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Old 03 October 2005, 12:15   #1
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Ringprop

Any views on this Des
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Old 03 October 2005, 12:27   #2
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cant believe it took 15 years of research to come up iwth a prop with a ring round it!!!!!!!!, the companies backing it must have been given a bit of a bum steer. i would have thought the variable pitch propellors that lots of stands at the boat show had would be a better leap forward in technology bring gearing to the boat world that is much needed
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Old 03 October 2005, 14:45   #3
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Reckon it would be worth a try. I bet the water flow over a normal prop blade is diagonally outwards due the the centrifugal force of the entrapped water and there will be drag formed at the tip of the blades where the waters from the front and back of the blades meet at different speeds. I would also put money on there being a tendency for the water on the high pressure (forward) side of the blade to attempt to leak over to the low pressure side, particularly at the tip. If the ring is able to exert some control over the this, it might be a good thing.

Of course, pehaps that's all Cod's wallop.


Apologies, Cod. The urge just overwhelmed me.
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Old 03 October 2005, 15:24   #4
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I've read some pretty unflattering reviews of that prop on iboats.com forums. People who have tried them mostly went back to standard props, as there were significant performance losses.

I was looking at those for my SR, due to safety concerns. A couple of years ago, a (Greek??) sailing coach in a RIB nearly killed a female US Olympic windsurfer. I met her last year at the Miami Olympic Classes regatta, she still couldn't bring herself to get in a boat... She's pretty badly disabled physically, never mind emotionally, plus Traumatic Brain Injury... Not a good scene, and I work with the US Disabled Sailing Team so I've got a good frame of reference!
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Old 03 October 2005, 16:23   #5
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we are doing a huge amount of testing with Ring Prop at work at the minute. Cant really say what we have found yet!. Doing some more next week with a Zodiac Inflatable and a Mariner 50hp.
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Old 04 October 2005, 17:08   #6
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Oops, I think I'd better clarify this.

Quote:
...the water on the high pressure (forward) side of the blade...
Should read:
Quote:
...the water on the high pressure (back) side of the blade...
Meaning the blade surface facing rearwards.
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