Specialising in the supply of custom and semi-custom tenders to superyachts, the Isle of Wight, UK, based company Superyacht Tenders produces a range of ribs and tenders that focus on fire protection, functionality and performance. To help achieve this, the company asked SP, the marine business of Gurit, to provide a package of materials to cater to its requirements.
In order to achieve a seamless performance, SP – known for offering turnkey solutions for the build of performance boats – provided the composite materials to help create a new Lloyds tested superyacht tender compliant with the requirements of the UK Maritime and Coastguard Agency (MCA).
Working in partnership with SP, the team at Superyacht Tenders manufactured the hull using a combination of engineering materials which included SP’s ST70FR and Ampreg 21 epoxy wet laminating system, polyvinyl chloride (PVC) core, and glass reinforcements.
Fire retardant material
ST70FR, a fire retardant hot melt SPRINT®, was SP’s essential component in the development of the engineering solution as it is ideally suited to the manufacture of laminates requiring fire protection. SPRINT materials consist of a layer of fibre reinforcement either side of a precast, precatalysed resin film, with a light tack film on one face. Unlike conventional prepregs, SPRINT fibres remain dry and unimpregnated by the resin until the curing process.
ST70FR is capable of producing very high quality, low void-content components from a low cost vacuum bag/oven curing process and offers excellent mechanical performance on glass fibre reinforcements. It is known for its good handling characteristics and breathable nature. It was selected as being the most fire retardant of SP’s structural epoxy systems with the most external fire testing certification. Unlike other products, structural mechanical properties and panel weights are not unduly compromised by the incorporation of fire retardancy.
Setting ST70FR apart from most fire retardant epoxy systems is the fact that it does not use halogens such as chlorine or bromine to put the fire out. Whilst halogens can be very effective fire retardants, there is a major downside to the way they put out a fire, as highly corrosive hydrochloric acid or hydrobromic acid vapour may be liberated. These corrosive fumes are extremely dangerous to inhale. The SPRINT format results in high-quality, low-void content laminates, has low smoke toxicity, is self extinguishing and halogen-free.
Passing the test
To achieve Lloyds and MCA compliance the craft had to successfully withstand a series of demanding tests, including fire testing, being swung against a dock, drop tested from 3 m, and swamp tested.
“The handling and processing qualities of ST70FR made it ideal for the manufacture of the MCA Compliant Superyacht tender, while using Ampreg 21 delivered significant benefits in our production with reduced build times and good health & safety characteristics,” says Paul Jennings, MD of Superyacht Tenders Ltd.