Jump to content
Cruise Critic Community

Recommended Posts

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.

So, I know you weren't on board but if you would speculate for a moment, what would be your opinion as to what caused the propulsion problem? A couple of diesel generators down? An electric motor down or partially down? What do you think is most likely? I'm just really curious.

Share this post


Link to post
Share on other sites
So, I know you weren't on board but if you would speculate for a moment, what would be your opinion as to what caused the propulsion problem? A couple of diesel generators down? An electric motor down or partially down? What do you think is most likely? I'm just really curious.

 

I would go more for one control converter (takes the 10,000 volt 60Hz power the generators generate, and change it to 6,000 volt variable frequency power for the motors) going south and they needed either some power SCR's or a circuit card and possibly some technical advice from the manufacturer to get it back up. It could have been two generators, but even then there would have been less than a 25% reduction in available power to the propulsion (the numbers I used above are some conservative numbers that come from Carnival, the manufacturer, Wartsila, rates the engines higher than what Carnival states).

Share this post


Link to post
Share on other sites
I would go more for one control converter (takes the 10,000 volt 60Hz power the generators generate, and change it to 6,000 volt variable frequency power for the motors) going south and they needed either some power SCR's or a circuit card and possibly some technical advice from the manufacturer to get it back up. It could have been two generators, but even then there would have been less than a 25% reduction in available power to the propulsion (the numbers I used above are some conservative numbers that come from Carnival, the manufacturer, Wartsila, rates the engines higher than what Carnival states).

Thanks for the info and your educated speculation. It's really interesting to me to hear about the inner workings of a cruise ship.

Share this post


Link to post
Share on other sites
Thanks for the info and your educated speculation. It's really interesting to me to hear about the inner workings of a cruise ship.

 

 

Yes it is, especially from someone with that amount of actual experience.

Share this post


Link to post
Share on other sites
I know what I know Mr Heald.

 

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

 

So when I first read your accusation that ParrotRob was John Heald in another thread, I didn’t give it much thought to be honest. But seeing as how John Heald chose to address this issue by creating a post on his FB site solely to address that he is not ParrotRob...I am now thinking twice. Why create a whole post if this is false? Hmmmm....I do have to say that if ParrotRob is John Heald, he is not representing Carnival very well with his mean posts and tendency to call others names.

Share this post


Link to post
Share on other sites
So when I first read your accusation that ParrotRob was John Heald in another thread, I didn’t give it much thought to be honest. But seeing as how John Heald chose to address this issue by creating a post on his FB site solely to address that he is not ParrotRob...I am now thinking twice. Why create a whole post if this is false? Hmmmm....I do have to say that if ParrotRob is John Heald, he is not representing Carnival very well with his mean posts and tendency to call others names.

I read John's page daily, and I don't see any similarity in their writing at all. I could be being duped, but I don't really think so. I've seen several people on here accuse anyone who sticks up for Carnival of being an employee, John Heald himself, or a "cheerleader" of John. I just don't see it, and I hope nobody accuses me of being John or any of the others I listed for saying this.

Share this post


Link to post
Share on other sites
I read John's page daily, and I don't see any similarity in their writing at all. I could be being duped, but I don't really think so. I've seen several people on here accuse anyone who sticks up for Carnival of being an employee, John Heald himself, or a "cheerleader" of John. I just don't see it, and I hope nobody accuses me of being John or any of the others I listed for saying this.

 

Totally get what you are saying. However, I also read JH posts and have seen him respond in a similar mean, spiteful, attack sort of way. JH just deletes those posts, I guess after he realizes how bad he sounds. Whether ParrotRob is JH or someone else, what I mainly find telling is that JH felt the need to address this in an actual FB post. I don’t recall seeing him do that before.

Share this post


Link to post
Share on other sites
Totally get what you are saying. However, I also read JH posts and have seen him respond in a similar mean, spiteful, attack sort of way. JH just deletes those posts, I guess after he realizes how bad he sounds. Whether ParrotRob is JH or someone else, what I mainly find telling is that JH felt the need to address this in an actual FB post. I don’t recall seeing him do that before.

Now that you mention it, I don't think I've ever seen him actually include a username in a post he's made about Cruise Critic before. He normally just blanks it out or something. That part is interesting, but I think I'm still inclined to believe it's not John. Who knows though. It seems that a lot of people are somebody else on internet forums these days.

Share this post


Link to post
Share on other sites
I don't think JH has time for that nor cares.

 

I would think so too...until JH decided to create that FB post just about this. Plus JH visits here pretty often as you frequently see CC posts as a new topic on JH’s pg...just reworded with a made up name.

Share this post


Link to post
Share on other sites
I think we should all get t-shirts to wear on our next cruise that say "I am not John Heald." ;p

 

Seeing as I am a 5’10, thin, African American woman with braids to her waist...forget it...JH and I could be twinsies! LOL!

Share this post


Link to post
Share on other sites
I think we should all get t-shirts to wear on our next cruise that say "I am not John Heald." ;p

:') Nor do we want to be (or the other guy). Can't live my life with so much negativity;)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Forum Jump
    • Categories
      • Q&A: Cruise Insurance with Steve Dasseos of TripInsuranceStore.com
      • Forum Assistance
      • New Cruisers
      • Cruise Lines “A – O”
      • Cruise Lines “P – Z”
      • River Cruising
      • ROLL CALLS
      • Digital Photography & Cruise Technology
      • Member Cruise Reviews
      • Special Interest Cruising
      • Cruise Discussion Topics
      • UK Cruising
      • Australia & New Zealand Cruisers
      • North American Homeports
      • Ports of Call
      • Cruise Conversations
×
×
  • Create New...