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Post by tromp on Jun 25, 2016 13:24:28 GMT
Hello everybody,
this is my first message on this board, my Name is Peter and I'm from Germany. I am currently building a copy of the so-called Hohenzollernmodel in full size, i.e. in 1/22nd scale
bilder upload
This isn't the first model of a Dutch twodecker that I have built, the first was in the early 1990s and was in 1:50th scale.
I have noticed something regarding the Frames of Dutch-built ships which I would like to describe to you. This has been discussed on other fora, some scholars found my observations "interesting" others reacted downright furiously.
If you have a look at the Image posted below you can see that I have highlighted the rows of treenails with different colours.
bilder upload
The rows of ttreenails also show the positioning of the Frames beneath the hull Planks. The yellow lines Highlight the centerline of the putty on the quarter Gallery which are perfectly vertical. You can see the Frames are not. They are tilted Forward and the sides of the gunports are parallel to the rows of treenails (or vice-versa, whatever way you see it).
We can observe the the same on the Vasa bilder upload
I have seen Pictures of the Vasa in which can be seen that the treenails are also parallel to the gunports but I don't have any of my own, so here a Picture of the 1:10th scale model will have to do which I took in 1991
foto upload
My understanding is that the gunports were perfectly square, not trapeziodal or rhomboidal or anything like that. So the sides of the gunports were always at a 90° angle to the deck-surface beneath it. This can be taken for granted on the Vasa and my Research has shown, that it was the same on the Hohenzollernmodel. I am certain that the Frames weren't perfectly upright, they were tilted slightly in accordance to the sides of the gunports. Thus the aft frames were tilted forwards, the center-frames were upright and the forward Frames were tilted towards the Stern.
This can be verified by a relatively new plan of the Vasa: Bilder hochladen
And also the famous Stuckenburgh drawing Shows us exactly the same tilted Frames:
Bilder hochladen
Scholars argue that in Witsen there is no mention at all that the Frames are to be tilted. But on the other Hand Witsen also doesn't mention that the Frames are to be upright.
Thoughts are welcome!
Regards Peter
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Post by fredhocker on Jun 26, 2016 11:47:05 GMT
You are correct that the frames towards the ends lean in towards amidships on Vasa. I have seen the same thing on every Dutch-built ship of the 17th century which I have excavated or recorded, so it appears to be a typical practice. We could see it clearly when we removed some of the planking from the bottom and sides for inspections. The gunports are indeed square, not rhomboidal, but they frames are not necessarily exactly parallel to the gunports. The lean does not correspond directly, as the gunports are cut out after the framing is done.
Fred Hocker Vasa Museum
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Post by fredhocker on Jun 26, 2016 12:36:14 GMT
The reference surface for the lean of the frames is not the gunports, but the bottom planking. Because the frames are added to the bottom, they are set more or less perpendicular to the bottom plank surface, which minimizes bevelling of the edges.The gunports are cut to follow the curve of the wales, which is a smaller radius than the rise of the bottom, so the frame edges are less parallel to the gunports towards the ends of the hull.
Fred
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Post by tromp on Jun 26, 2016 14:03:57 GMT
Thanks for your replies Fred. Indeed many people say that the ports are cut out at a much later stage. However Witsen shows some illustrations that tend to show us that they might have been arranged much sooner. You can see in these images that the sills are already attached to the frames at a very early stage.
kostenlose bilderkostenlose bilder
fotos hochladen
kostenlose bilder
Also the Stuckenburgh drawing shows this, though many historians claim that this drawing illustrates a certain stage of construction.
I believe that the frames were tilted so that they were in a 90° angle to the deck beneath ist. This seems to apply to both ships being discussed here, the Vasa and the Hohenzollernmodel.
We need to bear in mind though, that the frames of a Dutch built ship are not a complete built unit like on English ships. The individual pieces of a Frame weren't attached to each other like on English ships. What we can see in the Images above are the "Stützen" the uppermost pieces of each frame. The Batavia wreck Piece gives one the impression that the frames also served as sort of filler pieces between in inner and outer hull Planks. I think the Dutch called the frames the "Inhouden".
Peter
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Post by Peter Jenssen on Jun 27, 2016 11:04:58 GMT
Isn't there also a change in how the gun ports were cut out sometime around 1630? Prior to that date, most ships appear to have their gunports follow the wales. After, they cut through the wales (indicating less aft incline in the corresponding gun deck)?
cheers, Peter
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Post by tromp on Jul 3, 2016 14:47:08 GMT
Peter, if the gunports follow the wales, then the decks would need to follow the wales too. Especially in stern this resulted in some very steep decks. Perhaps the change was indeed made around 1630. It seems that the shipbuilders were reluctant in cutting through wales amidships where the structure was weakened by removable gratings, the compromise seems to have been that it was acceptable to cut through wales at the bow and Stern where there were no gratings. Here I have photoshopped four individual Images of the Hohenzollnmodell together to one image. The rows of treenails have been highlighted with different colours. Kostenlos Bilder hochladenAnd this here was done at an early stage of construction of my model: bilder kostenlos hochladenPeter
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Post by Peter Jenssen on Jul 4, 2016 3:25:46 GMT
Peter, if the gunports follow the wales, then the decks would need to follow the wales too. Especially in stern this resulted in some very steep decks. Perhaps the change was indeed made around 1630. It seems that the shipbuilders were reluctant in cutting through wales amidships where the structure was weakened by removable gratings, the compromise seems to have been that it was acceptable to cut through wales at the bow and Stern where there were no gratings. Peter Hi Peter, I noticed the backward leaning frames at the bow on your model construction plan. I think for the Vasa, the forward frames do not lean aft. (Fred? Kroum? is Kroum Batchvarov on this board?) The Hohenzollern model seems to be different in this aspect? As to gundeck following the wales; I agree that there has to be a deck at a suitable level behind a gun port, but I don't think it necessarily follows that the deck has to exactly follow the slope of the wale. It is possible (as you can see for the last aft gun port in the Vasa) to put in a break in the deck in case the slope becomes to steep to be practical. I would suspect that while the gun ports are square and follow the planking and wales, that if you look at Vasa's aftmost gunports you may therefore measure a shorter distance from deck to fore gun port sill than to the aft gun port sill? It would be interesting to trace the gun ports onto the interior arrangement to check this, but I'm only mounting half guns here anyway, so for my model it does not matter, even if it's interesting. The frames do not seem to define the sides of the gun ports. Not cutting into the frames does not seem to have been a concern for the builders of Vasa and judging from that, cutting the ports seems to have been done at a late stage. Indeed, framing is quite haphazard and a frame might not even be parallel to its neighbour. Does not look anything like the Witsen plates. See below drawing from Eva-Marie Stolt: (Also interesting, -the Witsen plates seem show all the frames leaning aft?!) Fred's comment in the thread above regarding the frames following the angle of the bottom planking was a great "aha moment" for me. The frames have no bevel, they are just placed inside the planking, and therefore, as you work upward adding more timbers, they come to tilt forward. They lean forward already by building method, not in order to follow the wales. (There may be an exception in the bow, where following the bottom would be almost impossible due to the rapid curvature in this area) I have not heard before that deck gratings are a structural weakness for the hull. I would have thought the rather thin deck planking does not add much to hull strength? The king planks and the deck beams surely would be the structural components here, and they are present as per normal, even where the gratings are. I really like your model, and it's coming along really well! Thanks, Peter
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Post by jules on Jul 28, 2016 14:00:16 GMT
Hello Fred,
In your post of the 26th of June you say that the frames towards the ends lean in towards amidships on every Dutch-built ship of the 17th century you have excavated and recorded. Could you please tell me which Dutch ships that you have excavated and recorded showed this phenomenon?
Many thanks in advance and with kind regards,
Jules
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Post by fredhocker on Aug 9, 2016 13:42:47 GMT
Wow, a lot of questions, last one first.
I have personally examined the hull remains of the following Dutch-built ships which had enough framing remaining to assess whether they "lean in" or not:
Vasa E81 (pinas formerly on display at the old Scheepsarcheologie Museum in Ketelhaven) OB71 (passenger ferry or beurtschip built 1587 and sunk c 1625 in Lelystad)
I have also looked at my colleagues' drawings of other ships, such as the VOC retourschip Batavia, which seem to have the same phenomenon.
In most cases, there is more apparent lean in the stern than the bow, but I think that this has to do with the forward location of the midships section/flattest part of the bottom and the great upward sweep of the stern. The bow frames in Vasa do lean back, as we were able to document in detail during Kroum Batchvarov's project, but not as dramatically as the stern framing leans forward.
As for when the gunports were cut, it is not possible to be definitive about this in Vasa's construction, only that the sides of many of the ports are cut into the frames, and that the port edges are not always parallel to the run of the frames. There does appear to be some planning in the framing for the ports, but the port locations are irregular and do not match up between the port and starboard sides. The illustrations provided above which show sills in place quite early are from later periods, when the decks and ports no longer followed the sweep of the wales.
The change in port location, from following the sweep of the wales to a straighter line along a flatter deck, does seem to occur around 1630 - Vasa may be among the last major ships to be built this way. In Vasa's case, the sweep of the deck follows the wales more or less, so that the ports are of similar height above the deck over longer distances. For example, on the lower gundeck the second through ninth ports on the port side are all 59-60 cm (very close to 2 Swedish feet) above the deck at the center of the sill, while the tenth through thirteenth are 67-70 cm above the deck. The first port faces forward, with a contorted shape, but is in line with the wale, and the last port is a smaller port above the raised deck of the gunroom, 61 cm above its deck. The gunroom deck is an alteration made during construction, the beams for it continue in the same sweep as the rest of the gundeck, but there are graduated packing pieces on top of the beams to raise the deck and give it less sheer. I suspect this is to make it possible to handle the guns effectively, since the extreme sheer at the stern would have made it hard work to haul the heavy stern chasers (not mounted, but their carriages are in place, indicating old-style long 24-pounders, 2-2.5 tonnes each)up to the ports.
Cutting through the wales, for the flatter gundecks of the 1630s onward, was mostly an issue in the stern after hull shapes and sheers flattened out in the later 17th century. I doubt that it has anything to do with removable gratings, but is rather a consequence of the more pronounced sheer of hulls of the early 17th-century type. Flatter decks seem to have come in first, probably as a practical requirement of gun handling, followed by some adjustments in sheer and hull shape, which reduced the need to weaken the structure, although it was still common to cut the after ports into the wales in the 18th century.
Fred
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Post by tromp on Aug 9, 2016 15:15:08 GMT
Thank you Fred, that really clarifies a lot.
Regards Peter
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Post by jules on Aug 9, 2016 18:56:21 GMT
Hello Fred, Thanks for your answer. In my opinion Peter is trying to prove that the phenomenon of the tilted framing occured in ships built in the 1660s. That is the date of construction of the model he is trying to replicate. He turned to you to find archeological evidence for his tilted framing thesis. You state that the phenomenon occured in several wrecks. Of the wrecks you mention, only one is approximately from the era Peter investigates; the E81-wreck. As I explained in another thread of this forum, the only part that was found of the E81-wreck was the bottom part; the part far underneath the waterline. So the suggestion that the tilting of the frame phenomenon can be seen in this wreck, is an illusion, as all you can really see is the lower part of the framing. Luckily a very good model of the wreck is made, which shows this preserved lower part of the framing. Here is a photo of the Rijksdienst voor Cultureel Erfgoed of that model. I studied the wreck myself and can confirm that, as you may expect from a professional organisation as the RCE, the model is indeed a very good representation of the wreck. As one can see in the photo of the model, the framing that is preserved, does not show the tilted framing phenomenon. And, as I have seen for myself, neither does the wreck. And, since the lower framing does not show the tilting, it is unlikely that the upper framing would. I think we must conclude that there is no archeological evidence for Peter's thesis that the tilting of the frame phenomenon occured in ships from the 1660s. There are simply no wrecks of Dutch ships from this era that are preserved intill the upper railings. Therefore, in my humble opinion, we must turn to other sources than archeological sources to find information on the framing of Dutch ships from the 1660s. With kind regards, Jules
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Post by Peter Jenssen on Aug 10, 2016 1:33:06 GMT
Hi everyone, Very interesting discussion. From my point of view, (in my model) the frames will be hinted at by bolt placement mostly. Top timbers? Maybe the angle will not be discernible? I think many of the large bolts visible are for the riders, not the frames. Probably riders are not exactly aligned with frames either? In any case, I suspect once a reasonable bolt pattern is completed, it would be hard to deduce frame patterns from it anyway. With regards to wrecks, are there no further Swedish wrecks of ships built to the dutch method? Baltic waters should make preservation of higher timbers more likely than other places. The "Svärdet" (1662) for example seems to have a bow that looks quite a lot like the Vasa, at least superficially: www.sjohistoriska.se/svardetI suspect the shift to more English style framing practices happened around the 1660s in Sweden, perhaps not early enough to affect this ship? Cheers! Peter (J)
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Post by tromp on Aug 10, 2016 14:51:22 GMT
Peter (J) to determine the Location of the frames I follow the wooden treenails only and not the iron bolts.
Peter
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Post by Peter Jenssen on Aug 10, 2016 22:05:48 GMT
Ah, Of course!, Thanks! (Makes it somewhat easier for me then as I don't think I can do treenails in 1/75 without it looking out of scale.. -we will see..)
Thanks, Peter
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Post by Peter Jenssen on Aug 11, 2016 2:49:33 GMT
Is the Vasa framing analysis available to the public? I was looking at Clayton's framing pattern (developed from information obtained from the museum according to the website) where it looks to me that compared to the keel, all frames lean forward to varying extent. sites.google.com/site/clayton707/swedishwarshipwasaCompared to the waterline, possibly the first 10% lean aft slightly, but difficult to see.. I believe Clayton did the framing before Kroum's framing investigation though? (Not that the framing was entirely unknown before) Peter
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