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Post by jules on Aug 17, 2016 7:24:52 GMT
Hi Jan,
No, I didn't miss your mail. Just spent yesterday evening quizing through the Gent pictures to come up with an answer. The Gent model shows a lot of bolt heads in the whales and, as far as I can tell from the outside, in the knees and riders. There are also a lot of nails to be found on the outside and inside of the hull. They are not as easy to find as in the Hohenzollern model. So it would take a lot of work to find them all and chart them. But I have a problem with just assuming that when we have the nail patterns, we have the frame locations. This is true in real ships of course, but is it also true in models? Can we be sure that these models were built on actual frames? Or where they just built in a simplified way? Like, say, in the manner Peter uses to build his copy of the Hohenzollern model. Suppose the nails are only there to give the impression that there are frames underneath. That is what Peter is doing right now as well: he is just copying the nail patterns, there are no actual frames underneath. So my question would be: was the Hohenzollern model actually built on frames? And: is the Gent model built on frames? We know from Fred that we are not allowed to take Vasa apart, and I'm pretty sure we are not allowed to take the Gent model apart. I think that in the case of the Hohenzollern model we will never be sure, because that model was already taken apart in a rather destructive way. But maybe Peter and the guys from the German forum have proof that the Hohenzollern model was built on actual frames. Please help us Reinhold and Akexander. And that is why I'm trying to find another way of finding evidence for frame positioning then just nail patterns in models. I am pretty sure the vertical sills are formed by the frames in the real ships. And since we have a lot of paintings, drawings and so on that show the ships and their gun ports, we can make assumptions of how the framing was placed. I sure would like to hear what you think about this.
Kind regards,
Jules
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Post by amateur on Aug 17, 2016 7:54:10 GMT
Hi Jules, Thanks for the reply. The reason I asked, was that Peter quite st ongly focusses onthe HZ, while we can not check how this model was build. As the Gemt model still survives, a study of the Gent model is a way of escaping the problem of the relationbetween nailpatterns and actual construction of the model. It still does not answer the question whether or not the model can be taken as proof of actualbuilding practice. There are enough models that looklike good representations, but cannot be an actual scale model (william rex for instance looks like a truerepresentation, but can not be: calculations indicate that thehull has not enough buoyancy to carry the rig) The problem of drawings and paintings is that we do not know what the knowledge of the maker was, and more, what his intentions were. E.g. The Stu ckenburgdrawing: was it drawn as an idealized world, or did it actually match existing practice? We do not know. All the drawings of ships in the process of building give a nice view of how it looked, but I don't think we can draw conclusive evidence on details. (We can on he general things: looking at allthe drawn evidence, we can conclude that the ports existed in a rather early stage of the building process, and not, as sometimes stated, only to be hacked in as the last stage of building.) But on issues like the position of the actualinhouten, I very much doubt. As far as I know, the literature does not explicitly describe the way these inhout n were aligned, so perhaps it is as someone (werner) in a german formum wrote: as long as we do ot find contemporary written proof, we can only guess, and have to be carefull in ourconclusions. Butthen, I'm only a layman in these issues, only asking questions Jan
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Post by Peter Jenssen on Aug 17, 2016 8:02:05 GMT
From Eva-Marie Stolt's drawing a couple of posts earlier, it would seem that at some stage they were allowed to at least take some planks off the Vasa (notes on the sketch says to be pointing to areas where planking has been removed) Looking at this sketch though, it seems that even if the sides of the gun ports are made up of frames, they are not neccessarily parallel to the frames. There seems to be roughly an average of about four degrees more tilt to the gunport sides than the frames. The gun port partly cut into the frames. At least for the Vasa then it would be a mistake to assume the framing orientation to be conforming to the vertical sides of the ports?
Thanks, Peter (J)
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Post by fredhocker on Aug 17, 2016 8:05:11 GMT
This forum was created to allow the exchange of information that might be useful to people building models of Vasa, and by extension, the wider world of 17th-century ships. It is based on a free and civilized discussion, as well as respect for others. In this context, Jules, your comments on Peter's (Tromp) argument (the "misleading the jury" post above) are verging on attacks on his character, which is completely inappropriate among gentlemen. It is fine that you disagree with him, your research is a valuable addition to this forum, and the discussion is a lively and entertaining one, but please refrain from this kind of thing. Your arguments are persuasive on their own merits, without the need to make snide remarks about your opponents.
What we seem to have established through this discussion is that some Dutch ships were built with frames that leaned inward towards amidships at their ends, and that some were not - there is convincing evidence for both cases. The evidence also largely supports the idea that leaning frames are primarily a feature of ships built before the middle of the 17th century, more or less, and that ships built after this more commonly had parallel frames. This does not mean that there were not exceptions. Parallel frames also appear before the 1660s (some of the early-17th-century wrecks at Christianshavn in Copenhagen have evidence for this practice in ships built within the Dutch tradition). The Hohenzollern model may well have had leaning frames, for example, but it is no longer possible to confirm this by direct examination. Even if it did, this is not necessarily proof that actual ships of the same date did, since a model is a model, not a ship, and the maker may have learned what he knew about shipbuilding in the "tilted frames" tradition. That is one of the problems with the messy reality of shipbuilding, older traditions survive with older craftsmen even after newer traditions become dominant. No one decreed in 1661 that all frames had to be parallel, but it was increasingly the case, perhaps in some places more than others.
Part of the difficulty here is in the nature of the evidence. We are trying to make sense of a wide range of types of evidence, combining written documents (both contracts and treatises, which have different kinds of emphasis), images (whose accuracy cannot be proven definitively), models (the same) and archaeological finds (which only show how one particular ship was built). Even combining all of this, we do not have a comprehensive data set that would tell us definitively what was common or "normal" at any one time or in any one place, especially considering the range of regional variation that was already ackowledged by 17th-century writers. I think that Jules is correct that by the 1660s, parallel frames were much more common, and I believe that this is related to changes in design methods, but I would not be surprised to find some ships still being built with leaning frames at the ends.
As for the usefulness of the gunport edges in revealing the frame orientation, I do not think that this will be of much help except in a general sense. I do not know of a western shipbuilding tradition which did not use the frames to form the sides of the ports, but as archaeological remains show (Vasa among them), the sides of the gunports were often cut into the frames. Towards the ends of the ship, where the ports were bowed, the angle of the side of the port does not match the frame bevel, and so the frame has to be cut. If shipwrights were willing to cut into the main longitudinal members, the wales, to make gunports, there is nothing to stop them notching the frames, and there is nothing that requires that these cuts are parallel to the frame edges. There is also evidence that one or both sides of a port can be framed by extra timbers if the spacing of the framing and the location of the gunport do not work out exactly. English shipwrights tried to arrange the framing to correspond to the ports in a much more consistent way, but even they had to resort to some odd solutions, including frames with doglegs or fillers, to make it all work out. The gunport orientation is primarily tied to the location and sheer of the deck, for functional reasons, with the framing a secondary consideration, so I do not think that frame orientation can be determined from gunport contours with any reliability.
Fred
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ara
Junior Member
Posts: 69
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Post by ara on Aug 17, 2016 14:24:14 GMT
Hi Jules, this is you:
I want to ask you, if you have another close-up photo of a hull segment of the Ghent model. Maybe we can detect certain treenails patterns and draw conclusions from that concerning the inner structure. All in all I´m not so sceptical about the framing of a model. The builder would do, what he always does, only on a smaller scale and maybe only slightly simplified. Isn´t that the easiest way, after all, also for him? A model also needs structural strenght.
Sorry, currently I´m not able to upload pictures. I will work on that.
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Post by jules on Aug 17, 2016 14:50:18 GMT
Hi Reinhold,
Thanks for joining. Can't see your pictures.
Regards,
Jules
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ara
Junior Member
Posts: 69
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Post by ara on Aug 17, 2016 14:55:21 GMT
Hi, give me some seconds, please. Could be a problem with picture format. "Some data could not be parsed". No idea what that means.
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Post by jules on Aug 17, 2016 15:28:04 GMT
Hi Jan,
About your second question from this morning: do Witsen and Van Yk mention that the frames are perpendicular to the water line? As far as I can remember: no they do not mention that. But, that is why the Sturckenburgh drawing is so important. This drawing contains a lot of information about the framing. We can see the framing that Witsen and Van Yk describe, and you can see how the frame parts are related to each other: the 'stutten' above the 'zitters', de 'oplangen' between the two, and placed with a considerable overlap. Confirming what Witsen shows in his drawings on Plate XLIII, and the drawings V, W, X and Z on Plate LII (1671). And it provides us with extra information by showing a sideview, we were craving for. In this sideview it shows us the two strakes of 'closed' wood we find described in the government contracts for the Admiralties ship builders; one strake in the 'kim', and one strake near the wales, on the level of the 'scheerstrook'. On top of that the Sturckenburgh drawing shows that the frames are perpendicular to the waterline, and that the gun ports are placed between the frame parts. This all makes the Sturckenburgh drawing, in my opinion, a VIP: a very important picture.
Kind regards,
Jules
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Post by jules on Aug 17, 2016 18:25:06 GMT
Hi Peter (Jenssen),
First of all I want to thank you for your contributions. You're absolutely right in saying that for Vasa the vertical gunport sills were not formed by the frame sides. At least not in Mrs. Stolts drawing of the framing of a section of the ship. For the rest of the ship, I don't know, but that will no doubt show something similar. (We absolutely need Kroums work to be certain. Maybe Fred can tell us when Kroums work will be available.) What I'm trying to find out is if we can assume that the vertical gunport sills were formed by the frame sides in the 1660s. The date of construction of the Hohenzollern model. If we can assume that the ports were formed by the frames, the ports give us an indication of the direction of the frames: vertical ports show vertical frames, tilted ports show tilted frames. Witsen drawings and the Sturckenburgh drawing show that the gun ports were formed by the frames. What do you think?
Kind regards,
Jules
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Post by jules on Aug 17, 2016 18:48:54 GMT
Hello Reinhold,
Looking forward to your pictures. But first let's get on with your remark about the building of models. You say that the easiest way to build a model for the model maker would be to include the complete frames. I'm afraid that any model builder will tell you that this is not so. Making all the frames to scale for the plank on frame building method, is a lot more work than, for example, the method Peter is using to build the copy of the Hohenzollern model; which, I believe, is called the plank on bulkhead method. This method gives a hull with lots of structural strength in a lot less time. Don't forget that one of the famous models from the Rijksmuseum, the Prins Willem model, built in the 1650s, has a solid hull underneath the waterline. Is there evidence for the construction method of the Hohenzollern model?
Best regards,
Jules
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ara
Junior Member
Posts: 69
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Post by ara on Aug 17, 2016 19:14:59 GMT
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Post by jules on Aug 17, 2016 20:29:18 GMT
Hello Fred,
Thank you for your contribution, again. And, thank you for the kind words about my contributions. And, if my tone in my post to Peter offended you, I apologize. I would like to say in my defense that this tone was provoked by the snide remarks Peter makes about me in 'his' German forum. And also, a bit, by the not so gentlemanlike remarks Peter makes in this forum. Stuff like: 'Any other approach simply doesn't make sense!', '..., and believe me, they did it that way!', and 'Constructionwise anything else couldn't make sense', I do not consider very gentle. But maybe that's just me, being to sensitive.
Your point about the parallel frames in the Chritianshavn wrecks has made me doubt. I thought only the bottom parts of these wrecks were found, and that the upper part was mere reconstruction work of Lemée. I'll have to check his book again.
Then to your last paragraph. If I understand correctly, and again, correct me if I'm wrong, you say that, in the top view of the ship, the gunports at the end of the ship are not perpendicular to the center line of the ship. I always thought that this is only true for one port on the lower deck; the chase port (jaagpoort), which is positioned in the turn of the bow. The rest of the ports being perpendicular to the center line of the ship; as all of the frames that are near these gun ports. Except of course for the 'cant' frames in the bow. Placing the frames and the gun ports perpendicular to the center line, the lining up of frames and gun ports, is exactly what makes the forming of the gun ports by the frames so easy. And, if I remember correctly, this is also what reconstructionalists like Dik and Blom show. I'll have to check the sources again and will come back to you.
Kind regards,
Jules
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Post by tromp on Aug 18, 2016 4:53:16 GMT
Thanks for your Input Fred. Your post refelected my thoughts in every sense.
Regards Peter
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Post by jules on Aug 18, 2016 6:38:36 GMT
Hello Peter (D.G., Tromp),
I am not sure what part of Freds input reflects your thoughts in every sense. Is it the part where Fred says that if the Hohenzollern model shows tilted frames, this is not necessarily proof that ships of that date did? Is it the part where Fred says that he thinks that it is probably right to say that by the 1660s parallel frames were much more common? Is it the part where Fred says that he doesn't think that frame orientation can be determined from gun port contours with any reliability? (Which contradicts your remark in your first post: 'frames ... were tilted slightly in accordance to the sides of the gun ports'.) Could you please elaborate? Because if you agree on this, it practically means you've given up on your theory that the use of tilted frames is the only possible way of ship building in the 1660s.
Kind regards,
Jules
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Post by fredhocker on Aug 18, 2016 8:36:35 GMT
On Vasa, the ports on both the upper and lower gundecks are significantly bowed towards the ends of the ship, meaning that the sides of the ports are not perpendicular to the centerplane of the ship (see the first image below for a scale plan of the lower gundeck, with the guns oriented to reflect the angles of the port sides). Instead, the ports fan out in an arc. This is usually thought to be typical of the period before the Anglo-Dutch Wars, more or less, and reflects the tactical thinking regarding gunnery. The idea of a concentrated broadside, with all guns aimed at a single target, was still some way in the future; gunnery in the 1620s tended to use each gun as an individual, rather than as part of a larger battery, and so the ports were arranged to allow the broadside to cover the largest field of fire possible. As broadside tactics became more developed in the middle of the century, it was found that the ship's armament could be used more effectively in coordinated broadsides, and so gunports all pointed perpendicularly away from the centerline. What this means in Vasa's case is that the angles of the port sides do not match the sides of the frames in many places, and the frames have to be notched. This reflects an aspect of this question of tilted frames which I have tried to emphasize here before. The location and orientation of gunports is based primarily on their functional requirements: they need to point in the direction that current gunnery tactics require, they need to be a consistent height from the deck and more or less square to the deck, they need to be sized appropriately for the guns being pointed through them (to allow a tactically useful range of elevation and traverse), and the ports should be a square as possible (not parallelograms, which creates problems in opening and closing the ports). In practice, this means that the important relationship within the structure is between the ports and the deck. There is no functional requirement that they have any particular relationship to the framing, as long as the structure surrounding the port can accept and distribute the forces of recoil. It does, of course, simplify the construction process if the existing frame sides can also be the inner faces of the ports, as Jules suggests, but it is not a requirement, and there are plenty of other examples in shipbuilding of things not being done the easy way. The information we have, or at least the information that I have seen, concerning Dutch shipbuilding in the 17th century suggests that the basic hull structure of planking, framing and ceiling is quite similar in warships and merchantmen, but that warships have extra features added to handle the forces of gunnery (heavier and more closely spaced beams, riders, etc.). If you stripped out the deck structure of Vasa, it would resemble a big merchantman, not vastly different from a VOC retourschip (our framing resembles the framing of Batavia, a retourschip built at the same time and sunk in Australia in 1629). This leads to a related question: to what degree did Dutch shipwrights plan for gunport locations when framing the hull of a warship? In Vasa's case, the sides of a gunport are formed by two frames, with a third frame cut off under the lower sill. This is consistent throughout both gundecks, but in many cases it was necessary to notch one or both frames to get the right port width or angle (the gunports are consistently sized, but the frames are not consistently spaced). Did the builders anticipate this and choose a frame spacing that would be suitable? The ports are located more or less centered between the beams, but not exactly so, and they are not the same on the port and starboard sides. This is, I think, partly the result of the uneven frame spacing and the inconsistent angles at which the frames cross the keel (not just in terms of tilt, but when seen from above, the floor timbers are skewed slightly from square, as are the beams). This lack of regard for squareness is not unique to Vasa, I have seen it in other bottom-based Dutch hulls before the mid-17th century. Kroum's frame study is far from finished - we still need to complete the documentation in the upper part of the stern. Apparently no one is willing to believe what I write about how Vasa was built until they can see it for themselves, which I find a little disappointing and sometimes makes me wonder why I share unpublished research data so freely. But to allay fears that I am either not observing reality correctly or not interpreting it properly, here is a plot of the raw frame data from the starboard side, to show the angles between the keel and the main frame elements. This is based on TotalStation measurement of the frame edges, with an accuracy of 1 cm +/-. Draw your own conclusions. The numbers are the angles, in degrees, between the bottom of the keel and the frame faces above the turn of the bilge. Note that the frames do not consist of a central block of parallel frames with tilted frames at the ends, but that the tilt begins very close to amidships and increases more or less evenly towards the ends. Note also that the frames are not necessarily perpendicular to the deck, but over much of the length they are more or less perpendicular to the run of the bottom planking (represented by the curved red line above the keel, which is the outboard edge of the last bottom plank). Although it is harder to see at this scale, the drawing also shows that the frame tilt does not always agree with the gunport angle, although they are often close. There were some drawings made of the framing between the gunports when a few planks were removed in the 1960s for cleaning out the mud (the Eva Marie Stolt sketches referred to by Peter above), but the drawings are not scale representations of reality, they are schematic and regularized, so they are not entirely accurate. But the feature Peter mentions, that the port sides are not parallel to the frames, is still the reality. One does not have to have the remains of a vessel preserved to the railing to determine if the frames lean or not. A hull preserved only to the turn of the bilge can reveal tilted or parallel frames by the angle the floor timber makes at the keel. As we see in Vasa, the tilt does not begin high up in the ship, it is visible where the floor timber crosses the keel. It is sometimes the case in ships with parallel frames that some of the futtocks at the ends are tilted to reduce the need for extreme bevelling, which one would not see in a poorly preserved wreck, but this is a special circumstance not typical of the entire ship in any case. It is useful to remember that ships built in the bottom-based method have framing timbers which are not fastened to each other, so the futtocks do not have to follow the angle of the floor timbers. It is also important to note that in the real world of Dutch shipbuilding, as revealed by the archaeological finds, there was not much insistence on squaring up frames or siding them evenly, so there are often waney edges and sometimes considerable wind, which can complicate the process of determining the frame angles. One thing that does seem to be emerging from this discussion, which I don't think I have heard before in the academic side, is the apparent change in framing practice around mid-century. Frame angle or tilt is not something that Lemée specifically addresses in his report on the Christianshavn wrecks, for example, but it is visible (or parallel frames are) in some of the drawings, thanks to the level of detail in the documentation. This is potentially very significant, since it may reveal previously unnoticed changes in the design process. Fred Attachments:
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