13 March 2025

The Marine Accident Investigation Branch was notified of the collision of the Portuguese registered container ship Solong and the US registered oil tanker Stena Immaculate in the North Sea 14nm north-east of Spurn Head at the entrance to the River Humber. MAIB immediately deployed a team of inspectors to Grimsby to begin a preliminary assessment. 

MAIB has since been joined by representatives from the US National Transportation Safety Board, the US Coastguard and Marine Safety Investigation Authority Portugal. Having consulted with those flag state authorities, agreement has been made that the Marine Accident Investigation Branch will lead the safety investigation with Portugal and the United States acting as substantially interested states. 

The priority has been to allow the emergency services the time to undertake search and rescue operations, secure the vessels and assess the environmental impact.

While this work has been ongoing, MAIB’s enquiries have focused on gathering witness accounts and obtaining digital data. Once it is safe to do so MAIB will conduct a detailed inspection of both vessels and manage the retrieval of the Voyage Data Recorders (VDR) from both vessels.

The purpose of the MAIB investigation will be to establish the cause of events that led to this tragic accident, understand why it happened, and make recommendations to prevent similar accidents recurring.

From the initial enquiries made it is known that Solong frequently travelled between Grangemouth and Rotterdam and regularly used the route it took on the day of the collision. On Monday morning at 0130 UTC, Solong passed to the east of the Longstone lighthouse and altered course onto a heading of approximately 150° at a speed of about 16.4 knots. At 0947 UTC it struck the Stena Immaculate that was at anchor off the entrance to the River Humber. 36 crew from both vessels were recovered but tragically one member of crew from Solong remains unaccounted for.

As well as continuing to gather witness accounts, further investigation work will look to establish the navigational practices on board both vessels; the manning and fatigue management; the condition and maintenance of the vessels involved; and the environmental conditions at the time.