Lost Propeller

[Mike the sailor]

On the next to last day of a 4 week charter in the Cyclades in Greece, we picked up our anchor. motored out for about 1/2 hour, set the sails, motor-sailed for another 45 minutes or so and then stopped the engine to sail. When the wind started to die down about 2 hours later, we again turned on the motor, but there was no power whatsoever. Shutting down the engine, we sailed another 30 miles to reach our destination, albeit with minimal winds. Without the engine, we couldn't Mediterranean moor but were able to sail to a floating dock and tie up alongside it. When I got my mask and snorkel and checked below the surface, I discovered that the propeller was gone.

How could the propeller have fallen off after 4 weeks of no problems?

The owner of the boat (2002 Jeanneau 35) insists that it is our fault. He says we either ran aground or caught somebody's chain. Neither of those happened.

I own my own sailboat here in the U.S. since 1994 and have chartered 18 times in the Med (France & Greece) 1986. Sure there has been a damaged sail at some point over the years as well as some minor incidents here and there, that's part of sailing. But a lost propeller that was functioning fine for 4 weeks? How?

I'd appreciate any insights (other than the Outer Limits or the Twilight Zone) regarding this dilemma.

Thanks!

[DougR]

So Mike, here's my two cents worth as a boat owner for more than 40 years and also as a marine professional in the engine business for more than 30 years....

As a sailor, if props disappeared as a result of running aground, I and a lot of others would have replaced numerous props over the years. And if you snagged someones anchor or mooring chain, the evidence would be all over the boat bottom in the form of scratches and gouges on the shaft, strut, rudder, saildrive, etc.

But, as someone who worked in the engine business, I can tell you that props fall off shafts all the time, especially sail drives and stern drives....And the vast majority of these times it is the result of improper installation. Installers forget cotter pins, forget to fold over lock tabs, reuse locking bolts when they shouldn't, apply improper torque with dinky little screwdrivers, etc. The list is endless. One of the classic scenarios is the boat that pulls into the slip and shifts into reverse to slow the boat, but it just keeps on going. The prop pulled itself off the shaft in reverse because the nut or cone is gone and the prop is now lying on the bottom right below the boat.

Occasionally the rubber hub in an I/O or saildrive prop can fail, and the prop disappears, but these usually leave the remains of the hub still connected to the shaft as evidence.

Inboard prop loss is even more suspect.....a properly installed inboard propeller almost never falls off a shaft. You can go into boatyards all over the place and see props with blades folded back from grounding or hitting logs and the prop remained on the shaft. Boatyards don't invest in heavy- duty hydraulic prop pullers just because they like to spend money!

So if a prop parts company with a shaft, most of the time the prop wasn't installed correctly.

DougR

[Mike the sailor]

Doug,

Thanks for the reply.

FYI, when the boat was pulled out of the water, there were (as I told the owner) no indications of running aground or catching someone's chain. The owner will not admit any fault and still believes there is no other explanation other than I caused it.

In speaking with the marine repair person who attached the new prop so that we could get the boat back to Athens, he said that Volvo engines are prone to this problem of loosing a propeller and that he has seen it on many occasions.

Mike

[ggray]

I'd like to know the owner's explanation of how running a deep keeled boat aground could cause the propeller to come off.

[JPA Cate]

You cannot reason with someone who's angry because his boat has a problem. He has a vested interest in it being the charterer's fault. The fact is that the boat was okay when the charterer received it, and it no longer was when he got it back. A hard one to fight in a foreign land when you don't speak the lingo fluently.

Ann

[TurninTurtle]

Re-use a cotter key and it eventually fatigue fractures... (possible to fatigue without being re-used, but not as common)

Same for the bent tab washer type nut locking devices.

And then there's galvanic corrosion which could make a cotter pin (or bent tab device) "just disappear" if the wrong material pin was used.

Any device that could be used to retain the prop will have some mode of failure. Some the failure will be more common than others.

There should be some recommended frequency of inspecting the prop nut when a drive has a reputation for losing props.

[JPA Cate]

Honestly, when you charter somewhere you snorkel anyway, it can't do any harm to look at the underbody of the boat and look for any anomalies.

Please don't mistake me, here, i do not think the charterer is to blame, just that he's in a very difficult position if the owner does not want to take in his input.

Ann