Magic problems

[ParrotRob]

My son is so happy about the repairs being completed and no changes to the itinerary that he's treating everyone onboard to a Guy's burger!

 

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Don't forget a great big tip gets the freshest Guy's burger!

[LuckyZ]

Read cheng's dissertation on the topic and then you can apologize for running off about things you neither know nor understand.

 

 

 

I know what I know Mr Heald.

 

Signed: someone that’s actually been on the ship when all this was happening

 

 

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Edited June 26, 2018 by LuckyZ

[chengkp75]

I know what I know Mr Heald.

 

Signed: someone that’s actually been on the ship when all this was happening

 

 

Sent from my iPhone using Forums

 

Went back and read some of your earlier posts, and I don't think even John Heald would say that the ship was turning hot tubs on and off in an effort to "save energy" due to a propulsion problem. Let's look at this: Magic has power generating capacity of 75,600 kw. A hot tub draws 2-3 kw, and say there are 8 of them onboard, this is a total draw for the hot tubs is 24 kw, or about 0.03% of capacity, so shutting these on and off would surely be beneficial in keeping the propulsion (about 44,000 kw at max power) going as fast as possible. Even if two diesel generators were down, instead of a propulsion motor problem, that would still be 46,000 kw, so those hot tubs would still be a significant savings. :rolleyes:

[LuckyZ]

Went back and read some of your earlier posts, and I don't think even John Heald would say that the ship was turning hot tubs on and off in an effort to "save energy" due to a propulsion problem. Let's look at this: Magic has power generating capacity of 75,600 kw. A hot tub draws 2-3 kw, and say there are 8 of them onboard, this is a total draw for the hot tubs is 24 kw, or about 0.03% of capacity, so shutting these on and off would surely be beneficial in keeping the propulsion (about 44,000 kw at max power) going as fast as possible. Even if two diesel generators were down, instead of a propulsion motor problem, that would still be 46,000 kw, so those hot tubs would still be a significant savings. :rolleyes:

 

I know what I know

[chengkp75]

I know what I know

 

Yeah, I understand. I know brain surgery because I've watched it on TV several times.

[LuckyZ]

Yeah, I understand. I know brain surgery because I've watched it on TV several times.

 

Well congratulations . You must do very well at that . It’s quite an accomplishment .

 

Accomplished Brain Surgeon and Eliquent Cruise Critic poster

[joepeka]

Yeah, I understand. I know brain surgery because I've watched it on TV several times.

Give up Chief. You cannot have a rational, reasonable discussion with someone that does not want to listen and learn.

[LuckyZ]

Give up Chief. You cannot have a rational, reasonable discussion with someone that does not want to listen and learn.

 

Again , I know what I know so I believe what I believe. I know by personal experience, not what people chose to write as their own opinions.

 

There is no doubt in my mind, and many others, that the A/C issues were a result of propulsion issues. Seems pretty common sense to me AS I WAS THERE.

 

Either way it makes no difference. Wondering why everyone stresses so much about people’s comments that don’t match theirs. Personal attacks are not welcome here

Edited June 26, 2018 by LuckyZ

[jimbo5544]

I may be misreading the posts....but are you sure?

[jimbo5544]

Yeah, I understand. I know brain surgery because I've watched it on TV several times.

Makes me want to quote scenes from Tommy Boy about a butcher and the cow.....but I get in too much trouble as it is.....

[E@syPe@zy]

I know what I know

 

Do you happen to know Jack?? No...I didn't think so!

[LuckyZ]

Do you happen to know Jack?? No...I didn't think so!

 

 

Wow. Harmful. Where is this coming from ?

[joepeka]

Again , I know what I know so I believe what I believe. I know by personal experience, not what people chose to write as their own opinions.

 

There is no doubt in my mind, and many others, that the A/C issues were a result of propulsion issues. Seems pretty common sense to me AS I WAS THERE.

 

Either way it makes no difference. Wondering why everyone stresses so much about people’s comments that don’t match theirs. Personal attacks are not welcome here

I do appreciate the conviction of your beliefs based on what you witnessed (or were told) while on the cruise. Things are not always as they seem however and when expert input contradicts what is perceived, I have to go with the experts. No offense intended, I apologize if you were. My comment was probably uncalled for.

[declansdad]

I know what I know

 

 

So you were able to exam the ship's system while on board?

[LuckyZ]

I do appreciate the conviction of your beliefs based on what you witnessed (or were told) while on the cruise. Things are not always as they seem however and when expert input contradicts what is perceived, I have to go with the experts. No offense intended, I apologize if you were. My comment was probably uncalled for.

 

Apology accepted. I guess I don’t believe everything that is written and don’t believe that person to be an expert and hence choose to believe that it was based on propulsion system based on the large number of rooms that said they had no A/C.

 

I don’t know why so many people are taking offense to a different view. You can believe what you want, that’s OK with me. I will continue my conviction. Just respect that and let’s move on

[poz222]

Went back and read some of your earlier posts, and I don't think even John Heald would say that the ship was turning hot tubs on and off in an effort to "save energy" due to a propulsion problem. Let's look at this: Magic has power generating capacity of 75,600 kw. A hot tub draws 2-3 kw, and say there are 8 of them onboard, this is a total draw for the hot tubs is 24 kw, or about 0.03% of capacity, so shutting these on and off would surely be beneficial in keeping the propulsion (about 44,000 kw at max power) going as fast as possible. Even if two diesel generators were down, instead of a propulsion motor problem, that would still be 46,000 kw, so those hot tubs would still be a significant savings. :rolleyes:

And if it were a DG or two that was out of service in stead of a propulsion motor, would that change the equation? ;-)

Edited June 27, 2018 by poz222
Wish to delete

[Ramokk]

After 43 years of working on HVAC systems on ships, including 4 years on cruise ships, I think I might have an idea about how they work, especially more than John Heald. Here is a post I made back in March, but I've done dozens of them over the years, specifically about balcony doors:

 

https://boards.cruisecritic.com/showpost.php?p=55435571&postcount=42

 

Thanks for that; it effectively answered a question that I was puzzling over last week (why does the wind tunnel happen I accidentally open the hallway door while my wife is standing in the balcony door). Couldn't wrap my head around why that happened but your post made it clear.

[chengkp75]

And if it were a DG or two that was out of service in stead of a propulsion motor, would that change the equation? ;-)

 

For the hot tubs, no.

 

The ship is designed to operate with one generator down for service and still maintain full power to propulsion. This happens all the time, as small maintenance procedures are done weekly on each engine. Major overhauls will happen for one or two engines a year, and will take 3-4 weeks to complete, so the ship operates without one engine for extended periods without anyone knowing the difference. If two generators were down, then they could be limited on power to propulsion, but you have to again look at the difference in power consumption by the propulsion and just the AC load. Running on 4 generators, you would have about 75% of power available to propulsion (roughly 33,000 kw) giving you about 16-18 knots. Since the power required to generate speed for a ship is not straight line, but exponential, the missing 11,000 kw that you don't have for propulsion gives you only the last 4 knots of speed. The AC load for a ship the size of Magic would be around 4,000 kw, so if you shut this off completely, and used this power for propulsion, you would get between 1-2 knots of speed. The problem with doing this is that every time you restart one of these huge AC chillers, the motor starting surge, would require the ship to slow down to 7-10 knots to give enough cushion to allow each chiller to start, and then speed up again, which would most likely result in lost average speed.

 

And, no, while there are 3-4 chillers on the ship, they don't each cover one section of the ship, they all communally chill water which is then piped throughout the ship to cool the air. So, if they were leaving one or two AC chillers off to provide power to the propulsion, it would result in a shipwide increase in temperature, not a spotty, or zoned rise in temperatures.

 

And, finally, it would make no engineering sense to reduce AC power to try to increase propulsion power, since it takes more power to allow a space to heat up and then cool it off, than it does to maintain a constant temperature, and balancing that against the possible 24-30 extra miles that the increased propulsion power would provide for a full 24 hours of steaming (not sure of the itinerary that was changed), but given that the itinerary was shortened, they would have based this new itinerary on what the ship could do without either the partial propulsion motor or two generators, without having to resort to shutting off the AC or turning off the hot tubs.

Edited June 27, 2018 by chengkp75

[LuckyZ]

Unbelievable on the nerve that this has struck that it could have been the propulsion system, and how some have made it their personal mission in life to try to persuade us all otherwise. Makes you think if ........

 

 

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Edited June 27, 2018 by LuckyZ

[ParrotRob]

Unbelievable on the nerve that this has struck that it could have been the propulsion system, and how some have made it their personal mission in life to try to persuade us all otherwise. Makes you think if ........

 

 

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Unbelievable how passionately people will stick to their beliefs despite actual, real life engineers like Cheng kp educating them otherwise.

[jordanaire]

Regardless of the bashing that has taken place on this board, at least the Magic is up and running. No more missed ports! Let's all get back to what these boards offer...helpful information about what we ALL love and that's cruising!

 

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[BoDidly]

Regardless of the bashing that has taken place on this board, at least the Magic is up and running. No more missed ports! Let's all get back to what these boards offer...helpful information about what we ALL love and that's cruising!

 

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That's about it in a nutshell . No over drama reactions or embellished brain cell typing contest just to make someone feel important. ;)

[Hotdog 52]

Think its time to hit them with how reheat works? LOL;p

[poz222]

One last thing... everyone is always very quick to declare “the cruise line is hiding something, I wish they would tell,us the whole story”... for good reason as historically they are not forthcoming as they should be... so thankfully this is a case where from the get go, CCL said they are working on the engine and they fully expect it to be up and running with no changes to the June 30 itinerary... and that WAS the full story... even as some wanted to dramatize how their travel,agents had emails to send out cancelling a port etc... in this case, CCL seems to have been transparent about when it would be fixed... so not EVERY problem is a massive cover up, for that I at least give them credit. Just something to keep in mind. I shall report back after my cruise on her next week and let everyone know. But I am sure I have fun regardless, I always do!

[waldreps]

One last thing... everyone is always very quick to declare “the cruise line is hiding something, I wish they would tell,us the whole story”... for good reason as historically they are not forthcoming as they should be... so thankfully this is a case where from the get go, CCL said they are working on the engine and they fully expect it to be up and running with no changes to the June 30 itinerary... and that WAS the full story... even as some wanted to dramatize how their travel,agents had emails to send out cancelling a port etc... in this case, CCL seems to have been transparent about when it would be fixed... so not EVERY problem is a massive cover up, for that I at least give them credit. Just something to keep in mind. I shall report back after my cruise on her next week and let everyone know. But I am sure I have fun regardless, I always do!

I agree and please do report back to let us know how things are going on your cruise!