Sailing boats' Stability, STIX and Old Ratios

Discussion in 'Stability' started by Guillermo, Sep 3, 2006.

  1. Guillermo
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    Guillermo Ingeniero Naval

    As per a very first estimative, asuming MOC displacement as 6055 kg and Dfl angle of 120º, I get an STIX of around 34-35 which makes more sense.

    Maximum GZ for that asumed load condition is around 0,54m. If the PBO stated figure of 5725 kg is the real MOC, variations are not very great and GZ goes to around 0,58m.

    I still want to know what the curve for the shoal draught version is.
     

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  2. Vega
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    Vega Senior Member

    You seem doubtful:rolleyes: but that’s easy to understand.

    I have emailed them your post (link) and said that a Naval Engineer on a reputable boat internet forum had raised doubts about Jeanneau 36i stability.

    I have pointed out that your analysis was based on a RM curve that had been published by PBO as a GZ curve. I have said that the MaxRM values taken as MaxGZ values would be ridiculously low values that, if taken seriously, would give a very bad impression of the boat, as it was the case.

    I suggested them that they should demand a correction of the data published on PBO and Yachting Monthly and asked them to send me correct information on the boat stability.

    I have e-mailed them on 1/11 at 15.00pm and I received a reply on 2/11 at 8.23 am.

    I have also e-mailed PBO and Yachting Monthly, pointing out the mistake. The e-mail was sent on 1/11 at 15.30pm. They have replied to me on 2/11 at 9.52 and 10.11 am.

    I believe responsible people get worried when wrong information that denigrates a boat is published, in magazines or in reputable internet sites.


    I suppose that explains also why PBO also changed the decimals on that graph, from 1000 to 0.1, 2000 to 0.2 and so on:rolleyes: .

    About RM curve versus GZ curve, we are talking about giving to the public information on boat stability and no more.

    About this the words of Angermark Marin (the Architect of the Malos) are paradigmatic:

    "When we talk to "ordinary" yachtsmen, we frequently notice that it is very easy to misunderstand the meaning of the usually published stability curve that indicates the righting lever ( G-Z ). This curve alone is no measure of a yacht´s real stability.

    To illustrate this statement we have prepared stability data for three different boats, and it is very common that the G-Z curves as interpreted as indicating that all 3 yachts have roughly the same capacity to resist a capsize. In fact it is the curve of righting moment that illustrates this capacity. Every wave contains a certain amount of energy en every vessel requires a certain amount of energy to be turned over. The energy required to capsize a ship is represented by the area of curve above the baseline, and energy needed to return it to an upright position is represented by the area below the baseline. NOTE: This is only valid for the curve representing the righting moment, NOT the G-Z curve.

    Thus we can see that it takes more than 4 times more energy to overturn the MALÖ 43 as the 33 footer. To return the MALÖ 43 it takes a wave containing 1/9 of the energy required to turn it over.

    A much better assessment of the real stability is thus to compare the curves of righting moment… "


    http://www.maloyachts.se/YACHTS/Stability/tabid/134/Default.aspx

    http://www.maloyachts.se/LinkClick.aspx?fileticket=hzHfm/XKzyc=&tabid=134&mid=723

    I believe “mt” stands for moment?

    If this is the case I don’t understand what you mean. The units are clear, they refer to Kgf*m.
     
  3. Guillermo
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    Guillermo Ingeniero Naval

    Oh, Vega, Vega, savior knight of widows, orphans, boatyards and the like...! How I envy the strength of your arm and mighty sword...! :D

    You should have humbly stated: a "well reputed Ingeniero Naval...", as it is the case....:D

    On top of that I don't remember to have risen doubts on the Jeanneau 36i stability, only on the quality of the provided info. In my country we have a word for your attitude: "torticerismo" (do me a favour and look for a translation, please :) )

    Yes, you have posted about mr. Marin's opinion before. It seems to be one of your favourite 'strong anchors'. Of course his opinion is absolutely respectable and useful in certain cases, but I've told you: daily practice in naval architecture is rather to use GZ curves to assess a vessel's stability, precisely because their independence on size. I can swore this to you on the graves of my ancestors, if you don't believe me.....:)

    On top of this, I think if a layman is able to interpret a RM curve, he will easily understand also how to get the moment from the GZ one when needed. To understand a RM curve, first we have to understand what GZ is (As you do :) )

    I don't understand why you refuse to admit a different (and well supported) opinion to yours is possible and useful, my boy. Is it because you really don't understand this position, or just because you need to reinforce your personality trying to piss me off all the time? :)

    And here it is me, giving you 15 positive rep points, when I think your collaboration is positive (post 235), in spite of your patronizing words in previous posts (I hope you can understand this, and the like...). Am I not a perfect idiot? :( :D

    Cheers :)
     
  4. Vega
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    Vega Senior Member

    If you chose to insult a forum member, please do so in a language that everybody understands, do it in English.

    It is obvious that you have a memory problem. You have said on post 230 :

    You made a statement: "The boat has a Strange categorization "(Category A) and you have said : “is said to be a Category A boat”.

    If the boat is strangely classified as a Category A boat, it seems clear to me that you are raising doubts about the fulfillement of the stability requirements needed do classify the boat in the A class, therefore you are rising doubts about the boat’s stability.

    You know very well that this is a boat certified as a Class A boat. When you say : "IS SAID”, instead of IS A CATEGORY A, you are implying doubts about the correction of that classification.

    If you have any doubts about the boat’s stability and its requirements to be classified as a class A boat you should have asked Jeanneau information on the boat’s stability before stating that the “Boat has a strange categorization”.


    Jeanneau is one of boat manufacturers that provides very clear information about the performance and stability of their boats.

    Because I was personally interested in the 39i and 42i, I have asked them information on those boats (months ago) and I have received very complete and clear information about them, including different RM curves and different performance polars (according to different drafts, different masts, different sails).

    Yes I agree, you are making more sense. This means that your previous statements about the “strange categorization” of the boat and about the “26,667 STIX - DESIGN CATEGORY B "makes no sense?

    If you really are interested in the boat and want to know the STIX numbers why don’t you ask Jeanneau instead of posting STIX numbers that are most of the time different from the certified and correct figures?

    That doesn’t seem to me a correct approach to analyze a boat. You should not post incorrect data neither calculate STIX numbers or Stability curves that are based on insufficient or incorrect information.

    Basing a boat analysis on this kind of “material” can lead to gross error of judgment and bring unjustified prejudice over a given boat. This will affect the boat credibility and can contribute in some extend to a lesser commercial value.

    If you were not a "well reputed Ingeniero Naval..., as it is the case” (as you consider yourself), posting on a reputable Design Forum, this could have no meaning. As it is, a manufacturer that sees the image of his boats degraded this way, by a reputable Naval Engineer, can rightly feel that a lawsuit is appropriated to bring justice to the wrongdoing.

    I believe that if this is the case, it will not involve you, but the forum that has permitted that you repeatedly post incorrect data on boats and base boat analysis over incorrect information.

    Even if a judicial problem never occurs, it is just plain wrong to post boat stability analysis that are based not on the boat’s own characteristics (STIX, Stability curves, Displacement in Min. Sailing Condition, Displacement in Max sailing condition and Downflooding angle) but on ones that are estimated by you and that in many cases are different from the real data.

    Wrong data = wrong analysis.

    You don’t need to ask in bold:) , you have only to ask ;) (provided by Jeanneau).

    They have sent me also curves that take into account different types of masts (furling and classic) and polars of the boat speed. If someone is interested on the 36i and on this information say so, and I will post it.
     

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  5. Guillermo
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    Guillermo Ingeniero Naval

    Yes! A perfect idiot....
     

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    Last edited: Nov 11, 2007
  6. Guillermo
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    Guillermo Ingeniero Naval

    I've visited the Jeanneau's stand at the Barcelona Boat Show and had a look at the SO 36i. The exibited model had a nice keel with a conspicuosus bulb. I'll post some images tomorrow.

    As probably her MLC with 8 people is bigger than 1.15*MOC, I've estimated what the STIX for this last condition could be (asuming a MLC of 8110 kg) and I come to a figure under 32 (!!!). If this is so, then the boat categorization should be rather B, instead of A, as it is mandatory to choose the lesser of the two values.

    As I'm probably wrong, I would be very interested in knowing how her STIX numbers were calculated. I hope Jeanneau or Lombard will answer my mails some day, or either post here the proper info by themselves, not through well intentioned but not sufficiently informed and somewhat naive intermediaries.

    Cheers.
     
  7. Vega
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    Vega Senior Member

    I think you are wrong, otherwise the boat would not have been certified as a class A boat.

    I understand that you wish to know where you failed, but saying "and I come to a figure under 32 (!!!). If this is so, then the boat categorization should be rather B" ...makes no sense, because if it were the case, the boat would not have been certified as a Class A boat, or Marc Lombard would have made a mistake in his calculations, or worse, had falsified them..

    I don't think you should cast doubt about the boat stability unless you can demonstrate that Marc Lombard’s calculations are wrong. And if so, you should complain to the proper authorities.
     
  8. Guillermo
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    Guillermo Ingeniero Naval

    I'm not doubting about the boat's stability, nor designer's nor nobody's calculations or assessments. You're the one saying that. I'm just curious, trying to learn.

    I want to make it very clear that I suspect absolutely nothing in this case, as Jeanneau is a well reputed and respected manufacturer, not in needing of doing this kind of things, but now that you bring the issue up to light, I think you would be surprised to know all the tricks and loopholes (when not plain lies, sometimes) used to qualify boats under the RCD, specially when moving in border zones, my naive friend.

    Not to talk about the total lack of knowledge of the ISO rules many small boatbuilders have, who anyway riskly sign their boats' Conformity Certificates. They just do not know what they are certifying at all. Believe me.

    On top of personally dealing with such matters in my everyday's professional life, I've just had recently the opportunity of knowing about the inspecting action of the authorities (DGMM) at this year's Barcelona Show, regarding such tricks and loopholes, because of that poor auto-control and loose attitude of some boatbuilders and unluckily even of some notified bodies' surveyors.

    Several of our present clients, who were exhibiting boats at the Show, told us how right we were when we refused to hand over to their pressure on certain qualification demands (refusals that even have brought us to painfully lost clients in certain cases), because they passed unharmed through inspections, which not all of the exhibitors did.

    Felix qui potuit rerunt cognoscere causas....

    Cheers.
     
  9. Pericles
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    Pericles Senior Member

    A classical education Guillermo?

    Happy he, who could understand the causes of things.

    Virgil Georgics: Book 2, Line 490

    Vega is a bit of a pain in the bum, without much of a sense of humour. I had a look at his background and viewed his pretty pictures. He does not give any personal information as to age, career, qualifications or details about boats he has built. There is a vacuum there, where there should be a plenum. He talks in generalities without citing his authority, For example, he has a tendency to state the obvious as if it is a nugget of gold that only he has discovered, and then he gets it wrong!

    Transat Jacques Vabre
    This is a duo race mostly for Open60's, Openmultihulls (Orma) and Class40 boats.

    Big race, 60 pure racing boats on the way.

    Weak winds. Safran is ahead with a 6.8k average. First Class 40 is "Télécom Italia", the little brother of Safran (same designer:Verdier / Van Peteghem / Lauriot ) with an average of 6k. Lots of top class40 ahead of the old Open60's.


    Quote:
    Originally Posted by Chris Ostlind View Post
    Kinda confusing, guys.

    There are two types of craft entered... Monos and Trimarans with not one single cat of any kind.

    Within those type distinctions, the trimarans are classed as:
    Open 60, ORMA designated boats
    Class 50 tris

    The Monos are classed as:
    Open 60 IMOCA class craft
    Class 40
    Sorry about that. I wanted to say multihulls and I wrote Cats . I am going to edit that on the first post. Thanks .


    Quote:
    Originally Posted by Pericles View Post
    Vega,

    Open 50s rather than 60s, The chart is useful as it's possible to select all the boats and see their position relative to each other.

    Pericles
    Chris is right. The 50ft boat are Open multihulls.

    But it is very important to take in consideration that they did not start at the same time.

    About the monohulls, the first 40class boat is ahead of about 1/3 of the Open60s (6 behind) and that is awesome taking in consideration the huge difference in size, price and technology (canting-keels and materials).
    That's great but only possible on light winds.


    Quote:
    Originally Posted by Pericles View Post

    I would love to have a Gunboat 66, when and if the next Jacques Varbre takes place and shadow the leading ORMA, probably Groupama 2, all the way to Bahia, Brazil and about a few miles from the finishing line, let the Gunboat have its head and surge past the trimaran, to take line honours, whilst having a good meal at the table and glugging the Bolly.

    It's an eleven day passage, hardly time to get used to being at sea and the vessel would be on autopilot for 90% of the voyage. The helm is a joystick.

    Some may argue that the Gunboat 66 will not have the speed, but a heavier Gunboat 62 has exceeded 36 knots. I'd be delighted to give it a go.

    ….

    Am I dreaming? Absolutely!

    Pericles
    I hope you don’t mind that I reply here.

    Yes you are dreaming. There is an incredible huge difference between a fast cruising cat like Gunboat 66 and a top racing trimaran like Gruparama. It’s like to say that a Ferrari F50 can be a match for a F1. Fact is that a simple racing formula ford, with be faster on a track.

    Even an Open60 would be faster than the Gunboat. The Gunboat can make 36k? An Open60 also, even more. What counts is the wind needed to go fast.

    If the conditions were very bad, as had happened on other races, you would see that the difference between the trimarans and the Open60’s would be a lot smaller and that the trimarans would experience a lot more retirements from the race than the monohulls (breaking, capsizing).

    I like both types of boats, but we have to be fair regarding the strong and week points of each one and to see the diference between top racing boats and fast cruising ones.

    Regards


    "Even an Open60 would be faster than the Gunboat. The Gunboat can make 36k? An Open60 also, even more. What counts is the wind needed to go fast." Gunboat speeds are posted on their site. Where is your reference for IMOCA speeds and in what wind speeds?

    Vega with remarks like that , you should not be so eager to post. Better you hide your lack of knowledge, rather than confirm it to all and sundry. Learn from the man! Guillermo is a NA. See his site. http://www.gestenaval.com/

    Hell's teeth, if you bad mouthed my professional competence in the field in which my own company operates and I came face to face with you, I would not be so patient as Guillermo and you would be holding your teeth on your hands. I'm English and settling such contentious disputes after due warnings, is a great tradition with us.

    So, let's all shake hands metaphorically, agree to disagree and treat the professionals who share their knowledge here with due respect. If they were to leave, we would be the poorer.

    Pericles
     
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  10. Vega
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    Vega Senior Member


    Guillermo, refering to my knowledge on boat stability (yesterday, on other thread):

    http://www.boatdesign.net/forums/newreply.php?do=newreply&p=169941








    again:


    I have received an email from PBO, the magazine that had published that curve:

    "You spotted a mistake! We normally publish the GZ (righting arm), but the numbers on the vertical axis of the graph of the Jeanneau were incorrect.

    This wasn't inaccurate information from Jeanneau - it was a problem this end, for which I apologise.

    The shape of the curve is correct but the maximum righting arm should be approximately 0.66m".


    David Harding
    Technical Editor - Practical Boat Owner






    :rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes::rolleyes: :rolleyes: :rolleyes: :rolleyes:
     
  11. Guillermo
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    Guillermo Ingeniero Naval

    Thanks for the support, Perry.
    There are always people around these forums just owning a big ego but little knowledge, trying to teach even the more knowledgeable people. :rolleyes:

    We should follow Horacio when he says:

    "Beatus ille qui procul negotiis ut prisca gens mortalium,
    paterna rura bobus excercet suis solutus omni fenore,
    neque excitatur classico miles truci neque horret iratum mare
    forumque vitat et superba civium potentiorum limina."

    But we are not Horacio.... ;)
     
  12. Pericles
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    Pericles Senior Member

    Slightly off topic

    "Happy the man who, far from the troubles of commerce,
    just as the venerable ancients,
    works his inherited fields with his steers,
    free from money-lending,
    neither roused by grim battle signal, as a soldier,
    nor fearing the angry sea."

    Probably the only period in history to which those words would have applied is the Bronze Age. especially in Britain, so far from city states and early empires.

    Blood of the Isles by Brian Sykes.

    As every schoolboy used to know, the episodes of group migration into the British Isles were remarkably few between the Norman Conquest of 1066 and the beginning of modern mass immigration after 1945: the French Huguenot refugees, the modest flow of Ashkenazi Jews, and a few others. Nevertheless, in recent years the politically-correct elites on both sides of the Atlantic have begun to promote the improbable contention that Britain has always been a land of immigration.

    Ironically, just as this has become an article of faith, genetic evidence has begun to pile up about how profoundly wrong it is. Not only did immigration after 1066 play a vanishingly small role in the makeup of the offshore islanders, but even the famous invasions of previous millennia—Normans, Vikings, Anglo-Saxons, and Romans—merely added a fairly minor overlay to the prehistoric gene pool.

    Political control and even language varied in the British Isles over time. But the oldest occupants endured, adapted, and flourished. In the words of Oxford University geneticist Bryan Sykes in his new book Saxons, Vikings, and Celts: The Genetic Roots of Britain and Ireland [published in the United Kingdom under the title Blood of the Isles]:

    "We are an ancient people …"

    The family trees of the English, Scottish, Welsh, and Irish are overwhelmingly indigenous to the British Isles since far back into prehistoric times. The title of Sykes' first chapter, "Twelve Thousand Years of Solitude," summarizes this finding. The "average settlement dates" in the Isles for the ancestors of modern British and Irish people, he estimates, were around 8,000 years ago.

    Historical population genetics is an extremely complicated science. It's not uncommon for well-known authorities, such as Sykes and his rival L.L. Cavalli-Sforza of Stanford, to differ. Bearing that in mind, Sykes' recreation of the genetic history of Britain and Ireland appears plausible.

    Sykes' team obtained DNA samples from 10,000 individuals in the United Kingdom and Ireland and reviewed genetic records for 40,000 more. They looked at functionally trivial mutations in the Y-chromosome to group each man into clans based on patrilineal lines of descent (e.g., Abraham begat Isaac who begat Jacob who begat …). And they examined mitochondrial DNA to group individuals into matrilineal descent clans. (I reviewed in VDARE.com Sykes' 2001 book The Seven Daughters of Eve, which outlined the initial European-wide genealogical discoveries revealed by mitochondrial DNA. If you are interested in the understanding the technical aspects more, please see that article.)

    From his database, Sykes concludes that the majority of the genes of the peoples of the British Isles are descended from the oldest of the modern inhabitants: Mesolithic hunter-gatherers, who began arriving 10,000 years ago from Continental Europe after the end of the last Ice Age, as soon as the islands became habitable again.

    Global cooling had pushed modern humans out of northern Europe and down into refuges near the Mediterranean, remixing the early peoples of Europe. (This may be one reason that, as Cavalli-Sforza has noted, Europeans are the most physically homogenous of all the great continental races.)

    From the South, big game hunters trekked north again as the ice melted, some getting all the way to Britain. Before the seas fully rose, Britain was connected to Europe by a land bridge, and the Thames was a tributary of the Rhine!

    A smaller but still important genetic contribution later came from the Neolithic farmers, who had begun thousands of years before slowly spreading northwest from the Middle East's Fertile Crescent.

    Both the hunter-gatherers, who had sought refuge from the ice in Mediterranean lands, and the farmers, who had emerged from the Fertile Crescent, appear to have followed the same two main routes to the British Isles. One was a western oceanic route from Iberia north, primarily settling in Ireland and western Britain. (I would speculate that the somewhat darker coloration of the Welsh reflects this sunnier origin.) The other main path was a central continental route up the great river valleys into northern Europe, and then west to eastern Britain.

    In the British Isles, the hunter-gatherer-fishermen presumably stuck to the water's edge, while the farmers cleared the inland forest. This meant there were few incentives for a genocidal clash between them, allowing the genes of both to survive in large numbers. Over time, some of the hunter-gatherers must have learned to farm, permitting them to be fruitful and multiply. The two groups appear to have merged, a happier outcome than typically seen in more recent collisions between farmers and hunter-gatherers.

    Sykes writes: "Overall, the genetic structure of the Isles is stubbornly Celtic." (Interestingly, this means that the Irish and the English are largely the same—and Sykes is unable to discern any difference at all between the Ulster Catholics and Protestants, or “Scotch-Irish”, as they are known to American immigration history).

    Sykes points, out, however, that the term "Celtic" is something of a misnomer:

    "The 'Celts' of Ireland and the Western Isles are not, as far as I can see from the genetic evidence, related to the Celts who spread south and east to Italy, Greece and Turkey from the heartlands of Hallstadt and La Tene in the shadows of the Alps during the first millennium BC."

    The British “Celts” have been in the British Isles long before the emergence of Central European Celts known to anthropology and the military history of the Roman Republic. These British “Celts” adopted the Celtic language, but otherwise their relationship with the continental Celts, if any, remains unknown.

    Sykes guesses that the proliferation of La Tene-style handicrafts in Britain was not the result of mass immigration from Central Europe, as anthropologists have long presumed, but simply of British Isle goldsmiths learning to copy the latest style from the Continent. (Similarly, the recent mass-production in China of knick-knacks emblazoned with the Celtic Cross for Dublin tourist traps doesn't mean that Guangdong is suddenly filling up with Irishmen.)

    Sykes observes:

    "It seems to me that the constant tendency to interpret past events in terms of movements is completely the wrong assumption. Surely the correct starting point is to assume that our ancestors were sufficiently resourceful and skillful to pick up virtually any skill."

    The half of modern British/Irish DNA that comes from female ancestors is especially native to the Isles.

    Sykes points out that after the arrival of the agriculturalists in Britain:

    "The genetic bedrock on the maternal side was in place. By about 6,000 years ago, the pattern was set for the rest of the history of the Isles and very little has disturbed it since."

    The one region where there was subsequent large-scale female immigration was the northern islands of Shetland and Orkney. Some 30-40 percent of today's inhabitants trace their maternal ancestry to Viking women.

    There was also a limited immigration during historic times of women into eastern and northern England, accounting for 10 percent of the maternal genes in the east and 5 percent in the north.

    Whether these women were Saxons, Vikings, or Normans is hard to say because they are all so similar genetically. The Angles, Saxons, and Jutes, who invaded England after the Roman evacuation in 410 A.D., were from southern Scandinavia and northern Germany. The Vikings, who sacked the monastery of Lindisfarne as early as 793, were centered merely a little farther north and west. The Normans were simply Vikings who had conquered Normandy and adopted the French language.

    Sykes’ guessed, based on sketchy historical evidence: most of this newer maternal-side DNA was introduced by the Vikings.

    The Vikings/Normans were incredibly dangerous—their conquests ranged from the Volga to North America, from Greenland to Sicily—for the paradoxical reason that during the Dark Ages they cooperated with each other better than their less ferocious victims did. (To defend against Viking raids, Europeans eventually evolved feudalism, the fundamental institution of the Middle Ages, to support the expensive knights in shining armor needed to rapidly mobilize and defeat a Viking raid.)

    Yet, despite their taste for rapine and pillage, the supremely opportunistic Vikings were not averse to family outings either, apparently bringing their womenfolk with them to farm in Orkney and East Anglia.

    The Romans appear to have imported almost no women into Britain. Sykes found only a "tiny number" of examples of exotic mitochondrial DNA that might represent female slaves imported by the Romans from Syria or black Africa.

    The famous historic invasions left a larger, but still limited, mark on the male Y-chromosome.

    Roman soldiers no doubt left children behind, but it's hard to pick them out because, as the Empire matured, fewer Legionnaires were recruited from increasingly decadent Italy, and more from the northern reaches of the mainland Empire, where the men were genetically closer to the British.

    All together, the Saxons, Vikings, and Normans account for the ancestors of about 10 percent of Englishmen living south of the old Danelaw line between London and Chester, and 15 percent north of it, "reaching 20 per cent in East Anglia."

    (Remarkably, this ancient ethnic palimpsest can be seen to this day in the United States. As David Hackett Fischer pointed out in his great history of British settlers in America, Albion's Seed, the American Puritans tended to originate in East Anglia and other once-heavily Danish regions of England. In turn, the American states founded by Puritans and their descendents feature the most famous colleges and the highest NAEP school achievement test scores.)

    That the people of the British Isles, whose offspring founded and still profoundly shape the American nation, have been a homogenous racial group for 6,000 years has many implications.

    For one thing, it offers an important perspective on the current obsession with the supposed educational blessings of racial diversity. Virtually every college president in America publicly denounces the mentally-stultifying effects of a non-diverse student body. (Diversity of opinion, of course, is somehow much less fashionable on campus.)

    And yet, William Shakespeare, who likely never left homogenous England in his life, sketched what is perhaps the most diverse array of personalities in world literature. Nor have the British Isles—home to Samuel Johnson and John Lennon, Oscar Wilde and the Duke of Wellington—been grievously lacking in real life individuality.

    This is not to say that the close observation of racial diversity doesn't add interest to our understanding of humanity … or Shakespeare wouldn't have made Othello, the Moor of Venice, the tragic hero of one of his greatest plays.

    What it does show, however, is that even in the most superficially uniform racial groups, there is almost endless human richness to be found.

    The book is on my Xmas present list and Elliott will buy it!:?:

    http://www.amazon.co.uk/Blood-Isles..._1_1?ie=UTF8&s=books&qid=1194887179227&sr=1-1

    Perry
     
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  13. Pericles
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    Pericles Senior Member

    Vega,

    Who are you? We know what you are, but we don't know why you are being so obnoxious? You persist in making basic mistakes and appear to lack attention to detail. Unforgivable in an architect.

    "António, thank you for your kind words. I am just an Architect and an old salt (a capitán de yate, like you) that has taken an interest in sailing boat’s stability. I have learned a lot and there is always a lot more to learn. Anyway, I know something about it and I try to make that knowledge available to the ones that know less than me.

    As you can see on post 32 of this thread, I have said that probably your boat has been certified (some years ago) as having a 119 AVS and a 48 STIX


    Quote:
    Originally Posted by Vega View Post
    But I can tell you that the Stix of the boat is not 51 but 48 and the AVS is not 126, but 119, considering MinSC.

    But on post 39 I have wrongly referred the certified numbers as 51 STIX and 119º AVS instead of the correct numbers, posted by me on post 32, that were : 48 and 119.
    (red for mistaken number, blue for the intended one)


    Quote:
    Originally Posted by Vega View Post
    ...I agree that if this is the curve you are talking about (picture), probably the STIX is bigger than 51 (48)…but I am confused, because Beneteau had previously released as stability information: 51 (48) STIX and 119 AVS.

    On post 54, when trying to explain to you why Guillermo had obtained a significantly higher STIX, when using the curve you provided (the one with a bump) I have persisted in the mistake and I have used 119ºAVS and a 51 STIX, referring to the certified stability numbers, instead of the correct figures, I mean 119 and 48.

    I was trying to say that the curve that you have posted (with an AVS of 126º) and that Guillermo used to calculate a 51 STIX, without that bump (not considering the cockpit influence on the stability), would give 119º AVS and a smaller STIX, probably the certified 48 (and mislead by the previous mistake, I have posted 51).


    Quote:
    Originally Posted by Vega View Post
    ....
    If you pick that curve and take away the bump, continuing the line, you will see that you will obtain a 119ºAVS, if you continue that curve you will also have a lot more of inverted stability.
    If you consider that curve for calculating the AVS, I believe you will obtain 51 (48).
    ....
    Your boat was certified when the no-bump curves were used, so the certified values are AVS 119º, and 51 (48) (STIX. But if it was certified now, they would use the curve given to you by Beneteau, and the AVS would be 126º and the STIX higher.

    I am sorry for the confusion, that is, if you did not understand what I mean .

    I will edit posts 38 and 54 to correct those mistaken numbers."


    You are not helping with the discussions as you are not willing to learn. However we are most willing to learn about your credentials, your experience, your education, your career and the boats you have designed and built.

    In other words, as King Juan Carlos might have said to Chavez in Santiago, "Put up or shut up! "



    Pericles
     
  14. kwb1312
    Joined: Sep 2007
    Posts: 26
    Likes: 1, Points: 0, Legacy Rep: 19
    Location: Brittany

    kwb1312 Junior Member

    Pericles,

    interesting reading your post #252.

    Quote:
    That the people of the British Isles, whose offspring founded and still profoundly shape the American nation, have been a homogenous racial group for 6,000 years has many implications.

    Could we conclude that American politics today is the result of a low genetic diversity caused by a too small gene pool from the British Isles? ...si tacuisses:rolleyes:
     

  15. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    "Intellegis Pericles esse philosophum?" Tum kwb1312 nimium mordaciter: "Intellexeram", inquit, "si tacuisses" :p
     
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