Maersk Honam incident report

AN EMERGING HAZARD

INCIDENT REPORT • REGULATORY CHANGES ARE BEING ADVISED AFTER THE MAERSK HONAM INVESTIGATION POINTS TO IMPROPER CLASSIFICATION OF SDID

THE DISASTROUS FIRE aboard the containership Maersk Honam on 6 March 2018, which caused the deaths of four crew members and left one missing, was most likely caused by the spontaneous self-decomposition of a large consignment of sodium dichloroisocyanurate dihydrate (SDID), according to a report into the incident by the Transport Safety Investigation Bureau (TSIB) of the Ministry of Transport, Singapore.

The ship, carrying 7,860 containers, was en route from Singapore to the Suez Canal when the fire broke out when it was in the Arabian Sea, some 900 nm west of the Indian coast. As the fire took hold, the crew attempted to fight it by boundary cooling and the release of carbon dioxide into the cargo hold, but these attempts failed and the crew abandoned ship less than three hours after the first sign of fire.

TSIB subsequently engaged Dr JH Burgoyne & Partners to undertake a very thorough inspection of the vessel, once it was secured and moored off Dubai.

Due to the nature of the incident and the severe fire damage to the ship, it has proved impossible to determine with certainty what caused the fire to break out. However, it started in a hold that had 54 containers of SDID, as well as 11 containers with dangerous goods of Division 5.1. The crew all reported smelling chlorine and their boiler suits were bleached, strongly suggesting that a chlorine compound was involved.

RULE OUT THE IMPOSSIBLE The investigation team considered other causes. It was thought unlikely that another dangerous cargo had been misdeclared: there was no evidence found during the forensic examination of the hold where the fire started of anything that would indicate another source. The crew had not noticed any smell indicating combustion and no black or grey smoke was seen during the initial phase of the incident. The investigation team also ruled out the possibility of an electrical fault or that the heated fuel tanks had caused the fire.

TSIB says that the most likely explanation is that the integrity of the SDID consignment, carried in block stowage, had been compromised and that the heat generated by spontaneous self-decomposition worsened.

Although the crew demonstrated “good efforts” to take care of each other during the emergency, TSIB notes that the fire alarm was not raised at the onset of the fire, which led to a delay in the closure of magnetic fire doors in the accommodation block, immediately aft of the fire, and exterior ventilator vents. As a result, toxic smoke spread through the accommodation areas.

HAZARDS NOT RECOGNISED TSIB also looked at the current classification of SDID, which has a chlorine content of 56 per cent, under the International Maritime Dangerous Goods (IMDG) Code. Shipping SDID under UN 3077 environmentally hazardous substance, solid, nos, in Class 9, permitted by special provision 135, does not properly reflect the potential secondary hazards of decomposition and instability, its report says. SDID displays similar chemical properties to some substances assigned to Division 5.1.

In particular, the lower chlorine level in SDID compared to dichloroisocyanuric acid, assigned to UN 2465, Division 5.1, may have been deemed less risky when it was added to the IMDG Code. Test results for SDID, which formed the basis of its classification, had been derived from relatively small package sizes; in the Maersk Honam incident, the SDID was packaged into flexible intermediate bulk containers (FIBCs), each with around 1 tonne of product. In effect, this created a block of containers, each with around 20 tonnes of SDID, amounting to a cuboid of more than 1,000 tonnes.

As with the earlier problems encountered with calcium hypochlorite, it would appear that packing SDID in large volumes has the effect of lowering the temperature at which self-accelerating decomposition can occur; this can be further affected by moisture or impurities, Burgoyne thinks. In certain circumstances, the report says, this temperature can be as low as those that might reasonably be expected to obtain in a ship’s hold in hot weather, as might easily be encountered in the Arabian Sea. It is likely that the decomposition reaction began well before the fire broke out.

ACTION NEEDED The report includes a call for action: “As such, the investigation team deems that there is merit for SP 135 to be reviewed for the carriage of SDID and its secondary hazard to be addressed in such a review.” A relevant submission to the International Maritime Organisation’s (IMO) Subcommittee on the Carriage of Cargoes and Containers (CCC) should be considered at the earliest opportunity.

TSIB makes a direct comparison with calcium hypochlorite, saying that carriers should adopt similar requirements, as recommended by the Cargo Incident Notification System (CINS) and to consider stowing SDID on the weather deck and away from direct sunlight, so that water-based firefighting equipment can provide a better response in the event of a fire.

TSIB also notes that, even if the SDID was declared as a Division 5.1 substance, there would have been practical challenges to fighting the fire; the appropriate response would be to flood the hold with abundant water, as recommended by the IMDG Code’s Emergency Schedules (EmS), but this would have required cutting holes in the hatch covers. It is difficult to imagine how this would have been done, especially at night, and would in any case have been contrary to the EmS recommendation of moving crew away from the fire.

TSIB is aware that there are no statutory requirements for cargo holds to be fitted with water-flooding systems and calls for the International Convention on the Safety of Life at Sea (Solas) to be reviewed in this respect, particularly has containerships have become larger in recent years. It also notes that some classification societies have, since the Maersk Honam fire, developed standards and guidance on the installation and use of such firefighting system.

CONCLUSIONS AND RECOMMENDATIONS Since the fire, operator Maersk Line has made some operational changes, in particular by banning the stowage of IMDG containers immediately forward or aft of the accommodation block and engine casing. It has also made changes to fire drill procedures, firefighting procedures and the current training programme. In addition, it has strengthened its in-house IMDG acceptance procedure, focusing on safe stowage, and developed a scanning tool to improve the detection of undeclared or mis-declared dangerous goods. Maersk may also make technical design changes on future newbuildings, particularly in the area of fire protection and response in cargo holds.

Singapore, as the flag administration, has also recognised that existing fire protection, detection and extinction arrangements on containerships can be inadequate. In February 2020, in collaboration with the Marshall Islands registry, the International Association of Classification Societies (IACD) and the World Shipping Council (WSC), it submitted a paper to IMO’s Marine Safety Committee urging the evaluation of existing arrangements and a possible amendment of Solas and the Fire Safety System (FSS) Code, to include goal-based standards.

TSIB’s extensive report ends with recommendations for Maersk Line and for the flag administration. One of those urges Maersk to work with CINS or other organisations to produce guidelines for the safe carriage of SDID, recognising its primary and secondary hazards and in light of SP 135. Singapore is urged to consider submitting a paper to IMO or the UN Sub-committee of Experts on the Transport of Dangerous Goods, requesting a review of SP 135 and consideration of classifying SDID under Division 5.1.

The TSIB report can be downloaded here: www.mot.gov.sg/docs/default-source/defaultdocument-library/final-report_mib-mai-cas035---fire-on-board-srs-maersk-honam-on-6march-2018.pdf.

THE DISATROUS FIRE ABOARD MAERSK HONAM HAS

RAISED QUESTIONS ABOUT SDID; THE SHIP HAS SINCE

BEEN REBUILT USING THE SALVAGED PORTION OF