The Multi50 Arkema 4 trimaran

The design phase of the Multi 50 Arkema 4

The construction of the new trimaran Multi50 Arkema 4 got underway in September 2018, and its launch is scheduled for spring 2020.

Read on to find out all about the boat and the progress of the project run jointly by Arkema and Lalou Multi.

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, which will transpire in the boat’s design.

Versatility, the watchword for Arkema 4

Lalou Roucayrol sums up this versatility perfectly: “Our aim was to build a more versatile boat than the previous one, in other words just as effective in in-shore crew events as in solo ocean racing. We have put much thought into the masses and improved the aerodynamic brakes. It’s going to be a powerful boat!”


Romaric Neyhousser, the boat’s architect, details the work that has gone into aerodynamics to enhance this versatility: “The idea is to 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 we believe that the resulting gain will offset this additional weight.”

Skipper-focused ergonomics

Here too, 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 will offer greater protection in particular.


As Quentin Vlamynck, the future skipper of Arkema 4, explains, “It’s vital to keep up the pace more easily sailing as a pair or solo, and to be able to go fast over a sustained period of time, including in challenging conditions.”

Arkema 4 will offer greater protection for its sailors than its predecessor

The future Arkema 4 will offer greater protection for sailors than its predecessor (above is the previous Arkema 1 at a crew Grand Prix).

Lalou Roucayrol and Quentin Vlamynck heavily involved in the progress of construction

Both Lalou Roucayrol and Quentin Vlamynck are naturally heavily involved in the construction of Arkema 4, the former being in charge of running the project and an expert in Arkema materials, and the latter as the future skipper of the boat.

Quentin Vlamynck follows closely the construction of the Multi50 Arkema 4

Where does the construction of Arkema 4 currently stand?

Some twenty people are engaged in the construction of the new trimaran. Quentin Vlamynck details the work so far: “Construction is progressing at a good pace. The components are beginning to take shape, in particular those of the central hull which are now finished. Foam components are currently being glued in place, and the hull as a whole should be put together in the course of December. The teams are gaining more and more experience, and production of the components will follow on thick and fast over the next few weeks. The daggerboard is ready, and we are finalizing the orders for fittings and rigging and electronic equipment. We are saving a lot of time on these points as we have acquired data collected in situ with the Lalou Multi Multi50. Everybody in the team can’t wait to see it taking shape.”

Arkema materials will have pride of place

Already present on the previous Multi50 and the Mini 6.50, Arkema materials will have pride of place on the new Multi50 Arkema 4.


The Elium® thermoplastic resin, for example, is used to manufacture a number of components, including the crossbeam mold that will be recycled when construction is over. Other applications include an even greater use of the wide range of Bostik adhesives, the production of parts using 3D printing, and work on the batteries. 


The structural adhesives from Bostik used for the construction of the Multi50 Arkema 4 contribute a lot in terms of lightweighting, toughness and durability

Bostik structural adhesives used on the Multi50 Arkema 4 make a major contribution in terms of lightweighting, toughness and durability.

Gilles Galinier, Communication Vice President for the Arkema Group, sheds light on the Group’s materials on the Arkema 4: “The work undertaken with the Elium® resin has been extensive and complements developments in other markets such as wind power. And the construction of Arkema 4 will be an opportunity for us to demonstrate the recyclability of composites made from this thermoplastic resin. This latest trimaran is also a superb showcase for other products from our Group, including Bostik’s structural glues that make a major contribution in terms of lightweighting, toughness and durability. We have R&D teams dedicated to this construction project to identify materials already applicable and others potentially so in the longer term. A racing boat like this new trimaran is a tremendous driver of brand image, but above all it’s a full scale laboratory that enables us to show and test the performance of our materials in real-life sailing conditions. A “materials demonstrator” that can be transferred to other application sectors.”


New generation sails

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, as explains Pierre-Antoine Morvan, Head of R&D at Incidence Group: “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.”


Quentin Vlamynck and Lalou Roucayrol testing Strong Luff

Quentin Vlamynck and Lalou Roucayrol testing Strong Luff.


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® resin developed by Arkema. César Dohy, Master Sailmaker at Incidence, explains: “To hold these sails, there are two highly specific fittings called lugs. These are triangular aluminum parts measuring about 10 cm² with head and tack that literally secure the sail. Made from the Elium® resin, they are therefore lighter, with softer contours, and are now recyclable. Quentin and Lalou tested them in the Canary Islands, and the initial feedback was convincing.”


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