Freedom of the Seas drydock

[ckrobyn]

I will too -- maybe I'll open one of the bottles of wine we can bring and start feeding it to DH.

 

See? Now you're talkin'! :p

[Ourusualbeach]

Good info -- if RCI altered the itinerary to eliminate Coco Cay, they would be able to make the more distant ports. Hope I'm not offending folks who like Coco Cay or stockholders like myself who like Coco Cay's revenue enhancement (actually they could make lots of money from an extra sea day with the casino and all bars opened).

 

They can still stop at Coco Cay, that will just shorten the port time a bit in order to make the next stop. The biggest issue on the Easter is St. Maarten and the distance back to Canaveral. In order to make it back in time they need to leave St. Maarten by 1:00 at the latest which means all aboard by 12:30.

[DeepFreeze]

Realistically, any of us sailing in the next few weeks (or months) can expect either altered itineraries and/or shortened port times.....

Glad I bought that booze package yo :cool:

[SherriZ366]

And we were on FOS at the start of May last year, and the problems with that pod were already well known, and they were already discussing options. We skipped Coco Cay on a day where the seas were calm, and vibrated all the way to St. Thomas, St Martin, and back. The ship has been limping for more than a year. Contingency plans are what they are.

 

 

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We were on the same cruise and I think we may have gotten into St. Thomas a bit early.

[Ourusualbeach]

And we were on FOS at the start of May last year, and the problems with that pod were already well known, and they were already discussing options. We skipped Coco Cay on a day where the seas were calm, and vibrated all the way to St. Thomas, St Martin, and back. The ship has been limping for more than a year. Contingency plans are what they are.

 

 

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Yes and there is a big difference between a contingency plan that is put together more than 6 months in advance and a last minute change in itinerary that was cobbled together as you stated in your previous post.

[justjim312]

Good info -- if RCI altered the itinerary to eliminate Coco Cay, they would be able to make the more distant ports. Hope I'm not offending folks who like Coco Cay or stockholders like myself who like Coco Cay's revenue enhancement (actually they could make lots of money from an extra sea day with the casino and all bars opened).

 

The casino is open all day already when at Coco Cay. With more people and time maybe RCL will make enough money to fix the ship correctly this time. Carnival can't be any worse than this outfit.

[Cuizer2]

Are you saying that they can make this run to Port C in a timely manner at 18 knots or lower? I am going to be watching Marine Traffic to see when FR gets into Port C on Sunday.

 

Yes. It is about an 775 mile run. 18 knots is about 20.7 MPH. So at 18 knots it would take about 37 1/2 hours.

[ryano]

I know. I'm just mad for the moment I guess.:mad:

 

It's understandable! Especially that it definitely effected one your cruises and potentially could effect your other.

 

We were all expecting to read and hear about all the changes only to find out the MAIN reason she was drydocked early is still not fixed.

 

I will only get red faced at a total cancellation. There is nothing I can do about it but I know I will be terribly upset.

[SherriZ366]

Yes. It is about an 775 mile run. 18 knots is about 20.7 MPH. So at 18 knots it would take about 37 1/2 hours.

Thanks for the calculation.

[SherriZ366]

It's understandable! Especially that it definitely effected one your cruises and potentially could effect your other.

 

We were all expecting to read and hear about all the changes only to find out the MAIN reason she was drydocked early is still not fixed.

 

I will only get red faced at a total cancellation. There is nothing I can do about it but I know I will be terribly upset.

I agree about what we were expecting -- we were on one of the cruises that was cancelled for Drydock.

[Cuizer2]

They missed it the last time on the trip prior to our Eastern Caribbean. They arrived at Port Canaveral at 8:30 AM.

Bob E

 

Was it able to make the same speed it is making now? Was the ship late leaving Cozumel for some reason?

[Cuizer2]

Hard to say, I'm not tech savvy enough to enlarge it.

 

Here is as big as it gets ...

 

[OSUZorba]

Snip

 

chengkp, thank you for your informative posts. It is always nice hearing from another engineer in their area of expertize.

 

A couple of questions for you: 1) Is there any way they can brake the shaft to prevent the windmilling? 2) I believe the prop blades are fixed pitched, so they can not feather the prop, is that correct? 3) Is it possible for them to ops-check the pods in drydock, or do they have to be submerged to do operational checks?

 

Thanks!

[A2Mich]

chengkp, thank you for your informative posts. It is always nice hearing from another engineer in their area of expertize.

 

A couple of questions for you: 1) Is there any way they can brake the shaft to prevent the windmilling? 2) I believe the prop blades are fixed pitched, so they can not feather the prop, is that correct? 3) Is it possible for them to ops-check the pods in drydock, or do they have to be submerged to do operational checks?

 

Thanks!

 

Wouldn't braking the shaft create even more drag, further increased fuel consumption, and potentially additional wear on the two working pods? I would think that as long as the bearings are being lubricated, that the windmilling would be less stressful overall. IDK--not a marine engineer myself. If the Fixipod is not operating properly, best thing to do would be to remove the blades (again).

 

 

 

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[Cuizer2]

Wouldn't braking the shaft create even more drag, further increased fuel consumption, and potentially additional wear on the two working pods? I would think that as long as the bearings are being lubricated, that the windmilling would be less stressful overall. IDK--not a marine engineer myself. If the Fixipod is not operating properly, best thing to do would be to remove the blades (again).

 

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I agree.

 

However, before everybody starts looking for discount prices on ******, lets find out if it can be fixed without a dry dock. As I said, it took three cruises (30 days) to get the part(s) and fix the Enchantment in February/March 2012. They rearranged the itineraries a bit and everything was fine. I don't know of any unhappy people on my cruise. Most of us liked the revised itinerary better.

[A2Mich]

I agree.

 

 

 

However, before everybody starts looking for discount prices on ******, lets find out if it can be fixed without a dry dock. As I said, it took three cruises (30 days) to get the part(s) and fix the Enchantment in February/March 2012. They rearranged the itineraries a bit and everything was fine. I don't know of any unhappy people on my cruise. Most of us liked the revised itinerary better.

 

 

I wouldn't care too much if they change/modify our itinerary and reduce time at Coco Cay. I actually like St Thomas and St Maarten and have private tours booked on both and would rather have reduced time at CC rather than at St Thomas. Obviously if St Maarten has to be cut short for the return to PC, then that's what they need to do. See you in 75 days, BTW!

 

 

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[ahecht]

chengkp75,

 

Here is a picture taken off the stern of FOS 3 hrs ago.

 

What do you think? 2 or 3?

 

[ATTACH]339070[/ATTACH]

 

 

 

 

 

 

Hello! My name is Kevin.

 

Hard to say, I'm not tech savvy enough to enlarge it.

Here's a bigger version:

 

[A2Mich]

It does appear that all 3 screws are operating. Would make sense that the Azipod wash is less noticeable than the Fixipod's, as the Azipod screws are ahead of the pods whereas the Fixipod screw is behind the pod, and the rear sponson may also help to settle down the wash as well. Hard to say 100% for sure with that person's shoulder blocking the view.

 

 

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[OSUZorba]

Wouldn't braking the shaft create even more drag, further increased fuel consumption, and potentially additional wear on the two working pods? I would think that as long as the bearings are being lubricated, that the windmilling would be less stressful overall. IDK--not a marine engineer myself. If the Fixipod is not operating properly, best thing to do would be to remove the blades (again).

 

I'm an aerospace engineer, so not sure about the marine side, but I know in aviation a windmilling engine causes more drag than a locked up one. I assume it would be the same for a ship. I was also thinking that braking the shaft could allow them to work on it while not in port (only if the shaft was positively braked, not just by friction).

 

Basically a windmilling prop creates negative thrust, pulling the aircraft backwards. In addition to the negative thrust, you have all the friction in drive system that the windmillling has to overcome. A similar situation most people would be familiar with is putting your car in low gear while going down a mountain pass, your tires are basically windmilling and the friction of the drive system is creating drag (cars have more friction because you are compressing air in the engine, where a ship's pod isn't back driving an engine, but you'd still have friction in the bearings and any shaft driven accessories like oil pumps, etc).

[A2Mich]

I'm an aerospace engineer, so not sure about the marine side, but I know in aviation a windmilling engine causes more drag than a locked up one. I assume it would be the same for a ship. I was also thinking that braking the shaft could allow them to work on it while not in port (only if the shaft was positively braked, not just by friction).

 

Basically a windmilling prop creates negative thrust, pulling the aircraft backwards. In addition to the negative thrust, you have all the friction in drive system that the windmillling has to overcome. A similar situation most people would be familiar with is putting your car in low gear while going down a mountain pass, your tires are basically windmilling and the friction of the drive system is creating drag (cars have more friction because you are compressing air in the engine, where a ship's pod isn't back driving an engine, but you'd still have friction in the bearings and any shaft driven accessories like oil pumps, etc).

 

 

Interesting--exactly opposite of what I would expect. So realistically, the only option outside of repair of course, would be to remove the screw or the blades to further reduce the drag.

 

 

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[chengkp75]

Okay, questions in order.

 

It looks like the center prop is turning, but that could be freewheeling or they could be using it at reduced power.

 

As A2 says, the azipod propellers are ahead of the pod, one of the efficiency advantages of the pods in that the flow to the screw is unimpeded, while the fixipod has the prop behind. I'm not sure whether the azipods are inboard turning or outboard turning (the center pod makes a difference), as these give differing wakes and power curves (most twin screw ships are inboard turning).

 

Zorba: The difference between an airplane propeller and a ship's is that the blades of the airscrew represent only a fraction of the "swept area" of the blades, while the ship's blades make up nearly all of the area. Locking the prop would present a "barn door" to the flow of water, especially if the outer pods are inboard turning. Most airscrews are not close enough together to have their wash interact. The impact of that "barn door" would be enormous to fuel consumption and power. The only friction in a pod are the roller bearings of the motor. However, it does require some power to force the screw to turn, which comes from the ship's wake, so even freewheeling will require some power. An interesting note is that since the motor is driven by a Variable Frequency Drive, that converts the generated 60 Hz a/c power to a variable frequency to allow speed changes to the motor, these drives actually have "regenerative braking" in them, where when the prop is turning faster than commanded, the drive motor becomes a generator, and pushes power back to the electrical system, and the power needed to generate the electricity slows the propeller. So they could use the freewheeling pod to generate some of the ship's electricity, though that's not efficient as the power required from the other pods to turn the center pod is more than the power you would get back out.

 

Yes, if they cannot fix the problem in a fairly short period, they will remove the propeller blades again, and lock the shaft. The shaft lock is not sufficiently strong to hold the prop while doing 18 knots, it is used when the ship is stationary, or when there are no blades on the hub, so very little force. You've got to remember that this fixed pitch propeller can generate 20,000 hp. The area inside the pod is extremely limited, which is why you cannot go in them while operating. You have to crawl over, under, and lie on the shaft, and large service engineers need not apply.

[web2929]

I was on the 2 day cruise. We had no problems with propulsion. Probably why none of us has posted on that subject. The ship was amazing and we were running at 22 knots each time I checked it.

 

 

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[Cavy92]

OK, so I searched for GPS location and found her still 2hrs and 15 mind from Falmouth. Doing my math, she has averaged 18knots from Coco can to Falmouth. She is 2 hrs an 15 mins from Port (31 nm), and based on those numbers, she will be averaging around 14 knots.

 

Here is a screen shot of the info. Someone tell me if my math is wrong.

 

 

Hello! My name is Kevin.

[ckrobyn]

OK, so I searched for GPS location and found her still 2hrs and 15 mind from Falmouth. Doing my math, she has averaged 18knots from Coco can to Falmouth. She is 2 hrs an 15 mins from Port (31 nm), and based on those numbers, she will be averaging around 14 knots.

 

Here is a screen shot of the info. Someone tell me if my math is wrong.[ATTACH]339113[/ATTACH]

 

 

Hello! My name is Kevin.

 

Freedom isn't due into Falmouth until 10:00AM - so she is on time.....

[Cavy92]

Freedom isn't due into Falmouth until 10:00AM - so she is on time.....

 

 

And she left Coco Cay on time at 5. I think the telling sail will be between Grand Cayman and Cozumel.

 

 

Hello! My name is Kevin.

Edited February 4, 2015 by Cavy92