Mercury prop blade flies off while on plane

[sandydlc]

Earlier this month we were cruising up in Desolation Sound and while I was at the helm running about 26 knots at 2800 rpm, we suddenly felt a very bad vibration and loss of power. I immediately put the boat in neutral (450 DA with Zeus pods). We didn't feel that we had hit anything but checked the engine room just in case - all was fine. We tried getting up on plane again, no dice - terrible vibration. Then we tried one engine at a time and determined that the port engine was fine and we proceeded to limp into Gorge Harbour marina at 5 knots. Once we arrived we found a diver who confirmed that we were missing a blade from our rear prop on our starboard pod. There was no damage to the forward prop on starboard and no damage to either of the port props so the likelihood that we struck an object underwater is slim to none.

It took a week and lots of $$$ to get new props sent up to Canada. Our Z14 props were on back order for 4-6 weeks so our local Sea Ray dealer had Z15 overnighted to Seattle and re-pitched to match our Z14 props.

Our insurance only covered a small portion of the loss due to depreciation (our boat is a 2010) so I decided to contact Mercury since in my experience a prop should not throw a blade after only 600 hours of use. They got back to me yesterday and said that from the pictures I sent them they don't believe the damage was caused by bad casting. What do you guys think?

https://www.amazon.com/clouddrive/share/jKqfIFnHhNnUzuJbMqDAtmpiLSZo9YKjbdgLOzaXl6z

https://www.amazon.com/clouddrive/share/k3TJi8hzdAjk84WMGgLYJTdxDdDPoEv4V2OuN6bFsnW

I'm going to take our prop to a prop shop today to get a professional opinion as well.

Thanks!

Sandy

 

[Gofirstclass]

I think you're screwed. Merc has already made a determination that they are not at fault and I suspect that no matter how many opinions you get they're not likely to change their minds.

I wish this was not the case but they are probably going to refuse to pay for what looks like a bad casting.

 

[copb8tx]

On the first picture is seems to show that about half the sheer surface is a different color than the other half, almost like it had weathered. Is that the case or is it just the lighting on the photo?

 

[Sublimetime]

I have seen wheels that have hit pilings and such that have been twisted up into a tulip shape before breaking off at the hub like that. That sucks that they wont help you out. You would think that they would want to inspect it closer to verify its suppliers quality control.

 

[sandydlc]

On the first picture is seems to show that about half the sheer surface is a different color than the other half, almost like it had weathered. Is that the case or is it just the lighting on the photo?

I showed it to a lady who's a welder (she works on props) and it was her opinion that this was a fracture from bad casting which is why I'm trying to pursue. I haven't given up on Mercury yet. They just got back to me with their initial response. I'm hoping that the local prop shop will have more information for me to share with Mercury that might encourage them to take a look at the prop in person. Our last boat was 15 years old when we sold it and it had the original Volvo props. How can Mercury say that this is expected wear and tear?

 

[sandydlc]

I think you're screwed. Merc has already made a determination that they are not at fault and I suspect that no matter how many opinions you get they're not likely to change their minds.

I wish this was not the case but they are probably going to refuse to pay for what looks like a bad casting.

I'm going to see what the local prop shop says. If they're insistent that this is a production flaw then I'll pursue. I would hate for this to happen to anyone else.

 

[bobeast]

I showed it to a lady who's a welder (she works on props) and it was her opinion that this was a fracture from bad casting which is why I'm trying to pursue. I haven't given up on Mercury yet. They just got back to me with their initial response. I'm hoping that the local prop shop will have more information for me to share with Mercury that might encourage them to take a look at the prop in person. Our last boat was 15 years old when we sold it and it had the original Volvo props. How can Mercury say that this is expected wear and tear?

Line one of every tier 1 support script for virtually every manufacturer in the country, reads "It's not our fault". You'll likely have to escalate up a tier or two to actually have someone take it seriously.

 

[techmitch]

I'm going to see what the local prop shop says. If they're insistent that this is a production flaw then I'll pursue. I would hate for this to happen to anyone else.

I think you meant to say: If they're insistent that this "ISN"T" a production flaw.

The picture is clear but I sure would like a close up. Or better yet, on my desk with a magnifying glass but it sure looks to me like it is a casting flaw as copb8tx has said.

 

[aerobat77]

you see erosion on one part and a fresh shear off failure at another part of the cracked prop area . so it appears you have hit something earlier which made a hair crack and the incident waited some time to happen .

 

[sandydlc]

I think you meant to say: If they're insistent that this "ISN"T" a production flaw.

The picture is clear but I sure would like a close up. Or better yet, on my desk with a magnifying glass but it sure looks to me like it is a casting flaw as copb8tx has said.

What I'm hoping for is a formal report from a respected prop shop in Seattle (which is where we're headed right now) and then it will be far more difficult for them to dispute. I suppose I should have started with getting it evaluated but oh well.

 

[sandydlc]

I think you meant to say: If they're insistent that this "ISN"T" a production flaw.

The picture is clear but I sure would like a close up. Or better yet, on my desk with a magnifying glass but it sure looks to me like it is a casting flaw as copb8tx has said.

I meant that if the prop shop is of the opinion that it's a production flaw then I'll pursue with Mercury. Clear as mud, right? Sorry about that!

 

[Little Ducky]

Do props have serial numbers or batch numbers on them?

Would be nice to find out when and where they were made and also see if there is any data out there on similar failures.

 

[techmitch]

you see erosion on one part and a fresh shear off failure at another part of the cracked prop area . so it appears you have hit something earlier which made a hair crack and the incident waited some time to happen .

This is very possible.

 

[techmitch]

I meant that if the prop shop is of the opinion that it's a production flaw then I'll pursue with Mercury. Clear as mud, right? Sorry about that!

Gotcha, np.

 

[JVM225]

Not a prop expert at all, but I’d think that a manufacturing defect that would cause a blade to let go like that would have manifested itself well before 600 hours.
Seems more likely to me that you unknowingly hit something submerged with the prop which comprised the prop and then the prop blade let go.
If that were the case, then that would probably be covered by insurance.
Did you feel any thumping or hear any noise at anytime immediately before the prop let loose?
Could it be that it happened so quickly that you just felt the vibration you described and weren’t tuned in to anything else?
That would kind of make sense.

 

[sandydlc]

Not a prop expert at all, but I’d think that a manufacturing defect that would cause a blade to let go like that would have manifested itself well before 600 hours.
Seems more likely to me that you unknowingly hit something submerged with the prop which comprised the prop and then the prop blade let go.
If that were the case, then that would probably be covered by insurance.
Did you feel any thumping or hear any noise at anytime immediately before the prop let loose?
Could it be that it happened so quickly that you just felt the vibration you described and weren’t tuned in to anything else?
That would kind of make sense.

We did not feel any impact at all. I dropped off the propeller at a local prop shop this afternoon and the manager there said it certainly looked like bad casting in her opinion. She's going to have her lead tech (with 30+ years of experience) take a look at it tomorrow. She said that this is a known issue with stainless steel props. She said had we hit something there would have been significant damage to the other blades and there is none whatsoever. To be running at 2800 rpm it would be impossible to strike something and only damage just one blade.

As soon as I hear back I'll be sure to post here.

Our insurance did cover a portion of the loss but they depreciated the props by 50% so we only recovered about 16% of the expense of replacing the props/hauling the boat. (I am happy to report that Boat US covered 100% of our towing expense!).

I'm not asking for Mercury to compensate us for our losses - only to replace the faulty prop so that we have a spare. Even if they believe that the prop suffered from "normal fatigue", does that mean that we should expect a blade from our port prop to fly off at any moment? How is it that our Volvo props from our 15 year old Chaparral were still intact when we sold the boat two years ago? And the Mercury props can't last past 638 hours? I'm not buying it and I'm certain that we're not the only ones who have had this happen to them.

 

[sbw1]

Earlier this month we were cruising up in Desolation Sound and while I was at the helm running about 26 knots at 2800 rpm, we suddenly felt a very bad vibration and loss of power. I immediately put the boat in neutral (450 DA with Zeus pods). We didn't feel that we had hit anything but checked the engine room just in case - all was fine. We tried getting up on plane again, no dice - terrible vibration. Then we tried one engine at a time and determined that the port engine was fine and we proceeded to limp into Gorge Harbour marina at 5 knots. Once we arrived we found a diver who confirmed that we were missing a blade from our rear prop on our starboard pod. There was no damage to the forward prop on starboard and no damage to either of the port props so the likelihood that we struck an object underwater is slim to none.

It took a week and lots of $$$ to get new props sent up to Canada. Our Z14 props were on back order for 4-6 weeks so our local Sea Ray dealer had Z15 overnighted to Seattle and re-pitched to match our Z14 props.

Our insurance only covered a small portion of the loss due to depreciation (our boat is a 2010) so I decided to contact Mercury since in my experience a prop should not throw a blade after only 600 hours of use. They got back to me yesterday and said that from the pictures I sent them they don't believe the damage was caused by bad casting. What do you guys think?

https://www.amazon.com/clouddrive/share/jKqfIFnHhNnUzuJbMqDAtmpiLSZo9YKjbdgLOzaXl6z

https://www.amazon.com/clouddrive/share/k3TJi8hzdAjk84WMGgLYJTdxDdDPoEv4V2OuN6bFsnW

I'm going to take our prop to a prop shop today to get a professional opinion as well.

Thanks!

Sandy

That prop looks virtually identical to one of my props from a few years ago. And of course the vibration, checking for water intrusion, limping in to port, etc. was all the same as your experience. I hit an unmarked (illegal) Indian gill net and never did see it. Only found out they were everywhere when I got into port for the repair and saw a number to call if you lost running gear in the area where I lost the prop blade. The cost to replace it was about the same as my deductible so it was not worth filing a claim. I'm not sure how they can look at a pic and say it is a bad casting or that you hit something. I never felt I hit something either. It sure does spoil your ride and scare the heck out you when it happens. Sorry you are going through this.

 

[sandydlc]

That prop looks virtually identical to one of my props from a few years ago. And of course the vibration, checking for water intrusion, limping in to port, etc. was all the same as your experience. I hit an unmarked (illegal) Indian gill net and never did see it. Only found out they were everywhere when I got into port for the repair and saw a number to call if you lost running gear in the area where I lost the prop blade. The cost to replace it was about the same as my deductible so it was not worth filing a claim. I'm not sure how they can look at a pic and say it is a bad casting or that you hit something. I never felt I hit something either. It sure does spoil your ride and scare the heck out you when it happens. Sorry you are going through this.

Sorry that happened to you! Do you still have pictures of your damaged prop by any chance?

This happened South of Cortes island up in British Columbia. I don't know that there are any gill nets allowed or in use in that area and I would doubt it because we were in an area with heavy boat traffic and we were the only ones who suffered damage. We were traveling with two friends on their own boats and neither boat encountered anything (we were sharing the same route and ours was the 2nd boat to follow the route of the 3 boats). So, I'm not saying it's impossible that we hit something but very improbable. We have over 18 years of experience on the water, 17 of it in the Puget Sound and although we have hit small logs in the past (not in the this boat), I know what it feels like to hit something and it just didn't happen this time. My husband and I were both attentive at the helm and on the lookout for logs. There just wasn't anything there.

 

[JamesT]

Hi Sandy. Same exact thing happened to me last year. It was Friday of Labor Day weekend and we just left our inlet for a 3 hour run to Ocean City, MD when all of a sudden the same horrible vibration. I managed to get hauled out that evening and my blade snapped off just like yours in the exact same place. Because my skeg was missing, I assumed that my skeg fell off on its own and lodged in between the two props because my forward prop was chewed up pretty good. That same weekend, I found a new pair of props from Buster's Marine (on internet) and had both my starboard props replaced and now I carry a spare set with me just in case. BTW, ever since then I run without skegs. The darn things always seemed to fall off anyway so I said the hell with them. Cummins told me they do absolutely nothing to enhance the performance of the boat. That said, that obviously was not your problem.

 

[sandydlc]

Hi Sandy. Same exact thing happened to me last year. It was Friday of Labor Day weekend and we just left our inlet for a 3 hour run to Ocean City, MD when all of a sudden the same horrible vibration. I managed to get hauled out that evening and my blade snapped off just like yours in the exact same place. Because my skeg was missing, I assumed that my skeg fell off on its own and lodged in between the two props because my forward prop was chewed up pretty good. That same weekend, I found a new pair of props from Buster's Marine (on internet) and had both my starboard props replaced and now I carry a spare set with me just in case. BTW, ever since then I run without skegs. The darn things always seemed to fall off anyway so I said the hell with them. Cummins told me they do absolutely nothing to enhance the performance of the boat. That said, that obviously was not your problem.

It's such an awful feeling, right? We were so shocked and thankfully reacted appropriately. I very much appreciate that when we have an emergency my husband and I work really well together. We stay calm, we use our experience and knowledge to make good decisions. this is definitely not something I want to have to go through again.