HYDROcontest: honing the ships of tomorrow

Maritime transport is the fifth-largest source of atmospheric pollution globally. Each 1% reduction in fuel consumption by the global fleet translates to a 42-million-ton decrease in emissions. Recognizing this ecological potential, the Hydros Foundation launched a HYDROcontest competition focused on nautical energy efficiency to be held annually over five years and open to engineering and university students worldwide. After three editions in Lausanne (2014, 2015 and 2016) and two in St-Tropez (2017 and 2018), the HEIA-FR, with support from HEIG-VD and the EPFL, organized the final edition in 2019, held in Yverdon.

Participants were challenged to design the fastest, most energy-efficient remote-controlled vessel with a standardized motor and battery. The optimizable components included the propeller and the hull's hydrodynamic design. Teams competed in three tests across two distinct boat geometries, each with a specific load:

•     A personal vessel with a 20-kg payload to simulate the transport of people on a pleasure boat

•     A vessel with a 200-kg payload to simulate the transport of cargo

•     An endurance test to simulate long-distance transport in which boats with a 20-kg payload operated for 1-2 hours with a limited energy supply

During the six years the competition was held, the HEIA-FR team (led by its SeSi and iSIS research institutes) successfully designed and fabricated eleven different boats (six in the lightweight category and five in the heavyweight category). Similar to the custom vessels designed for the renowned Vendée Globe and America’s Cup, success in the HYDROcontest depended on the efficient design of lightweight structures and the optimal use of hydrodynamic foils—submerged wings that generate lift as they move through water. These features were refined continuously over the six-year competition period.

Deploying a fully functional vessel required the development and testing of several key components, including:

•        A design tool to simulate hydrodynamics (drag opposing forward motion), stability (balancing pitch and roll), and vessel topology (optimal material distribution within a constrained volume); 
•   Various boat geometries (single-hull, catamaran, trimaran) for both lightweight and heavyweight categories;
•           A propeller dimensioning and design tool; 
•    A rapid fabrication process for carbon-fiber hulls using infusion techniques to produce lightweight, hollow, compartmentalized, and waterproof vessels; 
•      A central electronic control unit managing the motor, rudder, and foils based on inputs from the remote control and onboard sensors;
•    Motor current regulation to prevent power limitation activation, ensuring optimal energy consumption, especially during endurance races;
•      Real-time parameter trnsmission (battery level, consumption rate, foil angle, rudder angle) to the pilot and crew for enhanced navigation and decision-making.

The team excelled in this multifaceted engineering challenge, securing podium finishes 13 times, including four consecutive victories: the endurance test in 2015 and 2016, and the lightweight category in 2017 and 2018. This was a remarkable achievement given the consistently competitive field of 15 to 25 teams.

The project delivered impressive performance gains over its six-year duration. The lightweight boat, for instance, saw its mass reduced from 60 kg in 2015 to just 20 kg in 2019. Over the same period, the boat’s top speed increased from 18 km/h to over 30 km/h in its final configuration.

The project also gave rise to a start-up named FRI-FOIL, founded by two former HEIA-FR students and HYDROcontest participants. The company aims to commercialize an innovative navigation technique that delivers exceptional energy efficiency. Building on lightweight boat developments conducted at HEIA-FR, the start-up has already produced a prototype equipped with foils, capable of transporting a person on water at nearly 30 km/h using only a 5 kW motor.

With the conclusion of HYDROcontest, Eco-marathon Shell has emerged as a new annual global competition for energy efficiency in road vehicles, challenging participants to travel the farthest distance on a single liter of fuel. The School of Engineering in Fribourg and the SeSi Institute aim to achieve similar success in this competition.