The Challenge
Baltic Yachts were quick to recognise the performance potential of installing a large hydrofoil to their 142ft sailing yacht. More righting moment with less drag is created for sailing, reducing heel and increasing speed and comfort.
The chosen system was a “Dynamic Stability System” featuring a 9m long foil spanning transversely across the midships (right beneath the owners cabin!) , producing 70T of lift, allowing a lower displacement hull shape to be used.
Several good partners were already involved in this great feat of engineering, but there was a piece of the puzzle missing. The foil must be actuated, retracting and extending from side to side while under very high loads. A problem well suited to the specialist experience and detailed mechanical design skills found in our team.
The Solution
Drawing on the extensive experience of foil actuation design from our America’s Cup heritage, BARTech provided a turnkey solution for the actuation. From conceptual design, detailed manufacturing drawings, to procurement and assembly of the system.
The foils operate in a free flooding cassette through the hull. A system of pulleys and lines was developed with routing to ensure watertight integrity of the hull is maintained, while running through to the captive winch. All whilst providing access for inspection and maintenance.
The actuation of the foil under high loads makes friction and also distortion of the carbon trailing edge of the foil a significant challenge. With experience in this area and years of microscopic material research, we were able to accurately calculate the impacts and mitigate performance loss with design and material selection. This resulted in the design of self aligning bearing cassettes containing Ultra high molecular polyethylene pads, capable of reactions loads of up to 200T.
The result was a system which integrated seamlessly with the yacht systems and structure, a “plug and play” solution delivered.
