IMO’s MSC raises concerns on IACS Rec. 34 revision

The International Maritime Organization published a document submitted to the Maritime Safety Committee (MSC) by Cyprus, Greece, Malta, Hong Kong, China, and maritime organizations (ICS, BIMCO, INTERCARGO, RINA), highlighting major concerns over the recent revision of IACS Recommendation 34 (Rec.34/Rev.2). This standard, essential for maritime safety, provides "Standard Wave Data" critical for setting structural design requirements for vessels, especially bulk carriers and oil tankers, operating globally.

1. Background and Importance of IACS Rec.34

IACS Rec.34 forms the foundation for defining the worst-case wave scenarios that ships may encounter globally. This data plays a crucial role in determining the hull load parameters, which are then used to calculate necessary plate thicknesses, as well as the sizes of stiffeners and beams to ensure structural resilience.
The data impacts not only ship design but also classification society rules that govern ship construction, directly influencing the safety and durability of ships, crew protection, and environmental preservation.
The Common Structural Rules (CSR) for Bulk Carriers and Oil Tankers, developed by IACS, are in line with the IMO's Goal-Based Standards (GBS) outlined in MSC.287(87). Because these rules are pivotal to ship safety, they are subject to periodic auditing by the IMO.

2. Concerns over the Reliability of the Revised Data (Rec.34/Rev.2)

Wave Data Issues: The original IACS Rec.34 data, last revised around 2000/2001, was based on wave statistics that are now considered outdated. Recent observations indicate an increase in significant wave heights, particularly in the North Atlantic, as well as an increase in extreme weather conditions. This includes phenomena like rogue waves, which are larger and more unpredictable.
Potential Impact of Climate Change: These changes in wave patterns are attributed in part to climate change, which suggests a shifting baseline for maritime environmental conditions that Rec.34 may no longer adequately represent.
Audit Findings: An earlier IMO GBS audit (MSC 96/5) pointed out that the outdated wave data might not accurately reflect the conditions ships face today, particularly in the North Atlantic. The audit also indicated that IACS had not shown evidence of new data assessment since adopting Rec.34, nor had it conducted sensitivity studies to evaluate how recent wave data might affect ship motion and hull loads.

3. IACS's Response and the 2023 Revision (Rev.2)

In response to these concerns, IACS reviewed Rec.34 and published Rev.2 in January 2023. However, stakeholders—including ICS, INTERCARGO, INTERTANKO, and RINA—found the revised methodology and data selection troubling. These co-sponsors argued that Rev.2’s approach and resulting wave data did not address the core issues raised, potentially compromising ship safety.
Through 2023 and 2024, co-sponsors communicated their concerns to IACS, both in writing and in meetings, emphasizing that Rev.2 may still inadequately capture current wave conditions and that further revision was necessary.

4. Request to the Maritime Safety Committee

Safety and Environmental Implications: Given the critical role of wave data in ensuring ship safety, stakeholders argue that Rev.2 should not be used in developing class rules or designing ships for worldwide service until it has been thoroughly re-evaluated. The co-sponsors fear that reliance on Rev.2 data might compromise the safety of ship hull structures, endanger crews, and increase the risk of environmental damage from ship incidents.
Proposed Action: The co-sponsors ask that the Maritime Safety Committee include a formal statement in its final report for the current session, explicitly recommending that Rev.2 data be set aside for now. Instead, they suggest further updates and revisions to the standard, incorporating more recent and reliable wave data that better aligns with current sea-state conditions.

5. Strategic Direction and Next Steps

The document relates to IMO’s Strategic Direction 7, specifically output 7.24, which deals with enhancing safety measures. The final recommended action is located in paragraph 19 of the document, likely outlining a procedural course for how to address and potentially resolve these concerns.
The MSC has been urged to consider the findings of the most recent GBS audit (MSC 109/4/1), which examined the adequacy of Rev.2 in light of the changing maritime environment, and to take corrective steps in subsequent sessions to ensure that ship safety standards remain robust and up-to-date.