Vibration problem on Caribbean Princess

[richmke]

We are underway, and I am sitting in the World Market on Lido deck. The Caribbean Princess has a really bad vibration problem. The silverware basket is rattling and slowly moving across the table. My wife was having a massage, and it felt like they installed vibrating tables.

 

Don't know if it is an HVAC, propulsion, or other problem.

Edited June 30, 2019 by richmke

[skynight]

Just underway? Could be the thrusters.

[zaks pack4]

Back in March 2018 on the Circle Caribbean cruise we also noticed a bad vibration on CB while having a late dinner in the buffet.  

It was a great cruise and we loved the CB!   

[Colo Cruiser]

I prolly wouldn't worry until the CB comes to a stand still in the middle of the ocean.  🤔

[DrivesLikeMario]

According to windy.com, you aren't experiencing big waves or high winds either.  Who knows what the problem is?

[medsed]

4 hours ago, zaks pack4 said:

Back in March 2018 on the Circle Caribbean cruise we also noticed a bad vibration on CB while having a late dinner in the buffet.  

It was a great cruise and we loved the CB!   

That was the best cruise!  

[Kingofcool1947]

6 hours ago, richmke said:

We are underway, and I am sitting in the World Market on Lido deck. The Caribbean Princess has a really bad vibration problem. The silverware basket is rattling and slowly moving across the table. My wife was having a massage, and it felt like they installed vibrating tables.

 

Don't know if it is an HVAC, propulsion, or other problem.

 

A friend emailed me today complaining the vibration is so bad that her  dentures came loose when she was having desert in the World Market .

Enjoy your cruise.

Edited July 1, 2019 by Kingofcool1947

[richmke]

During dinner in the Palm, I did not feel the vibration, but it was loud enough that you had to talk over it.

[richmke]

11 hours ago, skynight said:

Just underway? Could be the thrusters.

Nope. Middle of the ocean underway.

[richmke]

8 hours ago, DrivesLikeMario said:

According to windy.com, you aren't experiencing big waves or high winds either.  Who knows what the problem is?

 

Yes, seas are calm. no visible waves, other than the ship's wake.

[chengkp75]

15 hours ago, richmke said:

We are underway, and I am sitting in the World Market on Lido deck. The Caribbean Princess has a really bad vibration problem. The silverware basket is rattling and slowly moving across the table. My wife was having a massage, and it felt like they installed vibrating tables.

 

Don't know if it is an HVAC, propulsion, or other problem.

Shipbuilding is still more art than science, and ships, even of the same "class", will have different harmonics to their structure, and different harmonics at different locations around the ship.  You "felt" the vibration on higher decks, and "heard" it lower and aft.  This is most likely a propeller vibration.  Things that can make vibrations that occur in "normal" operation and don't indicate a problem with ship's equipment can be:  a particular combination of diesel engines in use, the speed of the propellers (there is a pressure wave hitting the hull each time a propeller blade passes the top of its circle, creating a vibration), the "synchronization" of the two propellers (if each prop has a blade passing the hull at the same time), the wind, the waves, and the current, all in relation to the ship's course.

 

What you are describing sounds like it is caused by a harmonic with the propellers and the hull, most likely from the speed of the propellers being exactly at the harmonic frequency of the hull, or portions of the hull (harmonics tend to increase the intensity of vibrations).  So, possibly a reduction of one or two rpm's could remove the vibration (but would affect the itinerary), or the two props need to be taken out of synchronization, or even a following current (not visible as waves or swells) could be influencing the propeller pressure waves.  Also, if the ship is even marginally "lighter" than normal (i.e. it has less water or fuel than other times), the propellers could be just that much closer to the surface to allow more cavitation, and cavitation is a great cause for hull vibration.

[cruzsnooze]

We had a vibration problem mid ship -  mid deck last year and it was significant. We were told it was the stabilizers and would be fixed when the ship went into dry dock. 

[chengkp75]

3 hours ago, cruzsnooze said:

We had a vibration problem mid ship -  mid deck last year and it was significant. We were told it was the stabilizers and would be fixed when the ship went into dry dock. 

Won't dispute what you were told, but stabilizers won't cause a vibration, unless they are just about ready to fall off the ship.

[PMGS247]

I was on 5/18-5/25 the second sailing after the work was done in freeport.  There's definitely vibration in the Buffet & Planks/Steamers seating areas.  I noticed it virtually every time I visited.  I didn't care, it wasn't that severe nor did it cause any problems or negatively impact my experience in any way, but I did notice it.

 

If the Lido staterooms are affected by the same thing causing the dining area to vibrate I feel for the people in those staterooms.  I found the vibration to be a non-issue for brief meals but it would have been like Chinese water torture if that was 24/7.  Our dolphin mini suite was unaffected.

[richmke]

Around 8pm the vibration noise suddenly stopped in the Palm dining room. Maybe he ship slowed down on its way to the next port.

[nukesubsailor]

 One night when on an old Navy surface ship with twin screws we experienced vibration in the after part of the ship.  At daylight we saw that a fishing net had gotten tangled up with one of the screws, shaft support or rudder.  Once we stopped and sent divers to clear the mess, the vibration stopped.  

Not saying that is what caused the vibration on the Caribbean Princess but it is just one of the many things that can happen to a ship.  As Chengkp75 says, harmonic frequencies are certainly important considerations.  Navy submarine designers go to great lengths to prevent any cause of sound or vibration from being transmitted to the hull.  It would not be cost effective to do that for a cruise ship.

[azbirdmom]

We've cruised twice on the Caribbean Princess, the last time was a couple of years ago.  It did have the worst and most long lasting vibration of any ship we've been on, especially aft, and could be felt all the way up to Horizon Court.  I hadn't seen any complaints about it for a while and thought it may have been resolved but sounds like it's back.

[FloaterBoat]

We're on the CB in a couple months, mid-ship club class mini suite.  I hope we won't have to deal with that noise and feeling 😕

[CCFC]

I'm on Lido deck in 4 weeks, I will report back.

[richmke]

During the Ultimate Ship Tour, I asked about the vibration. The Control Room guy mentioned something about the propellers turning at different speeds.

 

I also asked about the wet dock fix. He said each propeller shaft has 2 motors, and the wiring on one of the motors needed fixing. With just one motor, the propeller can run at 60%. For the fix, the shaft was partially removed so the motor could be taken out. The motor was then rewired. Sounded like it all happened internally to the engine room - no hole was cut in the side of the ship.

 

Don't know if there are 2 separate motors on the shaft, or if one of the windings on the motor was a problem.

[chengkp75]

1 hour ago, richmke said:

During the Ultimate Ship Tour, I asked about the vibration. The Control Room guy mentioned something about the propellers turning at different speeds.

 

I also asked about the wet dock fix. He said each propeller shaft has 2 motors, and the wiring on one of the motors needed fixing. With just one motor, the propeller can run at 60%. For the fix, the shaft was partially removed so the motor could be taken out. The motor was then rewired. Sounded like it all happened internally to the engine room - no hole was cut in the side of the ship.

 

Don't know if there are 2 separate motors on the shaft, or if one of the windings on the motor was a problem.

Each propeller shaft has one motor, with two windings in it.  Each winding is supplied from a separate source, so that a problem with one switchboard does not take the whole propeller out of service.  Each winding supplies 1/2 of the power, so its like about 60-75% of speed.  They could not rewind a motor onboard, they would need to renew the windings, and these are large enough that I don't believe they could get them into the motor room without cutting out the side, but it might be possible.

[Hlitner]

Engineers and Marine Architects can spend lots of time talking harmonics, cavitation, motor vibration,  prop design, etc.  But for the passenger it is simply a matter of vibration and often a "shimmy" which happens on many (if not most) ships.  The fact that this is primarily felt in the aft quarter of a ship has long made me wonder why so many cruisers seek out cabin towards the aft.  DW and I used to joke that many ships have a "happy spot" where the vibration is accompanied by a lot of smiles.   Look at the design of many smaller ultra luxury vessels (including yachts) and you will often find that most of the cabins (including the owners cabin) are located forward...far away from the props.  One irony regarding cruise ships is that some of the best deals can often be found for cabins located far forward where they are not subject to any of that aft vibration or shimmy or possible mid-ship vibration caused by the various mechanical system (i.e. Engines) always arrayed amid ship around the center of gravity.

 

Hank

[Ep010835]

 Most if not all of the Owner’s suites I’ve observed on Princess ships are fully aft. 

 

 Preferring the fully aft Penthouse Suites, we’ve never booked one. Just an observation. 

 

 

 

 

Edited July 8, 2019 by Ep010835

[Host CJSKIDS]

I noticed the vibrations the most when crossing the Straits of Florida in May on the Caribbean princess but once past that it was okay.

[kywildcatfanone]

We were on this past week and I personally didn't notice any vibration issues at all. We spent our day at the terrace pool and it was very smooth overall.  Never ate in the DR, so can't comment on that, but didn't notice any irregular vibration in the buffet area, or at the Crown Grill.