Man overboard on Anthem

[AmazedByCruising]

A satellite phone? You're going to stop stroking, trying to keep your head out of water, to use a phone?

 

I meant the phone as the device to send out the positions automatically. Not a person chatting with the Captain :D

 

 

Anyway, the two life rings attached to the bridge wings have EPIRB's (Emergency Position Indicating Radio Beacons) attached to them. These transmit on specific frequencies to dedicated SAR satellites. Within minutes, SAR centers around the world know there is an emergency, and where it is, and will call the ship using the call sign transmitted by the EPIRB. Why aren't all the life rings equipped with this? Because any life ring so equipped, and in a passenger area, would be an invitation to "test it out", or even just inadvertently turn it on (usually by turning them upright), and the ship has to pay a fine for each "false alarm". Best to keep this equipment under the control of the professionals.

 

How long does it take for a ship to return to those life rings? I wonder how far they can drift away from the passenger in that time, so how big is the area where the passenger can be once you returned?

[Ocean Boy]

Just be careful not to hit the person in the water with any deck chairs!

 

 

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A ship cruising at 18 knots moves abut 30 feet per second. I doubt that you'll be hitting anyone with that chair.:rolleyes:

[Capt_BJ]

How long does it take for a ship to return to those life rings? I wonder how far they can drift away from the passenger in that time, so how big is the area where the passenger can be once you returned?

Valid questions that are at the heart of any search at sea .... unlike a search on land it is virtually impossible for the target to 'stay in one place and wait' as wind and waves take control immediately ....

cruise ships / large ships don't stop on a dime nor are they famous for tight turns .... getting a boat in the water takes time .... and this assumes the bridge knows IMMEDIATELY that someone has gone over. When a person is noticed missing after an hour or more and the ship must backtrack .... One good thing is GPS provides a MUCH better system for being able to accurately backtrack. And as a technical point an initial action on the bridge is to press a button on the GPS for MOB which locks the spot ....

getting a life ring or something similar in the water quickly is VERY important / helpful as X marks the spot. BUT a life ring and a body drift at different rates, a lifeless body and a swimmer different, a person in a life jacket different again. Every minute that passes increases the size of the potential location 'circle' .... and the overall uncertainty.

More items in the water can be better - too many can get in the way .... a bigger target is always better tho which is why rule one if you have boat trouble is stay with the boat as long as possible. Staying with a capsized boat is better than trying to swim for it ... the hull is a bigger search target and drifts differently.

Imagine this: when searching for a person in the open ocean who's not in a lifejacket you are looking for a volleyball sized object - the head ... that may be covered in black hair. Even when the seas are perfectly calm you can't imagine how difficult until you try it. Got wind driven whitecaps from a stiff breeze? Problem just got WAY more difficult ...

CG assets will have thermal imagers but when the target is SMALL and the heat cools quickly (cold waves washing over) and when bouncing in waves will not typically present a 'solid hit' ... it is no magic answer.

[chengkp75]

I meant the phone as the device to send out the positions automatically. Not a person chatting with the Captain :D

 

 

 

 

How long does it take for a ship to return to those life rings? I wonder how far they can drift away from the passenger in that time, so how big is the area where the passenger can be once you returned?

 

The life ring is lighter than the person, so hopefully it drifts faster downwind than the person does, and it will catch up to the person in the water. This, of course, assumes the life ring was thrown in upwind of the person. Otherwise, it doesn't do much good, unless the person can swim to the ring. As to how far, that would depend on wind and current.

 

How to locate a person in the water? In the "old" days, we used "rescue turns" (https://en.wikipedia.org/wiki/Man_overboard_rescue_turn) to return the ship to its original course track, but in the opposite direction. The problem with this, if you read the link, is that the ship must put the wheel hard over (as far as the rudder or azipods will go, and in sea mode, azipods are limited like rudders to 35* each way). If the ship is moving above 10 knots or so, this places a great deal of change of momentum on the ship, and it will develop "turn induced heel", or listing away from the turn, which can become quite severe (approaching 35-40*), with attendant damage to china and passengers. Or, the ship can spend a lot of time/distance slowing down and then making the rescue turn.

 

A better way is the modern way. The ship has an ECDIS (Electronic Chart Display Information System) display, that takes an electronic chart and gets inputs from GPS, radar, speed log, and other inputs, and displays the world around the ship on an actively moving chart. The ECDIS has a special button to be used to mark a man overboard. This immediately places a fixed reference mark on the chart at that position, so the ship can return to that exact position any way it finds is best, without resorting to one of the rescue turns if not required.

 

Either way, you are likely to be turned around a mile or two from the spot of the overboard, and you head back at a moderate speed, just in case the person isn't where you thought they'd be.

 

You then start to search downwind and down current from the mark. Again, the area of the search depends on wind, current, and elapsed time. Higher wind, or higher current, or longer elapsed time, and the search area grows exponentially.

[LauraJeremy]

This photo shows one of the life rings and Norwegian Gem at 5:26pm yesterday. I shot it from the Diamond lounge on deck 4 (starboard).

 

 

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We watched that life ring be thrown over board by staff and was horrible to see so can't imagine the people who witnessed the man go over. So sad for the family.

 

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[AmazedByCruising]

Valid questions that are at the heart of any search at sea .... unlike a search on land it is virtually impossible for the target to 'stay in one place and wait' as wind and waves take control immediately ....

getting a life ring or something similar in the water quickly is VERY important / helpful as X marks the spot. BUT a life ring and a body drift at different rates, a lifeless body and a swimmer different, a person in a life jacket different again. Every minute that passes increases the size of the potential location 'circle' .... and the overall uncertainty.

 

Thank you for you elaborate answer.

 

Why would you throw a life ring that has expensive EPIRB, which will drift very different from a body? Wouldn't the information be better if you'd throw in a much bigger device that would drift similar to what a typical MOB from a cruise ship would do? A life ring and a bag of water attached, or similar.

 

You wouldn't need to throw it from the bridge, just a simple release mechanism on the aft that releases when the MOB button is pushed.

[ONECRUISER]

So here is a weird coincidence a woman fell off a ship half a world away at very close to the same local time

http://www.abc.net.au/news/2018-04-13/search-called-off-for-missing-cruise-ship-passenger/9652232

Yes, was talked about on this thread and couple others...

[ONECRUISER]

Thank you for you elaborate answer.

 

Why would you throw a life ring that has expensive EPIRB, which will drift very different from a body? Wouldn't the information be better if you'd throw in a much bigger device that would drift similar to what a typical MOB from a cruise ship would do? A life ring and a bag of water attached, or similar.

 

You wouldn't need to throw it from the bridge, just a simple release mechanism on the aft that releases when the MOB button is pushed.

Chief did say Ring being lighter then person would float to him, that is why you wouldn't throw it if wind/current going other way as would float away not towards him... Sure he will respond soon

[chengkp75]

Thank you for you elaborate answer.

 

Why would you throw a life ring that has expensive EPIRB, which will drift very different from a body? Wouldn't the information be better if you'd throw in a much bigger device that would drift similar to what a typical MOB from a cruise ship would do? A life ring and a bag of water attached, or similar.

 

You wouldn't need to throw it from the bridge, just a simple release mechanism on the aft that releases when the MOB button is pushed.

 

Well, one of the values of a life ring is that it provides the person some additional flotation, so they don't have to exert as much energy staying afloat, and also when tired they can just hang on. If you attach a weight to it, you then either take away that extra flotation (holding up your bag of water), or you have to make the life ring that much bigger to have buoyancy for the bag of water and for the person. And the bigger you make it, the different it will drift, and so on and so on. The EPIRB gets you to an area, not necessarily a spot, if the person can't get to the ring. Starting from a known position is better than starting from a guess. And you would be searching from upwind to down wind, so if the ring drifted faster than the person, you would theoretically get to the person before you get to the ring.

[Capt_BJ]

I'll not say Ch is wrong ..... but that's not the points I'd make. Ch is a very qualified ship's engineer. I was a CG Cutter CO who ran many an at sea search as on scene commander, after working up from search executor and search planner ....

 

First would be the most important. Assuming you don't find the target immediately .... we (CG and as built into our search planning models) have a historic baseline for the basic characteristics of a ring buoy and a person and many other standard search targets. If we can measure what the ring buoy ACTUALLY does and compare that to what the models projected, we can determine an 'adjustment' to be applied to the 'person' model ...... the we of much of this is computers of course the math is HEAVY. CG actually has had 'special buoys' in the aircraft for years .... these buoys have special transmit capabilities and known drift characteristics and are tossed into the water in a search area to provide updated/real time drift data which gets fed back into the computer models. This technology has been around for 40 + years but continuously updated ...... CG master search models get regular updates of currents and winds via NOAA and the network of weather buoys ...... how I could say the water wasn't 70 where this individual went in ....

 

CH assumes the ring and the body drift in the same direction and only the speed varies. This is usually NOT the case. Without going into super detail the easy version is the ring buoy has little water drag and is driven much more by the wind, while a body has only the head exposed to the wind but a large 'sea anchor' aka the body hanging in the water. Since the seas and the wind are seldom the same exact direction, the different forces can be significant, especially over time ... different 'things' in the water have very different drift characteristics. Before the computer and computer SAR tools were so readily available, CG SAR coordinators had large handbooks with charts that provided figures for drift rates of different 'things' in various conditions .....

 

(btw for engineers, especially civil, what we're talking about here is like using differential GPS for surveying. As you may know dGPS was developed for the maritime world to eliminate the 'uncertainty' of the degraded GPS signal available to the public until a certain President said "that's dumb" and turned off the degraded signal. So dGPS went away for maritime, but the technology increases the accuracy of GPS to survey standards. Hence, today most surveyors establish a position 'the old way', then set up a differential GPS station which determines the local correction "d", and measure all subsequent positions by GPS with the local "d" correction)

 

A Coast Guard product believe it or knot ......

[Familygoboston]

And that is also part of why people are asked NOT to leave things on their balconies.

And why i always tell people, never leave items unattended on the balcony that are not part of the ships equipment. Besides the fire risk, there is this false alarm MOB risk. Not good! The aft cabin I was just in someone had zip tied a whole set of clothes line/pins to the rail, obviously for the Purpose of drying laundry. Such a hazard! Hopefully this tragedy makes us all more mindful!

[ONECRUISER]

And why i always tell people, never leave items unattended on the balcony that are not part of the ships equipment. Besides the fire risk, there is this false alarm MOB risk. Not good! The aft cabin I was just in someone had zip tied a whole set of clothes line/pins to the rail, obviously for the Purpose of drying laundry. Such a hazard! Hopefully this tragedy makes us all more mindful!

Agree, over the years I've witnessed multiple items blown overboard from Balcony's...

[AmazedByCruising]

Well, one of the values of a life ring is that it provides the person some additional flotation, so they don't have to exert as much energy staying afloat, and also when tired they can just hang on. If you attach a weight to it, you then either take away that extra flotation (holding up your bag of water), or you have to make the life ring that much bigger to have buoyancy for the bag of water and for the person. And the bigger you make it, the different it will drift, and so on and so on. The EPIRB gets you to an area, not necessarily a spot, if the person can't get to the ring. Starting from a known position is better than starting from a guess. And you would be searching from upwind to down wind, so if the ring drifted faster than the person, you would theoretically get to the person before you get to the ring.

 

I'm trying to imagine what happens in case of a MOB when the ship is sailing at 20 knots. Best case: two people see someone falling in the water, one finds a phone and calls 911, the other throws a "normal" life ring. If the latter took 60 seconds to find it, detach it, throw it: the passenger, has to swim towards the ship for 600m/2000ft to find the ring. Provided he wants to be rescued, is conscious, and understands that he would need to swim at least that distance before starting to look for it. An object that's so small that even small waves will block you from seeing it when its 20 feet away. Usually in the dark.

 

Google wouldn't tell me, but I really doubt if anyone that got rescued after falling from a cruise ship actually found a ring at all.

 

Now the phone call. I guess 60 seconds to find a phone, or more if you need to find a crew member first. Calling itself, someone picking up: another 30 seconds. Then some miscommunication, and making sure the passenger is not joking and probably some explaining about the huge fine for making such jokes, the button is pressed and the expensive ring is released . Total 2 minutes. The ship is now 4000ft away from the swimmer, when the ring with EPIRB is released. The odds that the passenger would find that ring must be near zero.

 

My (newer) point would be that the latter ring doesn't function as a (direct) life saving device at all. It would be very useful for the location, but in that case it should have the weight, form, etc similar to a person.

 

(Of course the ship could be sailing at 6 knots, in broad daylight, and the sea could look like a mirror)

[BND]

I'm trying to imagine what happens in case of a MOB when the ship is sailing at 20 knots. Best case: two people see someone falling in the water, one finds a phone and calls 911, the other throws a "normal" life ring. If the latter took 60 seconds to find it, detach it, throw it: the passenger, has to swim towards the ship for 600m/2000ft to find the ring. Provided he wants to be rescued, is conscious, and understands that he would need to swim at least that distance before starting to look for it. An object that's so small that even small waves will block you from seeing it when its 20 feet away. Usually in the dark.

 

Google wouldn't tell me, but I really doubt if anyone that got rescued after falling from a cruise ship actually found a ring at all.

 

Now the phone call. I guess 60 seconds to find a phone, or more if you need to find a crew member first. Calling itself, someone picking up: another 30 seconds. Then some miscommunication, and making sure the passenger is not joking and probably some explaining about the huge fine for making such jokes, the button is pressed and the expensive ring is released . Total 2 minutes. The ship is now 4000ft away from the swimmer, when the ring with EPIRB is released. The odds that the passenger would find that ring must be near zero.

 

My (newer) point would be that the latter ring doesn't function as a (direct) life saving device at all. It would be very useful for the location, but in that case it should have the weight, form, etc similar to a person.

 

(Of course the ship could be sailing at 6 knots, in broad daylight, and the sea could look like a mirror)

 

The ring is usually tossed in as close as possible to the location the person was seen going in if they were seen. It's unlikely that anyone would actually be able to use it to be rescued.

 

The one or two people I've read about that have been rescued were found treading water and usually fell from just a few decks.

[chengkp75]

 

 

My (newer) point would be that the latter ring doesn't function as a (direct) life saving device at all. It would be very useful for the location, but in that case it should have the weight, form, etc similar to a person.

 

 

So, let me get this straight. You want a series of devices that are 5.5-6 feet tall, and weigh about 200 lbs hanging over the side of the ship (cause no one person could lift this and get it over the rail) to be released by pulling a pin, and it's available for everyone to walk up to and "see if this thing actually works"? It's bad enough that folks throw the life rings overboard when there is no emergency (happened last year in Oz), but this would just invite folks to stick their fingers into it.

 

The sad fact is that if you go overboard, the chances of being found and rescued are slim to none, and Slim just left the building. I know BJ will probably take offense to this, but it is something I've been told by active USCG cutter crews: Even with a full complement of trained personnel on lookout, and with a "dummy" in orange having been thrown overboard, there have been occasions where the USCG has not found their training dummy ever again. Looking for something the size of a soccer ball (the head is the only thing above water) in the vastness of the ocean, even given a fairly tight area to look in, is a difficult proposition at the best of times.

[SRF]

My Dad was one of the people behind US Navy pilots wearing white helmets with reflective decals applied. Previously the helmets were gold and almost impossible to see in the water.

 

Even with the white and reflective decals, some of his friends had a hard time being found when they ended up ditched, even close to the ships.

 

They also wore flotation devices and carried flares and smoke.

[AmazedByCruising]

So, let me get this straight. You want a series of devices that are 5.5-6 feet tall, and weigh about 200 lbs hanging over the side of the ship (cause no one person could lift this and get it over the rail) to be released by pulling a pin, and it's available for everyone to walk up to and "see if this thing actually works"? It's bad enough that folks throw the life rings overboard when there is no emergency (happened last year in Oz), but this would just invite folks to stick their fingers into it.

 

No, I still see why releasing those should be handled by trained people. The "normal" life rings would be available to the public but I believe they serve a symbolic purpose more that anything else. Those big devices should be designed for their purpose, which is providing a position rather than providing bouyancy. Out of reach of normal pax, to be released from the back of the ship by pushing a button. More or less a wetsuit filled with water, and of course the electronics.

 

The sad fact is that if you go overboard, the chances of being found and rescued are slim to none, and Slim just left the building.

 

But, you do agree that the life ring thrown from the bridge adds virtually nothing to your odds of surviving as a way to get bouyancy?

I know BJ will probably take offense to this, but it is something I've been told by active USCG cutter crews: Even with a full complement of trained personnel on lookout, and with a "dummy" in orange having been thrown overboard, there have been occasions where the USCG has not found their training dummy ever again. Looking for something the size of a soccer ball (the head is the only thing above water) in the vastness of the ocean, even given a fairly tight area to look in, is a difficult proposition at the best of times.

 

I'm sure BJ willl agree that falling from a ship has a very profound influence on your expected lifespan.

[Pellaz]

Does the Allure have infrared man-overboard sensors? If so, that would help fix the exact time the person went overboard, which would "tighten" the search radius somewhat. (Also assuming the detectors worked as designed.)

[chengkp75]

No, I still see why releasing those should be handled by trained people. The "normal" life rings would be available to the public but I believe they serve a symbolic purpose more that anything else. Those big devices should be designed for their purpose, which is providing a position rather than providing bouyancy. Out of reach of normal pax, to be released from the back of the ship by pushing a button. More or less a wetsuit filled with water, and of course the electronics.

 

 

 

But, you do agree that the life ring thrown from the bridge adds virtually nothing to your odds of surviving as a way to get bouyancy?

 

 

I'm sure BJ willl agree that falling from a ship has a very profound influence on your expected lifespan.

 

Well, the ring on the bridge also has a smoke pot for both visual aid and for the person to see and move towards. It also has a strobe light for the same reasons. And the long, floating rope can aid in getting you to the ring. Getting to anything that floats increases your chances.

[chengkp75]

Does the Allure have infrared man-overboard sensors? If so, that would help fix the exact time the person went overboard, which would "tighten" the search radius somewhat. (Also assuming the detectors worked as designed.)

 

As far as I know, only Disney has the thermal automated man overboard alarm system. I got into it with a manufacturer's rep here on CC a couple years ago about their claim that the device detected "mass" so it could differentiate between a smoldering trash can and a person (both are warm, not hot, and about the same "size"). They finally agreed that their system does not measure "mass". It measures temperature and size, and I'm not sure what the size limit is, so whether it can differentiate a small child or an adult in a tight tuck position I can't say.

[Pellaz]

As far as I know, only Disney has the thermal automated man overboard alarm system. I got into it with a manufacturer's rep here on CC a couple years ago about their claim that the device detected "mass" so it could differentiate between a smoldering trash can and a person (both are warm, not hot, and about the same "size"). They finally agreed that their system does not measure "mass". It measures temperature and size, and I'm not sure what the size limit is, so whether it can differentiate a small child or an adult in a tight tuck position I can't say.

 

Carnival's Freedom-class ships have the sensors installed; I've seen them on the side ("FLIR"), plus our tour guide pointed out the alert panel on the bridge during a behind-the-scenes tour. It was on the port side bridge "wing" although there may have been another panel on the starboard side as well.

I meant to actively look for the sensors on my last two cruises (Carnival Vista and Independence OTS)...and plumb forgot.

 

I'd have been very impressed if the sensors detected mass instead of size; that capability would practically be the stuff of science fiction. :D :o

[dogboy53]

So here is a weird coincidence a woman fell off a ship half a world away at very close to the same local time

http://www.abc.net.au/news/2018-04-13/search-called-off-for-missing-cruise-ship-passenger/9652232

 

Video has shown she jumped off the ship, did not fall off the ship.

[Megan_Strick]

I was on a Carnival Cruise last spring break when a man jumped in the middle of the night. Scared me when the announcement was made over the intercom. Us and a Disney ship circled for 8 hours. Man was on his honeymoon. The have video of him jumping. I sat on my aft balcony and watched the spot lights shine in the water. Very eerie

[AmazedByCruising]

Well, the ring on the bridge also has a smoke pot for both visual aid and for the person to see and move towards. It also has a strobe light for the same reasons. And the long, floating rope can aid in getting you to the ring. Getting to anything that floats increases your chances.

 

Yes, but given the speed of cruise ships, the life ring from the bridge increases your chances very, very little. It seems the odds of survival are increased when the positioning device looks like a person. You can always throw in an extra life ring.

 

The floating rope is cool, didn't know it existed. How long are they?

[chengkp75]

Yes, but given the speed of cruise ships, the life ring from the bridge increases your chances very, very little. It seems the odds of survival are increased when the positioning device looks like a person. You can always throw in an extra life ring.

 

The floating rope is cool, didn't know it existed. How long are they?

 

Polypropylene rope all floats. Life rings on ships have 90-100' of rope attached.