An investigation report published by the Marshall Islands has blamed the ‘catastrophic structural failure’ of the hull for the sinking of the very large ore carrier (VLOC) Stellar Daisy in March 2017, which killed 22 crew members.
Owned by Korean owner Polaris Shipping, Stellar Daisy was converted from a VLCC in China in 2008.
It sank on 31 March 2017 on a voyage from Ilha Guaíba, Brazil, to Qingdao, China, underway in the South Atlantic.
Issuing its Marine Casualty Investigation Report, the Republic of the Marshall Islands (RMI) Maritime Administrator said that the possible direct cause of Stellar Daisy foundering was a rapid list to port after a catastrophic structural failure of the ship’s hull due to which the ship lost its buoyancy and flooded uncontrollably.
During the probe, it was found that the structural failure and flooding started in the No 2 port water ballast tank (WBT) and then progressed quickly to contain structural failure and flooding in multiple WBTs, voids and cargo holds.
The report highlighted that various factors, including the strength of the ship’s structure being compromised over time due to material fatigue, corrosion, unidentified structural defects, multi-port loading and the forces imposed on the hull were contributing factors that resulted in structural damage of the ship.
According to the probe report, likely causal factors include large ballast water tanks, which may have increased the potential for a major structural failure and loss of buoyancy.
It also pointed to a gap in regulations in the additional safety measures for bulk carriers contained in SOLAS, Chapter XII, regulation 5.
The report also blamed ineffective assessments of structural damage when the ship was in drydock in 2011, 2012, and 2015.
Classification society Korean Register (KR) defended the 2011 failure analysis and said: “The RMI report correctly states that a failure analysis of the damage to the transverse bulkhead at frame No 65 was conducted as it was determined by the attending surveyor to be ‘out of the ordinary’ and similar damage was not found in other parts of the ship.
“However, the cracks/defects identified and repaired at the time of dry-docking in 2011 were determined to be those typically found onboard ships of a similar age (note that Stellar Daisy was 18 years old in 2011).
“Based on this observation, the attending surveyor determined that the cracks/defects were not ‘out of the ordinary’ and as long as proper repairs were performed, a failure analysis was not needed.”