Divinycell HM foam by Diab is being used to construct the Mayla 44, a new ultra-high performance electric power boat currently in build at Nova Mare, the marine division of Nova Composites.
Due to launch in early 2023 in Dubai, the Mayla 44 blends classic styling elements with a state-of-the-art composite construction and electric drivetrain. Designed around the patented Petestep hull technology, the Mayla uses uniquely shaped deflectors to push water downwards and to the stern of the yacht, generating energy savings of up to 35% as well as reducing slamming and increasing passenger comfort.
Even with its novel hull design, the Mayla 44’s 70knot plus top speed required an extremely lightweight construction in the form of a carbon fibre full-sandwich composite structure. With outright weight reduction a priority, Diab supplied Divinycell HM 80 and 130 cores in a range of thicknesses for the deck, internal structure and the complete hull surface including the hull bottom. Epoxy prepregs from Nova’s sister company Notus Composites will be combined with a range of woven, stitched multiaxial and unidirectional carbon fibre reinforcements on either side of the Divinycell HM cores.
Divinycell HM cores have been extensively evaluated in previous Nova projects, with the company also completing a programme of mechanical testing to validate the properties of the new Mayla 44 laminates. In-house composite tooling produced from CNC milled master plugs has been perfected and the NOVA technicians are scheduled to begin prepreg lay-up and positioning of the first Divinycell core sections in November.
“Divinycell HM core is a great fit for our prepreg process. Not only do we get the high toughness and mechanical properties we need for such a fast vessel, but HM foam also provides excellent bonding with our prepreg resin films, minimal resin uptake and trouble-free processing during our low temperature cure cycles,” added Oliver Janaranjana, operations manager, Nova Mare.
Divinycell HM is a high-performance structural core designed specifically for fast marine hulls such as the Mayla 44, where higher toughness is required. It combines a very high shear strength with outstanding shear elongation. As a result, Divinycell HM is an extremely tough product, capable of absorbing the high dynamic impacts and slamming loads generated by modern high-speed craft. Its elongation exceeds the requirements of ISO 12215, GL and ABS rules, allowing engineers to create lighter structures without compromising strength or safety.
“We believe that truly sustainable yachts are only possible with radical weight reduction,” comments Christopher Gelsdorf, co-Founder of Mayla Yacht. “The lightweight prepreg carbon fibre sandwich construction we use for the Mayla 44 enables a hull weight of only 1.35T (versus more than 4T for traditional high-performance yachts) creating less resistance and less drag. Diab’s Divinycell HM was fundamental in enabling those weight savings.”