To meet stringent offshore vessel standards, only materials and processes that have been fully approved by Det Norske Veritas AS (DNV) and Bureau Veritas (BV) are used in the production of CTruk’s multi-purpose composite marine craft. This includes Scott Bader’s Crystic Crestomer® 1152PA urethane acrylate structural adhesive, which is specified by CTruk for all FRP bonding.
To further reduce weight, increase productivity and cut labor costs, CTruk uses a structural adhesive where possible for FRP-FRP joint bonding in its designs. Scott Bader’s Crystic Crestomer 1152PA is specified in all CTruk composite marine craft for structural bonding in of hull stringers and bulkheads, transom sections, engine beds, deck sections and for hull to deck joints.
Jim Cutts, CTruk’s Director of Engineering commented: “As we manufacture vessels to full marine classification, the company must use materials that have gone through rigorous type-approvals. The CTruk design team only specifies proven products that are known to meet DNV and BV requirements with reliable and consistent results.”
According to CTruk, depending on the application area and vessel specification, most FRP joints must also be over-laminated. However, as saving weight and production costs are key objectives, the CTruk design team is constantly looking to identify any new areas where it is possible to only bond with Crestomer.
Seb Shillaker, Head of Production, explained: “Whilst most of CTruk’s construction applications for Crestomer 1152 include an over-laminating procedure, we do also use purely bonded connections in a number of areas, such as some structural flanged connections. This gives us clear advantages, with savings on labor, materials and a lower overall vessel weight.”
Optimizing safety with performance is critical and so the CTruk design teamuse Finite Element Analysis (FEA) to ensure that hull and deck structures meet rigorous strength criteria and comply with the relevant class specifications.
CTruk has obtained approvals for certain FRP bonding only application areas, so that in the current craft build specifications the main deck beam, in spite of it being a high impact area, is now also joined only using Crestomer 1152PA structural adhesive, as well as some of the hull and deckhouse structural flange connections.
SC Falcon, which successfully completed sea trials in February 2014 and which is now in service, is the most recent CTruk offshore wind farm support vessel (OWSV) to be designed and fabricated using advanced composite materials and Crystic Crestomer bonding technology.
Press Release, May 7, 2014, Image: volvopenta