State of the Art
Steel and partly aluminium are the dominating solutions for RoRo decks. Innovative lightweight steel and steel-plywood decks are occasionally applied at small scale, primarily for liftable (intermediate) decks which do not contribute to global strength. Non-metallic composite sandwich deck panels in a steel frame structure, and few prototype applications at small scale and only one at a large scale (M/V Siem Cicero) exist. Assembly and outfitting processes are largely manual and not adapted to larger economy of scale.
Objective
Reduction of the weight of the strength decks with increased flexibility in the ship design due to modular system. Optimising the deck structure design using innovative materials and geometry results in more efficient production as well (shorter lead times, improved reliability, and quality).
Solution
The solution is a system for cargo decks based on standard lightweight panels and metallic or pultruded (composite) beams – including corresponding joints and outfitting elements (lashing devices, lifting elements etc.). Within the project, a FRP (fibre-reinforced polymer) pultrusion profile was installed in the top three decks of a car carrier which cover 12600 m² area. The deck arrangement consists of the composite module supported by a steel grillage system. The FRP pultruded profile production preparation activities were performed including the definition and production of the forming dye, preparation of the production facilities, and the FRP pultruded profile production. Several test arrangements are performed to qualify the pultrusion profiles as deck structure, including bonding test, small scale fire test, full scale fire test and mechanical tests. Further, demonstrator tests are planned. The target is to achieve an optimum between weight and payload, and production cost at reduced production lead time and reduced maintenance (corrosion).
Potential
There are several thousand m² of cargo decks in typical RoRo ships, the mass of which can be further reduced. The solution can be applied in other shipyards as well as in deck plating for offshore or civil (land based) applications, e.g. bridges. Using synergies and standardisation potential together with RAMSSES component demo cases, the application potential can be further increased.