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Panorama Nov-Dec 2023 sailings cancelled!

weezal

By weezal,
in Carnival Cruise Lines

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LaRue1975

LaRue1975

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On 12/4/2023 at 2:35 PM, chengkp75 said:

Again, don't want to be debbie downer, but those pictures worry me a little.  I don't see the scaffolding being set up that would be normal for a typical bearing/seal replacement problem.  The first picture shows what looks like a dock arm pressure washing the area around the azimuthing (pod rotation) seal area of the port pod, and the second picture shows what looks like oil dripping from the same azimuth seal on the starboard pod.  This could be more serious than originally thought, or it could just be early into the repair.  

 

Where are these pictures posted?  Hopefully we get some more, and I can try to remote guess what is going on.  Tomorrow should be an important day for clues.

I haven’t seen any additional pics of the repair so far but I did read on the Ship Report page that the Panorama is tentatively scheduled to depart Portland on the 12th with the emphasis on tentative. I believe the person that made the comment works at the dock. Also there have been comments on social media that I thought maybe you could comment on. We are all following along and sharing any info we get but don’t have the expertise to evaluate the repair situation. If it is correct they are redesigning the azipods so they can be repaired without a dry dock that would be great news for all the Vista Class ships:

 

"The 'culprit' is actually inside the hull. The bearing on the vertical shaft that allows the Azipod to rotate for steering overheats from vibration at normal cruising speed. Current design requires removal of the pod to service the bearing. Modified design will allow the bearing to be replaced from inside the hull while in port." 

Or in plane English.... As someone else said: "This will be repair only (just bearing replacement). All new redesigned Azipods will be installed during the Oct 2024 Singapore dry dock."

 

 

 

 

 

 

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chengkp75

chengkp75

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Posted (edited)
14 hours ago, LaRue1975 said:

"The 'culprit' is actually inside the hull. The bearing on the vertical shaft that allows the Azipod to rotate for steering overheats from vibration at normal cruising speed. Current design requires removal of the pod to service the bearing. Modified design will allow the bearing to be replaced from inside the hull while in port." 

Or in plane English.... As someone else said: "This will be repair only (just bearing replacement). All new redesigned Azipods will be installed during the Oct 2024 Singapore dry dock."

This is interesting, if accurate, as this is the first time I've heard of an azimuth bearing failing, in all the years that azipods have been around, even when subjected to extreme stress from storms like the Anthem of the Seas a couple years ago, where they burned out the azimuth brakes due to fighting the storm.  While they possibly could redesign the azipod for internal replacement of the bearing, since the bearings have not been known to fail all that much, I would be surprised if that modification was already available, and if not, then it would take a year or so to come up with a new design.  I am surprised that there were two azimuth bearing failures (or at least overheating), especially on the same ship, as this bearing does not rotate much, and at low speed, though if they are talking about vibration causing the overheating, this could be a design flaw in the Vista class ships, where the harmonics of the propellers turning at normal cruising speed, are in harmony with the natural frequency of the hull, causing excess vibration.  There may need to be other modifications done to the ship at the next drydock to dampen the vibration, and I think this may actually be what will happen, rather than a redesigned azimuth bearing.  This bearing is in the size of about 10 feet in diameter, and therefore even internal replacement would require cutting a large hole in the side of the ship to bring the new bearing in and the old out.  My guess at modifications would be either structural strengthening around the azipods to change the natural frequency, or a different propeller to again change the speed the propeller needs to turn for cruising speed, or both.

 

Panorama already has the newer XO type azipod, which allows replacement of the more commonly failed thrust bearing from inside the pod, so I had my suspicions about the azimuthing system when they needed to dry dock, though it could have been something else.  Now that I think about it, I don't see how they could redesign the azipod to renew the azimuth bearing without dropping the pod off the ship (which is what they will be doing now), as this bearing is the only support holding the pod into the ship.

 

Apologies if this has gotten a little technical.

Edited by chengkp75
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LaRue1975

LaRue1975

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17 hours ago, chengkp75 said:

This is interesting, if accurate, as this is the first time I've heard of an azimuth bearing failing, in all the years that azipods have been around, even when subjected to extreme stress from storms like the Anthem of the Seas a couple years ago, where they burned out the azimuth brakes due to fighting the storm.  While they possibly could redesign the azipod for internal replacement of the bearing, since the bearings have not been known to fail all that much, I would be surprised if that modification was already available, and if not, then it would take a year or so to come up with a new design.  I am surprised that there were two azimuth bearing failures (or at least overheating), especially on the same ship, as this bearing does not rotate much, and at low speed, though if they are talking about vibration causing the overheating, this could be a design flaw in the Vista class ships, where the harmonics of the propellers turning at normal cruising speed, are in harmony with the natural frequency of the hull, causing excess vibration.  There may need to be other modifications done to the ship at the next drydock to dampen the vibration, and I think this may actually be what will happen, rather than a redesigned azimuth bearing.  This bearing is in the size of about 10 feet in diameter, and therefore even internal replacement would require cutting a large hole in the side of the ship to bring the new bearing in and the old out.  My guess at modifications would be either structural strengthening around the azipods to change the natural frequency, or a different propeller to again change the speed the propeller needs to turn for cruising speed, or both.

 

Panorama already has the newer XO type azipod, which allows replacement of the more commonly failed thrust bearing from inside the pod, so I had my suspicions about the azimuthing system when they needed to dry dock, though it could have been something else.  Now that I think about it, I don't see how they could redesign the azipod to renew the azimuth bearing without dropping the pod off the ship (which is what they will be doing now), as this bearing is the only support holding the pod into the ship.

 

Apologies if this has gotten a little technical.

Thank you so much for your analysis, I find it very interesting. The general consensus is that a design flaw with the azipods is the lingering problem but I still don’t understand what an azipod is except that is key to propulsion and steering. I really like the Vista class ships and love their Havana area. The Panorama is the cream of the crop and fortunately for me Long Beach is 90 minutes from home so I have big plans for her.  When the current issue arose the word was it was something that had not happened before so everything was up in the air. I’m not sure if that is the case or if it was dry dock availability on the West Coast that was the problem.  Regardless, it definitely seems like things are heading in the right direction, no news today which means we are still on schedule. If I get pics of the repair or any other info I will post it here for those like me that are hoping our cruises are a go. Any input you have is greatly appreciated, I’ve learned a lot already, thank you!

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jsglow

jsglow

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Super interesting Chief. A harmonics problem certainly makes sense to me given that Panorama is at max cruising speed more than any other Vista Class ship. Now I suspect any type of propeller change designed to offset that might cost a little in efficiency (otherwise you would use that different propeller in the first place) but there's nothing more inefficient than sitting in a dry dock out of service for a month!

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chengkp75

chengkp75

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It still surprises me that this bearing is overheating.  Given that it does support the weight of the pod, and transmits the propulsive force from the pod to the hull, and this is quite a load, but the bearing is designed for this.

 

What a redesigned propeller would do is trade a little more "pitch" (the distance the propeller (a screw) advances in one revolution) for a little less rpm.  Rpm times pitch is the speed of the ship.  So, changing the rpm changes the frequency of the wave pulses from the propeller tips to the hull, which could get that vibration outside the natural frequency of the hull, and alleviate the vibration.  A redesigned propeller, that exchanges pitch for speed, would not effect efficiency to any real extent.  The pods hang the propellers far enough below the hull that the effect of blade passage close to the hull causing vibrations is minimized.

 

I would think that if vibration was so extensive to cause a very low rotational speed bearing to overheat, that it would be widely felt in the after areas of the ship, resulting in passenger complaints.  I'm a bit more inclined to think that there is a control issue here, where the bridge officers have set steering parameters such that the pods swing back and forth more than needed to maintain course.  I know that the QM2 had to go back into dry dock when first built, because they found that the 4 azipods could not keep the ship on a steady course with following seas, so they added a "skeg" or extended keel in front of and between the inner two pods to create some hydrodynamic stability.

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chengkp75

chengkp75

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I've never heard of one having problems before.  As I said earlier, the only azimuthing problem I've heard of was burning out the clutches (not brakes as I stated before) on the Anthem.  

 

Ship building is still a lot more art than science, and I've observed different vibration problems caused by harmonics on several ships that are "identical", resulting in different remedies on different ships.  The harmonics of a hull can vary between "sister" ships just because of the temperature in the shipyard when sections are welded together, or the very slight variations in steel thickness between batches of plating.

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chengkp75

chengkp75

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3 hours ago, LaRue1975 said:

The Panorama is officially on schedule to arrive in Victoria Tuesday at 7 AM.

That means she needs to leave Portland Monday morning, so to allow for some sea trials of the repaired pods, they would likely need to get her off the blocks and out of the dock this evening.

 

And, the estimates put into Marinetraffic via the AIS system, is manually entered by the navigating officer on the ship, and is frequently a "place holder" when waiting on more detailed information.  Not saying it isn't correct, but it is an estimate.

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LaRue1975

LaRue1975

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5 hours ago, chengkp75 said:

That means she needs to leave Portland Monday morning, so to allow for some sea trials of the repaired pods, they would likely need to get her off the blocks and out of the dock this evening.

 

And, the estimates put into Marinetraffic via the AIS system, is manually entered by the navigating officer on the ship, and is frequently a "place holder" when waiting on more detailed information.  Not saying it isn't correct, but it is an estimate.

This makes sense because the Ship Report’s info comes from the pilots on the Columbia River and it estimates the Panorama is leaving Portland at 2 AM tonight. So it looks like the sea trials will be the last hurdle they need to get over to be sure we are cruising for Christmas and New Years. There is a cushion for some delay but if the pods fail and she has to go back to dry dock that will not be a happy ending to 2023 for us. Thank you so much for sharing your expertise, I’m keeping my fingers and toes crossed! 🤞🤞🤞🤞

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jsglow

jsglow

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Going to be interesting to see if any 'redesign' work is added to the Singapore dry dock in less than a year. I'm fairly confident that what they simply did this time was a comprehensive repair. Assuming that work has been successful, the engineers have several months to design/build/implement any retrofit they decide to do going forward. I don't suppose we'll actually hear anything about it because everything is always supposed to be 'brilliant' but there seems little doubt that they will want to learn as much as they can about these Vista Class ships and respond accordingly. They are going to be a backbone of the fleet for many years. This all feels to me like that old adage about not buying a car from the first model year after a complete redesign.

 

Keep a sharp eye out for ship movement. No doubt holiday cruisers will benefit from the info.

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nwcruiselover

nwcruiselover

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This is such an interesting thread, and thanks to everyone who is providing information and insights.  My upcoming cruises on Panorama are 1/7/24 and 1/13/24, and I’ll be on the TP next October as well.  I’m hoping the Panorama will be ready for those with December 23 and December 30 sailings!

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LaRue1975

LaRue1975

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Looks like all is well with the Panorama, yay! She should be out of the Columbia River in a few hours and on her way to Victoria to retrieve her tail. The President of Carnival and now John Heald on Facebook have both announced that she will be ready for the Christmas cruise December 23rd. I think that is enough assurances to get out the suitcases! 🥳🛳️🥳 

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AZ-EmptyNesters

AZ-EmptyNesters

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27 minutes ago, LaRue1975 said:

Looks like all is well with the Panorama, yay! She should be out of the Columbia River in a few hours and on her way to Victoria to retrieve her tail. The President of Carnival and now John Heald on Facebook have both announced that she will be ready for the Christmas cruise December 23rd. I think that is enough assurances to get out the suitcases! 🥳🛳️🥳 

I'm a little concerned about the sea trials some have spoken about, as I imagine that can only happen once she's out at sea a bit.

But overall...YAY!!!  12 days and counting!

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