Aft Vibration on the Pride

[Narcussist]

On 9/8/2019 at 2:00 AM, drmom459 said:

It seems the only area in the Pride's MDR that the vibration is noticed is towards the rear of the room - this was on the left side aft of the MDR.  It was entertaining chasing your food around...

 

The video that drmom posted is from 2014. Is it still that bad, or it has been fixed since this video was originally taken?

[NCTribeFan]

I was in 4230 on Miracle way back in 2009.  There was vibration but nothing that bothered us too much.

 

Then, I was in 4232 on Pride in Spring of 2015, I think.  The vibration didn't seem to be any stronger, but this was just after she was having major azipod issues.  Then, there was that last night.  It was awful!  Not sure if we were sailing more slowly returning to Baltimore or what, but I was repeatedly awakened.  It was like I was sound asleep and someone grabbed me by the shoulder and shook me awake.  I was so tired when I got up the next morning, and had a 6+ hour drive home, I was petrified that I'd fall asleep at the wheel, despite the amount of caffeine I consumed.

 

I swore I'd never book another aft cabin again.

 

I don't know if the side cabins in the rear of the ships had the same problems.  I've been aft (not overlooking the stern) on other ships (Fantasy-class) and didn't have any problems other than the usual shaking when the thrusters are engaged.

[chengkp75]

Returning to Baltimore, the ship is sailing with the Gulf Stream, as a following sea.  Azipod ships habitually have poor directional stability (the ability to keep a straight course with little to no steering input) in following seas, so the pods sweep back and forth as I've described above, amplifying the "shimmy".  This got so great on the QM2 with her 4 azipods, that after sea trials they had to drydock the ship to add a "skeg" or false keel leading to the azipods on the centerline, to better direct the water flow along the ship.

[chengkp75]

Duplicate post.

Edited September 9, 2019 by chengkp75

[Steve551]

On 8/22/2019 at 7:50 AM, roxierox said:

We have not sailed on the Pride since 2015. At that time, there was a vibration that could be felt in the dining room in the back of the ship and there have been reports on these boards of people feeling it in their cabins. I was wondering if it is still noticeable after the dry docks that ship has had since we sailed on the Pride. We are looking at an aft cabin for an upcoming cruise. Any recent Pride cruisers have any helpful input? 

Reminds me of the Beach Boy's song, "I'm getting those good vibrations..."

[NCTribeFan]

chengkp75 - thanks for the explanation.  Maybe our sailing was particularly bad since Pride was having azipod issues at that time.  It was a very unpleasant experience (way stronger than a shimmy).  I'll not book one of those cabins on Pride ever again.  

[chengkp75]

2 hours ago, NCTribeFan said:

chengkp75 - thanks for the explanation.  Maybe our sailing was particularly bad since Pride was having azipod issues at that time.  It was a very unpleasant experience (way stronger than a shimmy).  I'll not book one of those cabins on Pride ever again.  

The other problem with following seas is that the stern has less reserve buoyancy than the bow, so the stern will lift out of the water further in a following sea than the bow will in oncoming seas.  This lifting of the stern will bring the propellers closer to the surface, increasing the cavitation created by the propeller due to less water pressure, and this cavitation causes pressure waves on the bottom of the hull above the azipods each time a propeller blade passes the top of its rotation.  The flat hull above the azipods makes this worse on ships with pods than the more "wineglass" shape of the stern of ships with shafted propellers.