Post by philemon1948 on Feb 19, 2021 17:16:18 GMT
Hello Jules,
I am sorry, I think I didn’t express myself clearly enough. First of all I didn’t say you are biased. I said I was, several times. And this resulted in a flawed concept and misunderstanding on my part. This is a danger that should not be underestimated. I worked for years as a ship- and millwright. Right now, the company I worked for facilitate me in making 1:10 models of some structures of this 155 feet ship I try to reconstruct. In all the years I worked as a ship- and millwright I learned one very important thing: never ever generalise. The production of traditional ships and windmills is so rich in diversity, shapes, sizes and methods that it is virtually impossible to say something about the building of these structures with certainty unless there are specific written sources. And even then, also written sources have to be interpreted. That is what I am trying to do now with van Yk’s book. I can tell you first hand how difficult it is to draw conclusions about traces in a building concerning its construction and history. Over the years I encountered many people who thought they knew, beyond the shadow of a doubt, that certain things were true. I will give two examples. Recently someone, I can’t remember his name, had the bright idea to investigate the Sound Toll Registers with regard to the question if the Dutch flutes had this strange narrow shape at the upper deck to avoid these toll or at least try to reduce it. The conclusion was this relation is a myth. But I encountered some people who were sure of this relationship. Without even bothering to look into the matter. Van Yk makes a remark about this. He says: “In ‘t kort geseid, ‘k heb nog noit eenige gegronde Reden gehoord, waarom datmen liever een Fluit, dan een Spiegel-Schip behoord te maaken”. “In short, I never heard a sound reason why one should rather build a flute than a square sterned ship”. And I think he was right. The other example I heard yesterday, which was a real surprise. For years I heard the story that the Amsterdam sawyers guild stopped the building of sawmills in the city. Because these mills destroyed their trade. This is also a myth. What strikes me in this is that discussions about these subjects are easily held hostage by these views. Unless there is someone who simply asks the question: how do you know? As I have learned from Socrates, asking questions like these doesn’t make you popular. But since that is not my intention I continue my investigations.
The essential thing in what I am trying to tell you is I think your reasoning is flawed. I am not interested in being right. I am only interested in trying to get closer to the truth. You ask me to give an example of a wreck with a chine. As this wreck has not been found up until now, you regard this as proof the chine is a misconception. But you can’t say that. This is reasoning in the category: all swans are white. Until you find a black one. The fact a big ship with a chine hasn’t been found does not mean they didn’t exist. Traditional ships with a chine did exist and still do. They make a ship quite stable, much more so than a ship with a rounded and smooth bottom and bilge. But apart from this discussion, I promised to present a construction of the main frame as Witsen describes in his book. And so I will. And this construction will yield a profile with a chine. A very subtle one but still: a chine.
I want to say wo last things. First about the sentence you wrote: ‘Again, Witsen does not talk much about design. He mainly talks about a building method, and gives a lot of formulas for the design of ship parts, not the actual design of the ship’. What would you call the drawing of the main frame between page 150 and 151? A building method or a design method? And could it be these two understandings are thoroughly intertwined in the seventeenth century?
The last thing I would like to show is something that bothered me for years.
What the books of Cornelis van Yk and Nicolaes Witsen have in common is both authors have a habit using understandings in an inconspicuous and almost invisible manner, while these understandings can have a profound impact on what they are saying in their books about shipbuilding in the Dutch 17th century Republic and our understanding of this process. One sentence van Yk wrote struck me when I first read it: “Hoe datmen, door de
Slaglijn, alle Hout na Schips beloop, hol, en rond moet strooken”, “How one fairs, by the chalk line, all wood to the sheer of the ship, hollow and round”. I worked for many years as a ship- and millwright and often used the chalk line to make straight lines by lifting the strung line, saturated with coloured chalk and let it bounce back leaving a straight line of coloured chalk on the piece of wood. But how do you fair a ships hull using this line? All discussions with colleagues were fruitless. We couldn’t figure it out. Until I came across a passage in the book ‘The Evolution of the Wooden Ship’ from Basil Greenhill and Sam Manning. This passage was accompanied by a drawing which leaves almost nothing to the imagination. (Attachment) The description by Greenhill is as follows: “Here’s the look of trimming double-sawn frames to final fairness of bevel on a vessel being planked simultaneously inside and out. A tightly-pulled string guides the dubbing through the square body of the hull. The foreman works ahead of the dubbers, lining-off the lay of plank and cutting channels or ‘spots’ across the faces of various frames in order to make the tightened string lie fair along the hull. His tool is a hollow or ‘lining’ adze. The dubbers remove the wood between the spots with a straight-bladed (English) or lipped (American) adze. Dubbing is awkward, exhausting, highly skilled work. Frame bevels accurately applied to the frame futtocks at the saw pit save a great deal of labour in dubbing when plank is hung later on”.
Knowing how the procedure of fairing with a chalk line works made me realise a few things.
First, the design of the hull, as van Yk describes this, is done in two stages, a ‘rough’ first stage and a second stage where the definitive hull shape is established together with the exact location of the planking. This procedure of ‘dubbing off’ was still in use in the beginning of the 20th century and apparently they did this the same way in the Dutch Republic in the 17th century.
Second, the knowledge about one, single, procedure can dramatically change your understanding of the complete design process of the hull or whatever process or sequence during construction. Remarkable is the fact van Yk mentions this only once and in a kind of casual manner, but for us this remark is crucial.
Third, it is nearly impossible to recall an ancient building process if there is no account of some sort of this process. If I hadn’t seen the picture and the description of the process ‘dubbing off’, chances are I still wouldn’t have known what van YK meant by this sentence. Apart from that, if van Yk hadn’t mentioned this in his text, we wouldn’t have known about it at all with a subsequent flawed understanding of the process of shaping the hull which makes you think twice of making firm statements about the process of shipbuilding.
Fourth, the building process is often described as a sequence. For instance: first you make the bottom, then you make the frames. But if you take the central procedure used in almost all of these building processes as a reference a complete other picture emerges. This central procedure is fairing. Fairing can be done in many different ways, with the building material itself or with tools like battens or even with a chalk line.
Cornelis van Yk mentions two different approaches who are usually referred to as ‘frame first’ or ‘shell/bottom first’. Van Yk says:
“Dog in Hollands Noorder-kwartier, alwaar men nog gewoon is ‘t Schips onderste Fatsoen, niet door Centen, gelijk aan de Maaskant, maar door de Planken selve, die om ‘t Schip vaaren sullen, te geven, en by haar Boejen genaamd werd (…..)”
“But in ‘Hollands Noorder-kwartier’ where one is used to establish the lower shape of the ship not by battens, like at the river Maas, but by the planking itself who are fitted around the ship, a proces they call ‘Boejen' (…..)”.
This sentence is an introduction van Yk uses to mention something else, the construction of the bilge, which does come out different if you apply the one or the other method. I interpret this sentence in such a way that van Yk does not regard these two methods to be essentially different which they, from the perspective of the understanding of fairing, aren’t. Establishing the shape of the bottom by battens or by the planking itself makes in essence no difference. He merely emphasises the consequence of the method described by Nicolaes Witsen which is the different shape of the bilge, something he doesn’t approve.
To be continued.
I am sorry, I think I didn’t express myself clearly enough. First of all I didn’t say you are biased. I said I was, several times. And this resulted in a flawed concept and misunderstanding on my part. This is a danger that should not be underestimated. I worked for years as a ship- and millwright. Right now, the company I worked for facilitate me in making 1:10 models of some structures of this 155 feet ship I try to reconstruct. In all the years I worked as a ship- and millwright I learned one very important thing: never ever generalise. The production of traditional ships and windmills is so rich in diversity, shapes, sizes and methods that it is virtually impossible to say something about the building of these structures with certainty unless there are specific written sources. And even then, also written sources have to be interpreted. That is what I am trying to do now with van Yk’s book. I can tell you first hand how difficult it is to draw conclusions about traces in a building concerning its construction and history. Over the years I encountered many people who thought they knew, beyond the shadow of a doubt, that certain things were true. I will give two examples. Recently someone, I can’t remember his name, had the bright idea to investigate the Sound Toll Registers with regard to the question if the Dutch flutes had this strange narrow shape at the upper deck to avoid these toll or at least try to reduce it. The conclusion was this relation is a myth. But I encountered some people who were sure of this relationship. Without even bothering to look into the matter. Van Yk makes a remark about this. He says: “In ‘t kort geseid, ‘k heb nog noit eenige gegronde Reden gehoord, waarom datmen liever een Fluit, dan een Spiegel-Schip behoord te maaken”. “In short, I never heard a sound reason why one should rather build a flute than a square sterned ship”. And I think he was right. The other example I heard yesterday, which was a real surprise. For years I heard the story that the Amsterdam sawyers guild stopped the building of sawmills in the city. Because these mills destroyed their trade. This is also a myth. What strikes me in this is that discussions about these subjects are easily held hostage by these views. Unless there is someone who simply asks the question: how do you know? As I have learned from Socrates, asking questions like these doesn’t make you popular. But since that is not my intention I continue my investigations.
The essential thing in what I am trying to tell you is I think your reasoning is flawed. I am not interested in being right. I am only interested in trying to get closer to the truth. You ask me to give an example of a wreck with a chine. As this wreck has not been found up until now, you regard this as proof the chine is a misconception. But you can’t say that. This is reasoning in the category: all swans are white. Until you find a black one. The fact a big ship with a chine hasn’t been found does not mean they didn’t exist. Traditional ships with a chine did exist and still do. They make a ship quite stable, much more so than a ship with a rounded and smooth bottom and bilge. But apart from this discussion, I promised to present a construction of the main frame as Witsen describes in his book. And so I will. And this construction will yield a profile with a chine. A very subtle one but still: a chine.
I want to say wo last things. First about the sentence you wrote: ‘Again, Witsen does not talk much about design. He mainly talks about a building method, and gives a lot of formulas for the design of ship parts, not the actual design of the ship’. What would you call the drawing of the main frame between page 150 and 151? A building method or a design method? And could it be these two understandings are thoroughly intertwined in the seventeenth century?
The last thing I would like to show is something that bothered me for years.
What the books of Cornelis van Yk and Nicolaes Witsen have in common is both authors have a habit using understandings in an inconspicuous and almost invisible manner, while these understandings can have a profound impact on what they are saying in their books about shipbuilding in the Dutch 17th century Republic and our understanding of this process. One sentence van Yk wrote struck me when I first read it: “Hoe datmen, door de
Slaglijn, alle Hout na Schips beloop, hol, en rond moet strooken”, “How one fairs, by the chalk line, all wood to the sheer of the ship, hollow and round”. I worked for many years as a ship- and millwright and often used the chalk line to make straight lines by lifting the strung line, saturated with coloured chalk and let it bounce back leaving a straight line of coloured chalk on the piece of wood. But how do you fair a ships hull using this line? All discussions with colleagues were fruitless. We couldn’t figure it out. Until I came across a passage in the book ‘The Evolution of the Wooden Ship’ from Basil Greenhill and Sam Manning. This passage was accompanied by a drawing which leaves almost nothing to the imagination. (Attachment) The description by Greenhill is as follows: “Here’s the look of trimming double-sawn frames to final fairness of bevel on a vessel being planked simultaneously inside and out. A tightly-pulled string guides the dubbing through the square body of the hull. The foreman works ahead of the dubbers, lining-off the lay of plank and cutting channels or ‘spots’ across the faces of various frames in order to make the tightened string lie fair along the hull. His tool is a hollow or ‘lining’ adze. The dubbers remove the wood between the spots with a straight-bladed (English) or lipped (American) adze. Dubbing is awkward, exhausting, highly skilled work. Frame bevels accurately applied to the frame futtocks at the saw pit save a great deal of labour in dubbing when plank is hung later on”.
Knowing how the procedure of fairing with a chalk line works made me realise a few things.
First, the design of the hull, as van Yk describes this, is done in two stages, a ‘rough’ first stage and a second stage where the definitive hull shape is established together with the exact location of the planking. This procedure of ‘dubbing off’ was still in use in the beginning of the 20th century and apparently they did this the same way in the Dutch Republic in the 17th century.
Second, the knowledge about one, single, procedure can dramatically change your understanding of the complete design process of the hull or whatever process or sequence during construction. Remarkable is the fact van Yk mentions this only once and in a kind of casual manner, but for us this remark is crucial.
Third, it is nearly impossible to recall an ancient building process if there is no account of some sort of this process. If I hadn’t seen the picture and the description of the process ‘dubbing off’, chances are I still wouldn’t have known what van YK meant by this sentence. Apart from that, if van Yk hadn’t mentioned this in his text, we wouldn’t have known about it at all with a subsequent flawed understanding of the process of shaping the hull which makes you think twice of making firm statements about the process of shipbuilding.
Fourth, the building process is often described as a sequence. For instance: first you make the bottom, then you make the frames. But if you take the central procedure used in almost all of these building processes as a reference a complete other picture emerges. This central procedure is fairing. Fairing can be done in many different ways, with the building material itself or with tools like battens or even with a chalk line.
Cornelis van Yk mentions two different approaches who are usually referred to as ‘frame first’ or ‘shell/bottom first’. Van Yk says:
“Dog in Hollands Noorder-kwartier, alwaar men nog gewoon is ‘t Schips onderste Fatsoen, niet door Centen, gelijk aan de Maaskant, maar door de Planken selve, die om ‘t Schip vaaren sullen, te geven, en by haar Boejen genaamd werd (…..)”
“But in ‘Hollands Noorder-kwartier’ where one is used to establish the lower shape of the ship not by battens, like at the river Maas, but by the planking itself who are fitted around the ship, a proces they call ‘Boejen' (…..)”.
This sentence is an introduction van Yk uses to mention something else, the construction of the bilge, which does come out different if you apply the one or the other method. I interpret this sentence in such a way that van Yk does not regard these two methods to be essentially different which they, from the perspective of the understanding of fairing, aren’t. Establishing the shape of the bottom by battens or by the planking itself makes in essence no difference. He merely emphasises the consequence of the method described by Nicolaes Witsen which is the different shape of the bilge, something he doesn’t approve.
To be continued.
Attachments:
