Concerns over the effectiveness of International Maritime Organization (IMO) measures to tackle the dangers posed by misdeclared and overloaded containers have been raised by the UK Marine Accident Investigation Branch (MAIB).
In its report on an incident in which the UK-flagged vessel Ever Smart lost 42 boxes overboard in the North Pacific in 2017, MAIB highlights the failure to stow or secure containers in compliance with the cargo securing manual (CSM).
Investigations showed that more than 36% of the boxes in the bay were outside the generally accepted verified gross mass (VGM) error limit of 5%.
'Of concern is that the VGM system was introduced to improve safety by assuring ships' masters that the weights of containers loaded were accurate,' MAIB said. 'The ship was carrying 3,533 containers; if the weight survey of the bay 70 containers is extrapolated to the whole cargo of 3,533 containers, 1,286 of them would have been outside of the 5% variance limit.
'In this case, mis-declared container weights of Ever Smart's bay 70 cargo inspection, the comparison between VGM declarations and actual weights, does not promote confidence in the process envisaged by the IMO,' it adds.
The stow collapsed as the 7,024TEU Ever Smart encountered winds up to force 8 and wave heights of up to 6m while sailing from Taiwan to Los Angeles in October 2017. Of the 151 containers in the stow, 42 were lost overboard and 34 were damaged.
MAIB concluded that the collapse was probably caused by a failure of the lashing system or a container structure. Investigators found that the stowage plan developed by shoreside staff failed to comply with the vessel's cargo securing manual, and the container weight distribution was not in accordance with the stack weight tables, hi-cube containers were loaded eight high in the outer stacks of the stow, and the ship's metacentric height (GM) exceeded the recommended full load GM – all increasing the risk of lashing system failure and stack collapse.
Shortcomings in lashings were also a key factor in the incident. Wind lashings in the outer stacks of six bays had not been applied, several lashing rods were found to be loose, lock nuts had not been applied to many of the lashing rod turnbuckles, and some twistlocks were heavily corroded.
'The maintenance of twistlocks by the ship's crew was problematic as they were in constant use,' the report notes. 'It was only when the ship had little deck cargo, or when Ever Smart was in dry dock, that the crew had the time necessary to carry out effective inspections.
'The maintenance of lashing equipment is critical to the secure stowage of containers on deck, and every effort should be made to ensure the equipment manufacturer's guidance is followed.'
MAIB said non-compliant and out of tolerance stows on the scale evident onboard Ever Smart are not uncommon and warned it is extremely difficult, if not impossible, to meet or match the stowage plan and weight distribution examples provided in CSMs.
'Regardless of the logistical and commercial challenges faced by the container shipping industry, the guidance provided in a ship's CSM and the warnings given by its loading computer should not be ignored. Ships' masters and C/Os might be able to identify and rectify isolated cargo stowage plan issues, but it is impractical to expect them to address large scale problems such as those identified in this report due to the potential commercial impact such interventions would have. The onus should be on the shore planners to deliver compliant and safe stowage plans.'
The report recommends the Evergreen Marine Corporation to improve the standards of stowage plans produced ashore, knowledge of the dangers of bow flare slamming and lashing gear maintenance management.