Sharrow Engineering boat propeller - This is an awesome design

[FastF30]

I was so impressed with this I had to post it... the secret is at the end of the video...

[vreihen16]

Interesting! I wonder if the wrap-around tips also prevent cavitation during hole-shots from a dead stop? I'm assuming that is the magic voodoo behind its performance.....

[Wolf 335]

Very interesting

[chassis]

Interesting. It's a variation of a Volvo Duoprop and using thinking similar to a submarine screw. The same laws of physics apply now as they always have, this is an iteration on prior art.

Long term reliability needs time to sort out. I'm thinking about fatigue cracking at the apex of the main lobe, i.e. where the pairs of sub-lobes meet.

[FastF30]

Originally Posted by chassis

Interesting. It's a variation of a Volvo Duoprop and using thinking similar to a submarine screw. The same laws of physics apply now as they always have, this is an iteration on prior art.

Long term reliability needs time to sort out. I'm thinking about fatigue cracking at the apex of the main lobe, i.e. where the pairs of sub-lobes meet.

I understand what your saying but at the same time they claim that vibration is greatly reduced resulting in less fatigue ... Time will tell...

[chassis]

Originally Posted by FastF30

I understand what your saying but at the same time they claim that vibration is greatly reduced resulting in less fatigue ... Time will tell...

Yes, and as in all new products, time is the truest test. What happens when the propeller is dinged on a rock or driven through a sandy bottom, and the geometry of the lobe apex changes ever so slightly? Tow-tank laboratory testing and long term real world testing can produce different results.

[FastF30]

Originally Posted by chassis

Yes, and as in all new products, time is the truest test. What happens when the propeller is dinged on a rock or driven through a sandy bottom, and the geometry of the lobe apex changes ever so slightly? Tow-tank laboratory testing and long term real world testing can produce different results.

Well one thing is it is machined out of a billet compared to casted like typical props... probably why they went that way just for strength alone possibly based on your comments and for saw this as a major issue...