Rogue Waves

In September 1963 as a student I travelled to Europe on the Bremerhaven (came back a year later on the Bremen, the Bremerhaven's slightly larger sister ship). We passed within a relatively short distance of a giant storm (hurricane?) and the ship had to go through huge waves. Everyone on board was seasick except me for some reason. I went out onto one of the upper decks at night and held on for dear life as the ship plunged in and out of waves and troughs that literally dwarfed the ship. I think the ship was 8 or 10 stories above the water line plus the stacks so these waves must have been over 80 feet peak to trough. As a young man I learned a powerful lesson about the awesome energy of the sea. I also gained a lot of respect for big ships. I also decided that if I am going to go on a boat of less than 700 feet, that I want to stay not too far from land!

 

What a coincidence!

I was in that very same storm, returning from the far east on board the aircraft carrier Hornet (CVS-12). It was quite an adventure! I can confirm the size of the waves: normally the flight deck on the Hornet was 90 feet above the water, and we were taking solid water OVER that deck about every sixth wave. I would estimate that the horizontal peak to peak distance of the waves was about 500 feet.

On an carrier like the Hornet the secondary control station is located just under the flight deck, forward. There are armored observation positions port and starboard on either side of the bows at the same level, just below the level of the flight deck. Being young (and stupid!) a friend and I went out to the starboard observation position to watch the storm late one night. We would dive through a wave and barely get wet as the water went over us in a solid wall . . . and then I happened to look aft and found that the catwalking for about 75 yards aft of us wasn't there any more! The ships bell was also gone, leaving a brass nub mounted securely to a steel fitting. That was worrisome!

We were standing in a steel box made from 1.5 inch armor plate, but decided it might be wise to get back inside . . . so after diving through the next wave we scrambled up on deck and ran like crazy for the island. When we got there we found the hatches securely dogged and had to scramble frantically to get one undogged so we could get in. We barely made it! Then, of course, we had to scramble out of there before someone caught us. We didn’t think “explaining” this little adventure would go over well with the captain.

We had four destroyers and a couple of DLG’s with us, and they were running low on fuel (the carrier in a task force like this is the tanker for all the ships) so we had to do an underway refueling in these conditions, while about three feet of water was sloshing about in the hanger bay.

As I said, it was an adventure.

But I think you may be wrong about the size of boats and seaworthiness. The carrier got quite a bit of damage from that storm, it even split the hull near the bows. And why didn’t we assume a less punishing course? The REAL NAVY guys would never consider that. It would be WAY too smart. Many years later I went to England and bought an extremely fine little boat called a Contessa 26. That Contessa would have weathered the same storm with no bad effects at all. It would just go up and down about 90 feet, and probably do it quite gently! In fact, I did manage to test some theories advocated by Mr. Coles in that little boat in a nice Atlantic storm. Thirty foot plus sharply breaking waves and wind so chaotic I literally couldn’t tell which way it was blowing except by observing the streaks in the surface. I was 400 miles away from land and well away from the usual sea-lanes, so I didn’t have to worry about hitting the land at least, for a while.

I went below and waited for it to all go away, which it did a few days later. Now, I would probably deploy a serial drogue as well and be a little more comfortable.

The point is, if the boat is truly seaworthy you don’t have to worry too much about storms . . . and that is a great comfort. Size is really irrelevant, especially beyond about 12 meters. In my opinion, most American boats are decidedly NOT seaworthy, however, and I wouldn’t consider going to sea in most of them under any circumstance!

I’m a very safety-conscious kind of guy!

 

BillyDoc

Wow, that's pretty amazing that we experienced the same storm! But my issue was not a simple one of seaworthiness. A bottle with a cork in it could have survived. I was thinking more of the comfort level. When I was on the deck of the ship hanging on to the railing for dear life, I tried to imagine what it would be like being tossed in around in a small boat hundreds of feet up and down with no chance of getting out on deck and witnessing the awesome forces and no chance of keeping my lunch..

Somewhere some guy is trying to build something called the freedom ship.
http://www.freedomship.com/
A mile long and 25 stories high it is an oceangoing real estate development. They claim that because of the scale of the ship, a 100 foot wave will cause a one foot vertical movement. Evidently size does matter!

 

Jonathan,

With such height what would be the lateral movement of the top stories?

Yoav

 

Yoav,

That's a very good question! My father lives on 33rd floor of Harbor Towers in Boston and in a strong wind moves that around quite a bit. A 100 foot wave hitting the freedom ship, may only rise vertically one foot, but it certainly is capable of rocking and rolling and actually the ship looks a bit top heavy as well. I don't even want to think about the capsize potential!!

 

That is some ship . . . and I sure wouldn’t want to be on it in a serious storm!

Assuming they are correct and the ship would only displace one foot in response to a 100 foot wave (which I don’t believe, what about broadside swells with a long wavelength?), then I think we can assume that for all practical purposes the ship is a stationary structure. Which means that all those apparent balconies along the side (it isn’t a big sea-going parking garage is it?) will not be riding up and over that wave, but the lower levels will be exposed to its full impact. Which could be very awkward!

The picture isn’t clear, of course, but now imagine all of the fine full “picture” windows behind those balconies. They would sure look great in the advertising brochures! And during a storm “hurricane” shutters would no doubt be provided and drawn . . . and any self-respecting wave would crash right on through. I recently had the dubious pleasure of seeing first hand what a lot of wind could do to “hurricane” shutters (hurricane Ivan, and more recently hurricane Dennis) made from roughly 1/8" polycarbonate. Polycarbonate in that thickness will literally stop a 45 cal bullet, but it didn’t stop Ivan! And by that I refer only to the wind from Ivan. I mentioned above that waves of lessor magnitude were capable of splitting the armor plate on the bow of a WWII aircraft carrier, and I believe that stuff was solid high-carbon steel 1.5 inches thick.

And now imagine the effect of hurricane force winds on that tall, flat-bottomed structure. A structure that is dependent almost entirely on form stability by definition (a barge), which as William Froude pointed out many years ago “is the handle which a wave uses to grab you (I’m paraphrasing from memory here, sorry). The plan put forth at the link is for them to cruise along just off shore, with only enough power to cruise very slowly. Which is to say, probably not enough power to claw off of a lee shore in a stiff breeze given the apparent windage, and not enough speed to avoid anything!

There is no question that size matters, in many things. And a big ship will certainly ride larger waves in greater comfort. But comfort at sea is also a function of sea-worthy design, and in my uneducated opinion the “Freedom Ship” is decidedly not sea-worthy as drawn. It looks down-right dangerous to me!

I hope some of the Naval Architects here will chime in on this issue.

 

Never mind the experts, as an old sailor of some 37 years experience - 10 Fighting Navy 27 Merchant Marine (including some 17 of them in oil rig work boats) I can assure you these things exist! And as the man said normally in three's normal, normal, normal, large, very large and bloody gi-normas in comparison to the surrounding seas. No body measures them 'cos they are too busy hanging on (not only that who'd bloody well believe you!)

 

Hey Billydoc bet they love you in the bar on a saturday night! three foot of water on the hanger deck, even in those barns the 'second best navy in the world' pushes around would turn the damn thing over - something to do with stability! But yeah a good 'dit' believable too! (see my line above)

 

Hey Safewalrus,

I wish I could hope to be tippin back a jar in some pub come Saturday, but the Missus and I will probably be putting up the shutters to welcome Katerina instead (another hurricane). And this when a local watering hole has just started carrying Guiness and Newcastle Brown on tap. I can't decide which one I like better, so I have to sample them both. And to be certain, of course, takes more than one sample.

I should clarify that three foot claim some I see. You are quite right that three foot of water in the hanger bay while riding level would put quite a strain on the stability of the old girl. But as it was, she was having a bit of a toss-up with Neptune at the time and was not at all level-headed about it. She rolled and tossed and pitched and yawed all over the place, so that the water in the hanger bay was sloshing back and forth giving us all an exciting time of it. There probably wasn't more than four or six inches worth if we had stayed level, but by the time it all accumulated and came chasing after any poor sailor out for a stroll it seemed like we could put a surf board to good use. And if any other Swabbie was also out for a stroll the competition for the bulkhead ladders could get a bit frantic. By the time we tipped over that water was at least three feet deep at the breaker end, and probably more.

If I can get myself back to England some time I’ll look you up and tell you about the Mermaid I saw one time . . .

 

No doubt at the Eddystone Light.

 

My father was the keeper of the Eddystone light
And he slept with a mermaid one fine night
From this union there came three
A porpoise and a porgy and the other was me!

 

Wave Atlas

Just happened to catch a new program discussing Rogue Waves on cable TV this evening (the history channel). Mention was made of a catalog of wave events being recorded in a 'WaveAtlas'. Thought it might be worth while re-mentioning this term.

...from Google....

World Wave Atlas (WWA) is in fact two things:

First, it is the collective name for a series of comprehensive high resolution interactive wind and wave atlases capable of providing accurate wind and wave climate statistics for any country or region worldwide.

Secondly, it is a global data base which we at OCEANOR use in our own consultancy work (for the offshore industry, wave energy interests, coastal engineers etc.).

 

very interesting, I found out that every 7th wave is bigger in stormes,and at normal tides, as I have stated before I fished offshore in 31 ft jc boats,it is like the cork in a barral you can slosh it around but it sill stays on top, like I said all along ,we fished in really rough seas all the time I believe there are rogue waves , oil riggs disapeer in stormes , the discovery of giant squid ,,,,after years of ledgond ,is fact there are monsters out there ,not all are animal,,,,,,,,,longliner

 

Great sea stories, good reading.

 

Video Link, Big Wave (x-rated?)

Posted on another forum.....

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.ph...fekteWelle.wmv