Samuel 1650 – a Dutch mid-17th century trader

[Waldemar]

 

This thread will show the result of a conceptual interpretation and a partial reconstruction attempt of an important, very well-preserved wreck of a mid-17th century Dutch cargo ship, excavated in the Ijsselmeer basin in the north of the Netherlands. The ship has been identified as the Samuel, serving the trade with the Iberian peninsula, among others.

 

A very extensive archaeological record of the shipwreck can be found at:

https://beeldbank.cultureelerfgoed.nl/rce-mediabank/?mode=gallery&view=horizontal&q=e81&page=1&record=bb0c9df7-b54d-2770-7cff-2d946e245039&sort=order_s_objectnummer%20asc

 

 

Shipwreck E81 (Samuel 1650), photo by Jan Rypma

 

 

Ship’s main dimensions (as recorded, read or interpreted):

 

Breadth: 26 feet

Length of keel: 78 feet (3 x breadth)

Length between posts: 91 feet (3.5 x breadth)

Depth in hold: 10 feet

 

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Keel assembly, lengthwise division & main design lines

 

Ratio of sternpost rake to stempost rake: 1:6 (note: stempost rake measured from the point where the rabbet line crosses the upper edge of the keel and enters the stempost)

Height of sternpost: ~2 x height of tuck (note: height of tuck at the waterline level)

Height of stempost: height of sternpost + 1 foot

Longitudinal position of master frame: 1/3 of keel length (see diagram for the determination method)

 

Note: the radius of the stempost in the diagram relates to the arc of the upper rabbet line.

 

 

 

 

According to the archaeological record, the following relationships and design sequence of Samuel 1650 have been found or guessed:

 

– the waterline level was set at eight feet, corresponding to the height of tuck (or vice versa), horizontally (as in the diagram) or, alternatively, angled to the lesser height of 7 feet at the bow,

– the length of the waterline (not including the posts) has been divided into seven parts (with a possible subdivision of 14),

– the line of the floor was set, terminating aft at the height of tuck and, at the fore, one foot below the horizontal waterline level (or at the intersection of the design waterline with the stempost for angled waterline); at the master frame deadrise has been fixed at three inches,

– the height of the greatest breadth at the master frame is 1/10 of the total length of the hull (i.e. between posts), about one foot above the design waterline,

– the wales are perfectly parallel to the line of greatest breadth (scheerstrook, scheergang).

 

Of note is the extensive use of logarithmic curves to define the shapes of the main design lines. These are one of the easiest types of curves (or maybe better: transformation) to use in practice, especially as they are ideally suited to achieving the contours of the frames straight away on the mould loft with a trivial simplicity, and without any real need to make any scale drawings on paper in advance. Essentially, no knowledge of theory is required, just familiarity with straightforward division operations is enough.

 

So much for the essentials of this rather simple design (in conceptual terms).

 

 

 

 

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Cross-sections

 

Dimensions of master frame components (as recorded, read or interpreted):

 

Width of the „flat”: ~17 1/3 (2/3 x max. breadth)

Deadrise (at the master frame): 3 inches

Design depth: ~9 feet (1/10 x length)

Futtock sweep: variable radius (equal to respective breadth) or fixed radius (equal to max. breadth); note: both variants result in almost indiscernible shapes for this shipwreck,

Bilge sweep: 4 1/3 (fixed radius; 1/6 x max. breadth)

Reconciling sweep: 17 1/3 (fixed radius; 2/3 x max. breadth)

 

It can also be added that the transverse contours of the „flat” for all leading frames are straight lines, except for the last leading frame it is in the form of an circular arc (note: on the diagram below one more frame was drawn between the last leading frame and the sternpost). Employment of the arc is for the smooth transition of the hull surfaces toward the sternpost, providing better waterflow for at least acceptable rudder efficiency.

 

 

 

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Possible appearance

 

The graphic below shows a hypothetical appearance of the Samuel 1650 once its upperworks have been recreated. The Samuel 1650 is actually almost the smallest ship for which the two-deck configuration was used. The distance between decks was taken from Grebber's table, reproduced in both Witsen's 1671 and van Yk's 1697 works. This feature, taken together with the relatively small size of the ship, make Samuel's silhouette quite tall, and despite the smallest distance adopted between these decks (about 4½ feet).

 

The very full shape of the underwater part of the hull, suitable for a cargo ship, is also evident. Taken together with the high freeboard, this must have made the ship very leeward, which ultimately surely contributed to her disaster, but also preserved her to our times.

 

The position of the masts, or rather the foremast and mainmast, was taken from the shipwreck documentation, but it must be said that it is altogether quite typical: the mainmast at the middle of the keel and the foremast above the gripe, i.e. above the junction of the keel with the stem post.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Also below are some graphics showing ships of a similar nature. While not all from the Samuel's particular period, especially the last two, they still can be relevant for various details, but also to get a better feel for this vessel’s general specifics (Dutch archives).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Reconstruction hull lines

 

As the below drawings are reconstruction plans, there is no need to take them too literally. For example, a 'perforated' railing may be added in the aft part to make the sheer of the ship more attractive, or the upper edge of the stern 'mirror' may be made as an arc. Some more wales with a smaller cross section above the three main ones drawn on the plan should actually be attached as well, and the sternpost possibly shortened a little, roughly to the height of the wing transom, for free entry of the tiller into the hull, etc.

 

The correct arrangement of the garboard strakes in Dutch convention is well shown below in the documentation of the Samuel 1650 shipwreck. Actually, in the central part of the hull, the garboard strakes are not in contact with the frame timbers at all. On the plans the garboard strakes are not drawn because these plans show the contours of the frames and not the planking. On the sheer view, however, both rabbet lines are plotted, just for this purpose.

 

The hull lines has been checked for fairness (as opposed to actually forming the shapes) with diagonals and waterlines.

 

 

 

 

 

 

 

 

Thank you for your attention,

Waldemar Gurgul