Global Response Maritime of the Netherlands has now completed the positioning of all twelve lifting chains under the wreck of the container vessel ‘Napoli’ off the coast of Devon, UK.

The lifting chains were put in place by a new subsea drilling system in less than three weeks. This marks the first total subsea use of the drilling system in an offshore wreck removal.

 

The drilling system employed consists of a 110-tonne subsea drilling module powering a remote-operated, transponder-guided drilling rod. The first lifting chain was pulled into place on withdrawing the drilling rod.

With all lifting chains in position, the main operational phase will commence in early May. Subcontractor Hapo, also of the Netherlands, will mobilise two 140-metre flat-top barges rigged with heavy mobile cranes, together with two support tugs. A series of 24 chain-pullers, installed on the flat-top barges, will be connected up to the lifting chains ready on location.

The two lifting barges will be moored parallel to ‘Napoli’s’ stern. When preparations for the main lift are completed, the barges will be ballasted down, to compensate for the forces acting on the pullers and reduce movement in the swell.

When the 'Napoli's' stern section has been lifted to the surface with the pullers, wreck sections of around 100 tonnes each will be cut and lifted onto the main decks of the barges, using the mobile cranes.

This work will progress until total weight is reduced to around 1,200 tonnes. At that point a decision will be taken on whether to lift the remains as one unit, or to continue to cut until the weight is within the capacity of the larger of the two deck-mounted cranes.