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Waldemar

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  1. Waldemar
    Or: „Another way for drawing or building as was practised by Sir Phineas Pett”.
  2. Waldemar
    Yet another passage dating one of the tables: „A Table of Timbers Whose Scantlings are thought fit to be Ascertained In the Building of the 30 Ships Built by Act of Parliament [...]”
  3. Waldemar
    After a first, quick look through: this is a unique, extremely valuable document. Firstly, these are records from the 1670s (I spotted two dates: 1675 and 1677). Where did the date 1695 come from? And secondly, in addition to the scantlings, it contains very detailed information about the ships' design concepts, or to put it another way, the geometry (shape) of the hull. This is simply a fantastic document of unparalleled value!!!
  4. Waldemar
    Many thanks Eugen! Have you posted a whole document?
  5. Waldemar
    Below is a variant of the London 1656 hull lines probably more realistic, and the fruit of a very useful dialogue with @Martes in private. There have been some fairly major changes done, which more attentive eyes will no doubt notice: – timber&room value has been reduced from 36 to 30 inches, which is more consistent with contemporary contracts and specifications ( @allanyed hit the nail on the head with his calculations above), – the stempost radius has been reduced from 40 to 30 feet (which is more in line with other period material, although not already quite with the original London 1656 plan itself), – hollowing curves of a more advanced shape were applied than those drawn on the original plan, which also improved the hull shape, – some additional light fairing of the hull surface has also been carried out. I have also added some diagonals to better illustrate the shape of the hull.
  6. Waldemar
    A quick 3D model was still created at Martes' request. I made a few minor adjustments to it: upper part of the stempost is shaped a little more upright, and the aft run at the very bottom of the hull is made sharper, which I think the maker of the plans had rather forgotten or refrained from drawing. Overall, it appears that all hollowing curves have been drawn in a somewhat simplified manner. Unlike the use of wooden templates in the yard, they are quite cumbersome to draw on a paper plan and the designers have been taking some drafting shortcuts (see, for example, Sutherland 1711, The Ship-builders Assistant). Hence the probably slightly less than ideal hull lines on the original plan. While doing a full reconstruction of the ship, I would probably still straighten the bow wings quite a bit, as suggested by van de Velde's drawings.
  7. Waldemar
    Due to the apparent and quite significant drawing inconsistencies in the aft body plan, it was felt that an alternative solution should be prepared. Paradoxically, although this alternative gives a slightly inferior rendering of the original lines, it is the one that is rather more likely. In the first place, the shape of the line of the breadth is now more in keeping with known English practices of the period. As a result of this change, the two toptimber curves have become arcs of variable radius. Below, in addition, an updated diagram showing the ship's longitudinal lines as they finally develop from both body plans.
  8. Waldemar
    Oh, no...! Martes. That's my love! 🙂 And she could be so very useful in a more comprehensive reconstruction of London 1656. Also, it would be great to do a reverse-engineering of her lines based on the 3D hull scans of this very important model, just like here for London 1656, i.e. in terms of the design methods used. We just happen to have an information gap for this particular period, and it turns out there was so much going on....
  9. Waldemar
    Yes, indeed. Old sailing ships are perhaps the most beautifully functional man-made objects. Now that the concept behind the design of London 1656 is better understood, one may be tempted to make a handful of concluding remarks. As stated earlier, the design is clearly more advanced than the methods as described in early English works on naval architecture from the first decades of the 17th century, and this is expressed primarily in the very extensive use of variable radius arches. This in turn translated into greater flexibility in forming the desired hull shape. Of course, this came at a price – now each frame (or at most a group of just a few frames) had to have its own separate templates, which certainly complicated shipyard work. The line of the floor is used in forming the shape of the frames in practice only in the midship part. At both ends of the hull, on the other hand, its role is taken over by hollowing templates. In general, the architect flexibly uses a variety of geometric transformations, freely selecting them as he deems most appropriate for a particular application and place. This seems to be the most advanced variant of the 'hauling down/pulling up futtock' method in its classic form. The next stage could be the reconstruction of the entire hull including all projections, but this requires an equally large amount of work...
  10. Waldemar
    The way the toptimbers aft were originally drawn can not be reproduced, as it was done apparently wrong. Instead, it is proposed the similar method as employed for the fore half of the hull, except that the upper breadth sweeps have a fixed radius of 15 feet, and there are only two arcs for a toptimber. Rather than logarithmic scales, it is even more proper to use (for both halves) guides similar to the line of greatest breadth, as described, for example, in Bushnell's 1664 work on shipbuilding. Naturally, they would first have to be defined on other projections. Again, thanks for watching, Waldemar Gurgul
  11. Waldemar
    It has to be said that for its time it is a geometric masterpiece. It is as if the shipwright wanted to show off his drawing skills. Either way, it shows the capabilities of the designers of the time, which was not so obvious until now. Even Deane is not so advanced or maybe better: so open with his professional secrets. Note, of course, that just drawing skills does not necessarily translate into a successful design. The topsides of the frames for the fore part are made up of three arcs, and they are all arcs with variable radii! Their construction can be seen in the attached diagrams. One important update has also been made: the rising line of the breadth fore is a simple arc now. This removes the kink in the area of the main frame, is more 'in line' with known English practices and reproduces the lines of the original plans even better. I rate this reconstruction as quite difficult.
  12. Waldemar
    However, it is still worth mentioning here that this is the area where the designer employed variable, increasing radii for the floor sweeps (only for the fore part of the hull; thin red arcs on the above diagram). They increase from 10 feet (for the master frame) to roughly 13.3 feet for the „L” frame. Also, look at how the length of this floor sweep vanishes, going towards the bow. These were the methods used then and there to achieve as smooth hull surfaces as possible, as opposed to the diagonals and waterlines only used later in ship design. And the physical ribbands could at most be used to help position the pre-designed frame elements that had already been cut out before actual assembly.
  13. Waldemar
    Martes vigilant as ever 🙂. Thanks for asking. While there are quite a few small kinks in other places (one of which I've shown before), right here is perfect. I've prepared an additional sketch where you can see how the transition of the shapes in this area takes place. It is, I hope, so clear that I will no longer describe it verbally.
  14. Waldemar
    Thanks Martes for additional pictures. With all this data, an attempt can already be made to reconstruct London 1656. The hull lines, according to the surviving plans, look as in the diagram below (no corrections have been made). It is quite certain that a few extra ribs (in the shape of the main frame) need to be added in the midship area. This is a fairly typical feature in ship design, both today and then.
  15. Waldemar
    Well, don't really know how to answer this question, but if I understand it correctly, not very much. Over time, once you become more proficient, it's more a matter of getting a feel for the shapes/curves and where they can be applied, and the range of possible proportions. Other than that, it's very much a matter of using templates and geometric (graphical) transformations, where you don't really need to use many numbers, hardly at all. Simply put, it's the geometry rather than the numbers that count. It may be added that it was not only possible to reproduce the way these plans were drawn, but it is now also possible to try to reproduce the actual shape of the London 1656 hull in a feasible way, and maybe some other ships from this period too. This would only require slight modifications to the curves at the very ends of the hull. For example, using exactly the same methods/transformations discovered here. Overall, this method is very typical of English 17th century practices, only details were, and are still somewhat blurred. It was very advanced for its time, but by about this time, elsewhere in Europe and among leading designers, other concepts were already being born. But that's another story... Below, the finished frame contours for the fore part. Thank you for watching so far, Waldemar Gurgul
  16. Waldemar
    The application of the hollowing curves in the aft section of the hull is the same as for the fore half. Up to the frame '15' these are straight sections, and later templates consisting of a straight section and a 14ft radius curve.
  17. Waldemar
    First, the parameters of the rising line of the floor have been modified slightly, by reducing its height fore from 12 to 10.5 feet. This is precisely half the height of this line aft (a typical value for the period). The hollowing curves were applied to the fore body. From the frame '0' to the frame 'M' they take the form of straight sections tangent to the floor sweeps. The next ones are templates consisting of a straight section and an arc with a radius of 30 feet, which is the same as the radius of the futtock sweep. I have already described how to apply the hollowing templates here: Looking at the changes in the position of the futtock sweeps in the individual ribs (thick red lines) it becomes clear why the name 'hauling down/pulling up futtock' has been attached to this method.
  18. Waldemar
    This stage proved to be quite a killer, probably the most difficult in the whole reconstruction. The surprise is total, because the floor sweeps turned out to be arcs of variable radius. What a tremendous advance has been made in just a few sparse decades over the methods known from the English early modern written works of about 1600–1625 on naval architecture! The first dimensional values are beginning to appear (still to be verified): stempost radius: 40 feet (equal to the ship's width) height of the rising line of the floor at the stem: 12 feet distance between ribs: 3 feet Actually, the underwater shape of all the frames is ready, it only remains to apply hollowing curves to them.
  19. Waldemar
    Consistently following the designer's paradigm, the rising line of the floor aft has been reconstructed (green line). At this point, it is now possible to apply a futtock sweep of a fixed radius tangentially to both arcs – the lower breadth sweep and the floor sweep (thick red lines). And this is the reconstructed shape of this guide line as seen in the sheer projection:
  20. Waldemar
    Jaager, what you have written is utterly misleading. You are confusing Deane with van Yk. You are confusing the English with the Dutch, and their practices. At least read Deane's work, it is in English. Apart from that, you can also read the numerous English works on shipbuilding that were written before Deane, both printed and unprinted. But if you intend to create an alternative history of shipbuilding, no problem, you can always do that, best in your separate thread.
  21. Waldemar
    Typically, designers used proprietary methods in a fairly uniform way, so the shape of the breadth line fore was already somewhat easier to reproduce. The logarithmic curve was a perfect fit here, however, a curve composed of two circles of different radii, which approximates the logarithmic curve quite well and commonly used by English designers up to this time, could also be chosen with almost equally good results. I have also updated the master frame diagram. Here the only difference is the correction of the lower breadth sweep from 13' 10" to a round 14 feet.
  22. Waldemar
    The bend is not very dramatic, you can see it in my post here: https://modelshipworld.com/topic/32948-bow-shape-of-le-françois-1683-and-la-néréïde-1722/#comment-935696 ... and this was most likely smoothed out during actual construction.
  23. Waldemar
    From the initial chaos, something is beginning to emerge, and although these plans are not a demon of precision by today's standards, it is already clear that they have been drawn according to the rules of the art by a professional. One of the main goal of this reconstruction is to find the correct types of curves used by this shipwright, or in other words, to find the specific geometric or mathematical methods employed to profile these crucial to the conception longitudinal guides. This is considered far more both important and interesting than the comparatively secondary, case-to-case variable proportions. Below just reverse-engineered line of the breadth aft is shown. The found method is identical to that presented, for example, by Dassié in his L'Architecture Navale published in 1695. The application of this particular transformation means that the hull had a slight transverse kink at the main frame. The scattered points close to the blue arc in the top diagram correspond to the original contours of the uncorrected frames.
  24. Waldemar
    Oh...! Almost forgot... This should be perhaps clear to everyone, but to lead you out of this strange misconception I will also add that these very plans of London 1656 are extant sources themselves, and one might even say – extant sources par excellence. Together, of course, with the values of the specific radii they contain. I am also pleased to inform you that the graphics in period works of technical nature are as important as the text they contain, exactly as they are in modern technical documentation. Wayne, is there anything else I can do to help you?
  25. Waldemar
    Right, good question. If you mean the radii of the main frame, they were read by me from the original drawing by fitting circles of different diameters to the original curves. In contrast, the early modern shipbuilder chose these radii arbitrarily, within the limits imposed by past experience, the geometrical constraints of the designed ship's hull, the properties of the available material and the result he wanted to achieve (e.g. greater capacity or better seaworthiness of the ship, etc.).

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