Following a successful test, the project team, led by Global Response Maritime, the Netherlands, has completed positioning all twelve lifting chains under the wreck of the container vessel MSC Napoli to remove the stern section. The chains were put in place by a revolutionary subsea drilling system. More pictures can be found in this https://www.swzonline.nl/fotoverslag/9[photo album].
The twelve lifting chains were put in place in less than three weeks. This marks the first successful, totally subsea, use of the drilling system in an offshore wreck removal.
The drilling system employed consists of a 110 tonnes subsea drilling module powering a remote-operated, transponder-guided drilling rod. The first lifting chain was pulled into place on withdrawing the drilling rod. The drilling and positioning of the lifting chains was subcontracted to a joint-venture consisting of Belgium company DISA, specialists in subsea works based in Beerse, and drilling technologists Gebr. Van Leeuwen Boringen of Harmelen, in the Netherlands. Another subcontractor, Hapo International Barges, has mobilised the crane barge Missing Link, now acting as the main surface platform for the project team.
Operational Phase
With all lifting chains in position, the main operational phase will commence in early May. Hapo will mobilise two 140 m 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 MSC 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 MSC 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 1200 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.
MSC Napoli
The MSC Napoli stranded off the Devon Coast on 18 January 2007 in heavy seas. An article on this incident recently appeared in SWZ Maritime of March 2009.
Picture on site by Pim Korver Film + Video. More pictures can be found in https://www.swzonline.nl/fotoverslag/9[this photo album].
