thickness in Abaqus Quasi-Static and applying boundary conditions in the form of temperature increase up to 800°C and subsequent cooling back to the initial temperature. At the maximum temperature, the most significant mid-span displacement occurred in the circular core sandwich panel, with a value of 4 mm. The axial force in the structure was inversely proportional to the mid-span displacement. In the case of the circular core sandwich panel, the axial force was 96 kN. The most resilient core type was hexagonal because it experiences the least deformation when compared to circular and square cores.

The importance of using active thermal protection following restoration work on old buildings

The paper deals with the issue of humidity and the unhealthy environment of old buildings. Humidity is a very widespread problem not only in historical buildings, but also in newer buildings. This problem can be observed in various parts of the world and thus it can be said that it is a global problem. Humidity in these buildings causes an unhealthy environment, which has a negative effect on individual building constructions, but also on people’s health. Humidity is also associated with the form of disruption of the individual layers of the construction and the disruption of the thermal resistance of these constructions. Buildings such as these subsequently have an unhealthy environment. After a part of the description of the known issue, the contribution follows on from this part by indicating possible remedial interventions and analyses the systems of additional thermal insulation (ETICS, ATP), ensuring the improvement of the internal environment. Finally, the article presents possible connections and extensions of this research and its application directly in practice. The results of the proposed research will significantly contribute to the approach to rehabilitated older buildings and their long-term sustainability from an economic point of view, as well as the possible use of them.

Analiza literature o utjecajima na okoliš i međunarodnom zakonodavstvu relevantnom za brodogradilišta

Shipyards are the place where the life cycle of a ship begins and ends. The life cycle of a ship, which starts with painting, blasting, and welding processes during the construction, is completed with the recycling of the steel parts and other equipment after the ship is scrapped. In this study, the harmful waste generated during the construction and recycling of ships in the shipyard and the environmental damage caused by this waste were investigated through a literature analysis. The content, implementation procedures and development processes of the relevant regulations are also examined. To fully evaluate the cumulative and holistic environmental impacts of shipyard processes, it is recommended to make greater use of the life cycle assessment approach. In this way, it will be possible to determine which process is more environmentally harmful during the shipbuilding, operation, and recycling phases, and to accurately determine the overall impact.

Research on the bending and tensile mechanical properties of ceramic yarns

Research on the bending and tensile mechanical properties of ceramic yarns

Impact of Ship Noise on Seafarers’ Sleep Disturbances and Daily Activities: An Analysis of Fatigue Increase and Maritime Accident Risk through a Survey

This study delves into the impact of ship noise on seafarer well-being, emphasizing fatigue—a significant contributor to maritime accidents due to human error. The investigation, centered around the hypothesis that IMO ship construction standards may not adequately minimize noise levels in seafarer cabins, seeks to establish whether these levels are sufficient to ensure seafarer security and prevent sleep disturbances. According to current IMO regulations, noise levels are set at 55 dB for vessels under 10,000 gross tonnage and 60 dB for those over 10,000, yet WHO guidelines recommend a maximum of 40 dB in bedrooms to avoid sleep disruption. A comprehensive survey involving 221 cadets demonstrates that 79.6% of participants experience sleep disturbances, work disruptions, and stress due to noise, indicating that the present noise standards are insufficient. This paper argues that reducing noise levels in individual cabins to below 40 dB is critical for enhancing seafarer health and safety and could significantly reduce human error-related maritime accidents. The findings advocate for more stringent noise control measures and regulatory reforms to bridge the knowledge gaps and improve labor protection in the maritime industry.

Prediction and optimization method for welding quality of components in ship construction

Welding process, as one of the crucial industrial technologies in ship construction, accounts for approximately 70% of the workload and costs account for approximately 40% of the total cost. The existing welding quality prediction methods have hypothetical premises and subjective factors, which cannot meet the dynamic control requirements of intelligent welding for processing quality. Aiming at the low efficiency of quality prediction problems poor timeliness and unpredictability of quality control in ship assembly-welding process, a data and model driven welding quality prediction method is proposed. Firstly, the influence factors of welding quality are analyzed and the correlation mechanism between process parameters and quality is determined. According to the analysis results, a stable and reliable data collection architecture is established. The elements of welding process monitoring are also determined based on the feature dimensionality reduction method. To improve the accuracy of welding quality prediction, the prediction model is constructed by fusing the adaptive simulated annealing, the particle swarm optimization, and the back propagation neural network algorithms. Finally, the effectiveness of the prediction method is verified through 74 sets of plate welding experiments, the prediction accuracy reaches over 90%.

Assessment of the Carbon Footprint of Large Yellow Croaker Farming on the Aquaculture Vessel in Deep Sea in China

The present study conducted a Life Cycle Assessment (LCA) to evaluate the carbon emissions associated with large yellow croaker farming on Aquaculture Vessel “Conson No. 1”. The functional unit considered was 1 kg of fresh large yellow croakers delivered to a wholesaler. The life cycle of large yellow croaker farming on the aquaculture vessel was divided into five processes: feed production (FP), ship construction (SC), fingerling breeding (FB), adult fish farming (AF), and fish distribution (FD). Results showed that the carbon footprint (CF, kgCO2e/kg LW) for the complete life cycle amounted to 6.2170 kgCO2e/kg LW, while the CF per unit economic value of “Conson No. 1” large yellow croaker was estimated at 31 gCO2e/CNY. Among all processes, AF and FP had the highest CF contribution rates at 69.30% and 24.86%, respectively. Notably, energy consumption by aquaculture equipment on board emerged as the primary contributor across all sources of CF comparative analysis demonstrated that the CF of marine fish farming on the aquaculture vessel was lower than that of closed aquaculture systems’ average level and it was a viable option for implementing low-carbon aquaculture in the deep sea. In order to reduce energy consumption and promote a low-carbon economy in aquaculture vessels, several suggestions were proposed, including adjusting energy structure, enhancing energy efficiency, improving feed ratio, and optimizing feeding methods.

Vibration assessment of dual core sandwich beam with a biomimetic lamellar honeycomb core and MWCNT reinforced facesheets

The usage of sandwich structures has been increasing in the field of defense, transportation, and aerospace applications due to the many advantages like, thickness to mass ratio, high bending stiffness, and strength. In this present work, the vibration assessment of the dual-core sandwich beam with biomimetic core and multiwalled carbon nanotube (MWCNT) reinforced composite face layers has been performed. The lamellar honeycomb (LHC) core is a biomimetic design developed here from the pistachio shell structure and manufactured by 3D printing process. The mechanical characteristics of biomimetic core are measured using an alternative dynamic technique and impulse excitation test was used to assess the material properties of MWCNT composite laminates. Using finite element software, a numerical model is created for a composite dual-core sandwich beam containing MWCNTs and a biomimetic core. The developed numerical model is validated with experimental and available literature results in terms of natural frequencies and it shows good agreements. Additionally, parametric studies are performed to investigate the natural frequencies of MWCNT composite dual-core sandwich beam with biomimetic cores for ply orientation angles, aspect ratio, and support conditions. The MWCNT reinforcement in the facesheets and LHC core enhances the structural performance and stiffness of the laminated composite dual-core sandwich beam. This research will provide the valuable insights to engineers and scientists for the construction of large capacity ships and race boat structures.

ANALYSIS OF SHIPPING FINANCING SOURCES IN THE CONTEXT OF UNCERTAINTY

The article is aimed at identifying the peculiarities of financing shipping under conditions of uncertainty and analysing the sources of financing of shipping companies. Methodology. This study is based on the analysis of trends in the socio-economic, military-political and environmental situation, which cause global uncertainty and limit the ability of shipping companies to obtain external financing. The article compares the Petrofin Global Ship Finance Index with the dynamics of seaborne trade volumes for the period from 2008 to 2022, determines the correlation coefficient of these indicators and identifies the leaders among the banks-creditors of the shipping industry in terms of the volume of shipping loans in the loan portfolio. Results. The study shows a direct correlation between the shortage of shipping financing and the three main forms of global uncertainty. The results of comparing the Petrofin index with the growing dynamics of seaborne trade indicate a decrease in the role of banks and an increase in the role of alternative sources to cover the shortfall in shipping financing, such as raising resources from capital markets, financial and leasing companies, private equity funds, private equity and venture capital investments, investment platforms, hedge funds, state capital, and capital from international organisations. The main reasons for the change in the structure of shipping companies' funding sources are the conservative lending policy of banks in the crisis, tighter regulation, higher interest rates, lending only to borrowers with a positive credit history, and increased loan collateral requirements. Instead, the advantages of alternative sources of financing are flexibility, speed, less regulation compared to banks, the ability to provide large volumes, new types and forms of financing, and more competitive rates. Practical implications. The volatile external environment complicates the process of finding financing for shipping companies, which directly affects fleet renewal, the increase in the cost of ship construction and refurbishment, and the digital and environmental modernisation of shipping. Therefore, shipping companies should diversify their sources of financial resources, have a margin of safety in equity, and redistribute their borrowing portfolio between bank loans and alternative forms of financing. Value/Originality. The analysis of traditional and alternative sources of financing for shipping in the context of macroeconomic instability allows to identify key trends in investment policy towards shipping companies, to identify the specific needs of shipping companies in the face of various forms of global uncertainty and to outline the features of the most common sources of financing.

Analysis of the Impact of Large Container Ships on Port Capacity

Facing the fierce competition in the shipping market, major container liner companies are constantly increasing the scale of container ship construction in pursuit of scale effect, and the trend of large-scale development of container ships is increasingly obvious. The enlargement of container ships not only intensifies the competition of shipping companies, but also brings profound changes to the port's facilities and equipment. This paper analyzes the development process, background and reasons of the large-scale container ships, as well as the future development trend of large-scale ships. The qualitative and quantitative method was used to analyze the current status of ship enlargement on the development status. Through the corresponding data and cases, combined with the current rise of international trade protectionism and the global spread of new pneumonia, the impact of ship enlargement on port development was analyzed with a view to the port Development provides corresponding theoretical references and suggestions.

Analysis Of Ship Main Engine Procurement Process In The Shipyard Industry Using Supply Chain Operation Reference Method (SCOR) (Case Study: PT XYZ)

As a sector playing a crucial role in ship construction and repair, the shipbuilding industry faces significant challenges in material procurement, where materials constitute 50-70% of the total project cost. One of the materials requiring paramount attention is the ship's main engine. Effective supply chain management is critical to enhancing efficiency and effectiveness in the procurement process of ship engines. However, supply chain performance measurement research, especially in ship engine procurement, still needs to be improved. Therefore, this study aims to identify relevant performance metrics, analyze critical performance indicators, and provide recommendations based on the SCOR (Supply et al.) framework to improve ship engine procurement. The research results present 24 metrics distributed into four performance attributes based on SCOR 12.0, with 22 selected metrics aligned with the company's context. Analysis using the AHP method indicates that the reliability attribute has the highest weight (0.296), with the metric "Percentage of procurement received on time as per request" being the top priority (weight 0.143). This study provides a holistic view of crucial aspects of the ship engine procurement supply chain, supporting companies in enhancing their performance in the procurement process.

Enhancing fatigue performance of AZ31 magnesium alloy components fabricated by cold metal transfer-based wire arc directed energy deposition through LPB

Cold Metal Transfer-Based Wire Arc Directed Energy Deposition (CMT-WA-DED) presents a promising avenue for the rapid fabrication of components crucial to automotive, shipbuilding, and aerospace industries. However, the susceptibility to fatigue of CMT-WA-DED-produced AZ31 Mg alloy components has impeded their widespread adoption for critical load-bearing applications. In this study, a comprehensive investigation into the fatigue behaviour of WA-DED-fabricated AZ31 Mg alloy has been carried out and compared to commercially available wrought AZ31 alloy. Our findings indicate that the as-deposited parts exhibit a lower fatigue life than wrought Mg alloy, primarily due to poor surface finish, tensile residual stress, porosity, and coarse grain microstructure inherent in the WA-DED process. Low Plasticity Burnishing (LPB) treatment is applied to mitigate these issues, which induce significant plastic deformation on the surface. This treatment resulted in a remarkable improvement of fatigue life by 42%, accompanied by a reduction in surface roughness, grain refinement and enhancement of compressive residual stress levels. Furthermore, during cyclic deformation, WA-DED specimens exhibited higher plasticity and dislocation density compared to both wrought and WA-DED + LPB specimens. A higher fraction of Low Angle Grain Boundaries (LAGBs) in WA-DED specimens contributed to multiple crack initiation sites and convoluted crack paths, ultimately leading to premature failure. In contrast, wrought and WA-DED + LPB specimens displayed a higher percentage of High Angle Grain Boundaries (HAGBs), which hindered dislocation movement and resulted in fewer crack initiation sites and less complex crack paths, thereby extending fatigue life. These findings underscore the effectiveness of LPB as a post-processing technique to enhance the fatigue performance of WA-DED-fabricated AZ31 Mg alloy components. Our study highlights the importance of LPB surface treatment on AZ31 Mg components produced by CMT-WA-DED to remove surface defects, enabling their widespread use in load-bearing applications.