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Ovation dry dock


Trixie21
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There are actually three bearings. The propeller shaft in the pod has a radial bearing (a ball bearing just like any fan or motor) and a thrust bearing that transfers the thrust of the propeller to the ship to move it. The radial bearing is typically not a problem, but the thrust bearing is much higher loaded and can be problematic. Then there is the azimuth bearing, that allows the entire azipod to swivel around and steer the ship. Because of the slow speed of rotation and lighter loading, this bearing also does not present many problems for many years.

 

I had not heard of the ship being in a storm, and am a little skeptical of reported damage to a bearing from the storm. It may be that the thrust bearing monitoring equipment showed that the bearing was wearing faster than planned, and they wanted to renew it early as a preventative measure. But given the quick period in the dock, and this being a shipyard without extensive experience with azipods (even given the almost universal use of ABB engineers to supervise the repairs), I have some doubt that bearings were renewed. I still hold with shaft seals, which keep the oil in the bearings and the sea water out, and which require the removal of the prop or use of a hand-held vulcanizing tool to install (can't be done in the water by a diver).

 

It is also possible that with the ship moving to Alaska, an environmentally sensitive area, they needed to switch to an "environmentally acceptable lubricant" (EAL) in the azipods and thrusters, and these EAL's, which are somewhat new technology in the oil game, require different rubbers in the seals than conventional lubricants, and so they may have swapped out all 5 seals (two pods, three thrusters).

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It is also possible that with the ship moving to Alaska, an environmentally sensitive area, they needed to switch to an "environmentally acceptable lubricant" (EAL) in the azipods and thrusters, and these EAL's, which are somewhat new technology in the oil game, require different rubbers in the seals than conventional lubricants, and so they may have swapped out all 5 seals (two pods, three thrusters).

Wouldn't she have been fitted with these on the assembly line - that was only 2+ years ago?

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Wouldn't she have been fitted with these on the assembly line - that was only 2+ years ago?

 

Not sure. The shaft seal on my ship, while 8 years old, has had a waiver for EAL since the propeller manufacturer, Rolls Royce, did not have a seal that had sufficient data to allow it to be classed as EAL compatible until about 6 months ago. So, we now have until our next scheduled dry dock to install. I would suspect that ABB has been having the same issues. The propeller manufacturers, RR or ABB, have had to test various seal rubber compositions on a limited number of ships to see what is compatible, and they are just now assigning compositions as EAL compatible.

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There are actually three bearings. The propeller shaft in the pod has a radial bearing (a ball bearing just like any fan or motor) and a thrust bearing that transfers the thrust of the propeller to the ship to move it. The radial bearing is typically not a problem, but the thrust bearing is much higher loaded and can be problematic. Then there is the azimuth bearing, that allows the entire azipod to swivel around and steer the ship. Because of the slow speed of rotation and lighter loading, this bearing also does not present many problems for many years.

 

I had not heard of the ship being in a storm, and am a little skeptical of reported damage to a bearing from the storm. It may be that the thrust bearing monitoring equipment showed that the bearing was wearing faster than planned, and they wanted to renew it early as a preventative measure. But given the quick period in the dock, and this being a shipyard without extensive experience with azipods (even given the almost universal use of ABB engineers to supervise the repairs), I have some doubt that bearings were renewed. I still hold with shaft seals, which keep the oil in the bearings and the sea water out, and which require the removal of the prop or use of a hand-held vulcanizing tool to install (can't be done in the water by a diver).

It is also possible that with the ship moving to Alaska, an environmentally sensitive area, they needed to switch to an "environmentally acceptable lubricant" (EAL) in the azipods and thrusters, and these EAL's, which are somewhat new technology in the oil game, require different rubbers in the seals than conventional lubricants, and so they may have swapped out all 5 seals (two pods, three thrusters).

 

All of that makes sense. I have no idea if she was in the storm or not, I hadn't heard of any cruise ships but know of a few Navy and cargo ships caught up in Mangkut. The storm went from the Marshal Islands to Guam/CNMI and then on to the Northern Philippines (Luzon) then onto Hong Kong and the South China coast. I am not even sure where Ovation was at that point. It would have been around the 16th of September. We were still without power and with limited cell service at that point so I wasn't really following the storm much after it passed us.

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Thanks, Cheng! I saw photos of the starboard side propeller being mounted again. And I read that with the newer azipods at least one bearing set should be accessible from the inside.

 

 

steamboats

 

Yes, the problematic thrust bearing is renewable from inside the pod on the newer version. What I've seen is that at the 5 year dry docking, they renew the entire shaft module, which includes the shaft, the radial bearing, the thrust bearing, and its housing all in one piece, and send the removed one off for overhaul and use on the next ship needing one.

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Cheng,

 

 

isn´t the newer azipod version around for more than 2 years now? The Ovation is just 2 years old. But they had problems with the propulsion from the beginning. The ship went into dry dock in Hamburg prior to the hand over to exchange the propellers.

 

 

steamboats

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Cheng,

 

 

isn´t the newer azipod version around for more than 2 years now? The Ovation is just 2 years old. But they had problems with the propulsion from the beginning. The ship went into dry dock in Hamburg prior to the hand over to exchange the propellers.

 

 

steamboats

 

Yes, they are, and that's why I don't think it is a bearing problem this drydock. I hadn't heard about them changing propellers, but that would indicate more of a balance problem of the prop than any azipod problem. As far as I know, ABB doesn't build the propellers (I think Lips builds them for ABB). It may also have been a seal problem that required removing the prop to change the seal.

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Cheng, the propeller change was prior to the hand over of the Ovation. She had to go into dry dock at Blohm & Voss in Hamburg twice prior to delivery. I have no idea whether the problems now are still related to those first problems.

 

 

steamboats

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  • 3 months later...

I read that the Ovation was going to dry dock for a 50 million dollar renovation since China is no longer its home. The long article I read discussed making several changes to the ship now that the US is its home port.  What they are changing, I cannot say but I am sure it will be a lot of the restaurants, casino's, and stores.  Everything was written in Chinese. If you look at youtube videos of the ship you can see the Chinese influence all over thee ship and all the writings. I am sure they want to make it more Americanized. I didn't hear anything about mechanical problems but obviously I don't know the whole story. 

 

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On 1/6/2019 at 10:15 PM, shipmate13 said:

I read that the Ovation was going to dry dock for a 50 million dollar renovation since China is no longer its home. The long article I read discussed making several changes to the ship now that the US is its home port.  What they are changing, I cannot say but I am sure it will be a lot of the restaurants, casino's, and stores.  Everything was written in Chinese. If you look at youtube videos of the ship you can see the Chinese influence all over thee ship and all the writings. I am sure they want to make it more Americanized. I didn't hear anything about mechanical problems but obviously I don't know the whole story. 

 

 

That sounds like Norwegian Joy, not Ovation of the Seas.

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  • 2 months later...
On 1/6/2019 at 10:15 PM, shipmate13 said:

I read that the Ovation was going to dry dock for a 50 million dollar renovation since China is no longer its home. The long article I read discussed making several changes to the ship now that the US is its home port.  What they are changing, I cannot say but I am sure it will be a lot of the restaurants, casino's, and stores.  Everything was written in Chinese. If you look at youtube videos of the ship you can see the Chinese influence all over thee ship and all the writings. I am sure they want to make it more Americanized. I didn't hear anything about mechanical problems but obviously I don't know the whole story. 

 

that is what i had heard as well

 

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