Mathew Baker's early concept of ship hull design, ca. 1570

[T. Pevny]

@trippwj

 

Wayne - I am so happy you are familiar with my website. Some day I hope to get back to it. I think the format that I created for the posts (with perpetual updates that could be referenced) has a lot of potential, but since I was building the web site myself from scratch - it was very time consuming. For others that may not have seen my website is tangencypress.com (hopefully one day active again).

 

I found the Nowacki (and company) publications very exciting at the time they came out (& the associated workshop...). I was hoping that level of intensity of work and exchange of ideas on ship design would continue - maybe it still will one day.

 

I actually think that model building - like you all do - is critical to the research as well. Richard Steffy - as you no doubt all know - was a committed research model builder. I worked building a partial full-scale "reconstruction" of the 7th-century Yassiada vessel in a museum in Turkey, and Mr. Steffy's original model was in the room as a reference (as well as often the original reconstructor of the archaeological remains - Fred van Doorninck). I love working with original written sources, but ultimately one has to establish/confirm their relationship to the practical realities of shipbuilding (at whatever scale possible & affordable:)

 

 

Edited March 1, 2023 by T. Pevny

[B-Ram]

Hello Taras,

 

Thank you for the link to your site. It looks to be filled with lots of very good information on the history of shipbuilding. This will give me many hours of interesting reading. I hope you are able to someday continue with this site. 
 

Thank you for sharing this information with us.

 

Bill

 

 

[Waldemar]

 

@T. Pevny

 

Nihil novi sub sole!         I must repeat this paremia to myself even more often.

 

 

Mr. Pevny, first of all my sincere thanks for your interest and your post in this thread. A few sparse hours were obviously not enough to thoroughly study the very work of yours that I was not familiar with until today, i.e. Capturing the Curve: The Development of English Ship Design in the 16th to early 17th century. However, the wonderful diagrams along with their commentaries already speak for themselves. 

 

I already thought that my findings came first, but it is now clear that the palm of precedence belongs to you, of course. Still, I am happy and elated because my analysis was independent and the conclusions turned out to go in the right direction, finding their confirmation in your particularly professionally conducted analysis.

 

There may naturally be some minor differences of interpretation, but the substance of our findings really challenges the current orthodox order. I have this liberty because I am not part of a small community of people attending symposia and have not had to be careful not to offend anyone, but even here the reception has not been very enthusiastic and has even met with some active resistance.

 

Be that as it may, your approach, as well as my experience, shows vividly how important research methodology is, and how different results can be obtained with limited methods compared to more complete methods. In this particular case, one simply cannot limit oneself to reading the text and looking at the pictures, because eminently graphic subjects must necessarily be analysed by graphic methods as well. And the result of using these flawed methods is that we now have a whole body of modern works containing a multitude of anachronisms and their authors unhappy with this turn of events.

 

For the time being, let me add that your previous work, Capturing the Curve: Underlying Concepts in the Design of the Hull, 2017, impressed me greatly and also contributed significantly to my activity in this difficult and usually little understood matter.

 

The best,

Waldemar Gurgul

 

 

[T. Pevny]

As  a person very devoted to quality in this field of research I am moved by your comments Waldemar and by the warm reception I have received from the members of this Forum as a whole. I am excited by the prospect of future exchanges of ideas!

 

P.S. @Waldemar I am of the same thinking in terms of our work being an interesting case of confirmation of ideas by independent work. I have looked enough at drawings  and such studies to know you never saw my work on English design before today. We can both still be wrong together:) but I think it adds weight to the underlying ideas.

Edited March 1, 2023 by T. Pevny

[Waldemar]

 

Oh yes, we even had an argument here recently in a somewhat jarring style with Richard Endsor about the use of complete plans and variable radius floor sweeps in 17th century England. Apparently we each stayed with our opinions....

 

 

[T. Pevny]

I saw that exchange Waldemar -" jarring style" is one way to put it. Richard Endsor does very nice work & is very diplomatic:) Varying radii to gain design flexibility is an interesting topic. Eventually, it became apparent that all the "geometric fairing" systems might just need to be abandoned for "optical fairing" after the introduction of as much variability in radii as possible and a whole web of "controlling" and additional "fairing" lines. I tend to think that varying floor radii at that early time might have lacked a motivating factor (so maybe other explanations/possibilities in terms of the draft should be thoroughly explored, but... ). With introducing varying radii one always has to consider how the variability was controlled.

[Waldemar]

 

This is true. I find Richard's work particularly valuable, and I myself have been struck by the climate of exchange that has developed quite quickly. As for the variable radius arcs, now is perhaps a better opportunity to add to the statements made so far.

 

For one thing, I myself was greatly surprised by their use at such an early date, and I really tried hard to rule out this possibility by applying fixed radius arcs in various ways, but to no avail. In the end I had to decide that a discussion with the source itself was pointless. Now I have not the slightest doubt that this is how they were drawn intentionally.

 

In the next step I reconstructed a possible way of drawing them, obtaining a complete geometrical construction with a perfect matching of the contours for all the frames. This happens to be a method known, for example, from Williams' 18th-century designs, but even so, there seems to be no other way to draw these arcs with variable radii.

 

The use of a single arc of variable radius for the underwater part of the hull is apparently questionable, but somehow no one has pointed out the toptimber curves, which consist of as many as three arcs of variable radii! After all, this is a more sophisticated geometrical construction, from which one can conclude that the use of one such curve for the underwater part was entirely within the capabilities of the draughtsman of this plan.

 

* * *

 

A separate issue is the use of correction lines (waterlines and diagonals) in the design process of the ship, which is of course directly related to the use of complete plans on paper. At the moment I have this working hypothesis that these lines were adopted in England from Continental methods, based for some time now on the harmonious division of the diagonals. This came to me after looking at plans of captured French ships from the turn of 17th/18th centuries, in which the traditional hauling down method attempted, necessarily rather ineptly, to reproduce the shapes obtained by the more advanced and more flexible Continental methods.

 

 

[T. Pevny]

One of the benefits when someone presents such ideas (& graphic analysis that one can look at in detail) is that it inspires you to take a much closer look at the drawing and comparative materials- radii and all. I will go to that thread and give it a careful read. The drawing is certainly worth the attention.

[Waldemar]

 

20 hours ago, T. Pevny said:

I tend to think that varying floor radii at that early time might have lacked a motivating factor (so maybe other explanations/possibilities in terms of the draft should be thoroughly explored, but...).

 

I didn't want to repeat myself (see my post #72 in the thread about London), but we also have a pretty concrete motivating factor. However, it can only be realised by those who also use graphical analytical methods, because it is a subtlety that cannot be picked up in the manuals of the period. And it so happens that I have already designed some hulls myself using the classic hauling down method (without correction).

 

The thing about this method is that in the fading area of the floor sweep, going towards the bow, bumps notoriously form, and floor sweeps with variable radii help a lot to smooth out this area even without using correcting waterlines or diagonals.

 

Below are graphics made by @Martes, my friendly partner in the London 1656 case so to speak, who kindly did an evaluation of the ship's hull shape, as it emerges from the original drawing, and also noticed this problem. In the first graphic you can see the dark spot in this area, and in the second the problem areas marked by Martes with rectangles. Admittedly, this drawing of London has variable radii, but still with insufficient variation to be fully effective.

 

 

 

 

[Waldemar]

 

One can conclude from this that it is precisely without the use of correcting lines (waterlines and diagonals) that these variable radii floor sweeps are particularly needed.

 

 

[T. Pevny]

True. I should have written "enough of a motivating factor":))) Just kidding.  We do know that level of care (skill; particularly mathematical & graphic skill) varied with the shipwright. So in this period there is no discounting exploration by individuals (and their motivations). So I am not discounting it.  I really need to go to these original London posts. Although, I should say, that sometimes it takes me years to settle on an conclusion:) 

 

Oh - I see - the London thread was closed; it is a shame it came to that.

Edited March 3, 2023 by T. Pevny

[Waldemar]

 

@T. Pevny

 

Mr Pevny. I would also like to say that when designing hulls using the ancient methods, the issue of tilting/sliding the futtock template in Mediterranean methods is not just a theoretical issue for me, but a fundamental and very practical dilemma to be resolved. Therefore, the clear description and diagrams in your 2017 study regarding this issue already cleared my doubts and gave me confidence, and the evidence found even later only confirmed the validity of this direction. This was a really important event for my needs. Thanks again.

 

 

[Waldemar]

 

@T. Pevny

 

In the context of the variable floor sweeps of the London 1656, it is still worth recalling my reconstruction of the lines of a yacht from the Stuart Restoration period (ca. 1680), based on 3D scans of a period model, and which I have already presented in the thread William Sutherland's concept of ship hull design, 1711 on this forum. There is no exaggeration to say that the resulting conformity of the original lines and those resulting from the found method is perfect.

 

The lines of the lower conoid in the reconstruction drawings attached below (in red), are nothing more than the equivalent of the floor sweeps in the classic hauling down method. As can be seen, except for the hollowing curves, and only for the fore part of the hull (unimportant anyway in the conceptual sense), there is not a single fixed radius sweep in this design. So the London 1656 with its variable floor sweeps is no longer so lonely for the 17th century, all this indicating that a quite sophisticated level of design in England was achieved much earlier than previously thought.

 

 

 

 

Just for the sake of argument, I still have to mention here an alternative reconstruction of the method used to design this yacht, which I nevertheless find totally implausible: firstly, it is incomprehensible and it is doubtful whether it could be practically applied, secondly, it is not clear why the lines conceived as curves of the least resistance should have been applied transversely to the hull and thirdly, the correspondence of the reconstructed lines presented in the publication with the original lines is only illusory, as I have personally verified (for more on this, see Effie Moneypenny, David Antscherl, A Restoration Yacht's Design Secrets Unveiled: An examination of a ship model with reference to the works of William Sutherland, The Mariner's Mirror 2021, Volume 107, Issue 2). 

 

 

[Waldemar]

 

I should add that this probably only for the most accomplished shipwrights at the forefront of design. Most others were possibly content with rather simpler methods, such as from Bushnell's 1664 manual, republished many times well into the 18th century, which is the best evidence of its popularity among adepts of the profession.

 

 

[SYRGEM]

Mr Waldemar makes the following statements:

 

A) "I still have to mention here an alternative reconstruction of the method used to design this yacht, which I nevertheless find totally implausible"

 

I think this statement reflects on Mr. Waldemar's ability to understand it, not on the method which is elegantly simple. In fact the most simple contemporary method that the authors of the paper are aware of. 

 

"it is incomprehensible and it is doubtful whether it could be practically applied"

 

That it is incomprehensible to Mr. Waldemar suggests more of a closed mind in the commentator than in the method. It has been practically applied as demonstrated in the paper that he refers to. Both authors reconstructed the lines independently. I used ACAD and my fellow author used the traditional 17th century way of paper, pencil and cut out reconciling curves (based on the cono-cuneus geometry defined by Dr. Wallis). That Mr. Waldemar cannot see how a method derived and drawn on paper cannot be scaled up to apply on a prototype ignores the obvious truth that nearly all of the documented methods of mid to late 17th century do exactly this! i.e. draw them on paper using a mechanical process and then transfer this to the actual construction by scaling up the patterns used.

 

C) "the correspondence of the reconstructed lines presented in the publication with the original lines is only illusory, as I have personally verified"

 

You cannot verify a negative Mr. Waldemar. You may have found a method which does something similar but have not disproved the method.

 

D) "it is not clear why the lines conceived as curves of the least resistance should have been applied transversely to the hull"

 

The cono-cuneus curve was not conceived as a line of least resistance. It was conceived as a reconciling curve of the type known by us today as a 'French curve'. Peter Pett's method of arriving at it by cutting through a cono-cuneus solid was so ingenious that it amazed Dr. Wallis, one of the most eminent mathematicians of the day . . . so much so that he derived a mathematical treatise to define it. Its use in conjunction with a 'hanging conoid (as understood by Sutherland) guarantees a solid of low resistance. The author's investigated this by constructing numerous flow lines along the solid. They were all perfectly smooth -  unlike earlier methods which resulted in ripples in the flow lines. The method, thus, required no fairing.

 

Also, might I add, that if Mr. Waldemar has found a method which apparently is not dissimilar to Sutherlands published method, why was Sutherland so impressed with Pett's method? Why did he state in his treatise that he did not know how Pett did it?

 

I hope the points I have made might at least support our honest attempt to resolve a previously unsolved mystery. I congratulate Mr. Waldemar on his own work. However, I would like to point out that the only methods we know to be actually true are those few published by the contemporary practitioners such as Anthony Deane and William Sutherland. We do not even know for sure if the published methods were actually used as presented on real vessels. We have no extant ships to compare against, only models.  So all methods, including our C-C method, are conjectural. We have shown that this method fits some of the clues in the written literature and that it reasonable fits the shape of several yacht models.

 

My fellow author, and others I believe, has found the style of Mr. Waldemar's rhetoric so impolite that they have opted to withdraw from this debate. I, as the researcher who proposed this method, felt duty bound to respond on our behalf. In justification I can only point out that our paper was peer reviewed and published by the leading journal on Maritime History. We are humble enough for it to be criticised based on its content but not dismissed as illusory because Mr. Waldemar has found another method which satisfies him. If he is as confident in his research as implied by his statements, then let him go to the effort of substantiating it and getting it published it in a peer-reviewed academic journal.

 

I will not re-enter this debate as I fear it will once again deteriorate.

 

I, for one, am humbly amazed by the obvious ingenuity of those 17th century shipwrights. We follow them today 'on the shoulders of giants'.

 

Effie Moneypenny

 

 

 

 

 

[Waldemar]

 

As a kind of host of this thread, I thank you Effie for your input, and as a contributor to the debate – I stand by everything I have written so far on this issue. Thank you again.

 

 

[T. Pevny]

@Waldemar

Waldemar - I have read through the London thread, and I have a few thoughts and drawings that I hope to share; I think some very important points were raised between all the bickering.

 

I need to read the Sutherland thread and the Moneypenny & Antscherl article has long been on my re-read and study list (it has been a hard few years, so I am a little behind). Right now I'm not informed enough with the material to even put a like on a post.

[Waldemar]

 

@T. Pevny

 

Thank you, Mr. Pevny. There is no rush, as I too have a lot of work at the moment. In the meantime, I show a graphic strictly based on the content of the publication criticised above. The graphic shows a comparison of the original scanned lines with the lines obtained by the authors, exactly to the scale at which they were printed (scaling makes it even worse), and aligned with the hull axis.

 

In particular, the compared frame lines cross each other, the breadth of the hull is too small, the radii of the curves are quite random and have little relation to the original lines, which is particularly noticeable for the hollowing curves. Sorry, but this cannot be considered a correct reconstruction of the lines (or at least my reconstruction standards are incomparably higher). This way one can draw anything similar and then claim anything. Also evoking, why not, a group of some 'giants'.

 

 

 

Edited March 10, 2023 by Waldemar

[Martes]

I wonder how peer-review system passed a reconstruction that does not provide a clear comparison to the original and did not attempt to compare 3d meshes of both.

Edited March 10, 2023 by Martes

[Waldemar]

 

Perhaps the number of likes was the deciding factor? For example, from the giants.

 

 

[Mark Humphrey]

On 10/12/2022 at 3:33 PM, Waldemar said:

 

Druxey, please have a look at the zoom below. My measurements show quite accurately 3 inches for the deadrise at this place.

 

While the deadrise is real, I think it possible in this instance that it may indicate a carved garboard rather than a detail of framing.