MAIB investigation report 9-2021: Stolt Groenland

Summary

On 28 September 2019, a cargo tank containing styrene monomer on board the Cayman Islands registered chemical tanker Stolt Groenland ruptured due to runaway polymerisation. The catastrophic rupture released a large quantity of vapour to the atmosphere, and it subsequently ignited. 

Fire-fighting efforts by the emergency services took over six hours and involved more than 700 personnel and 117 units of fire trucks, pumps and fire tugs.

 Safety Issues

·         the styrene monomer was affected by other heated cargo tanks

·         heat transfer from other cargoes was not fully appreciated

·         the styrene monomer temperature was not monitored

Recommendations

A recommendation (2021/122) has been made to Stolt Tankers B.V. aimed at ensuring the wider marine chemical sector benefits from the lessons learned from the Stolt Focus incident and research initiatives that were carried out as a result of this accident.

The Internantional Chamber of Shipping and INTERTANKO have been recommended (2021/118 and 2021/119) to promulgate our report to their members.

Recommendations (2021/117, 2021/120 and 2021/121) have also been made to the Cayman Island Shipping Registry , the Chemical Distribution Institute and Plastics Europe (Styrene Producers Association). These are intended to assist in ensuring that the guidance provided in certificates of inhibitor and styrene monomer handling guides is consistent and achievable given the limitations of equipment and testing facilities on board ships.

Full report at,

https://assets.publishing.service.gov.uk/media/60f93e2cd3bf7f044c51590b/2021-09-StoltGroenland-Report.pdf

Grounding of ro-ro freight ferry Arrow

At 0727 on 25 June 2020, the Isle of Man registered ro-ro freight ferry Arrow grounded in thick fog while entering Aberdeen Harbour. During its port approach, a pilot exemption certificate (PEC) holder provided by the vessel’s charterer was navigating by radar and steering the vessel.

The vessel encountered the thick fog a few minutes before it entered Aberdeen’s 70m wide Navigation Channel, and with limited support from the bridge team, the PEC holder became overloaded. Consequently, while attempting to correct a deviation to the north of the planned track, he over corrected to the south. The over-correction was not noticed by the bridge team in time to avoid the grounding.

After grounding, the vessel began to list significantly in the falling tide. After confirming no water ingress into the hull, with the assistance of a tug, the master used Arrow’s engines and bow thruster to refloat the vessel. There were no injuries or pollution but there was significant damage to the hull.

Safety issues

·   Arrow’s bridge team was not fully prepared for pilotage in restricted visibility. There was no effective shared mental model of the pilotage plan and the vessel’s progress along it.

·   The level of support provided to the PEC holder by the bridge team was poor.

·   Navigation techniques used did not provide Arrow’s bridge team with an accurate view of the available safe water in the Aberdeen approach channel.

·   Poor bridge ergonomics and limited electronic chart system capabilities meant that the PEC holder was navigating by use of radar alone.

 Full report may be read at

https://assets.publishing.service.gov.uk/media/60dc6b66e90e077176c20127/2021-08-Arrow-Report.pdf

https://assets.publishing.service.gov.uk/media/60dc6ba0d3bf7f7c389ab2c0/2021-08-Arrow-Annexes.pdf