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Old 30-07-2010, 15:13   #16
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"Testing has clearly born this out and one must remember that air is less dense, "
Density and bouyancy have nothing to do with it, PAR. NASA did extensive research on micro-textured surfaces and how they REDUCE DRAG by changing the interaction on the boundary between a fluid and a solid surface. It is very similar to the dimples that make a golf ball fly further. Introduce the right kind of surface or the right "lubricant" on the hull, and you reduce drag. There have been boats built to test this concept with "slime" injection and air injection, and the concept works and was very specifically banned in racing, as far back as the late 80's IIRC.

Sven, I was taught, perhaps incorrectly, that the Norse "went out Viking" meaning "went out raiding" and that the "ing" suffix was doing the same thing that it usually does in English, describing action. I don't know enough Icelandic or Old Norse to tell you if there's a word akin to "Vik" or "Vike" or what that would translate into.

But then again, for how many years were the Icelandic Sagas laughed at because they talked about the BLUE MEN IN THE SOUTH, when the joke was on the so-called scholars who didn't realize "blue" meant the blue-black color of a raven, and there was no word for a darker black? Which was simply how Africans were being described.

No drinking horns? I'm not talking about hats, I'm talking about what you used to drink from, if you didn't have the skull of an enemy or the money to buy metal cups. Don't tell me it was only Anglo-Saxons who drank horns of meade?!
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Old 30-07-2010, 17:11   #17
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The noun viking in Old Norse refers to an expedition (or maybe a cruise).

It is true that lapstrake planked hull has more drag then an equivalent smooth hull. However, any downward or rolling motion of the hull when combined with its forward motion through the water results in the planks displacing the water downward and aft. This causes the hull to be thrust forward. Further, this displaced water pushes against the stern increasing the forward thrust applied to the hull. These forces combine to overcome the additional drag of the lapstrake planked hull and then some.

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Old 30-07-2010, 18:23   #18
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Your right Hellosailor, I don't have a clue, I've just made a living at it for over 30 years. I've been involved in this testing and you're talking about two, very different things in an attempt to intermingle them. Laminar flow modification tests have been preformed since the 1930's, with huge gains of understanding in the 1960's. In fact, my best friend as a young man was the son of the DuPont engineer that invented the golf ball that had bumps, which flew 40% further then the dimpled variety and was promptly banned from the PGA, as it rendered all current courses too short. This has nothing to do with what laps do.

Without getting real technical, these modification schemes (holes, bumps, texture, etc.) only work (effectively) over a small Reynolds number range, making them one; impractical and two; a detriment across the Reynolds number target range for the form's (in this case a yacht hull) operation. Yep, you can modify the boundary layer dynamics to some benefit for fairly specific Reynolds numbers, but yachts, unlike golf balls, operate in pretty dramatic speed range swings. On the occasions you are in the operational "window" of effectiveness, then you are advantaged, but in others disadvantaged. Since the window is narrow and a typical yacht's speed requirements and implementation is fairly wide, the net is actually a lose, not a gain in performance.

If this wasn't the case, every racer since the late 1950's would have cleverly arranged lapstrake planks aft, naturally following flow lines and likely smooth planking forward. Now, in this same vain most ocean racers now employ a chine aft for the very reason you might think, to shear the flow when necessary (plane mode) not modify the boundary layer..

Viking Sailor, the same vertical acceleration element that you imagine pushing forward in the aft sections, also applies to the forward sections, which push aft. In reality, the two cancel each other out, though there is considerably more roll resistance in a lapstrake hull then a smooth one. A 1/2" wide lap 24' long is exactly the same as having a 12" square, flat plate mounted perpendicular to the exterior of the hull. Now add up all the length of the exposed laps and calculate how much area effectively resists a roll moment . . .
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Old 30-07-2010, 20:59   #19
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The show said the hull was designed for the bow to raise up on and ride the bow wave so that very little of it was actually wet at speed. That state where the bow is riding the wave and the air is being channeled under the boat is why they said it was so fast.
I don't remember the beam, but it was very narrow for a boat that length.
I am not arguing. I am a beginner that knows nothing beyond what they said on the show. I would also expect to find most racers using that type of hull if the air bubbles cut friction and made a boat plane easier. That is part of what confused me.
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Old 05-08-2010, 14:38   #20
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As to sailing into the wind, or at least very close to it, this was possible due to the innovation of shaping poles (beitass) which could be rigged to sockets in the deck and points on the edges of the sail to shape the sail when sailing close to the wind.
With your name and sig, not to mention knowledge about long ships ... are you an Icelander who got lost and ended up in Canada ?



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Old 05-08-2010, 14:43   #21
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With your name and sig, not to mention knowledge about long ships ... are you an Icelander who got lost and ended up in Canada ?



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Astrid knows all about boat design but her nav skills need some more practice
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Old 05-08-2010, 17:41   #22
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Blown off course and never found my way back.
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Old 05-08-2010, 18:06   #23
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Blown off course and never found my way back.
Well, at least you didn't get stranded on Greenland.

Guess svrodeorm has Nordic roots too and may still be back home.



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Old 06-08-2010, 00:31   #24
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I am swedish, the boat in Portugal and for the moment I am in France, on shore, with family.

That's why I am on the internet instead of sailing

I am not a geek re. the longships and the Vikings, but it is an interesting heritage and it was certainly an exciting time in our history...

I still wonder where they found the inspiration for their shipbuilding talents, after all, it seems like it popped up out of nothing.

Last year I saw an interesting documentary about the stone-age rock carvings in Scanidinavia, and according to the scientists, they have strong evidence that trading existed at the time with people living far furhter south, maybe even in the Med, by the means of navigating along the coasts of Europe.

The reason we all heard so much about vikings, is of course because they did molest their neighbours a bit. And mostly the (hi-)story is told through there saxon/french etc. counterparts.

The Icalandic Sagas (Snorre Sturlasson) and the runic stones and megaliths are about all there is from the era in Scandinavia.


Sven G.- are you scandinavian, or your ancestors?

Fair winds! on viking ships or 'yachts' alike!
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Old 06-08-2010, 01:07   #25
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I have personally sailed on similar vessels, under 30' in length, while traversing Lake Hjalmaren and other bodies in Sweden having considerable fetch and large waves. Running downwind, with the huge single gaff sail squarely abeam and lightly skipping outboard over the following waves in strong afternoon winds, I was surfing. My Swedish friends just smiled because I knew how to handle this thousand pound monster built entirely of oak. The only thing that differentiated these lake boats from ocean craft were three additional planks to house the long oars and to keep the seas out, and of course, considerably greater length. I can easily believe these boats having legendary speed. I can't find my own pics but here is one off the web: http://www.flickr.com/photos/kerolic...n/photostream/
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Old 06-08-2010, 08:03   #26
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Sven G.- are you scandinavian, or your ancestors?
Jag är svensk men bosatt här i decennier

We try to return to the Baltic every summer to bareboat out of Västervik but some summers we just don't make it, like this one. "Vik" in Vastervik is of course the Swedish word for bay but I think there is still some dispute if that is the "vik" in viking.

My parents lived in Vallentuna when I was a kid and one of the claims of fame for the county (kommun) was that we had more runestones than anyone else in the world

Love klinkerbyggda boats, as long as someone else takes care of varnish and water tightness ! My first boat was a ~5 m klinkerbyggd open oak sailboat with a daggerboard and a 2.5 hp Monark outboard. That boat was somewhat unusual in that it had a hard chine. It certainly didn't do 16 kts.



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Old 06-08-2010, 09:00   #27
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One theory, if I remember correctly, is that vik in vikingr might, only might, be a reference to baylings or people of the bay, i.e., younger men who, being landless did not inherit the family farm or trades, and consequently took to raiding. The start of the viking age had been preceeded by a major growth in population and there was not enough usable land to go around. It certainly appears in skaldic poetry from that time, and appears on several memorial runic stones erected to individuals who went on or never came back from an overseas expedition. In poetry, it is possibly used as a circumlocution or kenning as a descriptive term in place of the more common day-to-day nouns. Its contemporary use was not as a description of Norse people of the time, but a specific participant in an activity, unlike the modern English usage in which it describes Scandinavians of that age as a whole.
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Old 06-08-2010, 09:03   #28
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Jag kan taller litte svenska....mycket litte.

I was told that the Scandinavians went "aviking", kind of like off wandering or venturing off somewhere. So could your Vastervik bay be the western bay for departure and adventure?
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Old 06-08-2010, 11:22   #29
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Astrid, apparently (from the surviving literature) it wasn't just the landless. A successful Icelander, one who was a warrior, poet, and land-owner, was also expected to go off raiding after the harvest season. At least, some of the sagas told it that way, and as we now know, there were a lot of truths in the sagas.

Norse raiders basically sacked and burned their entire known world. Named the Volga River, pentrating way upstream. Hit Constantinople, which was not a short trip. Got tired of "blue" men and burning decks in Africa, and apparently decided Newfoundland had nothing worth plundering.

But simply had no desire to *conquer* any of it. Which is not surprising, it doesn't sound like they had any "professional bureaucrat" genes.<G>
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Old 06-08-2010, 12:54   #30
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Hey, what a nice little gathering we've got going here...

And everybody contributes a piece or two to the jigsaw. I just wonder how many non-'scandihooligans' are interested enough to keep on lurking ?

'och sven, av en händelse har jag haft ett hus i Gamleby. Fantastisk skärgård.'

I do agree regarding your comment on the klinker-built boats ...and the maintenance on them.
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