Shipbuilders’ and owners’ involvement in research projects, and thus a focus on the shipbuilding industry’s real needs, places emphasis on the most practical technology. Solutions are found faster than if research was done in isolation from industry, and are more likely to be cost-effective and realistic in a shipyard environment.
The British shipyard Vosper Thornycroft (UK) Limited, participates in the European research projects Bondship and Euclid RTP 3.21, both co-ordinated by DNV. The first is primarily concerned with the bonding of aluminium superstructures on civil vessels, while the Euclid project addresses naval applications of composite materials.
Vosper Thornycroft designs and builds vessels in steel, aluminium and fibre reinforced plastics (FRP). This ability to select appropriate materials for particular applications takes into account the need to achieve a balance between cost and performance. Working with such a wide range of materials also means it is important to sustain continuous effort in research and development, to maintain competitiveness at the forefront of naval technology.
We have been working in composite materials since the late 1960s, and we built the worlds first FRP ship, HMS Wilton, in 1972, says Alan Dodkins, who has been chief structural engineer at the yard since 1988. He manages the Structures Design Group, comprising 16 engineers, and is responsible for the structural integrity of all Vosper Thornycroft ships.
Experience in composites
Over the years the yard has built 11 Hunt Class mine countermeasures vessels and 15 Sandown Class minehunters. By the end of 2001, it will have delivered 30 FRP vessels. The companys role in the Bondship programme is to co-ordinate a work package to design and build a demonstration patrol vessel superstructure. Working closely with other industrial and research organisations, a wider role will be to develop design guidelines and production procedures, which will benefit the European shipbuilding industry in the future.
Vosper Thornycrofts input will encompass:
- Size of fabrications possible in a single bonding operation
- Handling of partially complete structures within the yard
- Requirement for jigs and tooling
- Accuracy control of joint geometry and 3D structures
- Surface preparation methods
- Shop climate control
- Practicality of post-curing methods
- Quality control and NDE techniques
- Special skills required of the workforce
- Bonding of dissimilar materials
We will be applying our collective experience with adhesively bonded aluminium and FRP structures to ensure that solutions are as reliable and cost-effective as possible, says Dodkins.
In the Euclid project, Vosper Thornycroft will be undertaking design and production engineering of joints, and fabrication of test panels and structures for testing by the other partners. The areas of prime importance are composite/composite and composite/steel joint design, and fire performance of composite structures. Such large test projects are an expensive undertaking for a single country in these days of shrinking defence budgets, so collaboration with other European NATO Alliance countries makes a great deal of sense and should avoid duplication of effort and re-inventing the wheel, Dodkins explains.
Vosper Thornycroft built the FRP-hulled trimaran Cable & Wireless Adventure, designed to DNV Rules, which in 1998 gained the record for circumnavigating the world by a powered vessel, with a time of 74 days. Another vessel, by far the world´s largest powered trimaran, RV Triton, was launched at Southhampton on May 6th this year.
Dodkins emphasises that shipbuilders and owners involvement in research projects is vital to ensure the results are achievable in practice. But it is equally important to the marine industry that classification societies have a central role in such projects. By being involved from the beginning, DNV has helped to assess any risks in the new technology and to gain approval for its application.