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Thread: Rogue waves & yacht design

  1. #36
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by Dirc View Post
    Now that reality is setting in, and the actual cases of rogue waves have been better documented & found to be more common than imagined - how must naval architects respond?

    Here are a few videos: https://youtu.be/zlPpAhDBlfk
    https://www.youtube.com/watch?v=0YVZ...FBE5EA5E56AF7E

    A few highlights from the videos, when they used the satellite system to count the actual number of waves over 75 feet in a 3 week time frame, they got 10 of them.
    (Granted, this was off the south cape of South America, but still)

    We've also had various cases of sunk cargo ships due to rogue waves:
    https://en.wikipedia.org/wiki/List_of_rogue_waves


    Will design change to reflect these common rogue waves? Can a 30-50 foot yacht be designed for safety in rogue waves?
    etc etc

    thanks for your thoughts
    I believe that anyone going offshore into some areas of the worlds oceans in a small boat, that being anything under 100 ft, needs to choose a vessel that can withstand very unusual seas.
    A full rollover is to be planned for as a "survivable" event, as is a dismasting. This can be done, but "Exploration grade" small craft are rare, expensive to build and there are so few people going into those areas that the market for this kind of little ship is very small, so they're rare.
    But yes, it can be done.

    John Welsford
    An expert is but a beginner with experience.

  2. #37
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    Default Re: Rogue waves & yacht design

    Just to add to the confusion, I have come across holes in the water; no apparent current (I am acquainted with whirlpools etc), not part of a wave train, just the opposite of a standing wave! I did go around them (maybe 20 ft across), they existed briefly and then vanished. It was in an area where there are strong tidal currents and offshore swells; but still perplexing (north of the Brooks peninsula Vancouver Is). Presumably if you can accept anomalous high waves, you could accept the opposite as well.

  3. #38
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    Default Re: Rogue waves & yacht design

    That scares me... the thought of the bottom dropping out on you. Bermuda triangle stuff... the best explanation of which I've seen by possible gas releases from the ocean floor, which drastically lowers the density of water translating into big drops (to the bottom on any semi-open boat)

    Yes, the rogue waves... here are some other stories, great ships which did survive, but it wasn't pretty:

    http://www.bbc.com/news/uk-38944629 60 foot yacht:

    The Challenger's skipper, Roy Graham, said problems had begun five days after leaving the Azores when a large wave hit the yacht.
    "We got hit with a rogue wave coming in the opposite direction," the 66-year-old Scot said.
    "It hit us and knocked us over and dragged the crosstrees into the water, which dragged the mast into the water and snapped it at deck level."



    http://www.bbc.com/news/av/world-163...t-of-australia the custom world racing vessel named Brigitte Bardot

    ...
    under the command of Captain Jonathan Renecle, was damaged by a rogue wave of 11 m (36.1 ft) while pursuing the Japanese whaling fleet off the western coast of Australia on 28 December 2011.[9] Brigitte Bardot was escorted back to Fremantle by the SSCS flagship, MY Steve Irwin. The main hull was cracked and the port side pontoon was being held together by straps. The vessel arrived at Fremantle Harbour on 5 January 2012. Both ships were followed by the ICR security vessel MV Shōnan Maru 2 at a distance of 5 nautical miles (9 km).[10] The repair process, with a cost of over $250,000, included placing the ship in a hermetically sealed chamber. Composite yacht experts from across the globe, including the ship's designer, were flown in to assess the damages and recommend a course of action. Sea Shepherd's 18 Australian chapters raised the money necessary to repair the vessel. Repairs to Brigitte Bardot were completed and the ship set sail for sea trials on 16 April 2012.[11]




    I know it can be done, but yes, back to Lloyd's scantlings etc? (and applied to the whole structure, not just below the WL)
    Last edited by Dirc; 05-23-2017 at 07:33 PM.

  4. #39
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by john welsford View Post
    I believe that anyone going offshore into some areas of the worlds oceans in a small boat, that being anything under 100 ft, needs to choose a vessel that can withstand very unusual seas.
    A full rollover is to be planned for as a "survivable" event, as is a dismasting. This can be done, but "Exploration grade" small craft are rare, expensive to build and there are so few people going into those areas that the market for this kind of little ship is very small, so they're rare.
    But yes, it can be done.

    John Welsford
    is there anyone out there, with specially outfitted yachts, and video equipment... chasing rouge waves? like tornado chasers in the USA mid west?

  5. #40
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    Default Re: Rogue waves & yacht design

    Not this guy, that's for sure.
    If one advances confidently in the direction of his dreams, and endeavors to live the life which he has imagined, he will meet with a success unexpected in common hours.
    -Henry David Thoreau-

  6. #41
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    Default Re: Rogue waves & yacht design

    As a teenaged surfer I spent a lot of time studying waves and looking for a good one to ride. My cousin and I were fearless and surfed the Northeaster storm-brewed waves that were the biggest we ever saw here in Northeast Florida. In big storm conditions it was extremely difficult to get outside the break to catch your breath enough to be able to paddle, stand up, and actually ride a wave. In those conditions we only rode one or two waves for the day and we would be exhausted. We quickly learned that when faced with a giant wall of white water coming at you, the best thing to do was to dive as deep as possible holding the nose of your board and hope like hell you can make it to the backside portion of the wave to get to where the thing is cycling upwards instead of downward. Then and only then is the wave working for you instead of against you. Sometimes you lose and that white water gets a hold of you and won't let go. You end up 100 yards closer to shore and having to start all over again. But then there are times when you are perfectly positioned and you take off on a mountain of a wave and the adrenaline is just about squirting out your fingernails!

    You learn a lot about the power of waves from surfing. There's so much power in them because of the density of water, the circular cycling motion inside a wave and the overall speed of the wave itself. Also the bottom can amplify the size of a wave and so can what we used to call backwash which is a wave that slid up high on the beach and is returning to the sea in an opposite direction. Also two waves of different speeds can combine near shore and you end up with a wave almost twice as tall of any wave of the day.

    I have a very deep respect for the force of the ocean. In fact, I have spent much of my work hours in the last five months helping to repair the hurricane damage to my sister's house as the result of Hurricane Matthew. Nobody needs to tell me about the forces involved with ocean waves. You can call it fear or respect but I spent the entire time of Matthew beating up St. Augustine by watching it on TV from the safety of Tallahassee. Didn't really know if my house would be where I left it when I returned.

    Just thought some of you might enjoy the perspective of a surfer who has spent a lot of time struggling against waves, being beat up by waves, being squashed by waves, chewed up and spit out by waves, and even having my face slammed against the bottom and bloodied by a wave. Somehow it's all worth it if you get in that perfect place planing inside a wave with the whole thing curling around you harmlessly and you are hauling butt at high speed. Sometimes a plane comes together in a beautiful way.

    My perspective in regard to boats designed to handle rogue waves is to make them as much like a rubber duckie bath-time toy as possible. If it can hold together, not be crushed, torn apart, or flatten and then it can return to floating right-side-up all in one piece, then that would be a good design for blue water possibilities to handle a rogue wave. It would also probably be good if the inside of the rubber duckie was like a padded cell so you could survive spinning around inside the wave for as long as that takes. Pretty sure, however, that such a boat would not have much of a market in the blue water cruising world. That would be like having a Sherman tank for your everyday driver. The gas mileage would be terrible!

  7. #42
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by john welsford View Post
    I believe that anyone going offshore into some areas of the worlds oceans in a small boat, that being anything under 100 ft, needs to choose a vessel that can withstand very unusual seas.
    A full rollover is to be planned for as a "survivable" event, as is a dismasting. This can be done, but "Exploration grade" small craft are rare, expensive to build and there are so few people going into those areas that the market for this kind of little ship is very small, so they're rare.
    But yes, it can be done.

    John Welsford
    John, it can be done down to what size of boat?

  8. #43
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by kenjamin View Post
    As a teenaged surfer I spent a lot of time studying waves and looking for a good one to ride. My cousin and I were fearless and surfed the Northeaster storm-brewed waves that were the biggest we ever saw here in Northeast Florida. In big storm conditions it was extremely difficult to get outside the break to catch your breath enough to be able to paddle, stand up, and actually ride a wave. In those conditions we only rode one or two waves for the day and we would be exhausted. We quickly learned that when faced with a giant wall of white water coming at you, the best thing to do was to dive as deep as possible holding the nose of your board and hope like hell you can make it to the backside portion of the wave to get to where the thing is cycling upwards instead of downward. Then and only then is the wave working for you instead of against you. Sometimes you lose and that white water gets a hold of you and won't let go. You end up 100 yards closer to shore and having to start all over again. But then there are times when you are perfectly positioned and you take off on a mountain of a wave and the adrenaline is just about squirting out your fingernails!

    You learn a lot about the power of waves from surfing. There's so much power in them because of the density of water, the circular cycling motion inside a wave and the overall speed of the wave itself. Also the bottom can amplify the size of a wave and so can what we used to call backwash which is a wave that slid up high on the beach and is returning to the sea in an opposite direction. Also two waves of different speeds can combine near shore and you end up with a wave almost twice as tall of any wave of the day.

    I have a very deep respect for the force of the ocean. In fact, I have spent much of my work hours in the last five months helping to repair the hurricane damage to my sister's house as the result of Hurricane Matthew. Nobody needs to tell me about the forces involved with ocean waves. You can call it fear or respect but I spent the entire time of Matthew beating up St. Augustine by watching it on TV from the safety of Tallahassee. Didn't really know if my house would be where I left it when I returned.

    Just thought some of you might enjoy the perspective of a surfer who has spent a lot of time struggling against waves, being beat up by waves, being squashed by waves, chewed up and spit out by waves, and even having my face slammed against the bottom and bloodied by a wave. Somehow it's all worth it if you get in that perfect place planing inside a wave with the whole thing curling around you harmlessly and you are hauling butt at high speed. Sometimes a plane comes together in a beautiful way.

    My perspective in regard to boats designed to handle rogue waves is to make them as much like a rubber duckie bath-time toy as possible. If it can hold together, not be crushed, torn apart, or flatten and then it can return to floating right-side-up all in one piece, then that would be a good design for blue water possibilities to handle a rogue wave. It would also probably be good if the inside of the rubber duckie was like a padded cell so you could survive spinning around inside the wave for as long as that takes. Pretty sure, however, that such a boat would not have much of a market in the blue water cruising world. That would be like having a Sherman tank for your everyday driver. The gas mileage would be terrible!

    I agree with kenjamin that there is much that can be learned from experiencing the power of waves while surfing. But the shape of surf-able waves is generally created by a shoaling bottom and the best waves on a very shallow bottom like a reef. Rogue waves are deep water creatures and you pretty much have to go looking for them where the bottom is nowhere to be found or maybe 100 fathoms down.
    I can’t say that chasing rogue waves like tornado chasers is exactly what I have done, but it has been necessary to face the possibility of meeting one in the places that I have sailed and I have observed how different wave trains compound to create doubled up peaks that ‘throw out much like surfing breaks where waves meet in a wedge.
    The really steep walls are formed when there is a strong current flowing against wind and waves, such as the Agulhas current or the Gulf Stream.
    In those places, even a small craft can cope best when it can imitate a surfboard and slide down the slope with the stern quarter tucked into the face and the rudder preventing the stern from rounding up, like the skeg of a surfboard does to keep the board tracking diagonally down the face without slipping out (broaching in terms of boating).
    Here, a ballast keel would not help to stay out of trouble.

    When a rogue, roaring like an approaching train, hits such a craft (one that allows the bow end to slide away from the wave and never become buried in a nosedive) the power of the wave is absorbed like a blow from a massive foam mallet, with the craft moving along with the solid water to dissipate the wave’s power, in the way a boxer rolls with a punch, to lessen the damage of the impact.

    Solid wood is a very good and resilient material for boats in this situation ( moving with the flow), whereas a steel craft built like a tank, that is intended to stand unmoving against impact, will still possibly buckle and bend when opposing wave power.

  9. #44
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    Default Re: Rogue waves & yacht design

    As far as small craft design goes, traditionally there are only the NAs who have worked with surf launched lifeboats, and these have generally not considered sail carrying stability to be part of the design function.
    Still, lifeboats can be the basis for well-found hulls when it comes to coping with powerful waves.
    Getting a lifeboat type hull to perform in average sailing conditions is more of a challenge than getting one to ride rough water with storm sail set.

  10. #45
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    So true. The same tall superstructure that tends to ensure self-righting ability in a boat also tends to make it tougher to get to windward effectively.


    Sent from my iPad using Tapatalk

  11. #46
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by Lugalong View Post
    I agree with kenjamin that there is much that can be learned from experiencing the power of waves while surfing. But the shape of surf-able waves is generally created by a shoaling bottom and the best waves on a very shallow bottom like a reef. Rogue waves are deep water creatures and you pretty much have to go looking for them where the bottom is nowhere to be found or maybe 100 fathoms down.
    I can’t say that chasing rogue waves like tornado chasers is exactly what I have done, but it has been necessary to face the possibility of meeting one in the places that I have sailed and I have observed how different wave trains compound to create doubled up peaks that ‘throw out much like surfing breaks where waves meet in a wedge.
    The really steep walls are formed when there is a strong current flowing against wind and waves, such as the Agulhas current or the Gulf Stream.
    In those places, even a small craft can cope best when it can imitate a surfboard and slide down the slope with the stern quarter tucked into the face and the rudder preventing the stern from rounding up, like the skeg of a surfboard does to keep the board tracking diagonally down the face without slipping out (broaching in terms of boating).
    Here, a ballast keel would not help to stay out of trouble.

    When a rogue, roaring like an approaching train, hits such a craft (one that allows the bow end to slide away from the wave and never become buried in a nosedive) the power of the wave is absorbed like a blow from a massive foam mallet, with the craft moving along with the solid water to dissipate the wave’s power, in the way a boxer rolls with a punch, to lessen the damage of the impact.

    Solid wood is a very good and resilient material for boats in this situation ( moving with the flow), whereas a steel craft built like a tank, that is intended to stand unmoving against impact, will still possibly buckle and bend when opposing wave power.
    interesting pieceing together Alfred "Centannial" Johnson's storm/gale survival strategies from bits and snippets of old accounts and articles, seems he may have used a very similar strategy to what you outline Lug.
    With the tabernackle mast lowered and his centerboard raised Johnson rode out the worst of his tempests hunkered in the cockpit always at the tiller and quite possibly surfing these steep monsetrous sized seas.

    it's very possible this small craft along with the James Caird is one of the few Sail and Oar boats to encounter and survive a Rouge Wave on the open sea.


  12. #47
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by Daniel Noyes View Post
    interesting pieceing together Alfred "Centannial" Johnson's storm/gale survival strategies from bits and snippets of old accounts and articles, seems he may have used a very similar strategy to what you outline Lug.
    With the tabernackle mast lowered and his centerboard raised Johnson rode out the worst of his tempests hunkered in the cockpit always at the tiller and quite possibly surfing these steep monsetrous sized seas.

    it's very possible this small craft along with the James Caird is one of the few Sail and Oar boats to encounter and survive a Rouge Wave on the open sea.


    Yep Daniel,I get and agree with what you say here

  13. #48
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    Default Re: Rogue waves & yacht design

    Maybe ocean rowing boats are among the smallest ones? Even they seem to be mostly above 20' long and conform to the "rubber duckie" concept. Similar in size to Centennial?

    http://kk.org/thetechnium/hitech-ocean-row-boats/
    http://www.oceanrowing.com/sale/index3.htm

    I wonder what size of steep wave a small open boat like a faering or peapod can deal with without capsizing. A trough to peak height of a quarter the length of the boat? Less without active steerage to prevent broaching?

    I talked with a local fiberglass sailing yacht owner about his 30' boat and in our brief conversation he chose to mention encountering a 10' rogue wave (I imagine the inshore kind created from several coinciding wave trains). He said he was freaked out until he let it sink in that his boat was quite a bit bigger than the wave. Clearly he lived to tell the tale and he didn't mention any damage to his boat.

  14. #49
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    Default Re: Rogue waves & yacht design

    Modern lifeboats have been designed to be successfully launched from a 100 feet or so, with passengers aboard and restrained. So you know that such a vessel can likely withstand the free fall from a monster wave. The question remains as to the possibility of very unusual and unanticipated impact forces damaging the vessel and injuring the passengers.

    https://youtu.be/JgkvLSRQPOc

  15. #50
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by BOI View Post
    Maybe ocean rowing boats are among the smallest ones? Even they seem to be mostly above 20' long and conform to the "rubber duckie" concept. Similar in size to Centennial?

    http://kk.org/thetechnium/hitech-ocean-row-boats/
    http://www.oceanrowing.com/sale/index3.htm

    I wonder what size of steep wave a small open boat like a faering or peapod can deal with without capsizing. A trough to peak height of a quarter the length of the boat? Less without active steerage to prevent broaching?

    I talked with a local fiberglass sailing yacht owner about his 30' boat and in our brief conversation he chose to mention encountering a 10' rogue wave (I imagine the inshore kind created from several coinciding wave trains). He said he was freaked out until he let it sink in that his boat was quite a bit bigger than the wave. Clearly he lived to tell the tale and he didn't mention any damage to his boat.
    Just a hunch but I think the danger for small craft is the breaking tops described by many who encounter these waves.

    Shackelton aboard the James Caird describes seeing white clouds on the horizon at night only to realize seconds later the white was the foaming breaking crest of a on coming rouge wave, which swept the Caird from stem to stern.

  16. #51
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    Default Re: Rogue waves & yacht design

    Quote Originally Posted by kenjamin View Post
    So true. The same tall superstructure that tends to ensure self-righting ability in a boat also tends to make it tougher to get to windward effectively.


    Sent from my iPad using Tapatalk
    In my experience with a lifeboat like hull, the deck was highly cambered over the mid 1/3 part of the length, though the foredeck was flat, rather than high and slab sided like modern cruise ship lifeboats.
    This boat of mine could go to weather by bearing away (putting the helm up) at the crest of oncoming seas in the Agulhas current, and using the slope on the back of the wave to accelerate in semi-surfing mode and using momentum gained to steer closer to windward when in the troughs.

    Wind was sustained force 7-8 at the time and substantial ground was made to windward during the gales encountered in the Agulhas current between Durban and East London.
    No rogue waves were encountered, and admittedly the fast flowing current that contributes to formation of such waves did help in lifting my heading and the ground made to weather.

    This hull and topside buoyancy did pay off when there was no option to make way to windward, when the choice to run was the better one for survival.

  17. #52
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    Default Re: Rogue waves & yacht design

    Define a "Rogue Wave"? is it a breaking wave? a bigger wave than all the rest? These happen most typically when a deep sea wave starts up the continental shelf. The wave itself slows and starts getting more height, sometimes to the point of breaking. They can break in deep water as well but that is usually when two or more wave trains combine, and the face of the wave becomes steeper. The height may be greater as well. Deep sea waves can easily exceed 30 ft, though most do not. Roger Taylor of Ming Ming fame specifically avoided as far as possible approaching land ( continental shelf) if he was expecting heavy weather. The worst sea I have experienced was near Sable Island with 80 kt winds and 14 metre seas ( 46 ft-measured by a wave rider buoy within 5 nm of my location). The wave face was very steep, wave length perhaps 350' I do not remember depth but am thinking 60-80 metres. This was an incredible sea but I did not see a rogue wave there....nothing significantly larger than the rest. Another time we had very large seas somewhere north of Rockall. We did not see anything because it was dark but I was literally tossed through the air about 10' when the ship hit a larger wave and simply stopped. Maybe a rogue wave.....
    As Ian has pointed out we now know that these occur much more frequently than previously thought. I don't disagree with John Welsford that perhaps seagoing small yachts be designed and have the capability of a complete roll over, stronger deck and cabin area and better level of water tightness. Some attention to the rig, most likely you loose it, so diminishing the likelihood of further damage to the hull and reparability would be in consideration. Currently, boats considered suitable for offshore will meet the ISO standard for water-tight and stability >130 degrees.
    The odds of encountering a Rogue wave generally is very low, except in a few areas of the world.

  18. #53
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    Default Re: Rogue waves & yacht design

    As gilberj's post indicates, there are several different phenomena that are called "rogue" waves.

    The most common, experienced normally both at sea and along the coast, is really a compounding of two or more wave chains. The sharper the angle, the more they seem an isolated peak. These are easily two or three times the average wave height and are the waves that most often sweep people off beaches and jetties and such.

    There is more controversy over the differently formed wave once known as the "ultimate wave". As this thread shows, we now admit it's out there, more than thought before, and we know a bit more about where it's more likely. The actual physics, including the true shape, speed, size, duration, and almost all other qualities remain elusive.

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