chengkp75

It is not the MOV that is the problem, it is the way it is connected. Those DC power supplies don't place the MOV across hot/neutral to ground, just from hot to neutral, and are used to shut off the output power when the input voltage gets too high (voltage limitation, which is frequently advertised as surge protection).

Don't think I ever said that, unless you are plugging a surge protector in. I've plugged my laptop into ship's power for decades, and even had it plugged in and running when the ship was struck by lightning.

Your impressions are not quite right. Yes, noise from SCR drives can cause MOV's to fail, but not because there is a voltage spike of sufficient intensity or duration. None, repeat none, of any electronics that are part of the ship are protected by surge protectors, as they are not needed. This is true for all the computers used onboard, the navigation equipment, the radio equipment, the POS cash registers, and the engine automation that keeps the ship running. As for the "imbalance of voltage", not sure what you mean by this. But, the noise from the SCR drives, leads to the same failure of the MOV's as all other failures of surge protectors on ships, reverse voltage. What is reverse voltage? The MOV's used in surge protectors are designed to see a high voltage in the "hot" leg of the wiring, and low voltage in the neutral and ground. These MOV's bridge between the hot and neutral legs and ground, providing a path for current if the voltage on the hot or neutral leg are high enough. If the MOV senses a higher voltage on the ground, then is present at the hot or neutral legs, they will burn out, or go into "thermal runaway" and melt down. Now, how is it possible for the ground (which we all know is "ground") to be at a higher voltage than the hot or neutral? On a ship, the neutral and ground are not at the same voltage (60v hot to ground, and 60v neutral to ground), so that there is no possibility of the neutral current being carried in the ground conductor (which is the hull). Current in the hull can lead to corrosion of hull and fittings, so the condition of all wiring circuits is monitored with relation to ground. Now, if a 480v motor goes to ground due to insulation failure, the ground now has 480v on it, and the hot/neutral have 60v, so the MOV sees "reverse voltage", and melts down. This is why I call a surge protector the "silent killer" on ships, since a surge protector that is working perfectly fine, can catch fire from a cause entirely outside your control, and possibly at the other end of the ship. There are surge protection devices made for marine electrical systems, but they are very expensive, and for normal, commercial use they are not needed. Typically, only the Navy uses them. Why aren't surge protectors needed on ships? What are the two most common causes of voltage surges on land? Lightning and transformer shorts. With the ship's electrical system completely divorced from the "ground" (hull), lightning that strikes the ship passes harmlessly through the hull to the ocean. I've been on several ships struck by lightning, and have never had any electronics fail, and never have had surge protection. Land transformers go from 10k volts to the 220v that comes into your house. If that transformer shorts, you get 10k volts to your computer. On a ship, the 10k volts that are generated, are stepped down to 440v in one transformer, then to 220v in a completely separate transformer, and finally to 110v in a third transformer. So, to get more than 600 volts at the outlet in your cabin (the typical clamping voltage of a consumer surge protector), you would have to have a simultaneous failure of 3 transformers. Ships simply don't see the types of voltage surges that happen on land.

Well, surge protection comes from upstream, so if you plug a two prong device into a surge protector, yes it will get protection from surges, because the surge protector is between the device and the surge.

Pretty much anything that only has USB ports, will be allowed. It's the ones with both USB and power outlets that will draw attention, whether they are surge protected or not. You can get them with 4,6, 8 or more USB ports. I know its hard to read the molded writing on many of these devices, but this is where you can look. Unless it says "VPR = x volts", or "x joules of protection" (VPR is voltage protection rating, and is a measure of how good a surge protector it is), then the device does not have surge protection. And, here is the one bit of advice I give, but that tends to get twisted. "If it has a two prong plug, it can't be surge protected, since a surge protector needs a connection to ground (the third, round pin). Many here on CC get this mixed up, and say that "if it has a ground pin, it is surge protected", but this is not true.

No, its pool water, and can go overboard with no treatment, though some places have restrictions on pumping chlorinated water overboard near shore, and some places even have restrictions on pumping fresh water overboard in certain areas (affects the salinity in close proximity). Having said that, it is perfectly legal to pump gray water (sinks, showers, galleys, laundry, not black water from toilets) overboard when outside 12 miles, with no treatment whatsoever. Most cargo ships do this. Cruise ships treat their gray water mixed with the black water, because it dilutes the black water entering the treatment plant, and to get the effluent to near drinking standards.

These little gems are some of the worst for fires. Even if you have brought it on before, and the cabin steward doesn't say anything about it, because they don't know, or don't want to lose their DSC by ticking you off, doesn't mean it isn't a danger. Even a brand new, working perfectly surge protector, when plugged into the ship, can catch fire due to something completely out of your control, and at the other end of the ship. On another thread, I discussed this problem, and another poster reported that that was just what happened. They plugged the Belkin in, had nothing plugged into it, and it started to smoke and get hot. If left, it would have melted and caught fire. Actually, a surge protector cannot "damage the ships electrical system" in any way, the only danger is to the surge protector itself, which can catch fire. The bathroom outlets, marked "razor only" are limited to 40 watts of power, so only an electric razor, or an electric toothbrush or waterpik would work. These are fused, so if you overload it, it requires the electrician to dismantle the whole light fixture to replace the fuse.

For the larger 16 cylinder engines on Quantum, I would have expected a 4-6 week timeframe. Three weeks is overly optimistic, IMHO. Even if they brought on extra personnel to work longer hours per day, there is a physical limit on where you can stick all the pieces (each of the 16 pistons is 18" in diameter, and 40" tall, and the cylinder liners are larger) in ways that you can easily clean, inspect, and service everything in a logical order.

Just past Empire, mile post 27, about 65 miles to go.

Ships are very often "not 100%" with passengers onboard, and none the wiser. Every engine, every 2.5 years, is completely torn down for overhaul, that takes about 4-6 weeks. During that time, the ship is operating without one engine (i.e. not 100%), but as long as the itinerary does not require full speed, no one knows it is happening. I doubt they would cancel a Transpac due to one engine being down. The current problem is that there are two engines down, one for overhaul, and one waiting on parts. So, the one undergoing overhaul will be completed, even if they don't get the part for the other, and the ship can do very well without the one engine.

What you describe is a salt water pool in "flow through" mode. This can only be done when the ship is more than 12 miles from shore. There is no chlorine added when in flow through mode, as the water is not recirculated. The pool is constantly overfilled, and the overflow goes back to sea. A flow through pool, when the ship is within 12 miles of shore, must either be closed and drained, or switched to "recirculation" mode. In recirculation mode, they no longer draw sea water in, they just recirculate the water in the pool, as is done with home and land pools. All pools, whether salt or fresh water, when in recirculation mode, must be chlorinated to 4ppm residual. That is typically higher than most home pools. Most ships with salt water pools do not switch to flow through mode, unless the ship is going to have 2 or more sea days in a row, since once the change back to recirculation, they need to close the pool until the chlorine reaches the required level. Constantly switching from flow through to recirculation costs a lot more in chlorine than just keeping the pool on recirculation during sea days.

Guess what. The salt water pools are chlorinated as well.

No, ports require protection from the diseases that the rats from the ship may introduce. I know covid has dominated the headlines for the last couple of years, but there was a thing called plague. Also, hanta virus, typhoid, typhus, and a few others.

You may want to brush up on reading comprehension. I never said the vent didn't exist, I said I wasn't sure what it could be, and stated that it definitely was not an AC vent as the OP suggested it might be, knowing how ship's AC systems are built. But, again, you answered the question "is there proof of rodents" by saying that "there was a missing vent cover", but the vent cover being off is not proof of rodents, unless of course the passengers saw the rodents taking the cover off.

Did they see the rodents using this vent? And, being someone who lives in a 200 year old house that backs up to woods, I have quite a bit of experience with rodents (both mice and rats), and the damage looks more like a chemical burn than a rodent chew. Rats are a bit different, but mice tend to leave poop right where they eat, or chew things.

Rats coming up the mooring lines is a very minor problem. Many ports do not require rat guards anymore, and really only cruise ships use them all the time.

Each cruise ship is required to have a pest control officer, whose only duty is the pest control program. This goes beyond rodents to roaches and fruit flies. The rodents would not be in the cabin areas, they would be in the food prep and storage areas. And, if there were rodents in the passenger cabin areas, this would have been a long term problem, and this would have been found by USPH inspectors long ago. Not sure what a "disconnected" vent (between the rectangular and round) would be (not an AC return), they are never near the floor, and they don't go "outside".

I'm not aware of any microwave, anywhere on any NCL ship. Possibly the Captain has one in his suite.

Hair care appliances are the exceptions to the rules about things with heating elements. However, I have heard reports of Dyson products not working on ships. This is likely due to the "digital motor" which uses electronics to convert the power, and it likely doesn't like that the "neutral" and "ground" are not at the same voltage, or that the AC power is "dirty" (small voltage spikes) due to the propulsion system. Some have no problem getting them to work, some do.

Actually, this is not correct, either. RCI does not allow any extension cords, or are you going to debate that a power strip is not an extension cord?

The electronics in the straightener don't like the way that ship's power acts. Both the ground system, and the "dirty" AC power caused by the propulsion can make the electronics switch off.

Hair straighteners are allowed, but just be aware that I have seen several reports that the ceramic type straighteners (most likely your expensive one is) don't work on ships. And, anything confiscated on boarding is available to be picked up at the end of the cruise.

And, again, I am not talking about an insulation failure between wires, I'm talking about a failure between one wire and the case of the appliance. You stated that "the safest power strip" had a single pole breaker inside it. I said, that the "safest power strip" for a ship has a dual pole breaker, because even if you interrupt the hot leg, you could still have potential stray current flowing to the case from the neutral leg, as has been found with typical commercial power strips on ships causing fires (there is a USCG safety notice regarding this) because the neutral leg continued to conduct. I won't continue to argue whether a power strip breaker has a faster trip curve than a molded case breaker, but a dual pole breaker on the power strip is still safer than a single pole one, due to ship's grounding system.

Further, under the Submerged Land Act, while the Federal government controls the navigable waters of the US, the states regulate the "submerged land" (ocean bottom) under those waters, and can determine whether or not ships anchoring in places disrupts the ecology, and commerce of the waters, and could just as easily close the anchorages to all but small fishing boats, and pleasure craft.