What is the current policy regarding keeping connecting balcony doors closed

[chengkp75]

7 hours ago, AmazedByCruising said:

 

Then why bother about dividers between cabins being open? If the cabins simply don't have the capacity to keep themselves burning, let alone get hot enough to get cabins next to them burning, I'd want as many dividers open as people want. Firefighters would have quicker access and guests would have another route to escape. How would an insurer not like that?

 

The engine room is obvious, but the galley? Once burning, I can see how frying oil can keep burning but all around it there's is nothing but metal and food that contains so much water that it could be used to stop a fire. Also, when the oil is hot enough to burn there must be enough crew around to find the blanket that solves the problem immediately.

 

The engine room is dangerous because there's fuel I guess. Would it be possible to have the fuel stored in tanks that are attached to the side of the ship and could be released into the sea in case of a fire? Or, much less environmentally friendly but necessity knows no law, could a ship simply release all of its fuel in case a of a fire?

 

 

 

 

I will somewhat disagree with Heidi about some of this, though he is speaking from a Canadian viewpoint, and I'm no expert on their regulations.  However, at least on the ships I've served on, while many materials are low combustibility, not all are, and that is why there are sprinklers installed in cruise ship spaces.  As Heidi mentions, each space is considered for "fire loading" or the amount of combustible fuel there will be in the space, and fire suppression equipment will allow that fire load to be modified upwards.  Notice I said "fire suppression" not "fire extinguishing" as sprinklers such as used in cruise ship cabins and public spaces, and the "HiFog" high pressure systems used in engine rooms, are just that, they are designed to suppress a fire to the point where manual intervention by fire teams can extinguish the fire.  The point is to suppress the fire long enough to allow people to get out.

 

So, cabins are combustible, including the paint on the steel decks, bulkheads, and overheads.  Boundaries are classified by how long they will prevent sufficient heat from being transmitted to the other side of the boundary to start combustion on that new side.   Cabin doors and the non-structural walls of cabins are typically B-15 class (15 minutes), while the boundaries at the fire zones on the ship (the steel decks, and the steel bulkheads and fire doors in the passageways) are A-60 class (60 minute rating).  Notice that we have said "low combustibility" or "flame retardant"  not "non-combustible".  The terms we use mean that the materials are difficult to start burning, and when started, they burn slowly, but they will burn or generate heat.

 

Galley fires are most dangerous due to the grease buildup in the ventilation ducting.  Ever clean the filter on your kitchen exhaust fan?  To mitigate this, the ventilation systems will have "Gaylord" hoods over the ranges and fryers, which have filters, self-cleaning systems (used daily), and fire extinguishing systems.  However, these hoods are not on every ventilation duct in the galleys, and grease will build up in these ducts.  This is mitigated by monthly steam cleaning of the ducts, using fixed steam systems, and then opening of the ducts at access ports and hand cleaning of the duct interiors.  On a medium sized cruise ship, this can take 18-20 men 6-8 hours each month to complete.  However, a fire between cleanings, or an inadequate cleaning can lead to a fire in the ducts, and these can reach extreme temperatures and conduct that heat to adjoining spaces.

 

Another classic area for fire are the dryer ducts from the ship's laundries.  Again, these are designed with the minimum amount of horizontal ductwork to minimize the places that lint can accumulate, and these horizontal ducts have access ports for monthly manual clean out.  This is in addition to the filter screens mounted directly after the dryers which are cleaned several times daily.  An example is the Carnival Ecstasy in 1998, where a lint fire caused severe damage to large areas of the stern of the ship.

 

So, you would have "detachable" fuel tanks to be jettisoned in a fire?  These would hold several thousand tons of fuel, and the loss of this weight would seriously affect, negatively, the stability of the ship.  Let alone the maintenance and possibility of accidental release that such a system would require.  Or your alternative, of "releasing" fuel into the sea?  Again, if you had a system to do this directly, how do you ensure it doesn't fail and do this at some random time?  Or, using the ship's pumping system, it would take hours to days to empty the fuel tanks.  Another point, with fuel tanks in general, but with residual fuel tanks in particular, an empty tank that has fuel vapors in it is far more dangerous than a full tank.  I have welded plates onto the outside of a bunker tank full of residual fuel, with no danger, and you can literally heat a bucket of residual fuel with a blow torch and it will not ignite.  It is the vapors that are dangerous.  Now, with diesel fuel, the flash point is much lower, and the evaporation point is much lower, so heating the fuel will raise vapors much more quickly, but still if I'm heating several hundred tons of liquid, with a cool "heat sink" on one or more sides (the ocean), it will take a lot to ignite a tank of fuel.

 

The danger in engine rooms is that fuel needs to be heated (residual fuel) and pressurized to be able to combust in the engine.  This, possibly very hot (120*C), and pressurized (8 bar) fuel, when allowed to escape from the piping system becomes a mist of fine droplets, the perfect form for instant combustion (this is what a fuel injector does in the engine), and only needs a heat source (hot surface) to ignite.  Fuel systems are set up with "quick closing" valves operated remotely that will stop fuel flowing from storage tanks, or to each engine.  However, there are other flammable things in the engine room, that will burn once started by a fuel leak, like lubricating oil in the engines, paint, maintenance materials, etc.

 

Engine rooms are protected by fire suppression and fire extinguishing systems.  They will have either sprinklers, or far more commonly the HiFog system.  This takes a drop of water that typically comes from a sprinkler head, and turns it into 1000 mini-droplets.  This is similar to the cooling arches used at sports arenas in hot weather.  The smaller droplet size and the increase in droplets, gives much more surface area to the water, creating the ability of the water to absorb far more heat than a sprinkler system, and removing the heat from a fire keeps it from expanding.  These water mist systems also do not adversely affect running electrical equipment, so release of a HiFog system does not interrupt ship's systems.  The engine rooms will also have a fire extinguishing system, of CO2, which will blanket the engine room, displacing the oxygen, and without oxygen, the fire will go out.  However, the fire teams need oxygen to live, so release of CO2 means you have to send teams in with self-contained breathing gear, and even then it is dangerous.  Further, the diesel engines need oxygen to run, so release of CO2 means the engines will stop, and all electrical power will be lost for the hour or two it needs to be certain that the fire is out before you can restart fans and remove the CO2.

[gepgelmik]

I went with family on Anthem of the Seas, 2016. I asked the room steward to open the divider between our two rooms, and he indicated that he had to get permission from the occupants of other room. Later he came back and opened the divider.

[Heidi13]

Cheng - Affirmative, my later experience was most tonnage built without sprinkler systems or HiFog in the passenger spaces. We only had fixed systems in the E/R, Vehicle Decks and Galleys. Without sprinklers, it was a constant battle managing the fire loading. Only sailed with HiFog once and that was on a large high speed Ro/Pax, as it was  mandated by the High Speed Craft Code.

 

While the carpets were low flammability, and initially smouldered, they did eventually start burning. Unfortunately it has been over 10 years since I participated in these tests, so can't remember the metric we used.

 

The other reason for keeping most, if not all of the balcony dividers closed is for passenger comfort. While cruise ships rarely steam > 20 kts these days, even 20 kts with a 20 kt head wind gives 40 kts over the deck. Not many would enjoy their balcony with strong wind blowing along the ship's side.

[chengkp75]

11 hours ago, Heidi13 said:

Cheng - Affirmative, my later experience was most tonnage built without sprinkler systems or HiFog in the passenger spaces. We only had fixed systems in the E/R, Vehicle Decks and Galleys. Without sprinklers, it was a constant battle managing the fire loading. Only sailed with HiFog once and that was on a large high speed Ro/Pax, as it was  mandated by the High Speed Craft Code.

 

While the carpets were low flammability, and initially smouldered, they did eventually start burning. Unfortunately it has been over 10 years since I participated in these tests, so can't remember the metric we used.

 

The other reason for keeping most, if not all of the balcony dividers closed is for passenger comfort. While cruise ships rarely steam > 20 kts these days, even 20 kts with a 20 kt head wind gives 40 kts over the deck. Not many would enjoy their balcony with strong wind blowing along the ship's side.

Yes, without sprinklers, the requirments for low flammability are much greater.

 

I think the HiFog systems are the greatest thing since sliced bread.  It is so effective, and so low impact on equipment.  We had a planned maintenance task to actually release each zone once a year.  We had 12 zones, so one a month.  We even scheduled the engine room fire drills with the monthly release of HiFog, so that the fire teams learned to operate within the fog.  It completely removes the need for the second hose team to provide cooling fog for the primary hose team, thereby freeing up those assets for use elsewhere.  The only precaution we took when releasing into the working engine room spaces was to put trash bags over some of the electronic panels, but never worried about the motors or controller boxes.

[sparks1093]

1 hour ago, chengkp75 said:

Yes, without sprinklers, the requirments for low flammability are much greater.

 

I think the HiFog systems are the greatest thing since sliced bread.  It is so effective, and so low impact on equipment.  We had a planned maintenance task to actually release each zone once a year.  We had 12 zones, so one a month.  We even scheduled the engine room fire drills with the monthly release of HiFog, so that the fire teams learned to operate within the fog.  It completely removes the need for the second hose team to provide cooling fog for the primary hose team, thereby freeing up those assets for use elsewhere.  The only precaution we took when releasing into the working engine room spaces was to put trash bags over some of the electronic panels, but never worried about the motors or controller boxes.

Now that sounds like a great innovation. I hope the developer of the system received a medal.

[Sue Do-Over]

While on the Epic last Christmas, we were told that the steward could open the divider, but only when the other cabin resident was there to agree.  Makes sense.

Nobody cautioned us about the number that could be open at one time, or fire risk, but just that my neighbor (my sister) had to be fine with it open, too. 

[AmazedByCruising]

Again so much information, thank you and Heidi13! I almost feel like I should make a long response just to show my appreciation 🙂

 

 

 

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

The terms we use mean that the materials are difficult to start burning, and when started, they burn slowly, but they will burn or generate heat.

 

OK, but Heidi13 says 

 

On 12/18/2018 at 2:14 AM, Heidi13 said:

Have never seen a modular cabin burned. They also complete a calculation of fire loading for each space.

 

So when there's a fire in a cabin, I understand it would stop automatically even when nobody is present to fight it and sprinklers aren't working either?

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

Galley fires are most dangerous due to the grease buildup in the ventilation ducting.  Ever clean the filter on your kitchen exhaust fan?

 

Again I didn't see the real reason why a galley fire would be dangerous, thinking about oil. Did I tell you you should write a book? 🙂 

 

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

So, you would have "detachable" fuel tanks to be jettisoned in a fire?  These would hold several thousand tons of fuel, and the loss of this weight would seriously affect, negatively, the stability of the ship. Let alone the maintenance and possibility of accidental release that such a system would require.

 

In the Nieuw Statendam thread, the cruise log says 874 metric tonnes of fuel, for a transatlantic. That's not very much compared to the total weight of a ship, even adding the weight of the tanks themselves. I've never heard of complaints that the ship got unstable after burning most of the fuel. Probably because it was replaced by water? Given the choice between seasickness or a burning, but not sinking, ship I'd opt for seasickness 🙂

 

Anchors, lifeboats etc are not accidentally released either.

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

Another classic area for fire are the dryer ducts from the ship's laundries. 

 

Another thing I didn't think of ..  

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

Or, using the ship's pumping system, it would take hours to days to empty the fuel tanks.  Another point, with fuel tanks in general, but with residual fuel tanks in particular, an empty tank that has fuel vapors in it is far more dangerous than a full tank

 

And again, the pumps are indeed slow as I remember how long bunkering took on my first cruise. I did think of pumping out fuel and replacing it with seawater to prevent explosions. 

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

The danger in engine rooms is that fuel needs to be heated (residual fuel) and pressurized to be able to combust in the engine.  This, possibly very hot (120*C), and pressurized (8 bar) fuel, when allowed to escape from the piping system becomes a mist of fine droplets, the perfect form for instant combustion (this is what a fuel injector does in the engine), and only needs a heat source (hot surface) to ignite.  Fuel systems are set up with "quick closing" valves operated remotely that will stop fuel flowing from storage tanks, or to each engine.  However, there are other flammable things in the engine room, that will burn once started by a fuel leak, like lubricating oil in the engines, paint, maintenance materials, etc.

 

So that the real danger in an engine room isn't actually the fuel? I'm trying to envision the amount of energy that burning lubricating oil, pain and sloppy cleaning of the workplace can have.. Also, again the burning paint. Is there no other paint that is flame retardant to be used in sensitive areas like the engine room? Google says there are many.

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

The engine rooms will also have a fire extinguishing system, of CO2, which will blanket the engine room, displacing the oxygen, and without oxygen, the fire will go out.

 

In server rooms a combination of argon and nitrogen is used, which is a lot more expensive than CO2. Any idea why?

 

On 12/18/2018 at 11:46 AM, chengkp75 said:

However, the fire teams need oxygen to live, so release of CO2 means you have to send teams in with self-contained breathing gear, and even then it is dangerous.

 

Why would you need to send in firefighters when the CO2 makes sure there is not fire?  I assume everyone is evacuated before the CO2 is released?

 

 

 

[chengkp75]

1 hour ago, AmazedByCruising said:

Again so much information, thank you and Heidi13! I almost feel like I should make a long response just to show my appreciation 🙂

 

 

 

 

 

OK, but Heidi13 says 

 

 

So when there's a fire in a cabin, I understand it would stop automatically even when nobody is present to fight it and sprinklers aren't working either?

I don't think Heidi's saying a cabin won't burn, but that he's not seen one burned in a test.  Fire loading is a calculation of how much fuel (combustible material) there can be in a space before the existing fire extinguishing systems can no longer handle a fire in that space.  Cabins will not self-extinguish.

 

Again I didn't see the real reason why a galley fire would be dangerous, thinking about oil. Did I tell you you should write a book? 🙂 

 

 

 

In the Nieuw Statendam thread, the cruise log says 874 metric tonnes of fuel, for a transatlantic. That's not very much compared to the total weight of a ship, even adding the weight of the tanks themselves. I've never heard of complaints that the ship got unstable after burning most of the fuel. Probably because it was replaced by water? Given the choice between seasickness or a burning, but not sinking, ship I'd opt for seasickness 🙂

I think that number is a bit low for a 6(?) day crossing.  I would think more like 1000-1200 tons.  And, the ship would carry about 4000-6000 tons of fuel.  That is pretty typical to carry 4-6 weeks of fuel, when refueling every week, they are not running low each week.  And when you consider that the other major source of weight down low in the ship are the engines, and these are only a couple of hundred tons each, fuel is a major weight contributor.

 

Anchors, lifeboats etc are not accidentally released either.

Anchors and lifeboats are not the size and weight of fuel tanks either, and anchors are not designed to be "ready for use" in an emergency, but require some prep work to get them ready for use.

 

Another thing I didn't think of ..  

 

 

And again, the pumps are indeed slow as I remember how long bunkering took on my first cruise. I did think of pumping out fuel and replacing it with seawater to prevent explosions. 

The pumps used in bunkering are the ones on the barge, not the ship.  Compensating for fuel with sea water is not a good idea, and is only used in submarines where you need to maintain a constant weight.  Especially with residual fuel, which is heated in the tanks, you now have introduced hot/warm sea water to a steel tank, just perfect for corrosion.

 

So that the real danger in an engine room isn't actually the fuel? I'm trying to envision the amount of energy that burning lubricating oil, pain and sloppy cleaning of the workplace can have.. Also, again the burning paint. Is there no other paint that is flame retardant to be used in sensitive areas like the engine room? Google says there are many.

You are looking at "flame retardant" paints, not non-flammable paints.  Flame retardant paints typically require very thick paint films to be effective (and even then they only have 1-2 hour fire rating), and this thick film will generally not have a hard non-porous surface, so dirt and grime will adhere to the paint, putting fire fuel right on the paint.  Each engine will have between 1-2 cubic meters of lubricating oil inside, and there will be more in the piping to the associated systems like coolers and purifiers.  These systems, which will have pump shutdowns in case of fire, will typically not have quick closing valves, an accidental trip of which could starve an engine of oil and cause it to seize up and catch fire.

 

In server rooms a combination of argon and nitrogen is used, which is a lot more expensive than CO2. Any idea why?

CO2 is stored in liquid form to save space (on land you just make the building bigger), and when it is released and flashes to a gas, it cools down a lot (ever cool beers with a CO2 fire extinguisher?  No?) and can cause damage to electronics.  One of the most common effects of a CO2 release is paint flaking, as the paint contracts at a different coefficient to the steel.

 

Why would you need to send in firefighters when the CO2 makes sure there is not fire?  I assume everyone is evacuated before the CO2 is released?

Yes, CO2 systems have a warning siren, and a 60 second delay before release, to allow everyone to get out.  But, CO2 does not "make sure the fire is out", any more than the argon/nitrogen used in computer rooms.  An engine room is not an empty box to be filled with gas.  It is a complex shape filled with equipment with complex shapes, and there are spots that can possibly trap air when the CO2 floods the space.  A cooling "hot spot" in the engine room, if the CO2 is evacuated too soon, is just waiting for that air to flood over it and re-ignite.  This is called "re-flash" and is something we drill on continuously.  It is also what caused much of the problems on the Carnival Splendor, when it was not respected, the engine rooms were ventilated too soon in an effort to get power back on, and the engine rooms reflashed three times, and the fire had to be extinguished three times.  Those same pockets can trap CO2 when you are finally ventilating the space, and when a person walks into that pocket without a breathing device, they will suffocate.  So, re-entry into a space that has been flooded with CO2 is dangerous.  Typical use of CO2 will require leaving the space dormant, full of CO2 for two hours, and then risking ventilation and entry, or merely entry (which introduces air via the door) both with breathing gear, and with thermal imaging devices looking for "hot spots" that could re-ignite.

 

Well, crap, had a nice long response, and my satellite lost link.  Will try to recover it.

[AmazedByCruising]

 

31 minutes ago, chengkp75 said:

 

I don't think Heidi's saying a cabin won't burn, but that he's not seen one burned in a test.  Fire loading is a calculation of how much fuel (combustible material) there can be in a space before the existing fire extinguishing systems can no longer handle a fire in that space.  Cabins will not self-extinguish.

 

I asked what would happen during a Mythbusters kind of test, the extreme "will it burn, keep burning, and ignite the next cabin" and I understand the answer was "no". Heidi?

 

 

36 minutes ago, chengkp75 said:

I think that number is a bit low for a 6(?) day crossing.  I would think more like 1000-1200 tons.  And, the ship would carry about 4000-6000 tons of fuel.  That is pretty typical to carry 4-6 weeks of fuel, when refueling every week, they are not running low each week.  And when you consider that the other major source of weight down low in the ship are the engines, and these are only a couple of hundred tons each, fuel is a major weight contributor.

 

I lost my confidence in the "Cruise log" a long time ago. But even then, the ship shouldn't lose it's balance for disposing the weight of fuel. I saw your response to a ship that needed to make the upper decks a bit lighter for stability. 1200 tons of fuel is similar, if the ship would be in trouble after getting rid of all its fuel, the ship is not within reasonable bounds of safety. 

45 minutes ago, chengkp75 said:

Anchors, lifeboats etc are not accidentally released either.

Anchors and lifeboats are not the size and weight of fuel tanks either, and anchors are not designed to be "ready for use" in an emergency, but require some prep work to get them ready for use.

 

I'm quite sure you can design tanks in such a way that gravity will help you get rid of them really quickly when needed, while simple locks will keep them aboard when you don't.

 

 

52 minutes ago, chengkp75 said:

Compensating for fuel with sea water is not a good idea, and is only used in submarines where you need to maintain a constant weight.  Especially with residual fuel, which is heated in the tanks, you now have introduced hot/warm sea water to a steel tank, just perfect for corrosion.

 

I was talking about the once in a carreer huge fire where a Captain needs to make decisions about how to save people's lives and hopefully the ship itself. Preventing an explosion by allowing the tank to corrode would not be his first problem. 

 

1 hour ago, chengkp75 said:

Each engine will have between 1-2 cubic meters of lubricating oil inside, and there will be more in the piping to the associated systems like coolers and purifiers.  These systems, which will have pump shutdowns in case of fire, will typically not have quick closing valves, an accidental trip of which could starve an engine of oil and cause it to seize up and catch fire.

 

Would the energy from, 6 times (?) 2 cubic meters of oil in a vast engine room be enough to endanger the rest of the ship? Most of it would not be exposed to oxygen anyway?

 

1 hour ago, chengkp75 said:

Typical use of CO2 will require leaving the space dormant, full of CO2 for two hours, and then risking ventilation and entry, or merely entry (which introduces air via the door) both with breathing gear, and with thermal imaging devices looking for "hot spots" that could re-ignite.

 

I'm still thinking about filling the area with small fire-resistant CO2 or NO2 filled balloons that would fill the entire room to keep the fire enclosed, automatically releasing CO2 or NO where it's needed because the heat makes them burst, while allowing people to breath safely while trying to find the exit.

 

1 hour ago, chengkp75 said:

It is a complex shape filled with equipment with complex shapes, and there are spots that can possibly trap air when the CO2 floods the space.  A cooling "hot spot" in the engine room, if the CO2 is evacuated too soon, is just waiting for that air to flood over it and re-ignite.  This is called "re-flash" and is something we drill on continuously.  It is also what caused much of the problems on the Carnival Splendor, when it was not respected, the engine rooms were ventilated too soon in an effort to get power back on, and the engine rooms reflashed three times, and the fire had to be extinguished three times.

 

If the fuel isn't the problem, and there's only so much lubricant oil mostly hidden in a oxygen-free environment, what stuff did start to burn again? 

[Heidi13]

17 hours ago, chengkp75 said:

Yes, without sprinklers, the requirments for low flammability are much greater.

 

I think the HiFog systems are the greatest thing since sliced bread.  It is so effective, and so low impact on equipment.  We had a planned maintenance task to actually release each zone once a year.  We had 12 zones, so one a month.  We even scheduled the engine room fire drills with the monthly release of HiFog, so that the fire teams learned to operate within the fog.  It completely removes the need for the second hose team to provide cooling fog for the primary hose team, thereby freeing up those assets for use elsewhere.  The only precaution we took when releasing into the working engine room spaces was to put trash bags over some of the electronic panels, but never worried about the motors or controller boxes.

Totally envious, as my Ch/Eng and I tried to use the system during a drill, but could not get consensus with the Snr Master. Most unfortunate, as my research confirmed your experience.

[Heidi13]

3 hours ago, AmazedByCruising said:

 

 

I asked what would happen during a Mythbusters kind of test, the extreme "will it burn, keep burning, and ignite the next cabin" and I understand the answer was "no". Heidi?

Cheng is correct, I indicated I have not observed a cabin burned, as all tests we completed were performed in burn tanks. Given sufficient time, a cabin will burn, but low flammability permits safe egress from spaces and time for fire teams to mobilise.

 

 

 

I lost my confidence in the "Cruise log" a long time ago. But even then, the ship shouldn't lose it's balance for disposing the weight of fuel. I saw your response to a ship that needed to make the upper decks a bit lighter for stability. 1200 tons of fuel is similar, if the ship would be in trouble after getting rid of all its fuel, the ship is not within reasonable bounds of safety.

We could make cruise ships stable without needing consumable fuel, water, etc to maintain stability. However, when full of fuel and water the GM would be so high the ship's movement would be uncomfortable. Ship stability is a dynamic subject, with the crew balancing passenger comfort with safety. On a number of occasions I have dumped pools, when low on fuel.

 

BTW - 1,200 tons of fuel is nothing, as on SS Oriana we used over 500 tons per day at full speed.

 

I'm quite sure you can design tanks in such a way that gravity will help you get rid of them really quickly when needed, while simple locks will keep them aboard when you don't.

Anything can be designed, but before designing fuel tanks that drop, best to figure out how to remove 1 or more of the top decks, before dropping the tanks. Ship Stability 101 - weight low is good, removing weights down low is bad.

 

 

I was talking about the once in a carreer huge fire where a Captain needs to make decisions about how to save people's lives and hopefully the ship itself. Preventing an explosion by allowing the tank to corrode would not be his first problem. 

Concur with Cheng, fuel tanks should not be filled with water, due to a multitude of potential issues. Lots of other options are available to maintain stability within safe limits.

 

 

Would the energy from, 6 times (?) 2 cubic meters of oil in a vast engine room be enough to endanger the rest of the ship? Most of it would not be exposed to oxygen anyway?

I do not believe Cheng is stating the lub oil is itself a fire hazard, when properly contained, he indicated starving the main engine of lub oil could cause the engine to seize, which could cause a fire. A large medium speed engine that seizes or goes into over speed is not a safe place to be around.

 

 

I'm still thinking about filling the area with small fire-resistant CO2 or NO2 filled balloons that would fill the entire room to keep the fire enclosed, automatically releasing CO2 or NO where it's needed because the heat makes them burst, while allowing people to breath safely while trying to find the exit.

Sorry, but this one is actually rather comical. Will your CO2 be liquified or pressurised? BTW - CO2 systems are not required to fill an entire space, as the Naval Archs calculate the amount required. However using CO2 requires very detailed protocols, which includes completely sealing the space and evacuating all personnel. As Captain, before approving use of a CO2 system, I receive confirmation all vents are closed and personnel accounted for. CO2 is also a single use. If it doesn't work, their is no 2nd chance. CO2 is also not introduced slowly, the space must be flooded quickly.

 

 

If the fuel isn't the problem, and there's only so much lubricant oil mostly hidden in a oxygen-free environment, what stuff did start to burn again? 

See comments in red

[chengkp75]

Thanks, Capt.  I'm a little muzzy, just got upriver to Philly, about 3 hours nap, then a 0100 shift to the dock.

 

I'll just add a few comments.  I'm saying about lube oil that it is another fuel for the fire.  Engines will typically have lots of aluminum covers that are not structural, most notably the crankcase doors.  When these are exposed to fire, they will typically melt out, and then the oil in the engine is exposed to the atmosphere.

 

As for re-flash, what happens is that it takes some time to either starve a burning object of oxygen (since the object is burning, it is the fuel), or to cool it down below its fire point, and if CO2 is not used correctly, i.e. allowed to sit and penetrate every tiny spot in the space, and then wait until everything that is burning is cooled sufficiently, then a rush of air will re-ignite the fuel source.

 

Yes, as Heidi says, CO2 will not completely fill a space, but it will blanket everything, starting at the bottom and working up, since it is heavier than air.  Isolated pockets of CO2 released by "balloons" would not extinguish anything, as the CO2 would sink and provide an even, and very thin layer at the bottom of the engine room, not a fire extinguishing atmosphere where ever you "needed" it.

 

And, so you want to have a system to pump sea water into a fuel tank, for a once in a lifetime, possible happenstance?  How do you test this system over the life of the ship, without putting sea water into the tanks.  Seems like an expensive way to do something that may never be needed.  And even ships that have had the entire engine room burned out, like the Triumph and Splendor, have not had fuel tank explosions, as one side at least of the tank is being cooled by the sea.  Again, the real danger comes from an empty tank, where the vapors are more dangerous than the fuel.  Tankers will have fires in cargo tanks that are full, but the explosions happen in empty tanks where the vapors can reach the optimum "explosive level".  Suffice it to say, that too "rich" a mixture of vapors (too much vapor) or too "lean" a mixture (not enough vapor) will not explode or even combust.  

[NLH Arizona]

On 12/17/2018 at 6:03 AM, Bron_Holden said:

  I wanted not unreasonably a proper explanation of why NCL have a blanket policy on the opening of such doors when other cruise lines don't.  I also wanted to put to them a different scenario which they may not have considered.  

I'm confused as to why someone would feel that a company owes them an explanation of their policies.  It should have been enough for NCL to say, "I'm sorry, but our policies don't allow us to open these up".  As far as giving them a different scenario, because you only wanted a larger balcony to be able to visit with those in the next cabin, seems a little strange to me, as I'm sure they thought about all the ands, ifs and buts, before putting the policy into place and if it was for safety reasons, would you have given them the same senario if you didn't want the partition opened.

Edited December 20, 2018 by NLH Arizona

[sparks1093]

1 hour ago, NLH Arizona said:

I'm confused as to why someone would feel that a company owes them an explanation of their policies.  It should have been enough for NCL to say, "I'm sorry, but our policies don't allow us to open these up".  As far as giving them a different scenario, because you only wanted a larger balcony to be able to visit with those in the next cabin, seems a little strange to me, as I'm sure they thought about all the ands, ifs and buts, before putting the policy into place and if it was for safety reasons, would you have given them the same senario if you didn't want the partition opened.

Question authority! Isn't that the philosophy nowadays?

[jwcruise1]

3 hours ago, sparks1093 said:

Question authority! Isn't that the philosophy nowadays?

Almost. I think now it is question LOGIC buck authority!