Design and classification under DNV standards is a cornerstone of offshore, marine, and structural engineering. As of 2025, new editions and amendments to DNV class rules and structural standards are being rolled out, affecting everything from fatigue design to alternative fuel notations.
In this article we explore the major updates engineers need to know: how DNV’s July 2025 class rules will affect projects, what’s new in RP-C203 fatigue, changes in structural/OS standards, and how software tools like SDC Verifier can help you stay compliant.
What are DNV Standards?
The DNV Standards are a comprehensive set of technical rules developed by DNV (Det Norske Veritas) — an independent assurance and risk management company headquartered in Norway. These codes define the principles and requirements for the design, construction, and in-service inspection of ships, offshore units, and other marine and energy structures.
The DNV rules cover a broad range of topics, including structural design, materials, stability, machinery, safety systems, and environmental protection. They form the technical foundation for obtaining DNV Class, which certifies that an asset meets internationally recognized safety, reliability, and performance standards.
Why the 2025 Updates of DNV Matter?
DNV has published its July 2025 edition of classification rules and standards, which will enter into force on 1 January 2026. This update covers 119 documents and introduces many new notations, clarified requirements, and structural revisions.
Key Class Rule Changes in the 2025 Edition
Here are some of the most significant updates in the July 2025 rule set:
| Domain | Major Change | Implication for Engineers / Owners |
| Ship / Marine | Revised methods for evaluating propellers and thrusters (Pt.4/Ch.4, Pt.6/Ch.6) | Design of propulsor systems may need updates to sizing or loading checks |
| Ship / Marine | Full revision of water-jet rules (Pt.4/Ch.5/Sec.2) | New water-jet systems must follow updated structural and performance requirements |
| Ship / Marine | New qualifiers: Hydrogen Ready, WAPS Ready | New builds should be prepared for future installation of fuel alternatives |
| Ship / Marine | New class notation CO₂ RECOND | For vessels preparing CO₂ for offloading, requiring reconditioning equipment design |
| Ship / Marine | Walk2Work in-operation notation; new Clean notation | Safety systems and operations (e.g. gangways) will be subject to operational class notation requirements DNV+1 |
| Offshore / Production | Revised Abate class notation with qualifiers PE (external power) & CCW (carbon capture) | Production units must adapt design for external-power or carbon capture integration DNV+2DNV+2 |
| Offshore / Sustainability | New Sustainability class notation | Structures may need to demonstrate alignment with UN SDG goals DNV |
| Offshore / Mooring | New MIM (Mooring Integrity Management) notation | Mooring systems will face new classification verification demands DNV |
| Structural / OS Rules | Harmonization of materials, fabrication, and structural rules across ship/offshore | Designers must reconcile structural requirements formerly in different domains DNV+1 |
| Electrical / Systems | Updates to align with IACS and ship rules (OS-D201) | Electrical and control system design must comply with tighter alignment across domains DNV |
These updates reflect DNV’s emphasis on decarbonization, data-driven verification, and operational clarity under evolving technologies.
How Should Engineers Prepare?
Here is a practical checklist:
- Review the July 2025 rule draft and participate
The hearing period for the 2025 class rules is open (typically March–April) before final publication.
Engineers and firms should review proposed changes and provide feedback. - Upgrade software & workflows
Software must support the new DNV editions (class rules, RP standards). For example, SDC Verifier supports DNV standards from 1995 through 2024 (buckling, fatigue, welds).
Check that the tools implement new clauses, notations, and structural provisions correctly. - Revalidate key designs under new rules
For existing projects in progress, run sensitivity studies comparing compliance under old vs new rules (e.g. fatigue life under RP-C203 2024 vs 2016). - Train your team on new notations
Concepts like DDV, CO₂ RECOND, MIM, Sustainability notation must be understood across disciplines (structural, systems, mooring). - Engage with classification society early
During project definition, confirm with DNV how new notations will be granted, what transitional clauses apply, and which editions are required for contract compliance. - Ensure audit-traceable documentation
With new rules, classification societies may scrutinize calculation traceability more strictly. Tools and reports must clearly map each result to the clause in DNV standards.
Role of Structural Verification Software
To manage the complexity of multiple DNV standards, engineering teams increasingly rely on software support. SDC Verifier is one such software:
- It supports checks across buckling (CN30, RP-C201, CG-0128), fatigue (RP-C203), and weld strength (OS-C101, OS-C201) using both LRFD and WSD formulations.
- The software maintains clear traceability, showing intermediate variables, formula references, and usage factors, easing audit reviews.
- It offers benchmark comparisons (e.g. fatigue results under different editions) as demonstrated in published benchmarks.
By automating routine compliance checks, SDC Verifier helps engineers focus on critical decisions rather than manual calculations.
Conclusion
The upcoming 2025 updates to DNV standards represent one of the most significant shifts in recent years: new class notations, tighter fatigue requirements, structural harmonization, and data-driven verification. Engineers who stay ahead by updating tools, revalidating designs, and engaging with classification will reduce risk and ensure compliance.
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