OS 35 Update – New timeline and revised methodology for wreck removal - 294/2023

OS 35 Update - New timeline and revised methodology for wreck removal

The Captain of the Port, John Ghio, has received an updated timeline and revised method statement from the contractors on the preparations and plans for the final removal of the OS 35 wreck.

Updated timeline

The wreck removal process will be methodical and deliberate, and will involve a variety of intricate operations.

Both the forward and aft sections will first be made airtight. The contractors have advised that these preparatory works are taking longer than anticipated and that the wreck is unlikely to be totally removed by the 30th May deadline.

The aft section will then be floated out by re-establishing buoyancy, with a provisional date for this operation set for the 29th May. Contractors expect to be in a position to begin the operation to lift the forward section using barges on 2nd June.

The total removal of the wreck is now projected for the 16th June. Whilst this short extension to the timeline is unfortunate, it is vital that these processes are completed properly in order to ensure that the wreck is lifted safely and with minimal environmental impact.

Establish airtight seals

Lifting points have already been fitted to the hull of the forward section, and the lifting tools onboard the barges are ready for use. Extensive preparatory works are currently underway to make all compartments on the forward section airtight. This requires an experienced team of divers, who are working to maximum capacity to seal and test the compartments. Airtight compartments will help to lighten to lighten the load that needs to be lifted. As soon as it is confirmed that the forward section is airtight, divers will begin to seal all compartments on the aft section.

Lifting operations

The aft section will be refloated first by re-establishing buoyancy, in a reverse of the process used to lower it to the sea bed. This will be followed by the forward section, which will be physically lighted from the seabed using the lifting points. Once it is clear from the sea bed, additional chains will be passed under the hull to reinforce stability and provide further control to the lifting process.

Each section will be brought alongside the semi-submersible barge before being lifted out of the water.

These stages of the operation carry the greatest risk of the release of oil residues, an unknown quantity of which remains trapped within the hull and may escape during the refloating and lifting processes.

Detailed oil spill response plans

The Gibraltar Port Authority are working closely with Koole and the Department of Environment to finalise detailed tactical oil spill response plans for the refloating and lifting operations to minimise the impact on the start of the bathing season as far as possible.

Containment booms will be placed around each section of the wreck individually so that any escape of residues can be dealt with as soon as possible. Whilst this can't guarantee absolute containment, detailed contingency plans are also in place to mitigate the impact on the environment, including the potential deployment of preventive booms at Catalan Bay and Sandy Bay, and of a deflection boom at the Eastside Reclamation.

The Gibraltar Port Authority has ensured that the contractors will have enough oil spill response assets on site to deal with any potential release of oil, with the GPA providing backup resilience only. In this way, a closure of the Gibraltar Port in the event of an oil release is not anticipated. However, contingency plans are in place to scale down Port operations if necessary.

The Department of Environment will increase their patrols both on land and at sea during the refloating and lifting operations, with a rapid response plan for any potential release of oil.

Wreck removal process progressing well

The Captain of the Port, John Ghio, said: 'The works to remove the OS 35 are progressing well, but the reality of the state of the wreck is dictating the pace of operations. It is vital that every stage is completed in a way that is careful, deliberate and safe. Whilst the short delay for its final removal is unfortunate, this is the only safe way to do so that mitigates the potential future source of pollution and minimises the impact on the environment and Gibraltar's coastline. I'd like to take this opportunity to thank the public for their patience throughout this extremely complex and delicate process.'

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