chengkp75

The kids "splash area" is divided into two sections on Oasis, Quantum, and Freedom class ships. The larger area is for potty trained kids only. The smaller area, separated by a glass partition, is for kids in swim diapers. If you are taking older kids, they are not allowed to travel from one area to the other, without showering in between, to prevent cross-contamination. There are, I think, a couple of Voyager class ships that have the swim diaper area added, and all other older ships do not allow kids in swim diapers.

Every Christmas, the ship has to deal with phytosanitary certificates, and certificates of sterilized soil for all the Poinsettias used to decorate the ship. All natural Christmas trees had to have a fire retardant certificate as well.

The problem with PPV events is that the charges are set by the promoters, not the satellite service provider, and even though the fight may only be shown in one location, the ship gets charged for every TV onboard, as a potential viewing site. I remember we looked into it on a tanker, and with 20 TV's it was going to be $10k.

While you are correct about this, the PVSA was passed long before aviation was even thought about. The Civil Aeronautic Act, is another cabotage law, and this applies to aviation, as the PVSA does to marine passenger, and Jones Act does for cargo. Trust me, I know quite a lot about both the PVSA and Jones Act.

This is not correct. The PVSA does not apply to airlines, that is the Civil Aeronautics Act that limits domestic flights to US carriers. because it applies to more than cruise ships, and protects the jobs, adds to the US economy, and protects the environment and safety of passengers on vessels in the US like ferries, water taxis, commuter boats, tour boats, dinner cruises, casino boats, and large charter fishing boats.

Yes, but the MOV's across the hot leads do not see reverse voltage, and so are not susceptible to thermal runaway.

First of all, there won't be any surges, simply due to the nature of the ship's electrical system. Lightning strikes don't affect the ship's electrical system, and voltages are stepped down through multiple transformers. As you say, the hull is ground, but so is the ocean, so there is in fact, a "ground". The problem comes because there is no intentional connection to ground like you have with the neutral wire in your house, a high voltage motor could start to fail to ground somewhere on the ship, and this will send high voltage on the ground wire, compared to the two power leads (hot and "neutral"), which is "reverse voltage" for the surge protector, and which can cause the MOV semi-conductors to go into "thermal runaway" (generating high temps even at low amperages), and melt the surge protector down and catch fire.

That's one Schuko (European 220v) plug adapter, and a 6 port USB charging hub. Still should have one 110v outlet available for the hair dryer.

I can only hope.

Insulation checks are done annually, at minimum, and we start to worry when it gets less than 400 Megohms (.001 milliamp), nowhere near the breaker tripping point.

Are they metal? Yes. Are they magnetic? Maybe. It depends on the thickness of the vinyl covering they use, and the strength of your magnets.

They already do. It comes in your boxes from Amazon. You think it's "packing material", but it's just that someone figured out how to sell you air.

If a motor insulation fails, there will be a path from one conductor to ground, and if it results in a serious enough ground fault, then the breaker will fail. However, it could be a partial failure of the insulation, resulting in a lower current flow than the breakers are rated for, but which would still introduce enough current to start electrolysis. However, since this is the only path from the ship's wiring system to ground, there is no interference with the wiring system, merely the introduction of electrolysis of metals in the hull. This is monitored by a "ground fault meter", which is a milliamp meter that is connected with a resistor between line and ground, providing the return connection from ground to the system. If current is detected, the meter indicates, and the engineers start looking for the circuit, and then the device that is grounded. There is only one power source on the ship, all generators generate 10k volt AC power, and feed a common bus. This bus supplies propulsion, hotel, and engineering power. And, as I said, wherever needed, the 10k volt power is stepped down in steps from 10k to 440v, 440v to 220v, and 220v to 110v. And, the propulsion motors, as well as the thrusters, and AC chiller motors are 10k volt motors, not 440v. Most major motors onboard (pumps, compressors, fans, laundry machines, galley equipment like ovens, ranges, refrigerators) are 440v as well. The SCR drives are 3-phase, as is all equipment that is 440v and above, so you have a bridge of 6 SCR's to control the frequency of the output AC. It's been a while since I did a deep dive into the circuitry, but I believe that zener diodes are used to filter noise spikes to neutral ( the generators are star wound with a neutral point, and the motors and everything else are delta wound). I don't know enough about semi-conductor construction to know, but I believe that MOV's have a limited amount of joules they can shunt, and even small overvoltages, over small periods (noise spikes), can "build up" in the MOV and cause eventual failure. That is correct. There is 60v between neutral and ground. This allows for determination of a ground fault on the neutral wiring, to prevent electrolysis. And, yes, all breakers are two pole. I just got into this with another poster on another thread, who said the "safest power strip for cruise ships has a 15 amp breaker and no surge protection". I countered with the safest power strip is as he described, but with a two pole breaker in the power strip, as consumer power strips only break the hot leg, and not the neutral. He didn't understand the nature of the "floating ground" (not connected to neutral). All of the power strips I've used on ships over the last decades have been "European" ones (rated 220v, but that's not important), that have a two pole breaker in them for just this reason. We also cannot use things like household or commercial UPS, since these look for 120v hot to ground as the "normal" condition, and when plugged into a ship that is producing 120v AC power (hot to neutral), but with only 60v hot to ground, it immediately goes into "power failure" and "battery mode". We have to use special marine UPS that recognize the floating ground.

It is about the fecal coliform bacteria, more than phosphates in detergents. The ship has to be underway to discharge gray water, so it is dispersed, and the laundry water is small in comparison to the total gray water volume.

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.