Yachts vs. Rogue Waves...

video of Freak wave

I have a video of a cruise ship hitting a freak/large wave, originall from the German TV show Spiegle. The video was posted on the website Grosse seefahrt, but you need to log in to see it, and its in German. The ship is one of the mini cruise ships build by Blohm and Voss and it wa sin the mediterrnian, amazingly scary as there is a camera in the bridge and you see the wave comming up then breaking over the bow then smashing throgh the bridge windows.

Saw something about this the other night on the History Channel. It was a show about rogue waves and was very interesting.

Yes, they had a lot of footage from the movie.

A British research team has observed some of the biggest sea swells ever measured. A whole series of giant waves hammered into their ship that were so big, according to computer models used to set safety standards for ships and oil rigs, they shouldn't even exist...

http://service.spiegel.de/cache/international/spiegel/0,1518,408953,00.html

THIS... is why we use Dockwise!

Back to the topic of Rogue Waves, "Oceanography and Seamanship" by Van Dorn has an excellent discussion on constructive interference in a wave system. There are nomographs showing how for a given wind speed and fetch there will be waves of a given mean height with anomalous waves reaching 4 times to 8 times mean heights due to interference. I seem to recall that every 10,000 waves there will be one several times the mean height with many that are twice the mean.
Everyone who has been to sea knows that when the NOAA reports 8 to 10 footers you can count on getting hit by a few 15 footers even in a fairly short passage.

Van Dorn also has photos and reports from US Navy tank testing that show a vessel should survive an encounter with a breaking wave as long as the wave height is less than the dimension of the vessel's exposure to the wave...ie a 100 foot vessel going head into a 30 foot wave should survive. The same 100 foot vessel presenting her 22 foot beam to the 30 foot wave will have a good probability of capsize. And of course we all know that most motor yachts are NOT self righting!

Dave

Good post Dave! Speaking of wave frequencies and anomolies, "Davewb" sent the link below. He uploaded the Perfect Wave video to a hosting site. It's clearly a free hosting site based on the girls decorating the perimeter... all wanting your monitary attention.

If you think the bridge of a cruise ship is a fairly safe place to be, you're about to get wet...

http://www.yourfilehost.com/media.php?cat=video&file=DiePerfekteWelle.wmv

I uploaded the "roque-wave breaking through the glass of the bridge-video", but only after seeing it for the 5th time I noticed something strange: The vessel that has so much green water slamming into the bridge is probably NOT the same ship as the blue-hulled cruise ship you see earlier in the video. The bridge that is flooded seems to be located much lower than the bridge of the cruise ship. It's scary enough to look at, but I think it's a smaller vessel that gets hit by the wall of water.

I would say very plausible. Self-righting designs are rare, especially in the very large sizes.

Kelly

It is most likely that she would capsize once at 90 degrees. The superstructure
is not designed to be totally watertight like a hull. Once water enters the vessel rolls to upside down.
See the pictures of "In Full Bloom" from a few months ago.

I don't know anything about waves but I would say after the top of the wave breaks and hit the ship,just about that time the base of the wave will be following and lift the hull to help it over. thats my guess. Think of those "pipelines" they surf. the whole oceon upsets on it self.