710539Development of novel folding propeller for sailing yachtsClosedGRD Proof of ConceptInnovate UKAccording to Sailing Today Magazine (Sep 2011), fixed blades propellers are known to reduce speed “under sail” by a considerable 0.5-1.0knots. Therefore, many sail boat owners use folding propellers, as they minimise the unwanted drag induced on a sailing boat. Despite the predominance of folding propellers in the market, there are a number of issues associated with the folding propeller that prevent it from fully satisfying the needs of the sailing consumer. Firstly, folding propellers have a reputation for losing working parts before the end of their design life, leaving the boat owner needing a replacement device. The weight of existing propellers is known to affect the life of the cutless rubber bearings contained in the shaft support coupling. Finally, since reverse thrust is less than adequate, manoeuvring within or close to a marina or a berth becomes significantly more treacherous. Folding propellers can be up to 3 times more expensive than standard fixed blade. Super Prop Ltd. is a start-up company, set up to exploit specialist processing technology capable of producing a novel propeller that can address the aforementioned customer issues. Their concept solution is enabled through a specialist investment casting method developed over 30years by Micro Metalsmiths Ltd. The SuperProp propeller will weigh 30% less than its competitors, cost 50% less, have an average extended life of approximately 25%, and will produce more thrust by having a complex blade shape that is extremely difficult to produce by normal CNC machining methods.