Vasa 1628 – engineering a ship

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Thank you, Fred. The principle that depth is equal to 1/10th of length is expressed expressis verbis at the very beginning of the mid-17th century Dutch manuscript Evenredige Toerusting van Schepen Ten Oorlog Bijder See (Proportional Equipping of Ships for War at Sea), and also in Witsen's somewhat later work. Yes, it is true, these kinds of proportions should of course be taken more as suggestions of good, proven practice to be applied, rather than in a way that is too literal for each case, as Witsen himself emphatically points out already in the preamble, but who reads any preambles today?

However, apparently this very ratio (of length to depth) was indeed quite scrupulously applied for deep-water ships; here are examples of these dimensions taken from the contracts cited by Witsen 1671 (in addition to those already given in the table in the post above):

length​
depth​
Deventer 1627
112​
11 ½​
Campen 1628
112​
11 ¼​
Swol 1628
115​
12​
Over-yssel 1628
120​
12 ¼​
Prins Wilhelm 1630
157
18 ½
Mauritius 1637
128​
13​
Mauritius 1639
129​
13​
Burg 1640
115 ½​
11 ½​
Deventer 1640
130​
13 ½​
Hæn 1641
122 ½​
12 ½​
Elias 1641
131 ½​
13​
Salmander
135​
14​
Princes
137​
15​
Gelderlandt
133​
12 ½​
Leiden
126 ½​
12 ¾​
Graef Enno 1642
126​
12 ¼​
Eendracht 1660
133​
12 ½​


One of these ships, the Prins Wilhelm 1630, is particularly attractive from the point of view of the Vasa 1628 case, as both ships are almost the same length and breadth (but no longer depth). Out of curiosity, for a visual comparison of the contours of these very close equivalents, I reconstructed the master frame of Prins Wilhelm 1630 and superimposed it on the contours of Vasa 1628. The graphic attached below actually speaks for itself.


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However, apart from the far insufficient hull depth of Vasa 1628 itself, actually equally significant is the too small radius of bilge sweep in relation to the breadth of Vasa 1628 (equal to only 1/6). This is far too tight an arc, and not much of an exaggeration – used more for extreme or highly specialised merchantmen designs sporting radically boxy master frame contours. The normal bilge sweep radius, and even more so for warships, was a radius equal to 1/4 the breadth of the hull. In other words, this bilge sweep radius that we find on Vasa 1628 also indicates that the timbers were originally intended for a smaller ship, from a length category of about 120 feet and a breadth in the range of 25–28 feet.

This is already of rather secondary importance, but for the sake of completeness I would add that the thickness of the floor timbers for the Prins Wilhelm 1630 was specified at 13 inches.

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As for the reasons for using a smaller/shorter set of timbers, other, less glorious for Hybertsson circumstances are certainly also possible. For example, Hybertsson may have lied that he managed to accumulate two sets of timbers, for the large ship and for the small ship. Or he had euphemistically overestimated the amount of material he had gathered, so that when he had to irrevocably start building the larger ship under the terms of the contract, it turned out, after a more thorough inventory of his accumulated stock, that he did not have enough large timbers. Under the circumstances, could he admit to a lie or a mistake, equally embarrassing, or rather proceed to start building the larger ship with the material he actually already had? Such a scenario saves Hybertsson's professional competence as a designer, but calls into question his prudence, civil courage, management skills or even integrity.

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Who, for example, stated that depth should be one tenth of length?
- Nicolaes Witsen (1641-1717), Aeloude en Hedendaegsche Scheepsbouw en Bestier, 1671:
'About the depth derived from the length.
3 To get the depth from the length, take one foot of depth for each 10 feet of length. For instance, 100 feet length comes to 10 feet depth at the main frame, but for this depth one can find ships 4 feet longer or 2 feet shorter, yet seldom'. (translation Alan Lemmers) From: Nicolaes Witsen and Shipbuilding in the Dutch Golden Age by A.J. Hoving. Texas A&M University Press, page 37.
- Cornelis van IJk: De Nederlandsche Scheeps-bouw-konst Open Gestelt (1697) page 53:
'A well-shaped ship must be wide one quarter of its length....()... but no ship should have a depth more than half its width (12,5 % of length ship) and not less than 2/5 of its width (10 % of length ship).' (translation by me).
- Evenredige Toerusting van Schepen ten Oorlog bijder See. Manuscript to the attention of the Admiralty of Rotterdam:
'A good man-of-war will; be proportioned like this:
One quarter of its length for the width
One tenth of its length for the depth'. (Translation by me).

There are more books and manuscripts (of slightly later date) on the matter, although most of them based on the mentioned texts.
The conclusion must be that Vasa seriously lacked depth.
 
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Thanks Ab and Waldemar for the specific references. I think we have established that Hybertsson was clearly not following typical practice, but there is evidence that he consistently designed ships that were comparatively shallow.

First, was Hybertsson lying to the king? I appreciate that we would like not to think ill of the dead, but sacrificing his honor to save his technical reputation seems a step too far. It looks a lot like throwing out evidence that inconventiently conflicts with a theory. There is also no evidence that he lied, and it is hard to imagine the motivation for it. In Waldemar's scenario, Hybertsson was forced by external pressures (the king? economy?) to build Vasa with timber he had already cut for a smaller ship, and then lied to the king about having timber on hand for a smaller (108 ft keel) and larger (128 ft keel) ship. Why would he do this, when what the king was asking him to do in the autumn of 1625 was to build a lengthened smaller ship? If he had only timber for the smaller class, then adapting this to a somewhat longer ship with similar scantlings should have been a better alternative than building a much bigger ship, surely? Why insist that he could not fulfill the king's command if that was the only timber he had, then build a ship substantially larger than the king requested, and that fulfilled the original design brief for the larger class, but required getting into a dispute with the king? If one is going to bow to pressure from the customer, why not go along with the easy solution (build the 120-foot ships)? I think that we are making this situation much more complicated than it was or needs to be. There is a clear timeline and relatively straightforward explanation for the result: Hybertsson designed a ship without enough depth in hold to carry its upperworks, and this design was the original intention, but deeply flawed.

A clearer demonstration of the situation can be found by comparing the dimensions and scantlings for Tre Kronor as given in the spec Hybertsson sent to the king with the actual dimensions of Vasa, which I have just now gone out and remeasured to be certain that no errors have crept into my notes. One could of course argue that the scantling list Hybertsson sent to the king was a complete fabrication, but I see no reason to doubt its accuracy or to conjure a motivation for Hybertsson to lie about it. There is nothing in the other documentary evidence surrounding him that suggests he was prone to lying about professional matters (he was, for example, one of the people who was called to stand surety for new citizens or others taking oaths before the municipal court, a sign of his probity and the respect with which the Stockholm community treated him).

Here is the result, along with the proposed dimensions for the king's compromise (120-foot keel). Vasa's dimensions are converted at 1 Swedish foot (12 inches) = 297 mm, the standard Swedish foot promulgated earlier in the century, and which we can verify from the draught marks carved into the stem and stern. Where measurements are across the grain, shrinkage has been corrected (this averages 6%, based on tens of thousands of measurements taken since 1961), but even if one takes the uncorrected shrunken values, the overall picture does not change significantly:

ItemTre KronorGIIA’s proposed designVasa actual
Overall length (estimated at 1.25 * LOK)135 ft150160 (actual)
Keel
length108 ft120 ft130 ft
width21 in21 in24 in
depth21 in21 in24 in
Breadth (sail beam length)31½ ft32 ft34 ft
Depth in hold12 ft13 ft13½ ft?
Rake of stem21 ft23 ft24½ ft
Keelson
Thickness9 in9½ in10 in
Breadth29 in29 in30½ in
Floor timber moulded12 in12 in15½ in
1st futtocks moulded10 in11 in13-14 in
2nd futtocks moulded8 in9 in10 in
Plank thickness444½ in
Wale thickness778 in

Two things should be immediately apparent from this table:
1. All of Vasa's timbers are larger, sometimes substantially larger, than the equivalent timbers for Tre Kronor, including the first timbers laid down and the ones that determine the hull form. Note especially the moulded depth of the frame timbers, which are over 25% deeper over the floor of the hull. These timbers may well be shorter in length than they "should" be according to accepted contemporary design principles, but they are the correct scantlings for a ship the size of Vasa. It is thus hard to see how they could be timbers cut for a substantially smaller ship.
2. If we look at Tre Kronor's overall dimensions, we can see that Hybertsson also designed this ship with a shallow hold, where depth in hold is not even close to 1/10 of overall length, in fact less than 1/11, and the proportion is not vastly different from that of Vasa (depending on how Hybertsson measured depth; the figure given is top of the ceiling to underside of the lower deck at the widest point in the hull, but it is less farther forward and more farther aft).

It may be instructive to note that the opinion of the experts assembled at the inquest was that Vasa was too shallow for its size (as one said, the ship did not have enough belly) with upperworks too high and heavily built. We can see from the other dimensions of Tre Kronor (I have not provided the entire list) that Hybertsson liked plenty of headroom in the decks and heavy, closely spaced deck beams, so the peculiarities of Vasa are not unique. It seems to be part of his design signature.

My overall impression is that Vasa is more or less the ship Hybertsson intended to build, with some widening and some alterations to the configuration of the stern, and represents the design brief for the larger class of ship ordered in the 1624/1625 contract. This agrees with all of the evidence, both documentary and archaeological, and does not require excluding any evidence or constructing elborate subterfuges on the part of principal actors. Occam would be satisfied. From what we can see and measure on Äpplet, Hybertsson maintained the same scantlings for the sister ship, but integrated the changes he made in Vasa into the design from the start.

Actually, it would be more accurate to say that Hybertsson's successor, Hein Jacobsson, integrated the changes. Hybertsson had been increasingly ill during 1626 and gradually turned more of his responsibility over to his master shipwright, so it was Jacobsson who completed Vasa (and testified to the increased width at the inquest) and was responsible for Äpplet from the start of construction, although he was still stuck with the timbers that had been roughly shaped in the forest. I think that it is signficant that the big ships Jacobsson built later, starting with a clean sheet (Kronan and Scepter), differed substantially from Vasa and Äpplet. They were deeper, with more displacement, and carried lighter armament. They were much better ships, and served successfully for nearly forty years.

It seems that Hybertsson tended to build shallow ships. He got away with this when he was building ships with a single gundeck, as the result was still within the envelope of plausible seaworthiness, but his approach was fatally flawed when building a ship with significantly more topside weight. Whether he was aware of the more typical proportions found in Witsen and other sources is difficult to answer, but I think it is clear that he had his own set of proportions in mind from the start. It could even be that his original concept for Vasa was a larger, taller version of Tre Kronor, which is a possibility worth investigating graphically.

Fred
 
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Indeed, we can probably argue to the ends of the universe as to what, in the case of Vasa 1628, was the reason for the drastic departure from the typical design standards of the era (I had originally intended to post a much longer entry here, which I have even already created). However, seeing in Fred's above table that for a ship with a keel length of 108 feet (Tre Kronor), Hybertsson applied a depth of 12 feet, it is not easy to accept that an identical depth of 12 feet was also deliberately applied for a ship with a keel length of 130 feet (Vasa), as this is the only depth actually allowed by the timbers used to build Vasa. Not only is this dramatically inconsistent with typical proportions of the period, it is also too inconsistent with Hybertsson's alleged tendencies to design 'shallow', at least judging by the presented proportions of Tre Kronor.

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In all the contracts I studied (and it must have been hundreds), I never spotted a ship differing so much from the basic shipbuilding rules about the dimensions of ships. I have seen lots with much more depth in hold, but never a single one with considerable less depth, like Vasa shows. The exception to that rule may have been fluits that transported corn. They were deliberately made 2 feet less deep because of the excessive weight of corn. Same thing for the width, which should be 40 feet according to shipbuilder's rules, but the ship only measured 34 feet. A ratio of 4.7. That is a difference on both sides of almost a meter!
Shipbuilders did play with the ratio length-width: merchant ships usually were a few feet below the rule, (Witsen's pinas was 134 feet long and 29 feet wide, which gives a ratio of 4.6) while many men-of-war exceeded a quarter of the length by a foot max (same goes for slavers, which also showed more width, but the reason for that was more deck-surface, hence more 'accomodation' to transport slaves). Often a narrower ship was compensated by more depth and otherwise.
When I saw Vasa's measurements for the first time, long ago, I gathered that the method of measuring had to be different from what literature tells us, because I did not recognize them as the basic measurements. I concluded that with all the different decks the measuring points might have shifted. But they have not, and yet the ship needed to answer to the same basic rules. Which she apparently didn't.
A lack of depth of 2 1/2 feet (74 cm), combined with a lack of width of 6 feet (1.78 m), with decks exceeding 8 Amsterdam feet (2.26 m) (Evenredige Toerusting states that 8 feet should never be passed), together with an excess of high placed heavy guns could never have led to a stable ship. I must confess I am not sure about my supposition Vasa's deck height being more than 8 feet. But I remember I walked through the ship and never had to bend my head, not even below the deck beams, and I was 1.92 m at that time, which is no longer the case nowadays I'm afraid :cool: .
I'm sure Fred knows more reasons why the ship was not stable, but these basic measurements are enough for me to have second thoughts about Hybertsson's capability to build such big ships (even being an object of exceptional beauty in my eyes).
 
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but these basic measurements are enough for me to have second thoughts about Hybertsson's capability to build such big ships
Well let say Cornelis van Yk thinks the same about it as you Ab. :) pag 20 in his book

20240226_202503.jpg
Maybe you translate the last 2 sence for our English readers.
 
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Well let say Cornelis van Yk thinks the same about it as you Ab. :) pag 20 in his book

20240226_202503.jpg

Maybe you translate the last 2 sence for our English readers.

Quite outdated and even downright misleading comments, because in the year van Yk's work was published, in France ships were already being designed in a more modern way based on diagonals rather than the recipes described in Dassié's book, and in Sweden English techniques had already been used to build capital ships for a couple of decades.

Hence, it can hardly be said that van Yk was perfectly versed in current European trends in naval architecture. Given van Yk's good memory, perhaps this particular passage is better not translated.
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Quite outdated and even downright misleading comments, because in the year van Yk's work was published, in France ships were already being designed in a more modern way based on diagonals rather than the recipes described in Dassié's book, and in Sweden English techniques had already been used to build capital ships for a couple of decades.

Hence, it can hardly be said that van Yk was perfectly versed in current European trends in naval architecture. Given van Yk's good memory, perhaps this particular passage is better not translated.
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I think you don't understand the words of Yk right. But old Dutch isn't easy to read. So I forgive your words about a misleiding comment. :)
 
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In truth, in my thread I would have preferred a substantive statements rather than rhetorical displays. Thank you in advance.

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In truth, in my thread I would have preferred a substantive statements rather than rhetorical displays. Thank you in advance.

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Special for you I will give you a translation about the text that was not ment to you but to Ab. About his meaning about Hybertsson's capability. That Yk have the same meaning.
Translation
As for the Danish and Swedish ships how they largely follow our Dutch construction methods. No matter how good their builders are they can never match our way of building.

maybe you should be more freindly to people if they don't share your opinion. Sometimes you can learn from them, like Fred also said a few post before.
 
Nothing wrong with Ab's memory, the headroom in the middle deck is excessive, over 1.90 m under the beams amidships and about 2.20 m or a little more under the plank. The headroom in the lower deck is less (I have to duck under the beams there, and I am 1.80 m tall), but still more than would be necessary for the average Vasa sailor, who was about 1.67-1.70 m. The specification for Tre Kronor gives a height in the deck of 6½ feet (1.93 m), but does not specify if this is under the beams or under the plank.

Whether one measures the physical depth of the hold or the height of the maximum breadth amidships, Vasa is considerably shallower than contemporary rules suggest, at much less than 1/10 of the length over the stems. It does appear to be consistent with his designs, if Tre Kronor can be considered typical of his earlier work (12 feet deep for an overall length of about 135 feet). As I have noted in previous posts, the problem of too shallow a submerged body with too tall and heavily built upperworks was pointed out already at the inquest, so Hybertsson's colleagues appear to have recognized that his design was unconventional.

The contract breadth of 34 feet was clearly far too narrow, which appears to have been realized during construction, and the ship was widened by 3½ feet, closer to the theoretical optimum of 40 feet but still narrow. Hein Jacobsson took credit for 1½ feet of the increased breadth, but that does not account for the other 2 feet, wihch may have been Hybertsson's doing.

Ships with multiple gundecks are even more sensitive to departures from sound design principles than ships with one gundeck, and I agree with Ab, Hybertsson was not a good choice to design big ships with multiple decks. Although there was no official verdict rendered by the inquest, the implication of the testimony at the time was clear, that Hybertsson's design was flawed. It helped that he had been dead for more than a year, and thus was a perfect scapegoat, but the inquest successfully steered away from assessing the blame that lay with the admiralty and the captain for sending an unsafe ship to sea and sailing it with open gunports (even though the ship's master dropped the admiralty in it in his testimony). One thing that is interesting is that the discussion by the experts summoned for the inquest reveals that they correctly understood the forces at work in stability and the relationships between the different factors involved, even if the ability to quantify these forces was still over a century in the future. They correctly identified the problem caused by the shallow underbody and tall upperworks, as well as the limitations that the hull form placed on the amount of ballast that could be used to correct the center of gravity.

I think that one thing Hybertsson's long service, despite limited skill as a designer, indicates is the circumstances in Sweden at the time, with the crown intent on building up a new navy rapidly. Even a bad plumber can make a living if there is enough plumbing to be done.

Fred
 
The specification for Tre Kronor gives a height in the deck of 6½ feet (1.93 m), but does not specify if this is under the beams or under the plank.
If the height of a deck is given in a contract, it is measured to the top of the beam in the ship's side (so without the camber of the beam). 6 1/2 feet seems to be a reasonable height for a deck in those days. (reason for me to duck in time).
 
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Special for you I will give you a translation about the text that was not ment to you but to Ab. About his meaning about Hybertsson's capability. That Yk have the same meaning.
Translation
As for the Danish and Swedish ships how they largely follow our Dutch construction methods. No matter how good their builders are they can never match our way of building.

maybe you should be more freindly to people if they don't share your opinion. Sometimes you can learn from them, like Fred also said a few post before.

Pfff... Messages to other people that don't concern me, please pass on outside my thread. I didn't ask you to translate because I'm doing it myself, better. Hybertsson and his successor Jacobsson (and half the carpenters building the Vasa) were Dutch, not Swedish or Danish. It doesn't matter to me whether you share my views or not. And, Stephan, but I like you just as much as you like me :). Thank you.

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Regarding the height of the decks. From the inventories, contracts and shipbuilding manuals, one can read a fairly clear trend that decks of a lower height were used for smaller ships and proportionally higher decks were used for larger ships. Perhaps the easiest way to see this phenomenon is in the Grebber table (reproduced in Witsen and van Yk). In this light, the height of Vasa 1628's battery deck not only has nothing special about it, but, conversely, is precisely in line with a ship of this size in a fairly typical way (some other examples: 7'7", 7½', 7', 7½', respectively for the 172-foot ship 1629, Prins Wilhelm 1630, Göteborg 1631 large, Göteborg 1631 medium; see also other numerous contracts cited by van Yk).

In fact, the design of multi-decked ships does not in principle require any special skills or procedures, it is enough to increase the overall size of the ship and the same proportions as for single-decked ships will make room for another deck.

And more generally, it is clear that Hybertsson knew and practically applied common design rules. All except for one, the most important one? Instead of 1/10 only 1/13 of the depth-to-length ratio? To me this is a very unlikely assumption, just as I find certificates of integrity of any kind unreliable. After all, even popes have their confessors, probably for a reason, although at the same time I don't know if Occam would be happy with that either. Then again, maybe it's not even about honesty, but more about a lack of courage to admit a mistake or say no to the king.

And graphically, to better illustrate, could a professional working in the trade for several decades, consciously, i.e. without strong external pressure, design such a freak as the one below? This time I have aligned the contour of the master frame of the Vasa 1628 in an even more realistic way, i.e. not only to the level of the ship's draught (dashed line), but also – even more meaningfully – to the actual level of the line of greatest breadth. By the way, it must also be said that the dimensions/proportions of the Prins Willem 1630 , taken for comparison, are very representative of ships of this size, as is evident from reading the rather numerous contracts for ships of this size cited by van Yk.


ViewCapture20240227_123237.jpg


I do not insist on the general acceptance of my view on this matter, however, other explanations (such as Hybertsson's professional inexperience, the lack of sufficiently qualified specialists in Sweden at the time, etc., even – unfortunately – over-interpretations of my statements), for me personally, are not convincing.

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Pfff... Messages to other people that don't concern me, please pass on outside my thread. I didn't ask you to translate because I'm doing it myself, better. Hybertsson and his successor Jacobsson (and half the carpenters building the Vasa) were Dutch, not Swedish or Danish. It doesn't matter to me whether you share my views or not. And, Stephan, but I like you just as much as you like me :). Thank you.

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Thanks, you are also very nice and friendly. By the way are you aware that this is a public forum?
 
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Other possible reasons for this design 'mistake' can be added to the repertoire of diverse possibilities and motives. Specifically, the frustration, disappointment and simply threatened business of Hybertsson, essentially cheated by the authorities by notoriously making payments in almost worthless copper coin, or such attempts. This is not even necessarily about some form of retaliation by Hybertsson, but rather an attempt to prevent the real possibility of his venture going bankrupt.

In such circumstances, under intense financial pressure, his decision to use a cheaper set of shorter timbers, even against art and common design proportions, could not be surprising. According to the assumption – but perhaps it is worth risking a construction disaster that may hopefully not happen, just to avoid the inevitable financial disaster? This is naturally another conjecture, to be checked or at least taken into account.

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Quite outdated and even downright misleading comments, because in the year van Yk's work was published, in France ships were already being designed in a more modern way based on diagonals rather than the recipes described in Dassié's book, and in Sweden English techniques had already been used to build capital ships for a couple of decades.

Hence, it can hardly be said that van Yk was perfectly versed in current European trends in naval architecture. Given van Yk's good memory, perhaps this particular passage is better not translated.
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Hallo Waldemar, hallo Stephan, is there actually a translation of Van Yk's book into modern Dutch or another modern language. Any information would be very helpful for me. Thank you very much.

Stephan
 
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Hi Stephan

Unfortunately, in this case, probably no one has undertaken such a titanic effort as Ab Hoving & Alan Lemmers duo made with such success and with such great benefit for Witsen's work. As a result, we are stuck with our own translation (or friend's). It's entirely possible for anybody interested in the subject, however, for the whole van Yk's work, it would take a dramatic amount of time.

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