Atlantic 85
Atlantic 85 10th November 2006
When lifesaving charity the RNLI decided it wanted a high performance, four crew, radar equipped, inshore lifeboat that was also capable of 35 knots in extreme weather conditions, they approached SP as a supply partner for the project. With over 15 years experience in providing structural engineering and material packages for the RNLI’s fleet of all weather lifeboats, SP had recently established its prototyping facility designed to meet the increasing demand for cost effective parts production with a special emphasis on material development and process engineering.
The RNLI sourced and trialled a range of RIBS from manufacturers across the globe and put them to the test in severe weather conditions off the south coast of England. The Atlantic 75 model, which the RNLI was already using and will continue to do so with great success, outshone all the competition. As a result, it was decided the new four seater RIB would be a scaled-up version of the 75 – the Atlantic 85.
The brief was to provide a fast and efficient production process to assist the construction of a superior quality and light durable craft. Working with the RNLI, the development project would push the three critical areas of manufacturing; material science, manufacturing technology and tooling production methods.
Traditionally prototyping requires a collaboration of suppliers offering engineering design, materials supply and the actual manufacture of the prototype. A major benefit from the RNLI’s perspective was SP’s ability to undertake all three elements which simplified management of the project and ensured the project deadline was met.
SPRINT®, P-Foam Core-Cell® and Spabond 340LV were chosen for the construction of the Atlantic 85 as they offer a robust and reliable process with excellent laminate quality and the potential for greatly reduced production times. These materials allowed both the hull and deck to be produced in one-shot without the need to debulk at regular intervals. The first two boats were produced from glass with a carbon inner skin. This was changed to all carbon construction on subsequent boats and with the resulting increase in stiffness; the number of internal frames could be significantly reduced. Recent performance enhancements to the adhesive range meant the traditional tabbing of these frames was replaced by moulded flanges and a bond line using Spabond 340LV. The consequence of this work was a reduction in build time and secondly, a reduction in weight of some 200kg.
To simplify the build, attention was paid to the hull’s spray rails. This usually labour intensive process involves putting additional laminate and foam in the hull area to provide the toughness and durability that the spray rails would see in operation from slamming, planing loads and beaching. As this method however hinders a one-shot hull process, Gurit developed a mono component paste. The paste was gunned directly, void free, into the rails. The material design allowed the hull laminate to be immediately laid up and cured in one hit without the risk of an exothermic reaction occurring.
To ‘de-skill’ and reduce costs further, a complete materials kit was designed for the Atlantic 85. Both the SPRINT® carbon and the Core-Cell® high density foam were templated to determine the cutter path and then ‘nested’ into a cutting pattern to ensure optimum production rates were achieved and minimum material waste was produced. Each part was labelled and fibre orientation mapped to ensure that it was positioned correctly within the laminate stack. Using this kitting process significant savings were generated during the production process.
To ensure construction consistency and to further simplify the build, SP produced a Construction Guide which will be used by the RNLI’s sub-contractors during the final build programme. This 50 page pictorial guide includes detailed steps of the build, best practices, material processing and recommended cure schedules.
SP’s committed focus to the development of a simple manufacturing process resulted in an impressive production time saving of 70% when compared to the first Atlantic 85 prototype that was produced and an equalisation of material and man hour costs was achieved. These statistics highlight the fact that advanced composite technologies have moved away from predominantly specialist use and are fast becoming a more affordable and feasible option across the marine industry.
The first three Atlantic 85 prototypes have been put through their paces by the RNLI at The Lifeboat College, its state of the art new training facility in Poole, Dorset, and the crews have reported exceptional results. A further six boats have been produced by the Gurit prototyping facility and were delivered on schedule at the start of 2005.
