"A device on the mast of a ship analysing the surface of the sea could perhaps give a minute's warning that a rogue wave is developing," said Professor Nail Akhmediev, leader of the research at the Research School of Physics and Engineering.
"Even seconds could be enough to save lives."
Rogue ocean waves develop apparently out of nowhere over the course of about a minute and grow to as much as 40 metres in height before disappearing as quickly as they appeared. Ships unlucky enough to be where rogue waves appear can capsize or be seriously damaged, as happened in the Mediterranean Sea to the Cypriot ship Louis Majesty, which was struck by a rogue wave in 2010 that left two passengers dead and fourteen injured.
The research by Professor Akhmediev and the team at the ANU Research School of Physics and Engineering, Dr Adrian Ankiewich and PhD student Amdad Chowdury, is published in Proceedings of Royal Society A. Professor Akhmediev said that there are about 10 rogue waves in the world's oceans at any moment. "Data from buoys and satellites around the world is already being collected and analysed. Combined with observations of the surrounding ocean from the ship this would give enough information to predict rogue waves," said Professor Akhmediev.
The theory may also explain freak waves that wash away people from beaches, as the rogue waves can sometimes transform into travelling waves known as solitons, that travel through the ocean like mini-tsunamis until they hit the coastline.
Professor Akhmediev's theory also applies to other chaotic phenomena such as light travelling in optical fibres, atoms trapped in a Bose-Einstein condensate and the ionosphere in the upper atmosphere. The rogue wave is a special solution of the non-linear Schrodinger equation which is localised in time and space. The solutions were derived by adding terms to cover dispersion to the non-linear Schrodinger equation, forming the Hirota equations.
(Score: 2) by AnonTechie on Sunday August 02 2015, @07:23PM
How will a minute's warning help a big ship avoid the rogue wave ?
Albert Einstein - "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
(Score: 5, Insightful) by gman003 on Sunday August 02 2015, @07:29PM
On a big ship, that's time for everyone to get indoors and batten the hatches. The ship is usually fine, it's the people on deck you need to worry about.
On a small ship, that's enough time to turn the ship parallel to the wave (boating 101: you want big waves to hit you from the stern, or failing that from the bow, rather than from the sides).
(Score: 1) by koick on Sunday August 02 2015, @07:36PM
If they knew the direction it was coming from, they could turn the bow into the wave. This would have a much higher survivability versus being hit broadsides.
(Score: 2) by frojack on Sunday August 02 2015, @07:53PM
You can not turn a large ship in a minute.
No, you are mistaken. I've always had this sig.
(Score: 4, Informative) by Runaway1956 on Sunday August 02 2015, @08:17PM
Depends on the ship, and the circumstances. I rode destroyers for five years of my life, and I'm here to tell you, any destroyer can indeed make drastic changes in course in a minute or less. Cruisers can nearly match a destroyer. A huge gator navy ship is going to be somewhat slower, but then again, you won't always need to turn 90 degrees. And - 90 degrees is the max you will ever have to turn.
A big tank ship, or some run down coaster may not have time to maneuver to deal with the rogue wave - but they can at least get crew below decks. Besides which - the larger the ship, the less of a threat a rogue wave is. The smaller the ship, the more maneuverable it is. Looks like the people who can make the best use of the information are the most likely to benefit from it, right?
(Score: 1) by khallow on Sunday August 02 2015, @11:41PM
(Score: 1) by khallow on Sunday August 02 2015, @11:53PM
(Score: 2) by frojack on Sunday August 02 2015, @07:52PM
No, it isn't.
Not on any ship of size. The best you can do is warn everybody to grab something.
Even automated watertight doors take longer to close than a minute, to say nothing about the manual doors.
You can't turn a large ship in a minute. Something the size of a cruise ship might barely start responding to a full rudder input in a minute. Maybe.
No, you are mistaken. I've always had this sig.
(Score: 2) by Runaway1956 on Sunday August 02 2015, @08:20PM
I don't know anything about automated water tight doors - but I can state with certainty that a manually operated watertight door can be closed and dogged in about five seconds. If you're talking about doors large enough to drive a tractor through, well, maybe - but ships that large aren't especially threatened by rogue waves.
(Score: 2) by frojack on Sunday August 02 2015, @08:37PM
If you have exactly ONE such door you might get it closed in 5 seconds if you happen to be standing right there when the alarm sounded.
If you have even a pocket cruiser, you will have 20 such doors.
On a ship the size of the Louis Magisrty referenced in TFS and TFA, which (according to YOU) should be immune to rogue waves (but clearly wasn't), you will have well in excess of a hundred scattered over 5 decks and you will not turn that ship in 60 seconds.
No, you are mistaken. I've always had this sig.
(Score: 4, Insightful) by Runaway1956 on Sunday August 02 2015, @09:01PM
Ahhh - it's a matter of playing the odds then. How big is big enough to ride a huge wave? And, which way are you facing when the warning comes? And how many doors are there to dog? And, how many crew are in positions to act?
I insist that the larger the ship is, the safer the ship is. "Safer" being a relative term, of course. People who demand total safety don't go to sea, after all. They'll just remain sand crabs all of their lives.
Since my life at sea was spent on destroyers, I am quite certain that sixty seconds warning can and will make the difference between foundering and survival for a destroyer. We drill, and drill, and drill - the standard is 3 minutes from peace time steaming to combat readiness. We cut the standard by 50% when we had reason to do so.
Keep in mind that here, the ship doesn't have to achieve combat readiness - we are only concerned about watertight doors and hatches on the weatherdecks.
Civilian ships don't have our training, and they certainly don't drill like mad men either. But, depending on all those vagaries already mentioned, one minute of warning that a rogue wave is bearing down on you, people who WOULD have died, might be saved.
There is no cure-all solution possible. If you go to sea, your life is at risk. This warning system decreases the risk. That's good enough for me and the squids I've sailed with.
(Score: 3, Interesting) by fnj on Sunday August 02 2015, @11:59PM
It's not that simple. A comparatively tiny self-bailing lifeboat is probably "safer" than any size ship in the face of rogue waves. Coast guard boats and ships are also comparatively very small, but prodigiously seaworthy. I wouldn't give a plugged nickel for the chances of a grossly top-heavy container ship, even a gigantic one. And I'm pretty sure even a supercarrier could end up on her beam ends and in a very, very bad way.
In Typhoon Cobra in 1944, several aircraft carriers suffered hangar deck fires due to planes careening around and crashing into bulkheads and each other. One carrier rolled 20 degrees, the edge of the flight deck practically lapping the surface. Battleship Iowa suffered a bent propeller shaft. Heavy cruiser Baltimore required major repairs. Three destroyers went down with a total of 775 men. In another typhoon in 1945, heavy cruiser Pittsburgh had her entire bow ripped clean off and left floating on its own.
And these ships had HOURS to prepare for the lashing.
(Score: 0) by Anonymous Coward on Sunday August 02 2015, @09:25PM
but ships that large aren't especially threatened by rogue waves.
Evidently you never encountered one! 40 meters! Do you know how big that is in American? Many vessels would be pitch-poled by such a wave, and even a very large ship could be capsized.
(Score: 2) by tibman on Monday August 03 2015, @02:26PM
American sizes below one mile is the standard football field.
SN won't survive on lurkers alone. Write comments.
(Score: 2) by skater on Monday August 03 2015, @12:09PM
Modern cruise ships don't use rudders - they have "azipods" that can rotate 360 degrees and provide thrust in any direction. It's still not an instant turn, but it's a lot faster than the rudder era. But as others said, the other advantage would be giving time to get people away from the windows.
(Score: 2, Informative) by Anonymous Coward on Sunday August 02 2015, @07:53PM
> turn the ship parallel to the wave
Perpendicular to the wave. If you're parallel to the wave, you'll broach. The rest of your post is basically correct, just this term is wrong.
(Score: 3, Informative) by gman003 on Sunday August 02 2015, @09:20PM
I meant "parallel to the direction the wave is traveling", which is perpendicular to the wavefront.
(Score: 2) by Runaway1956 on Sunday August 02 2015, @07:38PM
No need to avoid it. A minute is time for the ship to maneuver. Ships have always had the choice of running before a storm, or turning to claw their way into the storm. A minute is more than sufficient time for almost any ship to come about on a new heading. Personally, I prefer to turn into the storm, or in this case, the rogue wave. The bow is designed to ride and/or part the wave, whereas, those megatons of water falling on the stern can be far more damaging.
Also, as has already been pointed out, a minute is sufficient for members of the crew who are on the weather decks to get inside, and secure water tight doors.
(Score: 2) by frojack on Sunday August 02 2015, @08:27PM
A minute is more than sufficient time for almost any ship to come about on a new heading.
Utter bullshit. Have you been on anything bigger than 30 feet?
Here is a Rate of Turn indicator [marine-data.co.uk] for a medium sized boat (maybe up to 150 tons). Notice it reads out in degrees per minute, and the scale only runs to 30 degrees. So at maximum rate of turn, with the meter pegged, you would be a third of the way through your turn and heeled over in EXACTLY the wrong direction at the end of your minute. You've just set your ship up for a roll over.
Typical turning rates for merchant vessels is .5 to 1 degree per second for lightly loaded vessels.
Certain naval Frigates, designed for tight turns of anti-submarine work have achieved 3 degrees per [youtube.com] second (at far less than full speed).
No, you are mistaken. I've always had this sig.
(Score: 5, Insightful) by Runaway1956 on Sunday August 02 2015, @09:14PM
How far do you need to turn? Never more than 90 degrees. If the rogue is coming at you directly from port or starboard, then you need to turn 90 degrees, right? What about when the wave is coming at you from a relative bearing of 270? You only need turn 30 degrees to meet it head on. Or, it's coming at you from 210 relative? Again, you only need come about 30 degrees to present your stern to the wave.
And, yes - I've already stated that I LIVED aboard destroyers for five years. Considerably larger than a 30 foot boat.
http://www.navsource.org/archives/05/01023.htm [navsource.org]
http://navysite.de/ff/ff1049.htm [navysite.de]
I've already stated that a merchant ship will probably benefit from this warning less than the Naval ships I am accustomed to. That doesn't mean that they can't benefit at all. At the least, those sailors can get inside and dog down the door they used to get inside. And - if they can turn only three, five, or ten degrees before the wave strikes, their odds of survival have increased by that much.
Why are you spending time arguing that the warning is worthless? Warnings always have value. How much value depends entirely on the immediate circumstances that you find yourself in. The warning system will save some lives - but it's not going to save every life.
(Score: 2) by fnj on Sunday August 02 2015, @11:34PM
Even as a landlubber I cannot stand avast.
If you're not too keen on taking a huge wave over the transom, you might have to turn 180.
Finally, face it, in picking a destroyer for your reference point, you've picked about the most maneuverable ship there is. There are not all that many destroyers sailing the seven seas. Not compared to the vast number of cruise ships and grossly top heavy container ships. These others do not have anywhere near the number of seamen hanging around ready to respond to orders to dog the watertight hatches, as destroyers do (which in turn are far inferior to WW2 crew count, for that matter).
(Score: 4, Informative) by Runaway1956 on Sunday August 02 2015, @07:41PM
http://rspa.royalsocietypublishing.org/content/468/2142/1716 [royalsocietypublishing.org]
I saw this story while it was in the queue, and followed the links around for a little bit. I'll be honest, I can't wrap my tiny little mind around all of that math - but thought some of you might like to see it.
(Score: 2) by cosurgi on Sunday August 02 2015, @10:45PM
Great! Thanks, exactly what I wanted to see :))
#
#\ @ ? [adom.de] Colonize Mars [kozicki.pl]
#