Although Hagen Oldendorff’s steering and rudder angle indicator systems complied with the applicable rules and regulations, neither the SOLAS regulations, nor the rules of the ship’s responsible classification society, Lloyd’s Register, mandated protection of the ship's rudder angle indication systems against a single point of failure in power supply, nor did they require installation of audible or visual alerts to notify the bridge team of a power failure affecting the indicators.
The ATSB will monitor progress of any safety action undertaken by Lloyd's Register and the International Association of Classification Societies to address this safety issue. The ATSB will regularly reassess the status of the safety issue and will publish updates on its website, including the response of Lloyd's Register to the ATSB safety recommendation.
Response by Lloyd’s Register
On 5 December 2024, Lloyd's Register (LR) advised the ATSB that while an additional alarm for a distribution circuit from a local distribution panel on the bridge may not be the best solution to this safety issue, alternate design solutions could include individual connection of each analogue rudder angle indicator to the local distribution board with each having its own short circuit protection. The LR response also noted that LR rules for rudder angle indicators replicated SOLAS regulations, and it therefore considered it problematic to amend or unilaterally re-interpret these requirements without amendments to SOLAS itself. However, LR advised that the Machinery Panel of the International Association of Classification Societies (IACS) may consider a unified interpretation (UI) of SOLAS requirements instead.
ATSB comment
The ATSB acknowledges that alternate design solutions may effectively address the risk associated with a single point of failure in electrical power supply for ship's rudder angle indicators and that this may take the form of a unified interpretation (UI) of SOLAS requirements. The ATSB does not prescribe the form that corrective action to address the safety issue should take and it is up to the responsible organisation(s) to identify the most effective means of addressing the risk. In the absence of a detailed proposal and/or timeframe to approach IACS, raise this safety issue and best ensure safety action that will address the risk, the ATSB issues the following safety recommendation.
The Australian Transport Safety Bureau recommends that Lloyd’s Register takes steps to approach the International Association of Classification Societies and seek safety action to address the risk associated with a single point of failure in electrical power supply for ship's rudder angle indicators.
Lloyd's Register (LR) advised the ATSB that, while there were elements of the safety issue which the organisation disagreed with, LR accepted the safety recommendation. LR agreed that the safety issue could be raised at the International Association of Classification Societies (IACS) to develop a unified interpretation and advised that the safety issue was raised within the Machinery Panel of IACS on 4 April 2025. Members’ comments on the subject were due to be received by 5th May 2025 following which LR would consolidate members' comments and propose further action as appropriate.
The ATSB acknowledges LR's acceptance of the recommendation. The ATSB will monitor the progress of efforts at the International Association of Classification Societies and re-assess the safety issue following any action to address the risk identified.
On 17 November 2025, Lloyd's Register advised the ATSB that, following discussion and consultation, the members of the International Association of Classification Societies (IACS) Machinery Panel had decided to develop a unified requirement (UR) focused on the monitoring and alarm systems for the power supply to rudder angle indicators.
URs are resolutions, adopted by IACS members, on matters directly connected to or covered by specific rules and are the minimum class requirements shared among all IACS members. URs were created to allow for uniformity in the implementation of International Maritime Organization (IMO) conventions among IACS members and to provide agreed interpretations of those Conventions which are otherwise vaguely worded or left to the satisfaction of each Administration.
The next steps will include the development of a draft UR followed by circulation of the draft to relevant industry stakeholders and shipbuilder associations for review and feedback.
The ATSB acknowledges the encouraging progress made in addressing this safety issue and will continue to monitor the status of the safety action as updates become available. The ATSB will re-assess the safety issue following the successful development and implementation of the proposed unified requirement.
