Sustainability and Moths – The Iridium Moth V1

By James Tomlinson

This competition focuses on sustainability within the Moth class, inviting university and postgraduate teams to compete. The boats are judged not only on their performance but also on their use of sustainable materials and manufacturing techniques, with innovation and eco-friendly design taking precedence over racing results.

One of the key successes of the SuMoth Challenge is that it showcases these innovations within the highly competitive Moth fleet, putting sustainability on the radar of top sailors and the wider sailing industry.

For this project, I developed a unique Moth design using a production mould to create a hull from infused flax fibre – a renewable, sustainable material. The wingbars were constructed from laminated ash, and the vertical foils were cleverly repurposed from sections of a broken TP52 mast. In addition, I sourced offcut cured carbon fibre from a local boatyard, further reducing waste, and developed a sail that is fully recyclable.

When looking for hardware to fit out the Moth, I approached Allen Brothers for several reasons. As leaders in Moth-specific hardware, their products were an obvious choice. But just as importantly, Allen Brothers share the sustainability values that underpin the SuMoth project. Their commitment to producing hardware in the UK reduces environmental impact by cutting out unnecessary shipping and air freight. I was particularly excited to see Allen’s “Eco Block” range, where recycled plastic is used in the construction. I hope to see this range expand, offering even more eco-friendly options for sailors.

Onboard my Moth, Allen hardware is integrated into key control systems. The vang, cunningham and mast base turning points all use Allen’s renowned dynamic blocks, allowing these systems to run aft through a custom deck organiser using Allen sheaves. The entire setup, which extends to the wingbars where everything is controlled, works in perfect conjunction with Clamcleats. One of the standout products I used is Allen’s XHL blocks for the vang system, which are unmatched in their strength and performance. Another highlight is the 20mm single blocks with swivel hooks, which are critical for pulling the deck sweeper down and creating the end plate effect. This hardware is essential for optimising rig tension and sail shape.

We completed the project on time and were able to test the Moth at Lake Garda, where it performed exceptionally, achieving a third-place finish in the SuMoth Challenge. The real success, however, was in demonstrating that this boat could handle full rig tension and a flat, taut sail, showing that sustainability and performance can go hand-in-hand. As with any development project, there are always more ideas to explore, and I look forward to further refining this design in the future.


At Allen, we are committed to reducing our environmental impact by integrating sustainable practices into every stage of our manufacturing process. Using advanced, energy-efficient machinery, we continually work to minimise our carbon footprint while producing high-performance sailing hardware. Our dedication to sustainability extends to the materials we use, with a focus on incorporating recycled and reusable components whenever possible. By investing in modern technologies and eco-friendly resources, we are able to deliver the same renowned quality while contributing to a greener future for the marine industry.