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.
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 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.
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.
