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Kenchington

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Everything posted by Kenchington

  1. And thank you, Waldemar. That helps a lot. I'm not as familiar with 16th-Century ship design as I would like to be, so it is good to see your explorations. One point though: That is certainly very true, as regards paper or scale drawing any other two-dimensional surface. But did English shipwrights of the early 16th Century not make much use of battens and ribbands to complete a faired design full-scale in 3-D? That had been the late-Medieval practice in the Venice Arsenal and it was still relied on in vernacular shipbuilding in 18th-Century New England. With the (Old) English familiarity with clencher construction through to 1500 and beyond, running a board across the futtocks to determine a fair curve to stem and stern would seem a natural choice. If they did "design" parts of the hull as it grew on the building ways, it may be impossible to match the finished shape using only the very simple graphical methods that I would expect so early in the adoption of carvel construction. Your curve of the maximum breadth forward of the main bend, for example, is not an arc of a circle. Either the original shipwright used a more complex curve or he did not draw that at all. Trevor
  2. Waldemar, I have been following along with your thread. You have presented some fascinating material, but I'm a bit lost -- maybe because you started with your finished renderings and then moved on to how you had constructed them. What I haven't seen (though that may be my mistake) is an explanation of how you came to your rules for developing the hull shape. Did you "reverse engineer" the shape from the archaeologists' reconstruction, fitting arcs and other curves to that? Or did you perhaps find an account of the design approach somewhere? You've certainly ended up with a close fit to the reconstruction. I'm just wondering how you got there! Trevor
  3. Thank you, Armchair Seafarer! I will try sending a personal message through this website, though I haven't used that aspect of MSW yet, so I may go astray. I have a pretty good grasp on most aspects of the Sovereign, from Charles' objectives in ordering her construction, through her role in Court masques and public pageants to her failure as a seagoing ship. It would be useful if Busmann has cited hard evidence for some of the more dubious claims made for the ship (ones that I tend to set aside but cannot entirely reject), but at this stage I'm mostly interested in what a specialist can deduce of her as an artwork. I can see much for myself but art history is not my thing! A doctoral thesis will probably be exactly what I'm looking for. Trevor
  4. The frames should have riser heights marked on, though the marks too easily get sanded off. If yours are gone: Lay the thwarts in position across the boat, at the height that has those touch the inside of the planks. The risers should support the thwarts at that height. If your risers end up a little low, you can sand the ends of the thwarts. If the risers are a little too high, very small gaps at the ends of the thwarts are not a problem. Trevor
  5. Thanks, GrandpaPhil! The nearest I have come to that involved typing Danish text into GoogleTranslate. That worked but it was painful! Another time, I will follow your advice and see what I can do with scans. Meanwhile, I aim to tidy up my existing draft and make it available as "Version 1", subject to revision if and when more information emerges. Trevor
  6. I'd have to see the original wording to be sure, but the rake of the after face of the post was a matter of hull design (influencing the run of the planking) whereas the gradient of the inner face was only of structural concern. Even then, the post was only one part of a complex structure involving deadwood, possibly keelson, likely a large standing knee, maybe an inner post and so on. It would make much more sense to quote a single value for the rake if that referred to the after, outer face. Rudders could (and did) function perfectly well on raked posts. Indeed, even a post erected perpendicular to the keel was likely to be raked once the vessel was trimmed for sailing, with the heel slightly deeper than the forefoot. Trevor
  7. If a contemporary source says that the post had 2ft of rake, then the outer (after) face (the one the rudder follows) would be 2ft further aft at its top end than at its bottom end. That's what the wording would have meant to any shipwright. There is, however, some uncertainty in just where the top and bottom were defined. The bottom was probably where the after face of the post met the upper surface of the keel, though it might be the projection down to the baseline (lower surface of keel), to the garboard rabbet in the keel or to somewhere else. The upper end could be where the post disappears into the planking of the counter, where the physical piece reaches its top or a projection form there up to the deck. I don't know what was normal practice at the time, nor even whether there was any agreement between shipwrights and/or yards. I'll not be dogmatic for a particular ship but it was normal for a post to be wider (fore-and-aft) where it met the keel than at its head, in part to compensate for having to be thinner (starboard-to-port) at the keel, where the planks draw close together. Thus the inboard face of the post (not usually visible in a model) was typically angled more than the rake of the outboard face. Hope that helps! Trevor
  8. Diagonal bracing was normal for large ships with high length:beam ratios by the time McKay was active. Humphreys' use of diagonal riders was cutting-edge in the 1790s but Seppings took the idea much further and, by the time he published his full account (1814, if I remember correctly), his line-of-battleships had extensive diagonal bracing, not only as riders but between the deck beams etc. His system could not be applied in frigates, nor merchant ships, as the riders took up too much space in the hold. The alternative was diagonal iron strapping, initially on the inboard face of the frames, later set between the frames and the outer planking. Adaptations of that approach were essential in the big wooden paddlesteamers built from the 1830s on (the biggest of them built for the Atlantic crossing, of course) as they had to bear the stresses of having the weight of engine and boilers localized amidships, as well as their regularly butting into head seas, which is infrequent for a sailing ship. Fast forward to Cutty Sark and similar diagonal strapping is riveted to her iron frames, under her planking. The idea only went out when riveted iron, the later steel, removed the need for separate diagonal braces. Back around 1990, I did a survey of a fragment of the hull of Humboldt (lost while entering Halifax in 1853) and got an intimate acquaintance with the details of her bracing! There's a rarely-told side to the development of the clipper-ship in the aspects that were drawn from paddlesteamer design. That tends to get lost as some authors want to write about the advent of steam, while others look at the perfection of sail, with the cross-links ignored. (Though I note that one of MacLean's comments that you have quoted goes to some pains to insist that McKay's clipper bow was not the same form as the steamers had!) Trevor
  9. I have no plans to show you but the Smithsonian does -- those of most major USN warships. Chapelle published versions of some of them in his "American Sailing Navy". The point is that smaller vessels built for private owners in North American yards were most often designed using half-models, but large ships built for the government were typically designed on paper. The question before us is whether large, expensive, innovative merchant ships (as in McKay's extreme clippers and their like) were designed using the approach preferred for fishing schooners or that used for major warships. Or maybe their designers preferred a hybrid approach. I don't think that we (yet) have grounds for a definite answer. Trevor
  10. No firestorm, ClipperFan, just a learning process for all of us -- each having our existing ideas corrected into a deeper understanding. Nobody could do that then or for a long time after. Scott Russell's waveline theory turned out to be completely wrong, once Froude got his towing-tank work going. (Though, as late as 1920, Roué used the waveline notion when designing Bluenose and there's no doubt that she turned out well.) Back in the 18th Century, even the great af Chapman held absurd notions about water pressure helping a ship forward if the wetted surface abaft the main bend was greater than that ahead. In one sense, they were all wildly wrong. Yet the best of them could and did design ships which met the specific needs placed on them, in the context of their times. I'm no naval architect but I think that computer-based designs still had to be checked in a towing tank up through the 1980s. Maybe they still do. And that's for the performance of motorships in calm water. The effects of waves still defy mathematical analysis, while relying on wind and sail for motive power adds a whole lot more complications. Trevor
  11. As best as I can figure, while the kit instructions call for the straps to wrap around the tube and pin (as you have made them), the kit-supplied straps are intended to bear their tubes+pins on their outsides, as the transom gudgeons carry their bits of tube. Maybe its all part of Model Shipways' "apprenticeship" ... a step towards learning never to follow kit instructions blindly 😎 Trevor
  12. I'm sorry, Rick, but that's a myth. The topic has been much debated, without a lot of firm conclusions, but it is certain that the more advanced yards (notably the Royal dockyards in Europe) built from designs draughted on paper from the 17th Century onwards and probably from the 16th too. By the late 18th, individual timbers were being drawn on paper, before being lofted. (Stalkartt's textbook of the 1780s details the methods.) Across The Pond, British shipwrights may never have used a (3-D) model-based design approach, not even in the small yards building vernacular coastal craft. Starting the design process by shaping a block of wood into a half-model seems to have been specifically a 19th-Century, North American technique (preceded by doing much the same with "hawks nest" models -- which look a lot like a modern plank-on-bulkhead model before most of the planking goes on). That sort of model-based design worked well with familiar hull shapes, as experienced skippers could say that they wanted a new schooner much like one that the same shipwright had just built but with a bit more fullness here or there, a slightly deeper keel or whatever. I'm beginning to wonder whether men of Donald McKay's time and stature draughted and faired the lines of their ships on paper, did all of the necessary displacement and stability calculations, then built a half-model so that they could get a look at the 3-D shape (much as modern naval architects do with CAD/CAM computers), with final modifications made on the half-model before it was sent to the mould loft. Half-models made at that stage had other uses too. Museums have models of steel ships with the plating marked on. It was likely much easier to lay that out in 3D than working a plating diagram on paper. Could be good for laying out planking too. And lastly, for now: I think that what he meant was the final fairing of the lines was done in the loft, where it could be checked at full-scale, not 1:48. Messing with a design when your nose is up close to the chalk lines and you can't get an overall view would be risky! Then again, the absolutely final shaping of a wooden hull was and is done with an adze, when a futtock needs trimming before a plank will sit firmly in place. Trevor
  13. Thanks for posting all that material, ClipperFan. But I am still at a loss. Last night, I did some trolling around on the WWW ("trolling" in the fishing sense, not the social-media one!) but couldn't find anything useful about McKay's design methods -- nor Webb's, come to that, for all that he is often described as "America's first naval architect". I did check Crother's book and saw that he thought the clippers were designed by shaping half-models. Maybe they were. The problem I see is that inspiration, talent and experience can allow a shipwright to use a model-based approach to modify earlier designs but striking out on a wholly new hull-form with that approach risks abject failure. When building a small racing yacht, that's OK. If the new idea fails, the cost is small. But to build Staghound with no more guide than carving a chunk of wood seems like a most hazardous venture. Turning to the academic literature this morning, I found two claims that Robert McKay [note not Donald] told Scott Russell (developer of the waveline theory), “I have adopted the wave principle in the construction of all my American clippers, and that is my secret. I first found the account of the wave line in the publications of the British Association.” That came with a citation of: The Literary Gazette and Journal of Archaeology, Science, and Art for the Year 1857, L. Reeve & Co., p. 980. I have not checked that source. One of those two modern sources boldly proclaims: "shipbuilders such as John Willis Griffiths, Donald McKay and George Steers designed their clipper ships (like Sea Witch and Flying Cloud) and yachts (America) with wave-line hulls". But it offers no evidence of that, aside from Robert McKay's statement. It would be nice to have some better idea of how the ships were designed! Trevor
  14. That seems definitive for the particular model. Yet the reproduced text refers to a "first, or the 'working' model, of a ship". On its face, that suggests that McKay was designing by half-model -- which I find surprising but interesting if true. However, the wording is less than fully clear and subject to interpretation. ClipperFan: Do you know of any definite evidence either way? I understand that nothing survives of McKay's original notebooks or draughts but is there anything in letters he wrote or some such? Trevor
  15. When you are able to offer just one piece of original evidence, of course I will accept it. What I will give no credence to at all are multiple repetitions of silly fallacies. You can find no end of those in published works. One of the challenges of any research task is cutting through such nonsense to find the truth. That's a big part of my day job. Trevor
  16. When your source spouts nonsense like that, everything else it claims should be taken with a truck-load of salt. What were drawn out on a mould loft's floor were the sections, from which the moulds for the frame timbers (floors, futtocks, top-timers) were shaped. As there were no pieces that followed the waterlines, there would have been no point in lofting those. Trevor
  17. For a 19th-Century fishing schooner, yes. But I very, very much doubt that Donald McKay designed a ship that way. He was working in the era of mathematical design of ships, then dominated by waveline theory as Froud's towing-tank wrk did not come before the 1870s. Trevor
  18. In an idle moment, I went searching for information on Muscongus Bay centreboard sloops more recent than Chapelle's "Small Sailing Craft". Initially, that led me to something older: His "National Watercraft Collection" (available for free on-line) has an entry on the boat type and specifically on a US Fish Commission model in the Smithsonian collection. I don't think that says anything that his later book missed. Of more interest: In 1994, Michael Tuttle (a nautical archaeologist and maritime historian) wrote a University of Maine PhD thesis with the intriguing title: "The Muscongus Bay Sloop: Study of a Nineteenth Century Small Sail Working Craft". That is not available on-line and I have no idea whether it contains anything of interest to model builders, but it might be worth a look, if anyone is near enough to a U of M library. Alternatively, the author is on Linked-In and might be willing to share. Trevor
  19. I may be wrong but my understanding is that it was normal for a vessel taken into the RN to be rearmed to current Ordnance Board standards once she was passed into dockyard hands -- which Lynx must have been or her lines would not have been taken off and we would not have plans of her today. Of course, what was normal did not necessarily apply in every case. Trevor
  20. Then they are (or approximate to) the older Armstrong pattern. (Long out-dated, in Ordnance Board issue, by 1812 but let's not quibble!) So the breeching needs to loop around the cascabel, with the loop seized (at least in full-size, maybe just glued in scale). The Duke of Kent (Queen Victoria's dad) was Governor of Nova Scotia in the 1790s and used his pull to have the defences of the Halifax fortress updated. We still have a whole lot of Blomefield guns here. Trevor
  21. Mark, There weren't before/after ways of rigging a gun carriage. Gun and carriage designs changed over time, between organizations that ordered their manufacture (e.g. the English Ordnance Board for your schooner) and between different designs for the same user (e.g. long guns vs. carronades). You are fortunate that there is a wealth of information on naval gunnery from the period of your build. If your model has long guns (not carronades), then British warships (and other Ordnance Board-supplied units, such as fortress artillery) of that time had Blomefield-pattern guns, with a ring above the cascabel as an integral part of the casting -- as in the image you posted. The breeching did indeed pass through that ring (which is why it was there). Trevor
  22. Hard to argue with that one! If you're happy with it, I'd say go ahead. You've got more of them to make than I'd want to have to do 😀 Trevor
  23. I bought a bag of suitable-size brass nails, 0.7mm I think. Model Shipways seem inconsistent in the size they supply with the kit (of the two sizes they sell). Some people have had their smaller nails, which should work well. Most of us get the large ones, which don't. Trevor
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