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| RMS Titanic was 100 years ago.... |
Weekend press speculation that the Costa Concordia will be floated by placing a series of deflated airbags underneath the wreck, and then inflating them has been questioned by cruise industry commentator Julian Bray from the UK
Bray points out in a new presentation to a marine business think tank, that the centre of gravity of modern cruise ships (the Costa Concordia was launched in September 2005) is set at around Decks three/four boat deck level which has clear access points from side to side of the submerged structure.
The current positioning of the wreck resting on a rock ledge or outcrop means that the bags could only be inflated against the lightweight upper decks (the Costa Concordia was launched in September 2005), and the superstructure of the Costa Concordia above the current waterline is made of lightweight materials such as aluminium, plastics, and fibreglass compounds.
The upper decks, and superstructure clearly not designed to be substantially lateral load bearing. By simply pumping out fuel oil, and making a few compartments watertight, Julian Bray suggests will be an astronomically expensive proposition with little chance of being successful, and will only marginally shift the centre of gravity from the upturned base as cruise ships unlike cargo vessels, do not have wide open spaces inside the hull to take flotation bags.
However learning lessons from another Italian landmark, the righting of the Leaning Tower of Pisa, successfully completed by British engineers using a cantilever principle. Bray is suggesting the retro fitting, in sections, of a series of initially near upright outrigger box section beams welded to and, projecting from side to side of the existing floor pan of deck four, and when fully constructed in sections by crane barges, the cantilevers, eventually towering some five times above the width of the ship.
Using gravity and the series of outrigger beams as giant cantilevers, and having buoyancy tanks fitted the length of the topside of the projecting upright beams; as the outrigger beam cantilevers are lowered into the sea, as the result of gravity assisted by weights (loads) plus cables connected to anchored winches, and weight added, piece by piece, to the upperside of the serie of cantilevers, (the cables being clamped to the tip of the outrigger beam cantilevers), the wreck can be returned to the uipright position and the centre of gravity literally exported or moved from within the hull of the wreck and spread to the whole area of the now sea facing level array of horizontal buoyancy supported beams.
Further Weight (loads) would then be applied to the uppersides, in effect a giant cantilever operation, and before complete removal further bouayncy aids attached to the projecting box section beams
Clearly the fixing points for the beams would have to be retro welded/clamped in place but that would be the only substantial retrofitting physically on the wreck, thus minimising the possibility of the wreck moving off its existing perch. In effect the whole recovery process and fixtures could be manufactured, possibly in the Fincantieri Italian Shipyard, where they will have all the original computer modelling for the Concordia Class of cruise ships.
The gash in the side of the wreck would be covered and secured by a custom made sectioned Kevlar skin which would externally mimic in engineering terms, the current buckled and misshapen hull section, and held in place by industrial fixatives and pressure pumped in buoyancy materials behind the skin. © Julian Bray 2012
Media comment with attributuion welcome, design sketches available
Contributor: Media, Aviation, Politics & Travel Expert, Broadcaster Julian Bray UK Landline: 01733 345581 Mobile: 07944 217476 ISDN2 downline +44(0)1733 555 319 (B'cast ISDN Remote Studio) G722/APT-X Dual Codecs Glensound C5
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