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Could Titanium in Ship Hull Construction be Cost Effective?


Delegates who attended a workshop to discuss and examine the potential use of titanium structures in ships concluded that not only is it possible to construct a ship hull from titanium, but that it could also be cost effective.


The Office of Naval Research recently sponsored a workshop which was hosted by the University of New Orleans, where an ONR research program on titanium in ship structures is being conducted. Delegates consisted of representatives from the shipbuilding industry, titanium suppliers, Navy, Coast Guards, Air Force labs and academia.


Steel is the primary material used to fabricate ships today, followed by aluminium and composites. However, the workshop attendees decided that although titanium is more expensive (on a pound for pound basis), its excellent properties contribute to lower the total ownership costs


(TOC) throughout the life of the ship.


Titanium offers a higher strength to weight ratio, offering a 40 percent weight saving in comparison to steel. Lightweight designs can lead to increased payload capacity, reduced fuel consumption and reduced carbon emissions. Its lower magnetic signature reduces the use of heavy, power-consuming degaussing coils to protect against magnetic influence mines. In addition, titanium has a high resistance to corrosion in seawater, so is a cost effective solution for sea water piping systems such as cooling water.


8 The National Metals Technology Centre Quarterly Journal Fabrication


Nevertheless, further research is required to develop high- productivity welding processes for ship construction. Titanium welding is a well established process, however, current process are too slow for the miles of welds needed for ship


hull construction. Despite this, the UNO investigation has highlighted the potential of advanced metal inert gas (MIG) welding and friction stir welding for this application.


“Titanium is highly reactive at elevated temperatures and requires shielding of the molten


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