Herring prop, broke or hit something?
#1
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Herring prop, broke or hit something?
We did a run down to the inlet and the waves were 6-7' I fell off plane going into the waves because I was going a bit too slow. Tried to get back on plane and didn't like spinning the props as much as I did so I backed off and cruised out further to get past the inlet waves. Turned around and got back on plane. Had a brain fart and was on the wrong side of the submerged jetty, more then 15' away from it. Turned around went back through the inlet. Cruised back and opened her up hit around 100 and got air about 3-4 times no vibration at all, then slowed down to around 60-70mph for about a minute and all of a sudden vibration.. I dropped the throttles immediately and had a lovely 2hour 7-8mph cruise back to the ramp on the other engine. My friends were in their boat too and my one friend thinks I hit the jetty. I saw that jetty and knew I was safe and far enough away. He thinks I hit it but I wasn't close enough and felt nothing and the boat performed like always after my brain fart. And if I did hit anything even something in the water after my high speed run wouldn't the other blades be messed up too? I'm thinking I cavitated the props too long and they heated up and caused a stress fracture or did the blade just snap off? But how could the blade fold in the direction of propulsion? It's like it bent in to create more pitch? I did use that engine to dock but I doubt low speed would bend the prop in reverse? Thoughts?
The following 7 users liked this post by Sydwayz:
Gimme Fuel (09-28-2020), Griff (09-28-2020), ICDEDPPL (09-28-2020), KNOT-RIGHT (09-29-2020), mike tkach (09-29-2020), PartyBarge22 (09-29-2020), speicher lane (09-28-2020)
#3
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I've had that happen with a bravo prop. I felt vibrations, when I stopped the blade was still there, but had a crack 3/4 of the way across the blade. By the time I idled back to the ramp, the blade was gone.
#5
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Appears the blade failure initiated at the "pit" at center of "beech mark" at the discharge or aft end on pressure side of blade. As the prop rotated the partial section of blade carried the complete load on a reduced cross section. The remaining section curled in and deformed until it eventually yielded and failed (in shear?). Sample beech mark. See yours now?
Last edited by 28 V; 09-28-2020 at 05:01 PM. Reason: sp
The following 7 users liked this post by 28 V:
beerock (09-28-2020), endeavor1 (09-28-2020), Gimme Fuel (09-29-2020), Helmwurst (09-29-2020), ICDEDPPL (09-28-2020), PartyBarge22 (09-29-2020), Rookie (09-29-2020)
#6
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Appears the blade failure initiated at the "pit" at center of "beech mark" at the discharge or aft end on pressure side of blade. As the prop rotated the partial section of blade carried the complete load on a reduced cross section. The remaining section curled in and deformed until it eventually yielded and failed (in shear?). Sample beech mark. See yours now?
#8
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