Function of the Funnel??

[bar1068]

Another social media group I follow had a little discussion about the function of the Funnel/Whale Tail on Carnival ships in the days following the Freedom incident. Someone in the group commented very factually, that the funnel on the Mardi Gras, Celebration and Jubilee is/will be for decoration only since those ships with those ships being powered by LNG. I thought wow, that is some piece of decoration. Not really knowing what all the funnel is there for, but thinking, can't be just for decoration on those ships i thought i'd see what anyone knows here. My thoughts are the funnel vents other "gases", steam, plumbing vents, something other than the engine exhaust, but I've really no clue. Figured, what the heck, post here, see maybe someone has a better clue than me, even thinking maybe chengkp75 could see this and 

[oyme]

I've found a few articles, it truly is just a vent on most ships (as you described). The reason CCL might keep them as decorative going forward is that they patented their design. CCL considers their whale tail to be a brand identifier since it can be spotted from far away and passengers know from a distance that the ship is a CCL ship based on their patented whale tail design.

 

I read: https://www.cruisecritic.com/articles.cfm?ID=3002 as well as some articles I found off of Google. I ran a search "how does the cruise ship's funnel work."

Edited May 31, 2022 by oyme
credits

[mz-s]

Well, nautral gas has exhaust. Anybody who uses natural gas to heat their homes knows that. Plus all the other gases that need to be exhausted - kitchen exhaust, plumbing, etc. So all ships need a funnel of some sort.

 

Carnival's funnels do not need to be shaped as they are, since no other ships do. But it is their trademark. That red, white, and blue whale tail seen over the buildings in Nassau is distinctively Carnival.

[joe/jack]

8 minutes ago, mz-s said:

Well, nautral gas has exhaust. Anybody who uses natural gas to heat their homes knows that. Plus all the other gases that need to be exhausted - kitchen exhaust, plumbing, etc. So all ships need a funnel of some sort.

 

Carnival's funnels do not need to be shaped as they are, since no other ships do. But it is their trademark. That red, white, and blue whale tail seen over the buildings in Nassau is distinctively Carnival.

Very Similar to the muffler on my

57 Chevy 

Lots of fumes 

[bar1068]

41 minutes ago, oyme said:

I've found a few articles, it truly is just a vent on most ships (as you described). The reason CCL might keep them as decorative going forward is that they patented their design. CCL considers their whale tail to be a brand identifier since it can be spotted from far away and passengers know from a distance that the ship is a CCL ship based on their patented whale tail design.

 

I read: https://www.cruisecritic.com/articles.cfm?ID=3002 as well as some articles I found off of Google. I ran a search "how does the cruise ship's funnel work."

Ok, ya got me there!! Usually before I post or ask questions online, I search things out online. I think i was sort of too specific in my searches looking for how the funnels on, what are they called, the Excel class of ships, Mardi Gras etc...how those differ from most other diesel or whatever powered ships. 

 I totally get how the Funnel is Carnival's brand identifier, and that they would probably put a "fake funnel" on any new ships even if there was no need for venting stuff, but I figured those things vent or exhaust "things" other than what's generated by the engines. Thanks.

[quattrohead]

The exhaust/funnel system will be basically the same for straight diesel or diesel/LPG.

LPG still needs diesel to start the engine and when running but only then as a kind of spark plug....LPG will not run on its own.

The FEC railroad have a twin engine setup with an LPG tank in the middle. It hauls full length trains easy and with no smoke.

[Indytraveler83]

My understanding is that the funnel was a Farkus element inspired by the winged funnel design of the SS Norway/France:

 

The design on the Norway was supposedly to push exhaust fumes away from the ship to better keep the passengers from getting caught in the ships exhaust. (No idea if it actually worked that well or not)

 

The Carnival version seems to be a part of the larger Farkus branding that was massive, bold and designed to make Carnival instantly recognizable as they tried to build a brand identity as most of the original Carnival branding/designs was just reworked Canadian Pacific designs from the original Mardi Gras.

 

I too would be curious to see chengkp's thoughts on actual design functionality.  

[K&RCurt]

I think some are confusing the ship's Funnel, which is where various gasses, fumes and vapors exit the ship, with the distinctive Carnival "Whale Tail" design of the funnel on Carnival ships.

 

Hopefully our resident Ship's Engineer will come along and explain it better, but any application with an engine that burns hydrocarbon fuel (be it gasoline, kerosine, diesel, LNG) needs a way to get the products of cumbustion away from where the engine is installed.  On ships those exhaust pipes exit through the funnel.  I do not see how the funnels on The Mardi Gas are "very factually just decoration."

 

Carnival decided that the funnel on their ships have a unique design.  The fact that it has a unique design does not make it just a decoration, the fumes still need to exit the ship, and if a big "Whale Tail" structure is sitting on top of teh ship, the pipes / ducts for those fumes are pretty much going to go through it.

 

Edited May 31, 2022 by K&RCurt

[JoeMo]

I spoke with an engineer on the Mardi Gras (in 1986). The funnel on Carnival ships was designed to exhaust the smoke, fumes, cooking smells and anything else they did not want drifting onto the rear decks of the ship. The shape of the funnel was secondary to the function of the exhaust piping. They had problems on the earlier ships (Mardi Gras, Tropicale, etc) with the smells from the engine room, galley, etc, making the rear of the ship less than comfortable. Some ships had cooking smells vented halfway up the funnel. It was a big funny to go up behind the funnel to try and figure out what was for supper.  At that time the only way to view the evening menu was at the entry to the dining room. At least one ship (I do not remember which) had a restaurant within the base of the funnel. 

Edited May 31, 2022 by JoeMo

[BlerkOne]

As pointed out, the LNG ships will still use some "real" fuel. And I suspect will still burn garbage.

[chengkp75]

For the most part, all ships' funnels are merely decorative, there is very little structural about them, particularly cruise ship funnels.  But, yes, even LNG powered ships will have exhaust gases that need to be taken away, and they will go up a funnel.  LNG is not a source of mechanical power, it is a fuel for a diesel engine, and all diesel engines need exhaust gases to be taken away.  LNG is a "real fuel", it just has less carbon per molecule, so it generates less CO2 per Btu of energy generated.  For a cruise ship, there will be one exhaust pipe for each diesel generator (4-6), one for each gas turbine generator (if fitted), and one for each boiler (usually two), one for each incinerator, and finally one for the emergency generator.  These will all go up to the top of the funnel to lift the gases as far away from guests as possible.  I don't know what the design idea was for the Carnival "whale tail", but other ships don't need these to take engine or galley smells away from the ships, I believe it is merely a trademark.  Carnival could just as easily had the exhausts go straight up the central funnel and leave the "fins" empty, but this would have sooted up the white mainmast that sprouts from the central funnel.  Inside the funnels are intake fans for the engine spaces, and exhaust gas scrubbers if fitted.  Galley exhausts go up as high as possible, but generally not in the funnel, due to the high heat in the funnels, as they tend to build up grease (another fire hazard), and are steam cleaned and then inspected and hand cleaned monthly.  Similarly, laundry exhausts go up high, many times into the forward mast of the cruise ship, to keep the lint from getting everywhere.  These are cleaned by hand monthly as well.

 

I believe that on the Norway/France, the "wings" had the boiler fan intakes in them, as these are very large fans and therefore noisy.

 

In short, a ship's funnel is primarily aerodynamic more than functional.

Edited May 31, 2022 by chengkp75

[Bgwest]

3 hours ago, chengkp75 said:

For the most part, all ships' funnels are merely decorative, there is very little structural about them, particularly cruise ship funnels.  But, yes, even LNG powered ships will have exhaust gases that need to be taken away, and they will go up a funnel.  LNG is not a source of mechanical power, it is a fuel for a diesel engine, and all diesel engines need exhaust gases to be taken away.  LNG is a "real fuel", it just has less carbon per molecule, so it generates less CO2 per Btu of energy generated.  For a cruise ship, there will be one exhaust pipe for each diesel generator (4-6), one for each gas turbine generator (if fitted), and one for each boiler (usually two), one for each incinerator, and finally one for the emergency generator.  These will all go up to the top of the funnel to lift the gases as far away from guests as possible.  I don't know what the design idea was for the Carnival "whale tail", but other ships don't need these to take engine or galley smells away from the ships, I believe it is merely a trademark.  Carnival could just as easily had the exhausts go straight up the central funnel and leave the "fins" empty, but this would have sooted up the white mainmast that sprouts from the central funnel.  Inside the funnels are intake fans for the engine spaces, and exhaust gas scrubbers if fitted.  Galley exhausts go up as high as possible, but generally not in the funnel, due to the high heat in the funnels, as they tend to build up grease (another fire hazard), and are steam cleaned and then inspected and hand cleaned monthly.  Similarly, laundry exhausts go up high, many times into the forward mast of the cruise ship, to keep the lint from getting everywhere.  These are cleaned by hand monthly as well.

 

I believe that on the Norway/France, the "wings" had the boiler fan intakes in them, as these are very large fans and therefore noisy.

 

In short, a ship's funnel is primarily aerodynamic more than functional.

This is a perfect example of why when a technical discussion takes place, I always wait until the Chief posts and then read his response. 

Saves having to wade through a litany of “experts” opining on matters on which they possess limited if any real qualifications. 
 

Thank you Chief!!

[BlerkOne]

Short and long

https://emmacruises.com/some-cruise-ship-funnels-have-wings-the-truth-behind-why/

[JoeMo]

1 hour ago, Bgwest said:

This is a perfect example of why when a technical discussion takes place, I always wait until the Chief posts and then read his response. 

Saves having to wade through a litany of “experts” opining on matters on which they possess limited if any real qualifications. 
 

Thank you Chief!!

Not being an "expert", I'll be on my way. Thanks

[Pellaz]

18 hours ago, quattrohead said:

The exhaust/funnel system will be basically the same for straight diesel or diesel/LPG.

LPG still needs diesel to start the engine and when running but only then as a kind of spark plug....LPG will not run on its own.

The FEC railroad have a twin engine setup with an LPG tank in the middle. It hauls full length trains easy and with no smoke.

 

Yes indeed, we've seen those FEC (Florida East Coast) RR locomotives on our Virtual Railfan camera in Cocoa, FL.  Really nifty to see LPG in use that way.

 

On the Mardi Gras, there are also smaller exhausts (or something) spaced along the top of the ship.  Not as tall as the funnel but presumably involved with LPG fuel in some way.  

 

12 hours ago, chengkp75 said:

For a cruise ship, there will be one exhaust pipe for each diesel generator (4-6), one for each gas turbine generator (if fitted), and one for each boiler (usually two), one for each incinerator, and finally one for the emergency generator. 

 

I did the Behind the Fun tour on the Vista back when the ship was relatively new, and when we were in Engineering Control a kid asked what exactly was located on the funnel and how it worked. 

 

Now, Vista's control room has a really cool digital "chart table" -- basically a touch-screen flat display.  Reminded me of a starship's bridge.  🙂   When the kid asked the question, our host (second engineer) pulled up a graphic display of the funnel and showed us exactly which exhaust port was for each...and it was exactly as you described above.   DGs, incinerator, emergency generator, etc.  

That was a great visit.  (And y'all, if they ever bring back the BtF tours, definitely do it on a Vista-class!  He even showed us a live underwater camera view of one of the azipods.)  

Edited June 1, 2022 by Pellaz

[chengkp75]

13 minutes ago, Pellaz said:

On the Mardi Gras, there are also smaller exhausts (or something) spaced along the top of the ship.  Not as tall as the funnel but presumably involved with LPG fuel in some way. 

Those will be the emergency vents for the LNG tanks.

[IrritatedEllipses]

4 hours ago, chengkp75 said:

Those will be the emergency vents for the LNG tanks.

 

Woah, that's pretty neat.

 

Is there something you'd recommend reading to learn more about details like this?

[chengkp75]

2 minutes ago, IrritatedEllipses said:

 

Woah, that's pretty neat.

 

Is there something you'd recommend reading to learn more about details like this?

Not off the top of my head, just google "use of LNG as marine fuel".

 

The tanks, unlike tanks for residual or diesel fuel, are essentially vacuum bottles to keep the LNG as close to -260*F (the boiling point of LNG at atmospheric pressure) as possible.  Also, unlike "regular" fuel tanks, the vents on LNG tanks are closed with valves to keep the pressure in, and to keep the nitrogen atmosphere in the tank (the space above the LNG in the tank is filled with nitrogen, not air, to prevent the LNG or vapor from igniting, this is called inerting, since if the oxygen content is too low, the methane vapors cannot ignite).  Some LNG will always "boil off" and increase the pressure in the tank.  This "boil off" is what is used in the engines.  If there is excess boil off to what the engines need, there is a system that draws off the methane gas, cools it back down below -260*F to liquify it again, and then pumps it back into the tanks.  If there is a problem somewhere, and the tank heats up too much for the engines or the liquifaction plant to handle, or the pressure builds too much, the valves on the LNG tank vent will open and vent methane into the atmosphere (something you really don't want to happen, as methane is 200 times more harmful as a greenhouse gas as CO2).

[satxdiver]

Attended a lecture several years ago about the birth of the modern cruise industry.  In the talk it was said that Arison was in the shipyard inspecting the first ship built specifically for CCL.  In the shipyard was the usual collection of large parts including a used airplane tail.  Arison saw it and thought that it would be a great idea to put it on the new ship and make it a trademark.  Hence the "whales tail" was born with the new Carnival Tropicale.  

[tidecat]

49 minutes ago, satxdiver said:

Attended a lecture several years ago about the birth of the modern cruise industry.  In the talk it was said that Arison was in the shipyard inspecting the first ship built specifically for CCL.  In the shipyard was the usual collection of large parts including a used airplane tail.  Arison saw it and thought that it would be a great idea to put it on the new ship and make it a trademark.  Hence the "whales tail" was born with the new Carnival Tropicale.  

There was an interview Joe Farcus did for Bright Sun Films (they did a "Cancelled" video on Carnival's Pinnacle project). The whale tail performed exceptionally well in testing the shipyard did.

[ProgRockCruiser]

I always thought the whale tail design was so that at full speed, or in a hurricane face-on, the tail would act like the reverse of a Formula 1 car tail, and lift the whole ship out of the water a bit like a hydrofoil.

 

😁

 

😉

 

You do know I'm kidding, right?

[JRG]

2 hours ago, ProgRockCruiser said:

You do know I'm kidding, right?

 

Yes but you are really in the Pipe 5 x 5.

 

One of our CC engineers was just discussing how a pickup truck with its tail-gate "down" displays more (or less) drag co-efficient vs a pickup truck with its tail-gate 'up' when they are being compared to underwater propulsion systems.

 

It was a question of hydrodynamics vs aerodynamics,  but we were only joking.

 

IMO,   the wing is decorative but camouflages the functional purpose of housing the exhaust.

 

It is not for aerodynamics though.

 

I like the story about Arison and he cashed it in bigtime because he created his Brand Identity with it,  much like the Golden Arches did.  

 

Olay,  Olay, 

Olay,  Olay

 

(repeat and fade)

 

 

Edited June 2, 2022 by JRG
edited because of more or less

[jgmpuma]

My wife thinks I'm nuts, but I really enjoy reading about stuff like this. I try to explain to her what I have learned. She just rolls her eyes.

 

[JRG]

I can't imagine anybody drilling down any farther than where this thread is,  when it comes to understanding the funnels function.   I think the previous posts say all there is to it.

 

That being said,  maybe we should think about what the actual cause of the fire was,   while we wait for the results of the investigation...I think it may have started by one of the above.

 

1) a flying bird got lodged in the vent and ignited

2) grease from all the great Steaks carnival serves*

3) a mylar balloon got caught

4) some other UFO got stuck and ignited.

 

I don't think it was the soot buildup itself that caught fire,   because normally you can't ignite a soot pile with a blowtorch (don't try this a home) .   So,  it is more likely that something with a relatively low flashpoint got caught up in the wind and perhaps got caught in the tail and ignited.  

 

That is what I think.   If it ends being a soot fire because of grease from the galley,   its because Carnival serves up the best Steaks at sea and you can order them from the MDR for $20 and alot of Carnival regulars do this,   so they do get more grease up their tail than the average cruiseline,  IMO.

 

You have to be an experienced cruiser to know that Carnival steaks are the best!

 

My money is on the flying bird winning the race,  with mylar balloon a close second and soot buildup  getting the show dough.

 

Edited June 2, 2022 by JRG

[chengkp75]

48 minutes ago, JRG said:

I don't think it was the soot buildup itself that caught fire,   because normally you can't ignite a soot pile with a blowtorch (don't try this a home) . 

Now, I know that down in sunny southern California there isn't much call for wood burning or coal burning stoves to heat a house, but anyone who has seen a chimney fire knows only too well that soot does in fact burn.  Both creosote and soot burn in a chimney fire.  The difficulty is that soot, being nearly completely carbon, does not give off a flammable vapor like most flammable materials do, so it will not sustain a fire by itself, it needs something that gives off flammable vapors, like creosote.  Many materials in the funnel will fall into this flammable material category, and keep a soot fire going until it ignites the fiberglass.

 

As for igniting "a soot pile" with a "blowtorch", it all depends on the composition of the "soot".  If there is a lot of ash, which is completely combusted material, then it will be very difficult to ignite.  If it is more "pure" soot, then an acetylene torch will readily ignite it.  (Haven't seen a "blow torch" in decades, unless you mean a propane torch, but even then, if you get a pure blue flame, you can get soot to ignite)