Hello Dear Friends. Today was the first day where I just walked away from the build. I have struck the proverbial brick wall with my planking - nothing that I try, works - and I can assure you, I have tried very hard. So, time for a break.
Much has been said about the planking of Dutch ships and the one overriding fact that we always seem to return to, is the lack of format, logic or pattern. I have thus compiled a through report on exactly how the Willem Barentsz was planked, how we came to know it and how it compared to other ships of that era. The information all comes from my Bible,
Het Schip van Willem Barents by @Ab Hoving Ab Hoving. Additional information was kindly supplied to me by Ab as well. The report may be a bit technical and long for some, but if you truly want to know about the planking of Dutch ships of the Sixteenth Century and why I deem the WB to be such a fascinating build, this is it! I call it:
DISCOVERY, DOUBLE-LAYER PLANKING, DOUBLING, THE FRONT-RUNNER OF HULL COPPERING AND TEREDO NAVALIS
In 1979, Russian amateur archeologist, Dmitry Kravchenko, found the wooden construction as part of a ship’s hull while searching for artifacts in and around Het Behouden Huys. He produced a drawing of his find, but because of the extremely difficult circumstances under which he had to work, it could best be described as “rudimentary”. Kravchenko left behind everything that he had found, untouched and in their exact original location and positions. Seemingly, the “discovery” then went into a thirteen-year long hiatus in which no further mention of it was made. In 1992, a Russian expedition led by Peter V. Boyarsky of the Russian Research Institute for Cultural and Natural Heritage arrived in Nova Zembla.
Interestingly, Boyarsky’s research did not focus specifically on finding artifacts connected to the WB expedition – it was a comprehensive mission (which included archeologists, ecologists, geologists and representatives of various other disciplines) – aimed at achieving a global picture of Nova Zembla which they viewed as a National Park of sorts. Be that as it may, they “re-discovered” Kravchenko’s find and deemed it significant enough to take back with them to Moscow.
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The discovered hull portion of Willem Barentsz's ship.
Six months later, a Dutch delegation comprising of Henk van Veen (Chairman of the Willem Barentsz National Committee), Pieter Floore (an archeologist on behalf of the Institute for Pre-and Proto History of the University of Amsterdam) and Ab Hoving (on behalf of the Rijksmuseum) traveled to Moscow in an attempt to determine whether this “wooden construction” was indeed part of the ship of Barentsz.
In Ab’s words:
Viewing this 4m x 1m section of the WB’s construction and its significance in world maritime history is hard to describe. Of all expedition ships which ever sailed the oceans, not a single piece has ever been found (obviously the book was published well before the discovery of the Endurance) –
not of Columbus’s Santa Maria, nor of Cook’s Endeavour, let alone the ships of Vasco da Gama and Magellan.
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A drawing of the discovered hull portion by the Boyarsky Group.
So, what can we learn from the hull portion of the WB that was found? The single most significant aspect is that the planking consisted of a double layer. It is important that we distinguish here between what the Dutch called a
“Dubbeling” (Doubling) and a
“Dubbele Huidlaag” (Double Layer of Planking).
"Dubbeling (Doubling)
“Dubbeling” (Doubling) was an extra layer of wood (normally consisting of fir- or firewood) of approximately 1 cm in thickness which was nailed on the outside of the hull below the waterline to prevent the hull from being infested or affected by “paalworm/shipworm” (Teredo Navalis). The flat and square-headed nails of which four were nailed into a square-inch of planking would rust to one another to form an impenetrable layer of corrosion around the ship. It was very seldom that the paalworm managed to penetrate this layer of corrosion*. In case the worms did manage to penetrate the corrosive layer, they would encounter a further layer of cows’ hair and tar which was smeared between the two layers of planking. Should the worms manage to penetrate that layer as well, they could well cause the total destruction of the ship. The “dubbeling” was replaced after each long or major trip.
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A piece of shipworm-infested timber.
*This was in fact the first iteration of what became common practice in the 18th Century – the coppering of hulls.
It is interesting to note that a particularly dangerous variant of the paalworm lived in the hot areas such as the tropics and therefore it is no wonder that “dubbeling” was found on almost all of the shipwrecks that have been discovered in these areas. However, ships sailing to and around the Scandinavian countries did not need “doubling” as the very cold and harsh water of the Oostzee was completely devoid of shipworm.
DOUBLE-LAYERED PLANKING
A Double layer of planking, however, was according to Ab, an altogether different story and is a concept which is not yet fully understood. This was something that was found almost exclusively on Dutch ships around the year 1600.
It is important to note that the discovered hull portion of the Willem Barentsz is not the only proof of the double layer at the time. In “bestekken” (specification lists) of the time it is expressly mentioned. The wreck of the
Scheurrak SO1 (previously mentioned in my log on quite a number of occasions) had a 4-inch layer of outer planking attached to the 4-inch layer of inner planking and the hull frames by means of wooden trennels. The wreck of the
Mauritius which has been lying off the coast of Gabon since 1609, not only featured double planking as well, but also had a layer of lead between the two planking layers. The outer planking layer, however, was not secured to the hull frames, but only to the first planking layer by iron nails; not trennels. In addition to all of this, the
Mauritius also featured “dubbeling” (doubling of the hull below the waterline as safeguard against the paalworm.
View attachment 322189
This is a drawing of the layout of the double-layered planking found on the wreck of the
Mauritius - a Dutch ship which stranded off the coast of Gabon in 1609.
On the Willem Barentsz, both layers of planking were only 4cm (1.5-inches) in thickness and were secured to each other by nails – just like on the
Mauritius. Which begs the following question: What was the purpose of the double layer of planking?
To be honest, there is no consensus or clear-cut answer.
- There are those who believe that it was done to reduce the chances of leakage – a fact which was borne out after examination of the Batavia wreck. There planks showed what seemed to have been an overlap of seams by the two different layers of planking.
- Others point to the era in which these ships were built – a time of transition from clinker- to carvel planking. With the latter, only the planks’ edges served as the contact area between planks – other than that, there was no additional contact surface between individual planks. Hull strength was achieved by two possible means: (a) A double layer of planking; or (b) thicker hull frames. Even though both options were initially tried, the eventual choice fell on the thicker hull frames
- A third group believes it has to do with the type of ship that was built. As trade became increasingly important, ships grew exponentially in size. Clinker planking, for instance, limited the length of the ships that could be built whereas carvel planking allowed ships of greater length to be built. However, as the ships grew longer, it placed severe stress on the lengthwise strength of planks. A logical solution would have been to adopt a double layer of planking to increase strength.
Did any of the above three rationales play in a role in the double planking of the WB? Ab Hoving reckons there are two more possibilities to consider:
- Sometimes, double planking could provide a ship with greater stability by making the hull somewhat wider – in English this is called a girdled ship. In such a case though, the girdle was never wider than one meter and was applied at waterline-height. This was not the case with the WB.
- Another reason could be the fact that the ship was destined for a polar expedition so a double hull would provide additional strength and provide protection against pack ice. This is specifically mentioned in the specification list of the Zeeland ship, De Zwane, as she was prepared for the 1595 trip.
In conclusion, Ab makes the following observations:
The thickness of the first layer of planking was much too thin for a ship’s length of 67.5 feet while the double layer was way too thick for a ship of the same length. If the double layer was intended as a means of strengthening the hull, why was it only nailed to the first layer and not secured to the frames as well? And why were nails used when trennels were stronger? In fact, the discovery of the hull portion seems to raise more questions rather than answer any.
TEREDO NAVALIS / SHIPWORM
There’s something interesting about Shipworms. They are not a worm but a saltwater clam. Shipworms get their name from their long, narrow, cylindrical bodies but the worm resemblance ends there. A closer look at the creature reveals a shell at its front. This shell has 2 halves with a gap in between like a clam shell. In the gap pokes a muscular foot that acts like a suction cup, holding the shell in place while its razor-sharp edges scrape the wood ahead of it. At the top, 2 flesh-toned siphons swish water over massive gills. At the bottom, a slimy, eyeless head resembles a mix of wet lips & diseased intestines. In between, a glistening gunpowder-blue body stretches up to 4 feet long.
View attachment 322192
View attachment 322193
Instead of eating, bacteria in the creature’s gills helps it suck energy from sulfur. The whole thing is sheathed in a curving tusk-like tube created from the Shipworm’s excretion of calcium carbonate. Shipworms eat sawdust and its stomach has a pouch for storing sawdust and a special gland for digesting wood particles. These “termites of the sea” also have an organ full of bacteria that digest wood. The bacteria take nitrogen from the water and convert it to protein for the worm, since wood doesn’t supply protein. The bacteria in return, get nutrients from their host. A Shipworm begins life like most marine invertebrates, as a tiny piece of meat in the plankton soup of the sea.
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If the spiling line shows, it's not good enough, so more sanding tonight. 
