Damaged running gear

[Skybolt]

Again hitting a stationary rock ripped nothing off. I just don’t get it. Anyway time to get her repaired.

No I understand what you have said and where you are coming from, not arguing that at all. It's just from an objective view that this doesn't make any sense and I agree with the assessment made by the surveyor's. Some serious forces had to rip the shaft out of the boat, it didn't just happen on it's own without external forces at play, unless nothing was tightened at all, but that was ruled out by the 3rd party surveyor as well.

EDIT: This is different from hitting a rock, something like a chain that was anchored, like an old channel marker buoy, would have had to be picked up and that is what did the damage. Would have happened very fast at the same time you noticed the engine wind up in RPM.

 

[Skybolt]

Okay.....I will admit this has been rattling around my head today. I think this is the right Force equation to use:

View attachment 155363

If I use 20,000 lbs (weight of the boat) and 12 miles per hour of speed ....I get 96,276 foot pounds (48 tons) of Force. I am sure I am missing something but that is a lot Force to exert on clamp coupling. I can't imagine any clamp coupling holding up to that.

Certainly geometry and a host of other variables could reduce it but I will bet if I set up a hub on my 50 ton press with a shaft locked in place.....it would push it out of the hub and shear the lock bolt without even getting close to 50 tons of pressure.

As Tom noted earlier......I would expect the initial amount of Force needed to shear the lock bolt to be one value and the Force needed to push it out of the hub to be far less.

Also to Tom's point, the transmission would be subjected to that force as well and most likely will need some attention, mounts rear case bearing - man what an unseen mess that can be.

 

[Lawrence Falco]

Not trying to argue either. I was on the boat it reacted like it came out of gear. You mean the “independent” surveyor that the mechanic paid for? I am sure I can pay one to say the opposite. Anyway going the get an estimate.

 

[Stee6043]

Okay.....I will admit this has been rattling around my head today. I think this is the right Force equation to use:

View attachment 155363

If I use 20,000 lbs (weight of the boat) and 12 miles per hour of speed ....I get 96,276 foot pounds (48 tons) of Force. I am sure I am missing something but that is a lot Force to exert on clamp coupling. I can't imagine any clamp coupling holding up to that.

Certainly geometry and a host of other variables could reduce it but I will bet if I set up a hub on my 50 ton press with a shaft locked in place.....it would push it out of the hub and shear the lock bolt without even getting close to 50 tons of pressure.

As Tom noted earlier......I would expect the initial amount of Force needed to shear the lock bolt to be one value and the Force needed to push it out of the hub to be far less.

I don't know...I'm pretty sure I've been up to 7kts in reverse on occasion and the shaft didn't pop out

 

[PlayDate]

I don't know...I'm pretty sure I've been up to 7kts in reverse on occasion and the shaft didn't pop out

I would have to rerun the equation but the issue is mass and the speed at which it is moving.

Say you dropped anchor and paid out 200 feet of chain, put it in reverse and firewalled the throttles. If you could get to 7kts in 200 feet....can you imagine the Force applied to the anchor when the chain tightens?

It isn't about the hub. The hub is designed for the pressures associated with rotation. The keyway takes the load in forward and reverse.

As to what he snagged......it had to be a marker of some kind firmly secured to the bottom. Maybe someone got an anchor stuck and put a marker on it to come back and get it. What ever it was snagged the prop and yanked the shaft, prop and rudder off the boat in less than a second at an angle that did not appear to damage the strut.

Someone better at geometry probably could pinpoint where the offending item was located since the water is only 10' deep in that area. The only item on his chart map was a lit marker about 200' behind him.

 

[Flyer5]

I would have to rerun the equation but the issue is mass and the speed at which it is moving.

Say you dropped anchor and paid out 200 feet of chain, put it in reverse and firewalled the throttles. If you could get to 7kts in 200 feet....can you imagine the Force applied to the anchor when the chain tightens?

It isn't about the hub. The hub is designed for the pressures associated with rotation. The keyway takes the load in forward and reverse.

As to what he snagged......it had to be a marker of some kind firmly secured to the bottom. Maybe someone got an anchor stuck and put a marker on it to come back and get it. What ever it was snagged the prop and yanked the shaft, prop and rudder off the boat in less than a second at an angle that did not appear to damage the strut.

Someone better at geometry probably could pinpoint where the offending item was located since the water is only 10' deep in that area. The only item on his chart map was a lit marker about 200' behind him.

Aside from being one hell of a strong chain or cable. It would have to pull almost perfectly straight back as well not to do other damage. I have a hard time with the chain / cable assessment. I would think something else would have broken before that a properly clamped hub should let go. The engine should have damaged mounts at the very least. Although the OP probably has a better chance of ins paying out vs last repair center. So maybe it is the best assessment.

 

[highslice]

Not trying to argue either. I was on the boat it reacted like it came out of gear. You mean the “independent” surveyor that the mechanic paid for? I am sure I can pay one to say the opposite. Anyway going the get an estimate.

Dude, all I can add is I really feel for you. That is a tough pill to swallow. I hope all goes well and you can resume your journey. Hopefully the rest is smooth sailing.

 

[spikedaddy99]

I had a shaft shear on my 320 years ago. But it was down near the prop, not inside the boat. No contact with anything. Sea Ray actually paid for the new shaft and prop. It was a known problem in a certain year or 2 for Sea Ray.

 

[Pirate Lady]

What is the latest with this saga? All fixed, get to south?

 

[Flyer5]

What is the latest with this saga? All fixed, get to south?

His latest reply was here.

Rudder Question

I need to replace a rudder on my boat. One has to be made and it is expensive close to 3k. I found a pair of rudders on eBay. They are not a direct match and the dimensions are not the same. I think it could work. The upper shaft is 3/4" longer but there is usually room for that. The length of...

www.clubsearay.com

 

[JHornsby3]

As I read through this post, one thing has been on my mind since the photo of the removed rudder from the shaft. In that first photo, at the top right portion, there is an old crack there. Slightly visible but a different color as the "new" break. That rudder, in my opinion, was damaged before it was forcibly removed from it's shaft. Whether from the first incident (hitting the rocks) or the second (hitting something under the water), it remains that it was compromised before this third incident.

EDIT: I went back and it was the photo in post 177.

 

[PlayDate]

As I read through this post, one thing has been on my mind since the photo of the removed rudder from the shaft. In that first photo, at the top right portion, there is an old crack there. Slightly visible but a different color as the "new" break. That rudder, in my opinion, was damaged before it was forcibly removed from it's shaft. Whether from the first incident (hitting the rocks) or the second (hitting something under the water), it remains that it was compromised before this third incident.

EDIT: I went back and it was the photo in post 177.

I'm pretty sure it would have been a lot worse for the boat if the rudder had not snapped. Keep in mind the rudder snapped after the brand new shaft was pulled out of a brand new coupler. Imagine the stress on the fiberglass hull if the rudder had not snapped. The boat would have sunk in just a few minutes if the hull cracked open around the rudder post.

I agree with you regarding the coloring of the shaft material but I'm not metallurgist. You would have to know metals really well to say that was caused by a previous strike.

 

[JHornsby3]

I'm pretty sure it would have been a lot worse for the boat if the rudder had not snapped. Keep in mind the rudder snapped after the brand new shaft was pulled out of a brand new coupler. Imagine the stress on the fiberglass hull if the rudder had not snapped. The boat would have sunk in just a few minutes if the hull cracked open around the rudder post.

I agree with you regarding the coloring of the shaft material but I'm not metallurgist. You would have to know metals really well to say that was caused by a previous strike.

I'm not an expert either, but I did stay in a Holiday Inn Express last night. Seriously though, going off of past experiences, is what I was basing the comment off of. That discoloration looks like, what is normally from the start of corrosion or exposure to elements. My experiences are from heavy equipment repairs and sheared pins and bucket teeth. Or forces applied to steel.

I've not had the pleasure of this style of drive system, so I'm not sure about what can be torn up. I'm more than sure the forces exerted could have done so much more. Lawrence got pretty lucky, so to speak, that it could have been so much worse. If it would have been me, the steering would have been ripped from the transom and the shaft would have pulled the engine from the mount and out of the bottom of the boat. Again, from my experiences.

I hope he can find a diver that can pull the shaft and prop from the depths and all is at least that much better.

 

[Lawrence Falco]

I finally got my survey report. It seems to back up what I said happened. I have officially disputed the repair with my credit card. Here is an excerpt from the survey:

“
The owner of the vessel stated that he was operating the vessel at cruise speed. This type of operation normally pushes the shaft forward in the coupling as the thrust generated by the rotation of the prop “pushes” the vessel forward. However, the owner stated that he had put numerous hours on the vessel while operating it from Delaware which includes many times shifting the vessel into reverse while docking and maneuvering. This operation would pull the shaft from the coupling which likely loosened it in the coupling. This could have damage or “bound” the key preventing it from being able to be pushed fully back into the coupling. Should the shaft not be fully installed into the coupling with only a short potion inside of the coupling, it is completely possible that it could have come out while operating.
The set screw that was found in the coupling was found to be flush with the interior of the coupling. It was secured firmly in place and not loose. The shaft coupling is an older model that has been used for many years and has been proven to be very reliable. However, the installation of the set screw requires that a “dimple” be drilled into the shaft which would allow the set screw to penetrate into the shaft slightly which prevents the shaft from sliding outward. As the set screw was securely mounted in the coupling and hadn’t loosened and was flush with the interior of the coupling, it is apparent that the shaft was not “dimpled” and the set screw did not penetrate into the shaft. It appears that the set screw was only contacting the surface of the shaft which limits its effectiveness and does not prevent the shaft from slipping out.
With these facts in mind, the Cause of this incident is from the shaft sliding out of the coupling and shearing the rudder when it exited the vessel and the Origin stems from the shaft not being properly installed in the shaft coupling which allowed it to come out of the coupling.”

Hopefully the yard will do the right thing we will see. In the meantime we are moving ahead with the repairs.

 

[Scott215]

Wow, that's a bold statement. But if that's what it was then you should be fine. Unbelievable, Hope you get it fixed and continue on your journey

 

[Flyer5]

I finally got my survey report. It seems to back up what I said happened. I have officially disputed the repair with my credit card. Here is an excerpt from the survey:

“
The owner of the vessel stated that he was operating the vessel at cruise speed. This type of operation normally pushes the shaft forward in the coupling as the thrust generated by the rotation of the prop “pushes” the vessel forward. However, the owner stated that he had put numerous hours on the vessel while operating it from Delaware which includes many times shifting the vessel into reverse while docking and maneuvering. This operation would pull the shaft from the coupling which likely loosened it in the coupling. This could have damage or “bound” the key preventing it from being able to be pushed fully back into the coupling. Should the shaft not be fully installed into the coupling with only a short potion inside of the coupling, it is completely possible that it could have come out while operating.
The set screw that was found in the coupling was found to be flush with the interior of the coupling. It was secured firmly in place and not loose. The shaft coupling is an older model that has been used for many years and has been proven to be very reliable. However, the installation of the set screw requires that a “dimple” be drilled into the shaft which would allow the set screw to penetrate into the shaft slightly which prevents the shaft from sliding outward. As the set screw was securely mounted in the coupling and hadn’t loosened and was flush with the interior of the coupling, it is apparent that the shaft was not “dimpled” and the set screw did not penetrate into the shaft. It appears that the set screw was only contacting the surface of the shaft which limits its effectiveness and does not prevent the shaft from slipping out.
With these facts in mind, the Cause of this incident is from the shaft sliding out of the coupling and shearing the rudder when it exited the vessel and the Origin stems from the shaft not being properly installed in the shaft coupling which allowed it to come out of the coupling.”

Hopefully the yard will do the right thing we will see. In the meantime we are moving ahead with the repairs.

I hope you get things straightened out and the new repairs are made properly. I also hope they check what other work was done and verify it was done properly. Good luck on your journey and hope to see some more updates soon.

 

[PlayDate]

Lawrence,

That is a favorable report. However, making a statement that the shaft was not dimpled is basically unsubstantiated. If the surveyor had pulled the other shaft and it was not dimpled then I would agree…..but not doing so is not consistent with the pictures of the hub which show scoring from the secure bolt out of the hub.

All he had to do was remove the set bolt and see if the round end was still on it. Perhaps he did that. The pictures show it was sheared off.

If he did and the round end is still there….then something else must have caused the scoring in the hub.

 

[Lawrence Falco]

Lawrence,

That is a favorable report. However, making a statement that the shaft was not dimpled is basically unsubstantiated. If the surveyor had pulled the other shaft and it was not dimpled then I would agree…..but not doing so is not consistent with the pictures of the hub which show scoring from the secure bolt out of the hub.

All he had to do was remove the set bolt and see if the round end was still on it. Perhaps he did that. The pictures show it was sheared off.

If he did and the round end is still there….then something else must have caused the scoring in the hu

Could the backing out of the coupling cause the scoring?

I received an email from the original repair yard, they basically ripped my surveyors report to shreds. Mind you they had one done on their own, but did not share the official findings with me other than to say that it was consistent with me striking something in the water or rope or cabling getting attached to the propeller. I provided my insurance company with the surveyors report that I paid for and they are not going to pay any portion of any claim. I’m trying to be reasonable, but I do feel the yard is somewhat responsible for this. I am hoping that they will at least meet me part of the way with the repair cost. I have disputed this with my credit card company. They don’t seem very happy about that. I guess only time will tell what’s going to happen this repair is going to be in the 10k-15k range.

 

[ttmott]

I still don't see how a shaft backing out of the coupling due to workmanship issues can take out the rudder. But I'm 10,000 feet on this one.

 

[Flyer5]

Could the backing out of the coupling cause the scoring?

I received an email from the original repair yard, they basically ripped my surveyors report to shreds. Mind you they had one done on their own, but did not share the official findings with me other than to say that it was consistent with me striking something in the water or rope or cabling getting attached to the propeller. I provided my insurance company with the surveyors report that I paid for and they are not going to pay any portion of any claim. I’m trying to be reasonable, but I do feel the yard is somewhat responsible for this. I am hoping that they will at least meet me part of the way with the repair cost. I have disputed this with my credit card company. They don’t seem very happy about that. I guess only time will tell what’s going to happen this repair is going to be in the 10k-15k range.

I hope somehow the old shaft and prop turn up . That would be the key. I still find it hard to believe a properly installed shaft would rip out without ripping the engine mounts loose as well. Or other damage.