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Lavaland

By Lavaland,
in Royal Caribbean International

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Mykitteh

Mykitteh

Posted
Posted
We had difficulty with loud noises coming from the back of the boat. Sometimes it sounded like a chain dragging, other times it was more of a grinding sound. You could hear it through the balcony windows. It made sitting outside on the balcony almost impossible some nights. On the comment card, I said that I hoped they got it fixed when they went into dry dock. I honestly wondered a few times if we would make it back with that loud noise. Wonder if that was the propeller or something to do with the propeller that finally broke.

 

We were on Adventure a couple weeks ago in an aft JS and my mom said that exact thing. This one night it was really loud at the back, but I can't remember which night it was.

 

Sucks for those on this week and next they won't get the full cruise they'd planned for.

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Folk Singer

Folk Singer

Posted
Posted
Just read on our Roll Call that the Adventure of the Seas, which I am supposed to be boarding in 5 days is currently stuck in St. Kitts with a busted propeller.... Not really panicking because I'm going on vacation NO MATTER WHAT!! But just curious as to what would happen if it's not fixed in time? Do they cancel our cruise or send in another ship? I imagine they are all pretty busy this time of year.... anyone have any experience with this?

 

 

sorry to hear this.:(

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cruizinawayinva

cruizinawayinva

Posted
Posted
We were on Adventure a couple weeks ago in an aft JS and my mom said that exact thing. This one night it was really loud at the back, but I can't remember which night it was.

 

Sucks for those on this week and next they won't get the full cruise they'd planned for.

 

:( Hope it's quieter now that it is officially broken. :)

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ahecht

ahecht

Posted
Posted

I know that Independence had its prop blades removed by divers during a normal port-of-call stop, so if it were something that simple it would likely be fixed during one of the extended port stops.

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daljettjockie

daljettjockie

Posted
Posted
Since they are azipods, which are variable speed motors, the propellers are fixed blade type, so there is no option of changing one blade. With the exception of US Navy nuclear subs, I don't know of anyone who "jumps" a wheel of this size in water. If the propeller is actually damaged, it will require drydocking, and the azipods on Adventure are the older V series, which require drydocking to renew the thrust bearings, though propeller damage is more dangerous to the roller bearings than thrust bearings. But then again, the roller bearings require drydocking, even for the newer X series pods.

 

While I cannot say whether they will cancel the next cruise to fix this, you cannot just say "well we were coming in for service next week, how about us coming this week?". Drydock slots are booked about a year in advance, especially for Grand Bahamas, so just taking the ship to the yard would not help the situation if they couldn't get into the dock.

 

 

Vibration noted on previous cruises, and the reported divers leads me to suspect that one of the propellers was bent or split on one or more blades. The normal remedy for this is to have divers remove the damaged section of the affected blade(s) and then remove an equal area from the opposite blade to balance the propeller. Doing this underwater is tough to do, and if there are an odd number of blades, it becomes something of a trial and error method: remove a little, try the propeller, if it vibrates, take a little more, and so on until the optimum balance is achieved.

 

I have not researched the itineraries in question, so I don't know the required speeds to make the ports. If the ship needs to make upwards of 75% of full speed, then taking one pod out would necessitate an itinerary change. The drag would not be too great with one pod out, as they will just let it free-wheel, as was done on Allure for the last couple of months.

 

As to maneuvering, one azimuthing pod would be quite sufficient for docking, as they are far more powerful than the thrusters (even 2-3 combined) that they replaced. The real problem will come with the ship's return to the US. If an azimuthing pod is affected, this takes out the second, redundant, means of steering the ship. This will require notification to the USCG prior to entering any port, and the CG will probably require at least one tug escort the ship from the sea buoy to the dock, in case the other steering pod were to fail. There will also be paperwork required to get permission from the USCG to leave port with only one steering gear working.

 

Again, just speculation, but my money would be on an abbreviated cruise next week and then to drydock.

 

Any ideas what her top speed in knots would be with one of the azipods inop?

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chengkp75

chengkp75

Posted
Posted
Any ideas what her top speed in knots would be with one of the azipods inop?

 

She has 3 14Mw pods and a design top speed of 22knots. With one pod out (67% propulsion), I would say 16-17knots (always remembering weather and current factors in transit speed).

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chengkp75

chengkp75

Posted
Posted
Not bad. I would have thought it would have been less. Thanks for the info.

 

The speed/horsepower curve is a hyperbolic, and the speed is roughly equal to the square of the horsepower, so the faster you go, those last couple of knots are quite expensive from a power and fuel standpoint.

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Worn out mailman

Worn out mailman

Posted
Posted
I was looking around for more info or an update from Royal, but I haven't seen anything on either the consumer nor agent site.....

 

The same thing happened to us in 2012, in advance of our sailing on Caribbean Princess. She started having problems on the two our three sailings before ours. On the sailing immediately prior to ours, she had an overnight in St Martin, skipped the other stops and limped back to San Juan. I knew all this was going on entirely due to the Princess boards here on CC.

 

We were officially notified by Princess 2 days before our sailing that it was canceled. We then scrambled and ended up on Allure. I can't imagine the shock for the non Cruise

Critic readers who get so little advance notice.

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LetsGetWet!

LetsGetWet!

Posted
Posted
Since they are azipods, which are variable speed motors, the propellers are fixed blade type, so there is no option of changing one blade. With the exception of US Navy nuclear subs, I don't know of anyone who "jumps" a wheel of this size in water. If the propeller is actually damaged, it will require drydocking, and the azipods on Adventure are the older V series, which require drydocking to renew the thrust bearings, though propeller damage is more dangerous to the roller bearings than thrust bearings. But then again, the roller bearings require drydocking, even for the newer X series pods.

 

While I cannot say whether they will cancel the next cruise to fix this, you cannot just say "well we were coming in for service next week, how about us coming this week?". Drydock slots are booked about a year in advance, especially for Grand Bahamas, so just taking the ship to the yard would not help the situation if they couldn't get into the dock.

 

Vibration noted on previous cruises, and the reported divers leads me to suspect that one of the propellers was bent or split on one or more blades. The normal remedy for this is to have divers remove the damaged section of the affected blade(s) and then remove an equal area from the opposite blade to balance the propeller. Doing this underwater is tough to do, and if there are an odd number of blades, it becomes something of a trial and error method: remove a little, try the propeller, if it vibrates, take a little more, and so on until the optimum balance is achieved.

 

I have not researched the itineraries in question, so I don't know the required speeds to make the ports. If the ship needs to make upwards of 75% of full speed, then taking one pod out would necessitate an itinerary change. The drag would not be too great with one pod out, as they will just let it free-wheel, as was done on Allure for the last couple of months.

 

As to maneuvering, one azimuthing pod would be quite sufficient for docking, as they are far more powerful than the thrusters (even 2-3 combined) that they replaced. The real problem will come with the ship's return to the US. If an azimuthing pod is affected, this takes out the second, redundant, means of steering the ship. This will require notification to the USCG prior to entering any port, and the CG will probably require at least one tug escort the ship from the sea buoy to the dock, in case the other steering pod were to fail. There will also be paperwork required to get permission from the USCG to leave port with only one steering gear working.

 

Again, just speculation, but my money would be on an abbreviated cruise next week and then to drydock.

Wow, sounds exactly like the trial & error process for balancing my ceiling fans with those little balance kits they sell! :D

 

Thanks for the detailed explanations, very interesting and appreciated!

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chengkp75

chengkp75

Posted
Posted
Wow, sounds exactly like the trial & error process for balancing my ceiling fans with those little balance kits they sell! :D

 

Thanks for the detailed explanations, very interesting and appreciated!

 

Yeah, but the ship doesn't have to worry about the dust bunnies on the blades!

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A2Mich

A2Mich

Posted
Posted
Since they are azipods, which are variable speed motors, the propellers are fixed blade type, so there is no option of changing one blade. With the exception of US Navy nuclear subs, I don't know of anyone who "jumps" a wheel of this size in water. If the propeller is actually damaged, it will require drydocking, and the azipods on Adventure are the older V series, which require drydocking to renew the thrust bearings, though propeller damage is more dangerous to the roller bearings than thrust bearings. But then again, the roller bearings require drydocking, even for the newer X series pods.

 

While I cannot say whether they will cancel the next cruise to fix this, you cannot just say "well we were coming in for service next week, how about us coming this week?". Drydock slots are booked about a year in advance, especially for Grand Bahamas, so just taking the ship to the yard would not help the situation if they couldn't get into the dock.

 

Vibration noted on previous cruises, and the reported divers leads me to suspect that one of the propellers was bent or split on one or more blades. The normal remedy for this is to have divers remove the damaged section of the affected blade(s) and then remove an equal area from the opposite blade to balance the propeller. Doing this underwater is tough to do, and if there are an odd number of blades, it becomes something of a trial and error method: remove a little, try the propeller, if it vibrates, take a little more, and so on until the optimum balance is achieved.

 

I have not researched the itineraries in question, so I don't know the required speeds to make the ports. If the ship needs to make upwards of 75% of full speed, then taking one pod out would necessitate an itinerary change. The drag would not be too great with one pod out, as they will just let it free-wheel, as was done on Allure for the last couple of months.

 

As to maneuvering, one azimuthing pod would be quite sufficient for docking, as they are far more powerful than the thrusters (even 2-3 combined) that they replaced. The real problem will come with the ship's return to the US. If an azimuthing pod is affected, this takes out the second, redundant, means of steering the ship. This will require notification to the USCG prior to entering any port, and the CG will probably require at least one tug escort the ship from the sea buoy to the dock, in case the other steering pod were to fail. There will also be paperwork required to get permission from the USCG to leave port with only one steering gear working.

 

Again, just speculation, but my money would be on an abbreviated cruise next week and then to drydock.

 

 

Hey thanks for the great info. I did know that the screws were fixed pitch, but didn't know whether or not the blades were replaceable individually or not. At one time, many ships did carry spare blades, but could they have possibly been for a variable pitch screw? I wasn't sure of the specs and construction details of the entire Azipod system, so was making an (incorrect) assumption that the blades may be replaceable independently of each other. Speaking of variable speed, do you happen to know if the drive motor itself is a DC motor or AC with a VFD type control syetem? I would venture a guess that the motors are AC, as if I'm not mistaken, a DC motor capable of the horsepower needed would likely be horribly inefficient.

 

I know that a wheel can be changed on smaller ships while in port, but don't know at what size or tonnage this becomes unrealistic or simply impossible. I may have to look up the specs on the ABB pods and see what I can find. Thanks for the great tech info!

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chengkp75

chengkp75

Posted
Posted
Hey thanks for the great info. I did know that the screws were fixed pitch, but didn't know whether or not the blades were replaceable individually or not. At one time, many ships did carry spare blades, but could they have possibly been for a variable pitch screw? I wasn't sure of the specs and construction details of the entire Azipod system, so was making an (incorrect) assumption that the blades may be replaceable independently of each other. Speaking of variable speed, do you happen to know if the drive motor itself is a DC motor or AC with a VFD type control syetem? I would venture a guess that the motors are AC, as if I'm not mistaken, a DC motor capable of the horsepower needed would likely be horribly inefficient.

 

I know that a wheel can be changed on smaller ships while in port, but don't know at what size or tonnage this becomes unrealistic or simply impossible. I may have to look up the specs on the ABB pods and see what I can find. Thanks for the great tech info!

 

Yes, wherever you see those spare blades bolted to the fore deck of ships, they are variable pitch. Most of the older cruise ships with shafted propulsion were both variable speed and variable pitch systems. The reason that pods are not variable pitch is that it would be very difficult to get the pitch mechanism into the pod along with the drive motor.

 

The ships generate 10,000 volt power from the diesels, and this is stepped down to about 800 volts, and goes through a variable frequency drive to accomplish the variable speed of the motor.

 

I don't think I've seen a prop removed in the water on any thing larger than a tugboat. One reason is that large props are "keyless" and rely on the shrink fit of the prop on the shaft to keep it in place, not a key like small props on pleasure boats, etc. This shrink fit is formed by having the bore of the prop and the shaft tapered, and the prop is moved up the taper as far as possible, and then 40,000psi hydraulic oil is used to expand the prop bore, and the prop is forced further up the shaft, when the oil pressure is released, the prop shrinks back down, gripping the shaft with tremendous force. Because oil is used to do this, it generally cannot be done in water, and you also don't want any contaminants between the prop and shaft.

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chengkp75

chengkp75

Posted
Posted
Much less stressed to know that it is the Fixipod. I think we will make the full itinerary now.

 

Can you post the itinerary? I can check and estimate whether it is possible. The fixipod still takes out 1/3 of the propulsion power.

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sjpsoccer14

sjpsoccer14

Posted
Posted

The original itinerary for next week is:

- San Juan

- At sea

- Barbados

- St. Lucia

- Antigua

- St. Marten

- St. Croix

- San Juan

 

I am hopefully but do not know how it will be possible with a reduce traveling speed.

 

 

Sent from my iPhone using Cruise Critic Forums mobile app

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