Danish man-of-war Hummeren 1624 – entry of the round tuck stern

[-Waldemar-]

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The very rich and valuable Danish archives contain a collection of technical ship designs from the very beginning of the 17th century, the equivalent of which is difficult to find elsewhere for such an early period. Among this group are also several designs attributed to David Balfour, a Scotsman in Danish service, and of particular interest from the point of view of this thread is the drawing denominated E9. This plan has been identified as the design for the warship Hummeren 1624, and several other vessels were built on its basis in a fairly short period of time, which in itself is the best indication of the good seagoing qualities of the vessel designed by Balfour.

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In a way, this plan is also complemented by the extant shipbuilding contracts for this ships' series. The dimensions specified in the specific contract for Hummeren 1624 (others may have had slightly modified dimensions) correspond perfectly with those measured on the plan. Thus:

Keel length: 80 feet
Rake forward: 23 feet
Rake aft: 4 feet
Rising line aft: 8 feet
Depth in hold (between ceiling and the lower edge of the main deck beams; the latter perfectly coincides with the level of max. breadth): 6 feet
Height of the gun deck: 6 feet
Breadth: 26 feet
Breadth of the transom: 15 ½ feet
Breadth at the gunwale: 22 feet

Dimensions were originally given in Danish alen equal to two feet; taken from the translation of the contract in David Balfour and early modern Danish Ship Design by Martin Bellamy, [in:] Mariner's Mirror 2006, vol. 92, no. 1.

The ship's crew is reported to have numbered 137 and the (main) artillery armament included 22 guns, almost certainly 18-pounders, as in other Danish vessels of similar size in this period.

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The plan of the prototype ship Hummeren 1624 is particularly interesting and important even for two reasons. Firstly, due to the very low draught required of the vessel, the designer decided not to use the more elaborate Mediterranean/English method, usually with as many as three sweeps for the underwater part of the hull (beside the hollowing/bottom curves), but instead opted for the much simpler North Continental/Dutch design method, and that too in its simplest form, with only one sweep (beside the surface of the „flat”).

Apart from that, this is perhaps the earliest evidence of a technical-drawing nature for the introduction of the round tuck stern already in this period. Such other early cases are the plans of two vessels from the Hermitage collection in St Petersburg (Russia) and a sketch of a bend from the so-called Newton manuscript, however, these materials, it seems, can only be dated to a slightly later period – the second quarter of the 17th century.


Below is a compilation of the relevant sections of the plans from the Hermitage and from Newton's manuscript. On the side views, first of all should be noted the characteristically tapered stern posts at the top (from the height of tuck) and the inclined lines running more or less parallel to the stern post, representing fashion pieces angled in this way, and on the last two reproductions the peculiar shape of the fashion pieces with an almost rectilinear run and a very small radius of lower breadth sweep, basically geometrically required for round tuck sterns. These are the features by which one can recognise what stern shape the designs below represent.

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And, just for fun, some more renders with reconstructions of the warship Hummeren made from the original 1623 technical plan:

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For interested, particularly relevant to this thematic specificity, both as a general reading and for some of detailed data, are the following works:

Niels M. Probst, Den Danske Flådes Historie 1588–1660. Christian 4.s flåde, Copenhagen 1996,
Ole Degn, Erik Gøbel, Dansk søfarts historie, 2. 1588–1720. Skuder og kompagner, Copenhagen 1997
Henrik Christiansen, Hans Christian Bjerg (ed.), Orlogsflådens skibe gennem 500 år. Den dansk-norske flåde 1510–1814 og den danske flåde 1814–2010, Copenhagen 2010,
Martin Bellamy, David Balfour and early modern Danish Ship Design, [in:] Mariner’s Mirror 2006, vol. 92, no. 1, pp. 5–22,
Martin Bellamy, Christian IV and his Navy. A Political and Administrative History of the Danish Navy 1596–1648, Leiden 2006,
Christian P. P. Lemée, The Renaissance Shipwrecks from Christianshavn. An archaeological and architectural study of large carvel vessels in Danish waters, 1580–1640, Roskilde 2006.

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[-Waldemar-]

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It was only yesterday, while browsing through the resources of the internet, that I came across the Hummeren – Project website, which aim is to build a real-size replica of the Hummeren 1624 ship. It is fair to say that even a cursory glance at the materials contained therein shows that, as far as the shape of the Hummeren hull reproduced for this project is concerned, the results of the work done so far can be considered a spectacular failure, as the specialists involved in this project have probably made all the most elementary blunders (and the objections do not even concern the shape of the stern at all):

– perhaps the gravest, cardinal sin of the experts is the lack of recognition and consequent unawareness of such nuances as the ship design methods or naval architecture of the time,
– instead, in order to obtain at least smooth hull shapes, a computer program (Delftship) was used which, although pretty adequate for the creation of new designs, is totally unsuitable and consequently useless for the reproduction of existing forms or those resulting from strictly defined design algorithms,
– finally, today's popular techniques for smoothing the surfaces being designed were applied, consisting of iterative synchronisation of waterlines, buttock lines and cross sections, which have nothing to do with the realities of the period, and worse, which naturally produced completely fanciful hull shapes for the designed replica (only that they are faired).

Below is a visualisation of one of the design stages of the Hummeren 1624 replica, taken as an example from the Hummeren – Project website, showing the recreation of the hull shapes using the Delftship program, or, in other words, practically on the principle of creating a huge, carpentry „snowman”, albeit sporting at least smooth shapes:

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[donfarr]

GETTING BETTER AND BETTER KEEP IT GOING MAYBE COMPARISON OF DIFFERENT NAVIES SAME PERIOD GOODE AND BAD THAT TO MW WOULD BE INTERESWTING. GOD BLESS STAY SAFE YOU AND NYOURS DON

 

[-Waldemar-]

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GETTING BETTER AND BETTER KEEP IT GOING MAYBE COMPARISON OF DIFFERENT NAVIES SAME PERIOD GOODE AND BAD THAT TO MW WOULD BE INTERESWTING. GOD BLESS STAY SAFE YOU AND NYOURS DON

Don, thanks, but I have no intention of creating a multi-volume work or, alternatively, applying deep generalisations that will instantly become anachronistic with each new discovery. Just as a fairly large batch of modern studies have just become anachronistic. And I have wasted such a large mass of money, and time, on it...

... anyway, for this reason mainly, I prefer case studies.

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[donfarr]

FULLY UNDERSTAND AND NOT A PROBLEM CONTINU THE GREAT WORK YOU ARE DOING. GOD BLESS STAYN SAFE YOU AND YOURS DON

 

[-Waldemar-]

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Yes, Don, it is probably necessary to move things forward somehow and perhaps in some way to bring the symposium community out of a state of capitulation and consequent cluelessness in matters of naval architecture of the period. For indeed, the content of their publications on the subject vividly resembles an episode taken from popular literature – the more Winnie the Pooh looked inside, the more the piglet wasn't there.

It's just a pity that nobody will reimburse me for the opportunity to read all these, er..., official philosophising. And as a result of them, Delftship software, essentially the bubble kneading tool, was put into action, hilarious.

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[-Waldemar-]

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In fact, the round tuck stern in its classical configuration, with the planks terminating on the wing transom at about a 45-degree angle, and widely known for its later widespread use, was nothing new in the north of the continent at the time of Hummeren 1624. A very well-known case of its earlier use in this form is the Swedish capital ship Mars of 1564, as in the illustration below. In general, however, the incontestable information known today is too sparse to reliably assess the birthplace, evolution or directions of the spread of this particular design feature.

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However, it is still worth presenting another case of round tuck stern, using the specific example of the Swedish ship Bodekull 1659, showing that ship carpenters did not hesitate to flexibly interrupt the run of strakes at points too sharp for the bending of a single, whole plank. Alternatively, carved them from one, naturally curved piece. Such a most difficult place in this sense for a round tuck stern occurred at the junction of the side and the ‘plane’ of the stern, just below the end of the wing transom:

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The illustrations reproduced here are taken from the following works, where also more on these specific cases:

Niklas Eriksson, Johan Rönnby, Mars (1564): the initial archaeological investigations of a great 16th-century Swedish warship, [in:] International Journal of Nautical Archaeology 2017, 46.1: p. 92–107,
Niklas Eriksson, A New View of the ‘Edesö Wreck’: identifying the Swedish naval vessel Bodekull, built 1659–1661 and sunk 1678 from written sources, [in:] International Journal of Nautical Archaeology 2018, 47.2, p. 391–404,
Niklas Eriksson, How Large Was Mars? An investigation of the dimensions of a legendary Swedish warship, 1563–1564, [in:] Mariner's Mirror 2019, 105:3, p. 260–274.

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[Maarten]

Hi Waldemar,

You would say that is also the design as seen on SotS. Is it more seen in early 17th century English ship design also?

 

[-Waldemar-]

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You would say that is also the design as seen on SotS

Hi Maarten,

Quite possibly. Despite those pronounced kinks seen in the Sovereign 1637 image, characteristic of square sterns after all, they still offer a legitimate and non-conflicting opportunity for round tuck stern, albeit in a transitional form. This is conditional on the assumption that the camber of the wing transom (in the horizontal plane, that is, in the longitudinal direction) and the shape of the fashion pieces were not yet quite optimised for round tuck sterns in Sovereign, but still had forms inherited from the square sterns in common use up to then. Thus, the lower and middle strakes could be run continuously to the post and to the wing transom, but already the several uppermost (outer) strakes had to be interrupted or carved from natural bent pieces of wood, such as we have seen on the Batavia 1628.

In fact, such a transitional form of stern shape, I had just envisaged for the Hummeren 1624, specifically – geometrically resulting from a rather large radius of the lower breadth sweep and a quite pronounced bend of the futtock sweep.

As for the interrupted strakes close to the ends of the wing transom on ships sporting round tuck sterns, I have seen such on a few period models, rather of a somewhat later date, but I beg you not to make me look for them again now. I'm away from home for a few days anyway, so the bulk of my material is out of my reach.

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[Daniel Caramagno]

The above painting of SotS is controversial. Some art historians believe it may be a later touchup or painter error.

Van de Velde drawings from 1661 suggest a round tuck.

https://www.bridgemanimages.com/en-...sh/graphite-grey-wash/asset/7342298?offline=1

Though rebuilt into the Royal Sovereign by this time, the stern was mostly left intact.

The late Frank Fox, expert on the 17th century English navy, was highly critical of a recent book on the SotS. A main criticism was the square tuck shown in the book. He firmly believed it was round.

Square tuck and round tuck sterns co-existed for a long time. Early 18th century Retourschip models have square tucks.

 

[donfarr]

HI WALDAMER I REGARDS TO YOUR POST ABOUT CONTRBTING I WOULD BE VERY, VERY HAPPY TO. GOD BLESS STAY SAFE YOU AND YOURS DON

 

[-Waldemar-]

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Thanks, Daniel, but somehow, at my current stage, I am already relying more on extant shipwrecks, source plans and other period documents, as well as geometry, rather than on the opinions of art historians on the subject.

I too am very critical of the recent Sovereign 1637 monograph. For a number of reasons, not necessarily related to the shape of the stern. But when it comes to the shape of the stern, I'm not even concerned with the author's particular choice, but more with the fact that the plane of his stern has been absurdly brought right up to the keel, quite like in kits of model ships fashioned by some random garden furniture designers, or similar, hired for the occasion.

Indeed, and the two forms still continue to coexist. It may be hard to believe, but even some of today's boats, pleasure yachts or large seagoing vessels still sport square sterns.

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[-Waldemar-]

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In the context of the form of the stern, an excellent complement to the wreck of the Swedish capital ship Mars 1564, would also be an illustration taken from a manuscript from the last decades of the 16th century, perhaps unknown to some readers, by Rudolf von Deventer, an artilleryman of German origin in Danish service (Bericht vom Pulver und Feuerwerken; Danish archives, NKS 101).

The stern of the Swedish ship depicted in the illustration quite accurately captures the character of the stern of the wrecked Mars 1564, and at the same time represents a form of stern, with the planks terminating on the wing transom in a way that is not unlike the ‘classical’ round tuck stern form, recognised today quite commonly only as a later invention.

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[fred.hocker]

Fascinating stuff, as usual! Very glad to see someone working with the Hummeren drawing in the this way. First saw this drawing over twenty years ago when I was working in Denmark and thought that it would be worth investigating carefully.

Fred

 

[-Waldemar-]

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Fascinating stuff, as usual!

Thanks, Fred. Do you know anything about the Hummeren 1624 reconstruction team starting all over again and doing a re-approach to design an already more historically realistic hull form? Or has this already completed stage consumed too much money and time for such a drastic step? After all, tourists even marvel at the still-floating but decommissioned metal-built, motor-propelled fishing boats boldly converted into 17th century galleons or pirate ships, certainly by formally qualified modern naval engineers.

The stuff below, fascinating in many ways too, isn't it...?

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[fred.hocker]

I do not have much contact with the replica project, and most of what I did have was more related to recreating the armament than the hull.

I have been involved with other replica/recreation projects for medieval and renaissance vessels, and there is always a challange in balancing historical accuracy with modern safety and licensing requirements, expecially if the business model for the project requires carrying passengers, as most do. Some licensing authorities, such as in Sweden, will grant exceptions to normal stability requirments for historic replicas if a good argument can be made and safety can be assured, but others are harder to please. Danish authorities in recent years have been pretty unforgiving about licensing existing historical vessels for passenger trasnport, so I imagine that the Hummeren folks will have a mountain to climb in their design, especially if they are going to carry authentic armament.

Fred

 

[-Waldemar-]

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Safety concerns and current regulations are of course an important consideration, but such a stance can also be perceived as a convenient excuse used by modern designers, because how can calculations be carried out at all for a shape which, after all, has not been reconstructed in the right way, but immediately for fantasy shapes. Even the upperworks of the reconstruction by Hummeren–Project are seriously out of sync with the original plan, moreover in a way that is unfavourable to the hydrostatic properties, which only proves the rather haphazard nature of this reconstruction and at the same time confirms the above assumption.

In conclusion, it could even paradoxically turn out that shapes closer to the realistic ones are more favourable both hydrostatically and hydrodynamically than a rather fanciful shape, obtained in a haphazard way and accepted for further realisation only because it already meets today's regulatory standards.

And besides, what about the scientific and educational value of this project? Just another tourist attraction? This was naturally rhetorical.

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[fred.hocker]

I have been involved in projects where safety considerations were used as an excuse for all manner of departures from accuracy, so I know what Waldemar means. I have also been involved in projects where it was difficult to convince modern craftsmen that their predecessors knew what they were doing - they had a firm belief that old techniques were necessarily inferior. So I have no doubt that there cases where replicas are less seaworthy than their supposed models, due to early abandonment of the prototype's design in favor of more "modern" ideas. There are also cases of unseaworthy replicas resulting from incorrect reconstructions of archaeological remains (read Vibeke Bischoff's recent PhD on the problems with building a replica of the Oseberg viking ship). I have even seen modern naval architects introduce construction and rigging features that were seriously dangerous for little more than aesthetic reasons.

I get asked to be part of replica projects fairly often, from making copies of cannon to whole ships (part of the fun of being "Mr Vasa"). One of the questions I always ask is, why are you doing this and what do you want to accomplish? Most replica projects have primary goals that are based on paying passengers or at least dockside attractions with paying guests as a key component of the business model, and very few are concerned with historical accuracy as a primary consideration. I am aware of very few projects, outside of the research projects conducted by the Viking Ship Museum in Denmark, where the principal goal has been accurate reconstruction and study of an historic vessel - most of the orgnaizations that start these kinds of projects cannot afford it, and their goals do not require it. An inaccurate copy can still be a valuable tool for introducing people to the maritime past even if those of us who know the difference are disappointed.

I am a little perplexed by the Hummeren project, since there is an excellent drawing and other primary evidence as a starting point for the design - many "replica" projects start out with a lot less. Why not start with an evaluation of that original design, to understand and evaluate its potential performance scientifically, before making gross departures from it?

 

[-Waldemar-]

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Fred, I admit that at this point, which is after discovering the Hummeren–Project creation, I have a bit of a problem with the competitive presentation of my reading and subsequent interpretation of this important and otherwise fantastic plan. Do you think it's still a good idea if there's going to be some wooden bubble floating around as a replica of Hummeren 1624 anyway?

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[Roger Pellett]

With the notable exception of the Titanic, the two most dangerous safety risks at sea are capsizing and fire. I’m not sure which has been historically worse.

Static transverse stability is usually separated into two parts; initial stability (aka stability at small angles) and range of stability (aka stability at large angles). To the unitiated, initial stability sounds like a contradiction in terms because how can a ship capsize at a small angle?

In fact poor initial stability can be quite dangerous particularly if connected with a path for downflooding. From what I have read both Mary Rose and Wasa capsized from poor initial stability connected with down flooding via gun ports. In 1913 the steamship Eastland capsized while tied up to a Chicago pier. 800+ passengers and crew lost their lives. Three factors were blamed; poor initial stability, free surface waster in ballast tanks, and a low freeboard gangway port, open while loading passengers.

Initial stability depends on two related factors; the height of the vessels center of gravity above the keel and the vessel’s hull form (how much the vessel’s center of buoyancy shifts with a very slight bit if heel.) Relating the the two is a calculated dimension known as the Metacentric Height. Another contradiction: the center of gravity is often higher than the center of buoyancy and initial stability is not compromised because of hull form.


While shipwrights of long ago might have understood that weights located high up in the ship contributed to poor stability, the idea of the Metacentric Height was not understood until the mid 1700’s, 100+ years after the vessel in question. It is not unreasonable for authorities to require Metacentric Height calculations for replica ships that will be open to the general public, and it should come as no surprise that many ancient hull forms will fail to meet this criteria.

Roger