Dry bulker safety is back in the spotlight as catastrophic structural failures and poor repair history are found to be at fault for the deaths of 22 crew aboard Marshall Islands flagged very large ore carrier. Andrew Linington lifts the lid on the damning safety report
Catastrophic structural failure caused the loss of the very large ore carrier (VLOC) Stellar Daisy, with the death of 22 crew members, a long-awaited investigation report has concluded.
The results of the flag state probe were revealed just a few days before the bulk carrier owners' organisation, Intercargo, published a report revealing that 188 seafarers have lost their lives on bulk carriers over the past decade.
The 266,141dwt Stellar Daisy sank some 1,700nm off the coast of Uruguay in March 2017 whilst sailing from Brazil to China, fully laden with an iron ore cargo. Only two crew members survived.
The 83-page Marshall Islands investigation report blames the accident on 'a combination of 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 because of the weather conditions Stellar Daisy encountered between 29-31 March 2017'.
Investigators said the structural failure probably began in a port water ballast tank and progressed rapidly to include structural failure and flooding in multiple tanks, voids, and cargo holds.
Stellar Daisy had been converted into a VLOC from a 1993-built VLCC in China in 2008. The ship's large port and starboard wing tanks increased the potential for a major structural failure and loss of buoyancy if one flooded while the vessel was carrying a cargo.
The report points to a loophole in the International Maritime Organisation SOLAS rules which exempted VLCC-to-VLOC conversions from the additional SOLAS Convention safety requirements for bulkers over 150m, stipulating that bulkers should have 'sufficient strength to withstand flooding of any space, or spaces, located between adjacent transverse bulkheads' when in loaded or unloaded condition.
It also notes that the master had rated the condition of the water ballast tanks as poor during inspections in 2016, and had found corrosion in ballast piping and a distorted watertight bulkhead between two ballast tanks.
Investigators said there had been ineffective assessments of structural damage identified when the ship was in dry dock in 2011, 2012 and 2015. This resulted in a failure to determine the cause of the damage, identify any potential defects with the conversion design, or require the development of appropriate repair plans.
Pointing to Stellar Daisy’s repair history and the number of cracks in bottom longitudinals that were subsequently identified on other converted VLOCs managed by Polaris Shipping and classed by KR, investigators determined that the initial ballast water tank was probably the result of one or more cracks in bottom longitudinals that either were not detected when the tank was last inspected in October 2016 or that developed after the inspection.
However, the report states that the that the fatigue cracking was probably undetectable by visual inspection prior to the sinking.
The report notes that the ship’s safety management system did not give any specific guidance to masters on changing course or reducing speed in response to weather conditions.
'Changing course could have reduced the potential for synchronous rolling and would have reduced the magnitude of the dynamic forces on the ship's structure,' it points out.
'Whether this reduction would have been sufficient to prevent the structural failure that initiated the loss of buoyancy cannot be determined based on the information that is available.'
Tinkering with regulations that will not apply to existing vessels will not solve the problem. It is about time these death trap vessels were consigned to the scrapheap
The weather conditions encountered by Stellar Daisy before the accident were common for the area and the vessel should have been able to withstand them, the report adds.
'However, because the strength of the ship’s structure was compromised, the dynamic loads resulting from this combination of forces had a higher potential to cause components of the hull structure to fail.'
The report makes 14 recommendations, including calls for owners Polaris Shipping and classification society KR to change various procedures, and for the flag state (IRI) to consider proposing changes to IMO codes and regulations.
Nautilus professional and technical officer David Appleton commented: 'This long-awaited report makes depressingly familiar reading. Yet again, seafarers have lost their lives because of catastrophic structural failure of an ageing, inappropriately converted vessel.
'Whilst we agree with the recommendation that IRI approach the IMO to address shortcomings regarding survivability of bulkers in respect to flooding of wing tanks and liquefaction of cargo, tinkering with regulations that will not apply to existing vessels will not solve the problem. It is about time these death trap vessels were consigned to the scrapheap.'
Meanwhile, Intercargo’s annual bulk carrier casualty report highlights the need for flag states to make 'timely' submissions of accident reports to the IMO – pointing out that reports on 23 of the 48 losses over the past 10 years have still to be produced.
'Lessons learnt from past incidents play an important role in determining where additional safety improvement is necessary,' it stresses.
The report says that while there are positive trends for bulker safety – and losses have been declining since a peak in 2011 – there is no room for complacency. Cargo failure and liquefaction continue as a major cause of bulker casualties and the most common cause of lives lost, Intercargo warns.
In the past decade, it adds, 101 seafarers died because of cargo-related failures – on six bulkers carrying nickel ore from Indonesia, two with laterite (clay) iron ore from India, and one with bauxite from Malaysia.
Groundings were the most common reported cause of bulker losses – 19 of the 48 over the past decade – while six ships lost because of unknown causes claimed 61 lives. The average age of the 48 lost bulkers was 19.2 years.