The innovations and eco-design of the Imoca P’tit Doudous

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The hull and deck of Les P’tits Doudous have just been removed from their molds at the Duqueine Atlantique shipyard, marking a significant milestone in the construction of Armel Tripon’s future Imoca. This is an opportunity to reflect with Quentin Lucet, associate architect at VPLP Design, and Katia Merle, structural engineer and eco-design specialist, on the approach taken by the agency with the Nantes-based skipper since 2021.

How did the meeting with Armel go, and what were the foundations of this new Imoca?

Quentin Lucet: It was at Airbus’s technocentre in 2021. Armel was in contact with the aircraft manufacturer, which had a stock of carbon that had exceeded its use-by dates for aeronautics due to COVID. However, Armel’s project was not to build an economically driven Imoca. From the outset, the ambition was to create a technically and sportingly competitive boat with the lowest possible carbon footprint. The two main ways to reduce this footprint were, of course, to work on the materials used, but also on the tooling. That’s why the reuse of the Malizia Seaexplorer molds is so relevant, as the production of molds is a significant part of a racing project’s carbon footprint. We took the time to optimize the boat without altering the hull, which has already proven itself, to tailor it for Armel. The process took nearly two years, and in January 2023, we all said “go!” even though the budget was not yet fully secured…

What technical issues arose from reusing this expired carbon, which wasn’t initially intended for offshore racing?

Q.L.: The fiber grade remained within the Imoca gauge, but we had to review the pre-preg curing cycle since the originally planned temperatures to activate the resin were 180 degrees, whereas the Imoca gauge tolerates a maximum of 135 degrees. Duqueine Atlantique, which invested heavily [a dedicated hangar was built at the Malville site by the shipyard, previously specialized in aeronautics, Editor’s note], created multiple samples that we characterized and tested. Mechanically, they proved to be successful. It should also be noted that Armel’s project was supported by Team Malizia for the design office part and site monitoring, which facilitated things.

Katia Merle: It’s important to understand that the technical ambition of the project far exceeds the environmental requirements of the new Imoca class rule, which will be introduced in August and mainly addresses molds and foil manufacturing waste. These areas certainly offer significant gains in eco-design but do not question performance. Armel Tripon and Duqueine Atlantique have taken a real pioneering step. Les P’tits Doudous will be a true prototype, in the literal sense, with all the beauty and risks that entails.

Was the boat entirely made with this downgraded carbon?

Q.L.: No, about 70%. We reserved certain parts, like the mast bulkhead made with new pre-pregs, but the vast majority of the carbon came from Airbus’s stock. The fabric weights from Airbus were different from those used for its sister ship, Malizia, so we had to recalculate many parts.

Armel announces 70% expired carbon in the construction for a 50% reduction in emissions. How do you go from one figure to the other?

K.M.: 70% of zero-impact pre-preg doesn’t equate to 70% of the total impact because many other components come into play. But these figures show that pre-preg, considering its manufacture and implementation, including curing and consumables, remains highly impactful.

Does the availability of these downgraded Airbus resources make Les P’tits Doudous a one-off project, or do you think it could be replicated in the future?

Q.L.: I don’t know if it’s replicable as it stands, but it’s certainly a strong signal. The stock of downgraded carbon from the industry is recurring, and the Imoca class is due to meet with Airbus shortly to explore potential future collaborations. Various isolated initiatives to recover composite materials (downgraded fiber, end-of-roll, rejects…) are emerging, and we need to stay alert.

K.M.: Before this project, there was clearly a technological barrier with the curing temperature issues, the compatibility of core materials, and molds with this unusually sourced carbon… If Armel’s Imoca is successfully born and proves itself on all fronts, these obstacles will be removed, and it will inspire new ideas. It will facilitate permeability between the sailing industry and the industrial giants who are the real decision-makers with material manufacturers.