HOW IT’S MADE – Multi50 Arkema 4 trimaran
The construction of the Multi50 Arkema 4 started in September 2018, and the brand new boat was launched in the water in September 2020. This shipyard of almost two years gave birth to a trimaran with an innovative design, particularly powerful and ergonomic, for both crewed and single-handed offshore races.
Arkema 4, Quentin Vlamynck’s new Multi50, has hit the water in September 2020
The Multi50 is the result of close and intense technical collaboration between the Arkema Group and Lalou Multi, partners for now 8 years. With recyclable resins, new adhesives, clean energy…, many innovative materials and technical solutions complement bold architectural choices.
A new philosophy in boat design
Designed by marine architect Romaric Neyhousser, Arkema 4 is the result of a new rationale, shared with Lalou and Quentin Vlamynck, skipper d’Arkema 4, which transpires in the boat’s design.
Romaric Neyhousser, Architect of Arkema 4:
“Thanks to feedback from the former Arkema 1, Lalou Multi and his sponsor-partner Arkema have laid down a new framework. The first trimaran built by Lalou Multi was based on a short-handed crew at sea. This new boat Arkema 4 has less typical features, is more versatile and more efficient for the crew as well as inshore. This has guided the choices regarding the platform, in particular for the “X” crossbeams (not parallel beams) used to optimize the ergonomics in crew sailing.”
Arkema 4 new platform, which used a “X” crossbeams (not parallel beams) to optimize the ergonomics in crew sailing
The aim was to build a more versatile boat than the Arkema 1, in other words just as effective in in-shore crew events as in solo ocean racing. They have put much thought into the masses and improved the aerodynamic brakes.
In this way, they reduce the aerodynamic drag as much as possible, even more than on the other Multi 50. The objective is to profile all the shapes that produce drag, in particular for the crossbeams, but also to work on the sheet effect of the sails. The fairing adds weight, but they believe that the resulting gain will offset this additional weight.
Regarding the skipper-focused ergonomics, there are many differences with the previous Arkema 1. The boat’s design makes it more versatile, but it must also enable the sailors to keep up the pace in all types of events, whether in crew sailing, solo sailing, in-shore or on the ocean. The cockpit offers greater protection in particular.
Arkema 4 offers greater protection for sailors than its predecessor,
with a headroom of 1.65 m high, some protected grinders, and a ~6 m2 sheltered from heavy seas
How it’s made: The construction of Arkema 4
As in the past, this new Multi50 is the result of intense technical collaboration between Arkema and Lalou Multi. With recyclable resins, new materials, 3D printing of technical parts, clean energy, many features are indeed driven by innovation, and others will remain flexible throughout the sporting life of Arkema 4. Quentin Vlamynck was naturally heavily involved in the construction of Arkema 4, as the skipper of the boat.
Quentin Vlamynck, skipper of the boat points out:
“We are using this building project to draw up an inventory of all Arkema materials that can prove beneficial to our boat’s performance but also the Class as a whole. I also know it’s vital to be as close as possible to the construction work and be able to incorporate my technical choices in consultation with Lalou, Nicolas Coudrais from the design office, and Romaric Neyhousser, the architect. The philosophy of Lalou Multi is precisely to keep the skipper involved in the strategic choices.”
1. Sails
Signed Incidence, closely involved with the Arkema 4 project since Pierre-Antoine Morvan, Match Racing European Champion and Technical Manager for Incidence sailmakers, will be the tactician for the Grand Prix. The gennakers, J2 and J3, are cable-less, therefore do not have any tension cable: the leading edge is thinner and the void better distributed.
Pierre-Antoine Morvan, Head of R&D at Incidence Group explains:
“It’s a sail without halyard, in DFi®, with many novel features. The major asset of the Strong Luff, as its name suggests, is the performance of the luff, but also a significant improvement in overall performance. It’s lighter, more versatile and more dynamic.”
Arkema 4 used a sail made by Incidence Group, without halyard, in DFi®, with many novel features.
In order to extend the innovation of this new sail, Lalou Multi has decided to go ahead with manufacturing various fittings for these sails from the Elium®/carbon developed by Arkema. There are two highly specific fittings called lugs used to hold these sails. These are triangular aluminum parts measuring about 10 cm² with head and tack that literally secure the sail. Their initial weight was around 250g. Made from the Elium® resin, they are are now lighter, around 110g, with softer contours, and recyclable. In addition, they are now able to resist a force of 3,5 tonnes, in other words they are able to lift on her own the entire Arkema 4 trimaran.
Lalou Roucayrol has been testing equipment for sailmakers Incidence for years. The boat was fitted with a test sail – a Strong Luff gennaker – in the Grands Prix of the 2019 season and during the training sessions. The trials were clearly conclusive.
Want to discover how reinforced fibres sails are made ?
Read this other story made by JEC Composite Media team, and learn how reinforced oriented fibre sails are made. Three different types of membrane sails are highlighted in this news: the D4, the DFi, and the DF panel, all made by Incidence Group company.
2. Deckhouse / cockpit:
Completely recyclable and made entirely of composite based on the recycled Elium® resin. Approximately 80 cm lower than on the other Multi50s, the cockpit allows for sheltered maneuvering. For superior visibility whatever the sea conditions, cockpit and deckhouse are fitted with Altuglas ShieldUp® Flex® PMMA glazing, the first flexible sheet recently developed by the Arkema subsidiary Altuglas International. This material’s flexibility makes it easy to install without thermoforming over substantial contours. This ”acrylic glass” is 5 times more impact-resistant than traditional PMMA. It also has an anti-scratch and water-repellent coating. The result: a remarkable and durable optical quality, even in challenging conditions, as well as a weight reduction of the order of 50%.
Quentin Vlamynck follows closely the construction of the Multi50 Arkema 4
3. Energy:
Latest-generation lithium batteries using Arkema’s Kynar® technology were selected. Developed by the young French company Powertech, they help increase energy storage capacity by 50%, with no increase in weight compared to Arkema 1. Combined with a larger surface of photovoltaic panels installed on the front outrigger arm, the system delivers fully autonomous energy supply to on-board equipment, without emitting a single gram of CO2.
4 & 5. Floats & central hull
Like its competitors, the Arkema 4 trimaran is made primarily of a foam-glass-epoxy sandwich with carbon reinforcements. But the construction of this new Multi50 has also been an opportunity to continue the research undertaken with the Mini 6.50 Arkema 3 involving the Elium® resin.
Construction of the Multi50 Arkema 4 in the Lalou Multi workshops in Verdon-sur-Mer
(@France3 Aquitaine)
This Elium® resin, a thermoplastic material formulated and developed by the Arkema Group has been used for all front fairings of the outriggers as well as the deckhouse and cockpit, which are areas where its impact resistance is invaluable. By using this resin for certain parts of the Multi50, the company has capitalized on its reliability and mechanical qualities. The construction of Arkema 4 was an opportunity to demonstrate the exceptional and unique recyclability of this resin.
The outriggers’ molds, for example, were made of Elium®, composite. They have since been cut up and crushed before the depolymerization and purification phases by which the monomer can be recovered. The monomer can then be reformulated into a new Elium® resin, therefore now a «recycled» resin, with identical properties. In turn, the regenerated resin will then reappear in the construction process for the production of new composite parts. This is the case with the cockpit as well as part of the outriggers’ fairing, built from recycled resin. So, the process has come full circle!
Arkema 4 is made primarily of a foam-glass-epoxy sandwich with carbon reinforcements
The choice to build the boat using pre-impregnated fabrics (“pre-pregs”) baked in an oven at 120°C, has ensured an optimum resin rates in the composite, thus the best weight/rigidity ratio. Insulating the workshop and installing an oven to bake all the components were therefore prerequisites for the new Lalou Multi project launched in September 2019.
The floats feature raised sections, but their volume is smaller than on its forerunner since the foil gives the necessary support. The dihedral angle (between outrigger and horizontal plane) has been increased to prevent the windward float from dragging in the water in light winds.
The hull which was validated by many digital simulations (CFD), is wide at the bridge to increase the sheet effect on the front sails. Below the waterline, it is deep with V sections for less bumpy sailing. The clear forefoot allows for more efficient rotations. As with the floats and the outriggers, the structure and bulkheads were assembled by structural bonding using methacrylate products from the Arkema subsidiary Bostik. Bostik structural adhesives used on the Multi50 Arkema 4 make a major contribution in terms of lightweighting, toughness and durability.
As with the floats and the outriggers, the structure and bulkheads were assembled by structural bonding using methacrylate products from the Arkema subsidiary Bostik.
Apart from the mast built by Lorima and the monotype foils, the Lalou Multi team has managed the entire building of Arkema 4, in close collaboration with Arkema’s R&D teams.
After 22 months and 30,000 hours of work, the Multi30 Arkema 4 trimaran is ready to sail.