NEWS & EVENTS
The folding propeller: An interest that goes beyond racing yachts
14 June 2021
A reflection on the choice of propeller, constrained but welcome
Vincent Thouvenel has been the happy owner of a 12-meter aluminum sailboat for 2 years. If he sails well, it is not a racing boat. However, he likes to keep performance and was forced to look at the type of propeller installed following the loss of his propeller. “My boat is an amateur design-build from the late 1980s, made by a friend of Michel Joubert. It would have inspired the naval architect for the JNF 38. It is a dinghy with a light displacement of 8.2 tons and a sail area of 85 m². It is well covered, but it is not a racing boat. I bought it 2 years ago with a Kiwi Prop folding propeller. Unfortunately, I lost it while reversing in the Erdre river and it was impossible to find it”, says the yachtsman.
Forced to find a quick solution, he bought a fixed 3-blade propeller. “It was complicated. I did extensive research to find this second-hand propeller, but there is no propeller with the right pitch that can be easily adapted. In the end, it worked well with the engine, but I quickly felt the brake under sail. So I quickly wanted to find a folding propeller” says Vincent Thouvenel.
A gain in engine manoeuvrability
After researching, he finally settled on the Gori brand. “The metal blades reassured me more than the composite, even if the Kiwi Prop was efficient, although the loss of my propeller obviously made me cold. And the Gori system is a beautiful mechanism, which seduced me from my job as a merchant marine mechanic” justifies the sailor. He also emphasizes the simplicity of assembly, carried out independently from the manual. Only a translation problem, currently being solved, left a doubt.
Vincent Thouvenel was impressed by the engine’s performance. “It’s efficient in forward motion, but there’s especially a gain in reverse, with a real boost. I only have 24 horsepower, which is low, but I can stop in reverse much better than with a fixed blade propeller and there is much less pitch effect” he says.
A faster boat under sail
The most sought-after effect for the yachtsman is that the gains are also achieved under sail. Without providing any figures, the owner estimates the boat’s acceleration at 0.5 knots, while pointing out that a fairing carried out at the same time as the change also comes into play. “There’s a real gliding feel, even in light airs. It’s more expensive than other propellers, but I see it as an investment that can be used when the boat is resold. And it’s like the sails, it’s important to invest in them to move forward” concludes Vincent Thouvenel.
Original article – https://www.boatsnews.com/story/37244/the-folding-propeller-an-interest-that-goes-beyond-racing-yachts