Nab-Bulker Ship Details and Seafarer Feedback

The Transport Accident Investigation Commission (TAIC) of New Zealand has published its conclusive report on a serious incident involving the bulk carrier 'Achilles Bulker,' now operating as 'Nab Bulker'. The findings reveal that inadequate welding during maintenance caused a catastrophic failure that resulted in the vessel losing its rudder and narrowly avoiding grounding. On July 24, 2023, the ship departed from Tauranga, fully loaded with logs intended for China. Shortly after navigating out of Tauranga Harbor, the crew reported unusual steering behavior and a deviation from its intended course. While attempting to regain control, the ship experienced a significant shudder followed by a loud bang. The pilot took command, but an even louder bang followed, exacerbating the situation. Struggling to redirect the vessel back into the waterway, the pilot ordered the crew to drop both anchors. Approximately 30 minutes later, the vessel came to a halt outside the channel, barely escaping grounding with less than one meter of clearance beneath the keel. Subsequent inspections by divers revealed that the rudder had detached entirely. It was later recovered from the seabed two days later. Investigators determined that the rudder pintle was missing, which led to the rudder becoming unsupported and allowed excessive movement in the rudder system. Eventually, the rudder broke off when the palm fractured on both sides. A review of maintenance records indicated that during a routine dry docking in 2021, the rudder pintle assembly had been removed and inaccurately reinstalled. The assembly failed to secure the pintle properly for standard operational conditions, which resulted in the pintle dropping unnoticed, ultimately leading to its sinking. Excessive vibrations caused the securing welds to fail, and the nut retaining the pintle unwound, allowing for further unintended movement of the rudder and consequent additional stress. Fatigue cracks developed until the rudder ultimately detached. After repairs were completed, the vessel was returned to service. In light of this incident, TAIC has issued a stark warning and urged for enhanced quality assurance protocols at shipyards for rudder pintle installation. Additionally, they have informed the Maritime Safety Administration of China and plan to collaborate with the International Maritime Organization in advocating for improved global standards concerning the quality assurance of rudder systems during their installation, maintenance, and repair.