We understand that shipowners, shipyards, Flag States and other interested parties will take a keen interest in the review of the Common Structural Rules that is now underway. We welcome interest from all industry stakeholders and have prepared a detailed FAQ guide to answer some of the most popular questions, covering the purpose of the review, the consultation process, and proposed changes.
If your question is not answered here, you can contact us by e-mail at csr@iacs.org.uk or see if it has been answered by our experts in our latest webinar.”
Frequently asked questions:
The CSR set the standards for the construction and maintenance of bulk carriers and oil tankers. These rules aim to ensure safety, structural integrity, and environmental protection, and meet the Goal-Based Standards (GBS) for continuous improvement set by the IMO. Casualty statistics underscore the positive impact of CSR, the Enhanced Survey Programme (ESP) and the Performance Standard for Protective Coatings (PSPC). These protocols represent the pinnacle of safety standards for oil tankers and bulk carriers constructed since the early 2000s. Additionally, data from special surveys, including steel repair and thickness measurements, show significant improvements following the implementation of these standards.
IACS has periodically conducted revisions to the Common Structural Rules (CSR) as part of the continual ‘class cycle’ of review and improvement, and based upon any observations from the IMO. The revisions reaffirm IACS’s commitment to maintaining the highest standards, based on the best available data, technologies and techniques. CSR revisions are based upon a mindset that seeks to consistently evolve in line with improved techniques; for example, new hydro-dynamic calculation techniques and new data. Data is constantly gathered and assessed from several touchpoints, including newbuild and five-year surveys.
The CSR were last significantly updated in July 2016, with regular smaller adaptations since then. In line with our commitment to continuous ‘class cycle’ improvement, we amend the CSR when needed in order to enhance them further. For example, this now includes the incorporation of innovative techniques such as Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) full ship models.
Driven by technological advances, we now have access to new and updated vessel data that can play a powerful role in informing our review of the CSR. Compared to the current CSR, this will ensure that the updated CSR is based on more accurate, rigorous and validated ‘in service’ data, which will strengthen the technical foundations for the CSR. The proposed revisions capitalize on advancements in technology and data collection methods, such as more comprehensive and accurate wave data, utilizing factors such as ship speed, heading angle, and weather routing. These enhancements represent a significant improvement to modeling real-world conditions, supporting the ongoing evolution of ship design and safety measures. The current CSR is based on data that is now outdated, and does not reflect the advances in technology, materials, and design methodologies that have emerged in recent years. Since the last major revision of the CSR, significant technological progress has been made, including improvements in simulation tools and structural analysis techniques, which can now be better integrated into the rules to enhance ship safety.
IACS prioritizes the safety of shipping operations and is committed to considering the interests of all stakeholders as part of its continuous improvement efforts, including the CSR revisions. This is underpinned by our commitment to Quality as a guiding principle that will deliver high standards for safety, pollution prevention, and ship operations. The shipping industry is also evolving, with new factors such as digitalization and environmental concerns becoming more prominent. A review of the CSR will help ensure the rules continue to support safe and sustainable shipping practices. Enhanced data can also help to ‘future proof’ CSR against future developments – including the demands of a new multi-fuel and clean technology future where vessel design and operation will become less standardized – allowing for better preparedness.
For shipowners, the revised CSR will ensure higher safety standards, reducing the risk of costly accidents and improving the longevity and reliability of vessels, ultimately protecting assets and investments. Incorporating the latest technological advances, the revised CSR will also facilitate more efficient and effective ship designs. For shipyards, the revised CSR will streamline the design and construction process, incorporating the latest standards that will reduce rework and enhance the quality, safety, and environmental standards of newbuilds. The revised CSR will also provide clarity and consistency, reducing uncertainties in the construction process, and helping with more effective project management. For Flag States, the revised CSR will enhance the safety and environmental compliance of vessels, reducing the risk of accidents and environmental incidents. The primary focus of the CSR remains on safety and environmental stewardship, which are critical to the integrity of Flag States. By supporting the adoption of the revised CSR, Flag States will have the opportunity to demonstrate safety and environmental leadership.
Given the importance of the CSR, we are committed to a rigorous review that gives a voice to all stakeholders. This is a thorough process that will take several years to complete. It has been designed to be inclusive and transparent, allowing for extensive consultation with shipowners, shipyards, Flag States, and others. This open process shall remain in place through to the adoption and entry into force of any new rules. As part of this process, a detailed timeline has been set out that provides multiple opportunities for stakeholders to consider the proposed changes and contribute to the process. This process has several staging posts along the way to ensure that the work conducted to date is comprehensive and fully reviewed. The revised CSR will initially be adopted by IACS. Following this, the IMO and Flag States will be invited to consider and review the recommendations emerging from the IMO Goal-Based Standards (GBS) audit once they are formally adopted. This process ensures that the new standards are carefully evaluated and aligned with global best practices.
To facilitate a smooth transition, there may be a need to allow additional time for implementation. An extended timeline for implementation has been proposed to allow all stakeholders sufficient time to adapt to the new rules without undue pressure, ensuring a smooth transition. This proposal is currently under internal discussion. At present (November 2024), we are continuing to review the draft revisions based on the considerable industry feedback received, as well as the valued expertise of IACS members. These will be further refined based on feedback, as well as to ensure alignment with IMO Goal-Based Standards (GBS) and verification audit findings. We anticipate releasing the draft rule revisions for further public consultation in the first half of 2025. This will include further industry outreach and engagement to help explain the changes, answer questions and collect input. Based on this feedback, we will prepare final revisions to the CSR. These will be subject to validation tests and simulations to ensure the robustness of the revisions, ahead of preparing the final technical background documents and consequence assessment reports.
We have put extensive consultation at the heart of this review. It is vital that CSR revisions are made with all stakeholders in mind, as part of a genuinely collaborative process. Proposed CSR revisions are subject to extensive stakeholder scrutiny including – but not limited to – an external advisory group (EAG), IACS members’ technical committees, and wider industry consultation. All rule changes are also accompanied by detailed technical background documents. Stakeholders are encouraged to actively participate in the consultation process, providing feedback and suggestions to ensure that the revised rules are practical, effective, and beneficial for the entire industry.
The updated CSR will incorporate the latest safety standards, which are based on more accurate and recent data, as well as new technologies and techniques. This will lead to improved ship design and construction, ultimately helping to reduce the risk of accidents at sea. There are two specific areas in which notable changes are expected to the CSR; the new wave loads and the improved corrosion analysis model. Both are explained in further detail in the next two questions.
The revision of the IACS Rec. 34 is a fundamental piece of work defining the rule wave scatter diagram. This was prompted by an IMO observation to consider the possible increase of design waves due to climate change. In carrying out this review, IACS derived the wave scatter diagram from a new methodology based on comprehensive wave and AIS data, rather than being based on outdated wave data that relied on visual observations (Global Wave Statistics – Visual observations BMT Atlas, 1986). This reflects IACS’s commitment to an approach that is based on the best available data and responsive to the evolving conditions of sea states, including such considerations for ship operations as speed, heading angle, and routing. Improvements in the latest version of IACS Rec.34 Rev.02 include:
IACS is not planning to make any changes to the corrosion margins in the upcoming revisions of Common Structural Rules (CSR).
IACS anticipates that revisions to CSR will not impact the potential lifespan of a vessel, and therefore has no impact on asset value. This conclusion takes into account the operational profile of all vessel types and is based on intensive data analysis. We also anticipate that long-term savings through improved efficiency and compliance are likely to outweigh any initial expenditure. Furthermore, concerns about increased complexity in the construction process are unfounded; the revisions are designed to simplify and standardise ship building practices, ultimately easing the construction workflow.
The CSR changes would not necessarily lead to increased steel requirements. More complex calculations for general ship design based on state-of-the-art computational tools will give a much clearer and realistic indication of how the design can be optimised. As safety is the core value that underpins all of IACS’s work, while we do not expect that there will be significant requirements for more steel repairs as a result of the review, it may be necessary in certain cases.
Further technical documentation is available elsewhere on the IACS website or please contact us at csr@iacs.org.uk if you have specific questions.
