Shipbuilding is undergoing a significant transformation, driven by the need for greater efficiency, increased complexity in design, and the ever-present push towards decarbonization and stricter safety regulations. Shipyards, designers, and classification societies are increasingly recognizing 3D model-based approvals (3D MBA) as a crucial element in navigating this evolving landscape. Moving beyond traditional 2D drawings, 3D MBA is rapidly becoming a reality, promising to streamline processes and enhance accuracy in ship design and approval. Let’s explore how NAPA is at the forefront of this revolution, working with industry leaders to implement this groundbreaking approach.
The modern challenges in ship design are multifaceted. From meeting stringent decarbonization targets to adhering to increasingly complex maritime safety standards and accommodating the rise of autonomous vessel operations, the industry faces immense pressure. These challenges demand innovative solutions and a departure from conventional methods. The essence of 3D Model-Based Approval (3D MBA) lies in its ability to directly utilize the 3D model, the very foundation of ship design, for classification rule checks and calculations. This marks a significant leap from the existing norm, where shipyards are compelled to laboriously translate detailed 3D models into a series of 2D drawings for classification approvals, only to revert to 3D for implementation. This cumbersome back-and-forth process, involving multiple conversions between 2D and 3D, is not only time-consuming but also introduces opportunities for errors to creep in, impacting efficiency and potentially the integrity of the design itself. The elimination of these conversions is a core benefit of 3D MBA, promising substantial time savings and enhanced accuracy.
Furthermore, the current standard process necessitates engineers to manually extract data from the 3D model and re-input it into various platforms used for rule calculations and Finite Element Method (FEM) analysis. This manual data entry is not only tedious and time-intensive but also prone to human error. A critical aspect of 3D MBA is the seamless conversion of the 3D model for direct use by classification engineering tools. This capability is pivotal in realizing the full potential of 3D MBA and truly transforming the ship design and approval workflow.
Two primary paths are being pursued by leading classification societies to bring 3D MBA to fruition, each tailored to their specific strategies and customer requirements:
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Application Programming Interface (API): This approach leverages the NAPA API, a software intermediary that allows classification societies to directly access the 3D model. Through this API, they can extract the necessary information to conduct rule checks and calculations. Pioneered by Korean Register (KR) and ClassNK, this API-driven method fosters direct information exchange and calculation result sharing on the 3D model itself. This establishes the 3D model as a “single source of truth,” centralizing all ship design information and ensuring data consistency across all stages of the approval process.
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Open Class Exchange (OCX): Developed as an industry-wide standard file format specifically for 3D MBA, OCX acts as a bridge between the software used by shipyards for design and the platforms used by classification societies for rule checks and approvals. NAPA Designer generates OCX files, extracting all relevant data from the 3D model and structuring it in a format readily interpretable by classification society software. Bureau Veritas (BV) and DNV have adopted this OCX approach, and the OCX Consortium has garnered support from other major classification societies, signifying its growing industry acceptance.
Bureau Veritas and Damen Engineering: Achieving a 3D Milestone
A NAPA Steel 3D model, meticulously crafted by Damen Engineering for structural design, served as the foundation for classification approvals by Bureau Veritas.
A landmark achievement in 3D MBA was realized earlier this year when a 2,500 m3 dredger, designed by Damen, became the first vessel to undergo a complete 3D model-based design, review, and class approval process. This accomplishment was the culmination of a year-long collaborative effort between Damen, NAPA, and Bureau Veritas. Leveraging the OCX standard file format, BV was able to seamlessly perform prescriptive rule checks and calculations using their in-house tools, MARS and VeriSTAR Hull. The results of these reviews were then delivered back in the same OCX format, eliminating the need for any 2D drawing conversions.
The implementation of 3D MBA yielded immediate and significant benefits. Damen’s teams experienced valuable time savings as they no longer needed to translate designs into 2D drawings for classification and then back to 3D for implementation. Communication between Damen and BV was markedly smoother, leading to more efficient and robust design reviews with a reduced potential for errors. Importantly, this streamlined approval process did not compromise safety; rigorous checks remained in place to ensure full compliance with all regulatory standards and rules. The success of this initial project has spurred Damen to adopt 3D MBA for subsequent designs, including two hopper dredgers of 1000m3 and 4000m3, demonstrating the tangible benefits and scalability of the approach.
ClassNK and Nihon Shipyards: Building a Single Source of Truth
ClassNK and Nihon Shipyards have taken a different yet equally impactful approach, utilizing NAPA’s Application Programming Interface (API) to achieve seamless integration. This method establishes the 3D model as the central, constantly updated repository of vessel information throughout the design and review process, truly embodying the concept of a “single source of truth”.
This collaborative project focused on enhancing the efficiency of the class approval process and addressing practical challenges associated with 3D MBA. With initial focus on hull structural design, they developed an integrated system linking NAPA Designer with ClassNK’s proprietary strength calculation platform, PrimeShip-HULL (PSH). This system handles both prescriptive rule calculations and Finite Element (FE) analysis, providing a comprehensive solution for structural assessment.
Integration fundamentally changes the ship design and approval processes, enhancing efficiency and accuracy.
Trials conducted on bulk carrier and oil tanker models validated the effectiveness of this integrated system, confirming its significant advantages in eliminating redundant work and ensuring design information consistency across structural drawings and models. Another key outcome was the validation of NAPA Viewer, a web-based application providing stakeholders with secure and easy access to review and comment on 3D models. NAPA Viewer serves as a central information hub, facilitating not only 3D MBA but also improved information sharing and collaboration among all parties involved in ship design. Trials have shown that this platform achieves efficiency levels equal to or exceeding the traditional 2D-based process, thanks to an automatic annotation tool that blends the advantages of 3D models with the intuitiveness of 2D drawings, enabling reviewers to quickly access design information.
Korean Register: Further Streamlining Engineering Processes
3D Model in NAPA Designer (Left) and 2D Sections from NAPA 3D Model in SeaTrust-HullScan (Right)
NAPA has also partnered with Korean Register (KR) to develop a direct interface connecting NAPA Designer, the shipyard’s 3D CAD system, and KR’s structural strength calculation software, SeaTrust-HullScan. This API operates in real-time, enabling designers to easily import complex cross-section modeling data and seamlessly transfer comprehensive ship design information, including modeling details, into the classification platform.
A primary focus of this collaboration was data reusability. Traditionally, hull structure design processes involve disparate software, each with proprietary file formats, leading to repetitive manual data input from the 3D CAD model into classification software for rule calculations. By tackling this issue, the aim was to streamline the design process, eliminating time-consuming and error-prone steps. The study confirmed the maintenance of data consistency, crucial for ensuring accurate reflection of changes across models and calculations, and for ensuring result reliability. The interface also significantly improved hull structure design accuracy and work productivity. Currently utilized in Korean shipyards, the system continues to evolve based on user feedback, with ongoing developments including a direct interface for Direct Strength Assessment processes, set to be presented at the 2023 NAPA User Meeting.
Charting the Future
These recent milestones and projects are just the beginning. 3D MBA is poised to become the standard in shipbuilding. NAPA is committed to continuous collaboration with shipyards and classification societies to refine the process and facilitate its industry-wide adoption. This collaborative approach extends beyond systems and data integration; it connects people, uniting them towards the shared goal of enhancing the efficiency of the design and class approval process.
3D MBA is not merely an end in itself, but a means to empower shipyards to achieve commercial success and deliver superior vessels more rapidly. By optimizing processes, it unlocks new potential for naval engineers and architects at a critical juncture, as they grapple with the immense challenge of designing sustainable fleets for the future. Furthermore, 3D models form the foundation for digital twins, which can be utilized throughout a vessel’s lifecycle to optimize operations and maintenance. The ongoing 3D revolution in ship design is paving the way for more efficient and sustainable vessels, poised to revolutionize maritime transport for current and future generations, ensuring both economic viability and environmental responsibility in the marine industry.
