Naseby 1655 - reverse engineering the ship model

[-Waldemar-]

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With the encouragement and help of Donatas and Martes, I decided to attempt to reverse-engineer the design lines of an attractive mid-17th century model of a ship now in the Maritime Museum in Stockholm.





Link to the museum's page with a description of the model:

Three-decker, c. 1660

Sjöhistoriska museet

digitaltmuseum.se

Link to scanned 3D model:

Three-decker (c. 1660) - Download Free 3D model by SWEDISH NATIONAL MARITIME AND TRANSPORT MUSEUMS (@maritima)

This unplanked model of a three-decker can be dated to c. 1660 and is one of the world’s oldest models of a warship. Although not definitively identified, recent research links it to the Swedish ship Riksäpplet, designed by the English master shipwright Francis Sheldon and launched in 1661...

sketchfab.com

It has been accepted that the model represents the English ship Naseby 1655 at a scale of 1:48. The recorded dimensions of this ship (as built), according to British Warships in the Age of Sail 1603-1715 by Rif Winfield, are 131 feet (keel) x 42 feet (breadth) x 18 feet (depth in hold).

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Edit:

Summary​

An attempt to reconstruct the design concepts of the Ö 3 model has been completed, with the process and methods used shown later in this thread. Its results can be considered an excellent complement and even correction of information coming from contemporary written works on shipbuilding (notably Bushnell's Vademecum 1664 and Deane's Doctrine 1670), which, as it turns out, are simplistic and even outdated in terms of the design practices already in use at the time.

As far as the identification of the model itself (so far uncertain) is concerned, in the briefest of terms, its read proportions perfectly match both Naseby 1655 and, most likely, the wreck of Riksäpplet 1663.

The analysis also showed that the size difference between the two ships is solely due to the difference in length between the English foot and the Swedish foot (304.8 mm and 297 mm respectively). In other words, apparently both ships were built to the same design and even the same nominal dimensions, just using different length units. More on this later in the thread.

In this context, it should also be added that the configuration of the upperworks (with its decorations) is considered an incomparably weaker interpretative 'argument', as it could (and indeed did) change frequently during the life of the ships and, besides, did not necessarily correspond to the original design from the beginning.

For the convenience of readers, the reconstructed plans (hull lines) of the Ö 3 model in modern convention are again attached below as a ZIP file, both as a high-resolution raster and in vector format. Both saved as PDF or JPG. Besides, a low-resolution preview of the content:

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[Uwek]

A beautiful contemporary model and a highly interesting work with this 3D-model
Great possibility to see all the details with the different views, which are definitely not possible visiting the museum.

And BTW: A warm welcome here on board of our forum

Would be great to see much more of your work

 

[-Waldemar-]

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Hi Uwe and thank you for your kind welcome. Of course, if an interesting topic comes up, I certainly won't miss showing it. Thanks again.

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The original model is so badly deformed that it required prior shape correction, consisting of local or overall rotations, bends, twists. It was then scaled up to the dimensions of Naseby 1655 and measured in other places. In doing so, it turned out that the proportions of Naseby 1655 (and therefore of this model) were identical to those of the original design assumptions for the ships of the 1654 programme (Dunbar, London, Richard). In other words, Naseby 1655 was built exactly according to the original 'plans' for the smaller ships of this programme, only multiplied by 131/120.

Dimensions of Naseby 1655:
131 x 42 x 18 (on the model 17'2"); measured timber&room 30 1/2 inches

Original dimensions of the 1654 programme ships:
120 x 38 1/3 x 15 3/4; calculated timber&room 28 inches

There is, admittedly, a discrepancy in the depth of hold, but at the same time that measured on the model, matching its design grid (as it would be normally expected), is perfectly correct. Now everything agrees nicely, as shown in the diagrams below.





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[shota70]

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Hi Uwe and thank you for your kind welcome. Of course, if an interesting topic comes up, I certainly won't miss showing it. Thanks again.

* * *​

The original model is so badly deformed that it required prior shape correction, consisting of local or overall rotations, bends, twists. It was then scaled up to the dimensions of Naseby 1655 and measured in other places. In doing so, it turned out that the proportions of Naseby 1655 (and therefore of this model) were identical to those of the original design assumptions for the ships of the 1654 programme (Dunbar, London, Richard). In other words, Naseby 1655 was built exactly according to the original 'plans' for the smaller ships of this programme, only multiplied by 131/120.

Dimensions of Naseby 1655:
131 x 42 x 18 (on the model 17'2"); measured timber&room 30 1/2 inches

Original dimensions of the 1654 programme ships:
120 x 38 1/3 x 15 3/4; calculated timber&room 28 inches

There is, admittedly, a discrepancy in the depth of hold, but at the same time that measured on the model, matching its design grid (as it would be normally expected), is perfectly correct. Now everything agrees nicely, as shown in the diagrams below.

View attachment 371567

View attachment 371568

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very impressive and interesting project, well done

 

[-Waldemar-]

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It should also be added that the model is slightly narrower than the known breadth of Naseby 1655, which can also be seen in the diagrams, however, it has been assumed that this may be the result of the fairly common practice at the time of measuring the ships' breadth including planking, so it was left as is.

On the other hand, the model suffers from very serious asymmetry problems – the right half is excessively distorted (shrunken) and only the left half will be considered for further analysis.

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Due to the need to get rid of the interfering wales, it was decided to cut the model with transverse planes to create a replacement hull surface for further work. The peculiarities of the hull structure (single frames with alternate elements) meant that this cutting has to be carried out in several stages separately for the three different levels: the floors, futtocks and toptimbers.

Below are some diagrams of this (not yet completed) process.











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[Herman]

Out of my league this 3D engineering, but very interesting to follow your work on this wonderful beauty.

 

[Allegheny]

Hello Waldamar,
Welcome to this site.
I'm relatively new to this site as well and do not nearly possess any level of knowledge that many here have relative to ship modeling/building.
This is a old/new hobby that I'm rediscovering - thus please excuse any newbie type questions.
I'm presently drinking from the preverbal fire hose and its not going well as I'm drowning!

If I understand the museum model correctly, the actual model is about 4ft in length and 1.16 ft high.
An actual ship called Naseby 1655, was built to this models build plan dimensions but scaled by a factor of 1.09.
Using known data on the Naseby and the model, you are trying to reverse engineer to create a set of drawings which would represent the original plan drawings for the 1654 program ships.
You noted that the museum model's right side is deformed and not the left, but looking at the photos on the museum website I couldn't see any real difference.
What am I missing here?
How were you able to determine that?
Also where or how did you develop the black & white 3D images to start your analysis of this ships construction as I find this project fascinating?

 

[-Waldemar-]

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Hello and thanks everybody,

Allegheny, yes, you are perfectly right, the model looks good at first glance, even very good. But in fact its condition in the geometrical sense is, one might say, tragic, and to the extent that extracting some meaningful design data is extremely difficult.

Please have a look at the below pictures of the model in orthogonal projections, to which I have added some lines, whether perpendicular, parallel or symmetrically placed, as appropriate. These are just the most obvious distortions.

Portside is not perfect either, and now, after even closer inspection and fits, I even assume a variant that it originally had a greater width too, more in line with the dimensions of the actual ship, i.e. 42 feet. It simply shrunk less than the starboard side.

But even that is not all – the original creator of the model also further distorted the geometry of the hull shape by sanding it more or less heavily in various places. The worst is probably at the very bottom near the keel. Something must have gone wrong during the construction, and by smoothing the hull there he literally destroyed the contours of the hollowing curves, so important for the accurate determination of the geometry of the bottom sweeps, which are of fundamental conceptual importance.

For all these reasons, the analysis goes so slowly and at the same time requires difficult, interpretive decisions. However, the work is moving forward. I'm not technically ready to show it yet, but the sweeps radii of the frames already read (some so far) also confirm that the model was built according to the proportions intended for the ships of the 1654 programme, simply up-scaled by 131/120 (if the assumed 1:48 scale is correct).

These black&white images are the 3D model in OBJ format, (without textures (colours) which are not needed for geometric analysis), imported into the CAD program Rhino I use. These OBJ files were converted by Martes and Donatas from those provided for download on the Sketchfab website, and kindly provided by them.







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[Martes]

@Allegheny ,

In very short, it is all made possible by the fact that the Swedish marine history museum has created and published a 3d scan of the model, which we downloaded from Sketchfab (see the link in the first post) and Waldemar has put it to analysis.

The size estimation - since the most standard scale for this type of models is 1:48, and if we assume this model is built to the same scale, it fits the dimensions of the Naseby.

 

[rick robbins]

Beautiful!

Rick1011

 

[Allegheny]

Dear Waldamar and Martes,

Thank you both for answering my questions as it helped clarify for me what was being done and how.

I find your analysis simply amazing given the detail you are able to pick up from the converted 3D scan.
You mentioned that there was some heavy sanding done and thus causing the loss of the contours of the hollowing curves.
How were you able to determine that?
Was it done on both sides of the ship model?
Also could the dimension variations be due to shrinkage of the model itself, after all it is 369 years old?

I also noticed that some of the repairs done to this model weren't necessarily very well done.
I see metal screws being used in some places and what looks like thin plywood being used.
Is there any way of determining what type of woods were being used in the models build?

 

[-Waldemar-]

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Allegheny, BTW, should be 'Waldemar', not 'Waldamar'. Thank you in advance .

The so-called Navy Board/Admiralty models were almost invariably built of fruitwood and boxwood (both very good choices). Today, when repairs are made to these models involving the replacement or addition of certain parts, a material of a distinctly separate colour is used to make it clear that these are new parts, not original, which is a very good conservation practice used in museums. This also applies to the type of material. In other words, all is fine if it is clearly seen that replacement parts are replacement parts. However, private collectors may follow different paradigms.

Shrinkage alone cannot account for the very 'suspicious' shape of the model's bottom. The anomalies here are too great, and at the same time highly localised and shape-specific. This can be seen especially in the unnatural connection between the hull surface and the keel. On top of this, the deadrise has a rather 'suspicious', twice the expected value known from written and graphic sources of the period and place. Although not entirely impossible. Unfortunately, this has happened on both sides and I am again faced with a very difficult decision. To correct or not to correct...

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[fred.hocker]

I am very sorry to disappoint everyone in this thread, but this model does not represent Naseby of 1655. It was once identified as such, and that identification has taken on a life of its own, but there is a very good paper trail in the naval archives, which has been investigated recently by Niklas Eriksson and published (in Swedish) in 2017. The historical record makes it possible to trace this model from its original construction in 1660 through two episodes of alteration as the deisgn was finalized before the real ship was built in 1662. This model was kept in my office for ten years, and I helped document it, so I know it well. I have measured it carefully, and its dimensions do not agree with Naseby no matter what scale is used. The reason it is difficult to make its dimensions agree with Naseby is that this model represents a Swedish ship, Riksäpplet, designed by Francis Sheldon. The well-preserved wreck of Riskäpplet has been documented, and it agrees very well with the model. At 1:48, the model agrees exactly with the known dimensions of Riksäpplet.

As for the model's shape, when it was found in storage over a century ago, it was in three large pieces plus small fragments. It was restored, quite well given its condition, and the current shape is probably reasonably close to the original, since the original parts fit together relatively well. There is some unevenness in the bottom, and some questionable restoration in the upper part of the stern, but I think that the shape of the underbody is pretty close to what Sheldon designed. It does have more deadrise than contemporary sources suggest was common, but it is the same on both sides, so I think one would have to accept that this was part of Sheldon's design. Sheldon did not publish his design thinking, so the model and the ships he actually built are the only clues we have to his ideas, which may well have diverged from what we today consider the "norm".

I think Waldemar's project is very interesting, regardless of what ship this represents, and I will look forward to the results!

Fred

 

[Allegheny]

Dear Waldemar - Please accept my apologies for the misspelling of your name.
I look forward to your complete 3D modeling analysis as it is most intriguing.

Dear Fred - this is most interesting as you have first hand knowledge what this model is all about.
Are there any links to the studies/photos/drawings you mentioned regarding the actual ship Riksäpplet and its sister model?

 

[-Waldemar-]

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Hi Fred. I'm very pleased to see your entry. I hope you will keep an eye on my doings and give constructive criticism where necessary, which quite often results in some new discoveries.

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I have to admit that you have knocked me off track so I returned to the question of model identification. Firstly, I discovered that there are two camps. One opting for Naseby 1655, the other for Riksäpplet 1663. I also looked again at Niklas Eriksson's articles on Riksäpplet from 2017 and 2019. Must say he does not seem so categorical to me, including one quote: "A model of the ship with inventory number Ö 3 has been used in discussions about the construction of Riksäpplet. There are many indications that the finished ship looked just like this" (2017). And overall, the arguments he cites are of rather indirect, circumstantial character.

However, I have to base my analysis on specific dimensions, and what you have written about them in the context of the scale of the model would have to mean that the provided scan of the model is dimensionally rather inaccurate, which would indeed ruin my measurements of this digital model made so far.

Admittedly, I do know Riksäpplet's dimensions (although I'm not entirely sure of them), yet their proportions match worse the provided digital model than those of Naseby 1655:

As given by Jan Glete:
158 x 37 x 17

From forgotten source:
140 x 38 x 14 x 7 (between decks)

And also:
"[A]nd the Schamplun of this ship [Riksäpplet] is almost like the Schamplun of Ollenborg [presumably referring to the ship Oldenburg], the lowest deck being within the deck clamps [the longitudinal beams on which the deck rests] 34 feet, the second 26, and the upper deck 23 feet wide" (Eriksson 2017).

If one compares dimensions given by Glete (i.e. the touch keel of 883 mm for the model and the length between perpendiculars of 158 feet for the actual ship), it comes out a scale of about 1:45.85 for English feet or 1:44.68 for Swedish feet.

There remains the question of the number of guns for the second and third decks, as the model lacks gun ports for the number of guns intended for the Riksäpplet (26, 28, 30, going from the lowest deck).

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Anyway, as you say, the unambiguous identification of the model per se is not that important to me, as I am mainly looking for a design method, but knowing even a few certain basic dimensions helps a lot in the analysis.

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[DonatasBruzas]

Hello,
I understand Fred is referring to the Niklas Eriksson book "Riksäpplet - Arkeologiska perspektiv på ett bortglömt regalskepp" published in 2017. On this book the author is referring to the Glete's work as a source of information about the model (page 105) when discussing the similarity to the Riksäpplet. Both Glete and Eriksson admit that the dimensions of the model were taken from the plan created in the 1930s by Hugo Åkermark. Now, when we have a 3D photogrammetric model, it is not very difficult to see that the plan does not portray the actual model very closely.
My version would be this:
Sheldon could use the enlarged ship of the 1654 group (Naseby) as a source when designing ships in Sweden. In that situation the Ö 3 may stand for a design proposal of a ship influenced by the Naseby (similar dimensions) but different (beakhead?, upper decks configuration, galleries). The Riksäpplet is a further modification of this concept with altered dimensions but similar decorations etc.

 

[Martes]

What probably makes the situation slightly easier is that the Naseby is (at least in principal dimensions) a direct upscale of the 1654 group, and Riskäpplet as built may have been direct downscale back from the same Naseby (on which Sheldon just might have worked at Woolwich, according to his biographies). But yes, it would be very helpful if we can ascertain if the 3d scan dimensions fit the actual model dimensions.

It is entirely possible that the project underwent certain modifications on the way and the model incorporates some of them, but if Waldemar's measurements (and the 3d scan dimensions) are correct it is probable that the model represents the larger variant of the ship, identical in size to the Naseby, that was ultimately downscaled when building the real ship.

 

[Martes]

---removed as duplicate--

 

[Martes]

On top of this, the deadrise has a rather 'suspicious', twice the expected value known from written and graphic sources of the period and place. Although not entirely impossible. Unfortunately, this has happened on both sides and I am again faced with a very difficult decision. To correct or not to correct...

Waldemar, I can't be sure for 17th century, but in the 18th there were several occurrences of attempts to introduce increased deadrise to existing design in order to apparently increase speed and/or weatherliness (compare the Colossus with Ganges ). Whatever the effect, it also decreased stability in all known cases and with the Ganges class was even reverted for later units of the class (see Tremendous).

 

[-Waldemar-]

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Many thanks for your feedback. Unless something unusual happens, such as obtaining some specific, hitherto unknown data, I will continue according to the assumptions and findings so far. I even have to admit that finding the dimensional features, already described above, is an additional incentive for me to continue working.

Below are some diagrams just to show the work in progress. This is still the stage of preparing replacement surfaces for further analysis. Lots of manual adjustments as the hull surface is not smooth (wavy frames). Even more importantly, it is at this stage that another, more precise correction has to be made to the geometry of the hull shape (the preliminary correction of the 3D scan was only approximate).

As for deadrise, indeed, it is directly related to stability. The best known examples of large ships with extreme deadrise are probably the Symond's designs. Excellent sailing ships, but hopeless gun platforms.

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