David Pryor discusses what we are learning about the shape of tholes for the Ship.
We know from the excavations at Sutton Hoo that our Ship was fitted with tholes for oar propulsion – Joe Startin’s (Director) paper “Tholes in the Sutton Hoo Ship” (in the research section of this site) discusses the archaeological evidence.
The midship model section that we are building in the Longshed is designed to accommodate four rowing positions on each side. Jacq Barnard (Project Manager) explains the purpose in this video.
Working from drawings that Pat Tanner provided as part of the work that was done to produce digital plans for the Ship, members of the Ships Crew constructed four tholes to be mounted on the port side model. They have also made experimental oars.
The tholes were constructed from softwood, generating a bearing surface on the thole face of 2 inches with the base of the thole piece measuring 3 inches so as to fit onto the 3-inch thick gunwale strake. That produced a thole with a radius of 3 inches.
However, when Jacq, a very experienced rower, tried using one of the experimental oars on the model she found that it was impossible to get a good purchase on the thole. The radius of curvature needs to be significantly smaller than 3 inches.
So we are now planning to construct tholes with a much shallower curvature – more like the ones shown on the banner in the Longshed (photo of one section below) which is a reproduction of the image in volume 1 of Bruce Mitford’s “The Sutton Hoo Ship” (published in 1975).
This one aspect of the Ship reconstruction perfectly exemplifies what experimental archaeology is all about. Needless to say, there is a lot more to find out about how the hull, the tholes and the oars interact. At least it is reasonably easy to change things on the model!
The Sutton Hoo ship is generally regarded as having a ‘plank’ keel. The British Museum suggestion for the cross-section in the middle of the keel published in 1975, is in the image above.
It’s broader than it’s deep, and the same goes for the projection of the keel below the bottom of the ship.
A clinker ship has rows of planking on each side, called ‘strakes’. These can be numbered, starting at the bottom. A plank keel is essentially ‘strake zero’, and its contribution to the strength of the hull arises from being part of an integral shell.
Later Viking ships tended towards a ‘beam’ keel, not so wide, but deeper. This provided additional longitudinal stiffness, and countered hogging and sagging along the length of the ship. The projection below the bottom of the hull was also deeper, which helped the ship to resist the wind pushing sideways across the water when sailing. The Vikings still valued a shallow draught, but the beam keel was a key step in the way their ships evolved.
The Oseberg ship, early Viking, was built around AD 800. Here is a section, from Vibeke Bischoff:
I don’t know anyone who really believes the Sutton Hoo ship had a beam keel. But the lack of evidence from underneath the ship makes it difficult to rule this out completely.
One niggling piece of context is the keel of the Kvalsund 1 ship. It has the characteristics of a ‘thin beam’. Generally dated around AD 690, this is less than one hundred years after the AD 600 date usually suggested for Sutton Hoo.
Remains and models can be seen in the Historical Museum in Bergen. The piece of wood bottom left is part of the keel:
However, a recent paper by Nordeide, Bonde and Thun re-examines the tree-ring analysis of the wood from the Kvalsund ships. It moves their dates about one hundred years forward, to around AD 790. This is now early Viking and scarcely different from the time of the Oseberg ship.
Should this affect my view of the likelihood of a beam keel for Sutton Hoo? Psychologically, I am swayed. It does seem to reduce it further. But am I being epistemologically naïve? What really counts when using data to try and extend knowledge? Why should the weakening of one tentative parallel piece of information really make any logical difference?
A way out of this sort of situation is sometimes ‘ask Damian’. Dr Damian Goodburn, little expecting to be quoted, replied:
“…The first beam form keels seen in NW European waters were used in Roman Mediterranean style sailing vessels. These ventured into the North Sea which also bordered SW Scandinavia. Some Scandinavians also seem to have served as mercenaries in the Roman empire or at least their near neighbours just to the south did. And of course we have the Varangian guard etc. in the eastern Roman empire….. So unless the practical sea folk kept their eyes closed they would have seen beam form keels…. So not adopting them must have been related to practical needs, such as hauling out etc but rowing requirements must have been a dominant factor, I would guess. Only one of the late Saxon period keel timbers found reused in London, had a beam-like form, so presumably by then they were not considered a central feature of regional clinker boat building.
Really we need more vessel finds from the 6th to 8th centuries in NW Europe…”
The film “The Dig” understandably focuses on the team Charles Phillips put together to handle the burial chamber and its contents. It omits the team he organised to survey the ship.
Phillips first met Mrs Pretty, at Sutton Hoo, on 6 June 1939. He made phone calls on her behalf to the British Museum and to the government (the Office of Works) that day. The government formally asked him to take over the excavation project at the end of June.
The survey team was led by Lieut-Commander J K D Hutchison, aged 38, married with no children, the Keeper of the Department of Ship Models at the Science Museum and a retired naval officer. His second, also from the museum, was A S Crosley, aged 45 or 46, with at least three daughters up to the age of 10. Crosley was an active member of the Newcomen Society and presented a paper about the ship to them in 1943. The other member of the team was young Frank Gillman.
Hutchison first visited the excavation site at Sutton Hoo on 12 July 1939, the day before serious work began on the burial chamber. After an inspection, he explained to Mrs Pretty what a survey of the ship would require, and she agreed to his proposals. On the afternoon of Tuesday 8 August the team of three arrived and “…..orders were given in Woodbridge for the construction of the necessary wooden apparatus for the survey”. This was one week after the work on the burial chamber had finished.
Mercie Lack and Barbara Wagstaff also arrived on 8 August. They were on holiday in the area. Schoolmistresses and companions, were very capable photographers with good equipment. They made an invaluable record and were among the last excavators to leave, on 25 August.
In his Newcomen Society paper, Crosley describes how the survey team measured the positions of certain rivets near each rib, relative to a datum line with plumb bobs hanging from it. This was a laborious three-man operation. Where that approach was not practicable, at the bow and stern, measurements and sketches were made from a bosun’s chair suspended above the excavation. Southampton University used this data as the basis of research to derive the plan that SHSC are using to reconstruct the Ship.
Hutchison and Phillips seem to have got on well. Hutchison took charge of most of the work at the site, while Phillips “was able to consider the problems of the ship at leisure and discuss them with Commander Hutchison”.
They pursued a number of investigations together – into the keel, for example, and how it connected to the stem and sternpost.
Hutchison’s signature can be seen on the legend for a tracing of the 1939 ‘provisional drawing’ done by Crosley – which can be seen in Ipswich Museum.
Hutchison died ‘of illness’ in July 1944. He was Acting Commander of HMS President, which I believe was a training establishment on the lower Thames. All his papers were burnt by his widow.
It was said that Crosley and Gillman did not like him. Perhaps he was a hidebound officer who rather stood on ceremony. At the end of his paper, Crosley says: “I thank the Director of the Science Museum for having allowed me to undertake this interesting survey and for permission to publish the results. In making the survey I would like to put on record the valuable help given by my colleagues, Messrs. Gillman and [John] Jacob, who showed untiring energy under difficult conditions.” There is a notable omission…
It is important for SHSC to have a scientific record of the components of the ship, as part of our experimental archaeology programme. As things progress, we need to be able to look back at the materials we used and what we did. Photogrammetry is the science of creating a three dimensional model from a series of standard two dimensional photographs. It is clearly the right thing for us to do.
What I have learned so far is that photogrammetry can be tricky!
I was already involved in The Ship’s Company as a volunteer, and as someone with an interest in photography starting off the photogrammetry project played to my strengths. In an initial meeting a group of interested volunteers discussed the use of photogrammetry to create 3D models of the ship, its parts and the tools we would use in constructing it. Subsequently we were kindly given access (by Felix Pedrotti of Southampton University) to some online tutorials about using software and how to upload and convert the images into a 3D model. I also did some research online and contacted Julian Whitewright for advice (there is a profile of Julian in the February 2021 newsletter).
Most people would choose to start with something relatively small that could be photographed under ideal conditions – like the clamp shown at the top of this post. However, we decided that the first photogrammetry project for the SHSC records should be the log that will form the keel of the ship. The keel log is 13 metres long and currently stored in a poorly lit barn. Our project was no small task!
In January, fellow volunteer David Keeble and I made our first attempt to record the keel log and a second log that will be used for the stem and stern. We had to decide on the section to be covered in each picture, and on how many to take down the length of the whole log. There would need to be a large enough overlap in each picture so that the software creating the 3D image can work out how each picture sits in relation to the next – and from that build a 3D model. Clever software!
We marked out locations about a metre apart with white tape down the length of each log , and about the same distance from the sides. We decided that three photographs would be needed at each location: close to the floor, about 75cm above the floor and looking down onto the log as close to vertically as possible.
The image below shows the plan that I sent Julian for advice on the angles we needed to cover.
On Julian’s advice we set more locations for pictures to be taken from each end of the log that would help the software interpret the images. So we marked 36 locations around each log and took three pictures from each one, starting off at the lower level and then going round the entire log again at the second and third heights.
The right levels of light are important so it was challenging at times – low light levels meant long exposures and in places we had to use extra lighting but too bright a light also causes problems. We ended up with 216 carefully taken photographs!
We sent all the images of to Julian to upload using the Agisoft computer programme at Southampton University. But after all the our efforts the software couldn’t create a 3D model. We needed even more pictures, especially at the ends and from the top.
So, we are going back to try again with more lights. I will fix the lens on the camera so that the zoom doesn’t change and we will need to work out the maximum possible distance that we can get from the trunk where space is limited. Hopefully second time lucky!
The photo below and video link show how well the technique can work.
This is the fourth in Joe’s series of speculative posts – click here for links to parts 1, 2 and 3
Edwin Gifford built a half-length replica of the Sutton Hoo ship in 1993 – Sæ Wylfing (moored outside the Longshed in the photo above). He was fed up with people saying that the shape of the hull meant that it could not sail in much the same way as the classic Viking ships.
He was not seeking authenticity in materials, building techniques, and so on, but he did take care over the shape of the hull. The weight of Sæ Wylfing is 675 kg. Crudely, you would then expect the full-size ship to weigh 2 x 2 x 2 = 8 times this, or nearly five and a half tonnes. The hull and the ribs of the reconstructed ship are indeed expected to come close to this, but the thwarts, other internal supports, and a deck will add further weight. Actually we are expecting it to weigh in at about 9 tonnes.
And of course he rigged a mast, and a yard and a sail to go up it.
Gifford gave the central thwart a thicker support in the middle, and some reinforcement where the front of the mast pushed against it. In the image below, down between the oars you can see a lengthways member, with a recess in it. This is called a keelson, and the hole is a mast step, where the bottom of the mast fits. The main force the mast exerts on the hull is downwards, and the job of the keelson is to distribute this.
Gifford recounts some of the adventures he had in Sae Wylfing between 1993 and 1995. All the pictures show him at the helm, and I suspect this was always the case. He made some small additions to the keel in the winter of 1993/4. In 1994, when he was double-reefed in a wind gusting to 22 knots, he found he could make no progress to windward. He “decided to lower mast, first time afloat, and row.” This must have been terrifying. The dedication and composure of his crew was admirable.
His best result sailing to windward was at the Maldon Festival in 1995.
“…we covered three nautical miles direct to windward in 3.5 hours, despite many short tacks and loss of ground in crowded anchorages.”
This is just under one knot for ‘course made good’. For a land lubber that’s about one mile an hour. And the effort of enforced tacks would have been a huge task for the crew.
The full-size reconstructed ship will be eight times as big as Sae Wylfing….Rowing (and paddling) it will be our priority. The first trials will be on the Deben; then the time will come to cross the bar and go out to sea.
When the trials in a seaway are complete, and the ship is much better understood, we can explore how the hull performs with a big sail and the wind from the side.
Did the Sutton Hoo ship ever sport a hefty mast and a big sail? It would help if we knew what the ship was used for.
An expert view is that it could have been a sort of royal barge, a means for the king to project his power and majesty throughout much of his domain.
One’s subjects should be clear about who is protecting them, and who they must pay their taxes to.
As king, it is a good idea to put oneself about and let oneself be seen. But travel overland with a large entourage would have been excruciating. Much of the populace would have lived in settlements up the estuaries, creeks and rivers which permeated East Anglia.
Using a large ship of shallow draft would be a practical alternative. Your bodyguard could show their devotion by rowing you wherever you needed to go.
The coastline would have been quite different then. Land reclamation had not begun. There would have been much more inland water about (particularly when the tide came in.)
Coastline in the area of Sutton Hoo. Modern coastline in feint, bold coastline follows 10 ft. contour. Crosses show sites of medieval churches. Based on an idea by George Arnott. (Drawing: Martin Carver)
A sail would be of limited use when you were winding up and down the rivers. Your oars can shift you in any direction whenever it suits you.
Moving from one river entrance to another would require a passage along the coast. The extra sea-room might allow and encourage the effective use of a big sail. Unfortunately, a large mast does no good for your rowing. The experience of a comparable Viking ship reconstruction was that you would lose a knot because of the windage on it. It would be soul-destroying for your oarsmen if you kept the mast up all the time, but rarely used it. But taking it down while on the water, or putting it up again, would be very risky.
The two photos below show boats with masts being rowed – not difficult in very calm water with no wind against you. It is also easier if like the Faroese boat on the right, the craft is designed to be dual purpose and your crew has experience of both sailing and rowing.
If you do have a following wind, and you do not have a big sail, all is not lost. The rowers can take a respite simply by holding out their oars. Better still, the skipper could deploy some sort of temporary rig, with a small sail – something quick to raise, and easy to stow away again. This would not be proper sailing of course, but for the oarsmen it would be a blessed relief.
None of this is to say the ship could not sail properly. It is just a way of wondering whether it was worth the bother.
Google “maul” and you will get a variety of definitions, like being clawed by a lion or clashing on the rugby field. The Merriam-Webster dictionary is the first one I looked at that defined a maul in the sense we are using it – a heavy often wooden headed hammer – which is what we asked Damian Goodburn, a very experienced user of a special version of this tool, to tell us about. All of us in SHSC have admired Damian’s own very special maul.
First of all, he added to the definition “Single piece mauls or mells are still used by some green woodworkers and hedge layers. They are generally stronger than those with separate handles and heads and this allows the handle shaft to be of thinner dimensions, which absorbs shock better than the modern separate timber handle.”
Well, how on earth can you get a hammer made from a single piece of wood? Of course, Damian has the answer
“Any tough species of timber can be used where a branch stem junction is the right shape, but if the large striking head is made of a knotty section of the main tree stem then it will last all the better.” And he knows, from experience “In my holly example the knots act as bolts holding the timber together, so it resists splitting for a long period of use. Holly is also a very hard wood and many of the branches join the main stem at about 90 degrees, just right for the job. My example is well over 20 years old and has been used for driving wooden wedges to cleave logs and driving fence stakes etc regularly during all that time. It still has some life left in it yet!”
And he ain’t just pussyfooting – “The largest log split using the maul was c. 1.2m diameter, of oak and used for making the pair of bottom planks for the research and display hull section replica of the Dover Middle Bronze Age boat.”
That seems particularly apposite because, he goes on to say – “The oldest single piece maul we have in British archaeology is an early Bronze Age example of Yew from the Somerset levels.”
Damian has recently been in action with his 20 year old maul “Most recently it was used to cleave a moderately large ash log at the Weald and Downland Museum in W Sussex during two weekends of demonstrating aspects of Saxon woodworking or ‘treewrighting’ in early September”
I hope we aren’t still going to need to be using the SHSC holly mauls in 20 years time – at least not on the current project!
Did the Sutton Hoo Ship buried in Mound 1 use a sail? The conventional wisdom is reflected on the British Museum website. “….it is just not possible to tell if the ship had a mast and was sailed in the open sea, or if it just had oars for rowing along the coast and rivers.”
But the romance of sail is strong. Edwin Gifford built a half-length replica, Sae Wylfing, to test some of his theories about sailing. There is a famous (infamous?) picture of her creaming down the Deben taken by Cliff Hoppitt in 1994
Who would want to imagine things otherwise? It seems unthinkable that the Anglo-Saxons would have been such spoilsports as to forego a mast.
The ‘sailing’ I am thinking of uses a sizeable mast and a big sail. And it is more than allowing the wind to puff you along from behind. To be a regular, practical option, you must be able to sail when the wind comes from the side too – you must be able to ‘reach’.There is nothing convincing in the written record to say whether the early Anglo-Saxons were sailing or not, let alone what our particular ship was doing. Scandinavians have plenty of evidence to show that they made brilliant use of sail from about 800CE onwards. How and when they got to that state is the subject of endless debate. There is some indication of earlier prowess in pictures carved on standing stones on the Baltic island of Gotland.
A simple sail, using sheets (ropes) at the corners, starts to appear around 500 or 600, depending on who you believe. The sea-faring kingdom of Dál Riata, covering the NE tip of Ireland, the Inner Hebrides, and the adjacent Scottish coast, was flourishing around 600CE. Their naval ships were ‘seven benchers’, with two men to each oar. But they are also said to have had a mast and a single sail as well with 28 rowers. Alas, Dál Riatans would not have had the slightest contact with East Anglia until Irish missionaries started arriving in the 630s.
There is a strong motivation for merchants to use sail. If they can turn up somewhere with rare and attractive goods, they might make a killing. They cannot afford to pay and feed lots of rowers, but they are prepared to hang around waiting for a fair wind. A shortish, tough, beamy old tub would do for a ship, so long as it could get there.
In the middle of the 6th century, the overland trade route from Byzantium to Scandinavia was interrupted. Goods went instead via the mouth of the Rhine, and along the coast, through the Wadden Sea, to Jutland and onwards. The trade grew, becoming dominated by the Frisians. Emporia (trading settlements) sprouted on the continental side, and had counterparts on the English side too, not least in Ipswich – “England’s oldest continuously inhabited town” – from about 600CE.
I think sailing would have been around in Raedwald’s time, if only for trade. And anyway, it would be odd if it had been completely forgotten since the Romans left for good in 410CE.
Building this great ship starts with construction of the keel. What did we need to look for when identifying suitable trees?
The key point is that finding a straight, and nearly flawless, oak for the thin plank keel is a huge challenge in England today as we have no wildwood. Damian Goodburn advised that “Even in early Anglo-Saxon times after intensive Roman use of the woodlands for 350 years this would have been a big challenge. It might have been easier later once the wildwood spread out further, until the 13th century in southern England.”
A deeper section of keel that could accommodate some knots would make the challenge a little easier, but this is not an option. That’s because we are constructing a ship that does not just exist in the Shipwright’s head. Our aim is to build a ship that is as near as possible to the original ship that was buried at Sutton Hoo, and we are working to a plan that’s based on what was found in the burial mound. The evidence from the burial mound is that the original ship had the shallowest keel imaginable, as you can see from this cross section of a (rather smart) model that Damian made for the original exhibition at Sutton Hoo.
The keel is the T shaped section in the middle of this photo. It is a slight thing, but it beautifully reflects the evolution of shipbuilding, from rafts, through hollowed-out logs, to hollowed out logs with planks attached at the sides to deepen the vessel, to a plank as the keel… The keel may be slight but it is a lot more sophisticated and allows the ship to grounded without damage. What extra strength it has over a plank isn’t clear – our ship probably flexed a good deal. The strength to keep its shape also came from the thwarts – 26 cross pieces that it was probably possible to sit on whilst rowing.
Our keel hunters have found a beautiful, straight grained and knot free tree. Although finding something in southern England long enough didn’t seem likely at one stage. Even so, whilst the keel needs to be straight, the stem and stern just aren’t. Luckily we also found a tree with a curved trunk that looks like it will fit the bill. Damian has provided a practical solution as to what to do to make the best of our lovely straight log and the curved one as well.
“I suggest that the practice attested in later Viking longships and later medieval clinker vessels be uses, that is a keel with two linking pieces – ‘lots’ or ‘underlouts’, and stems above each underlout. That is the main keel of about 10-11 metres with enough for scarfs each end be scarfed to more ‘v’ shaped and curved underlouts at each end about 6 metres long which are then also scarfed to the main upper stem timbers above them around 6.5 metres long. This approach could be adapted to the actual timber obtained and adjusted as required – though symmetry was likely. The scarf locations would also be bridged by garboards and other bottom planking.”
For those who aren’t boatbuilders or maritime archaeologists, this means: at the end of the straight bit of keel under the ship, the gentle curve upwards is produced by joining the keel first to one (underlout) then another, curved piece. The overlapping joints at the end of the keel and between the two curved bits are the scarfs – as you can see the scarf joint at point F in the photo below.
And the garboards are the first planks that make up the bottom, then the sides of the vessel. You can see them in the first photograph (of Damian’s model).
Damian again: “All the parent timbers found have to be cut out well over length ie 12-14 metres for the keel and about 7 metres, with appropriate curves, including scarfs for the underlout and stem logs. As the late Saxon Graveney boat has a stern post made from half a log and this – two stems from one curved log approach – was widely used in practice in later medieval vessels, I would suggest that each selected log be divided in two, length-ways, by sawing and then hewn into shape with Saxon style axes.”
There is an element of revolution in that advice. Damian is suggesting that we use saws for some of the processes and finish the work with traditional hand tools. The heresy is to saw the logs but he makes the suggestion with good reason:
“The Anglo-Saxons did not have saws of any size. But I personally think that splitting the log for the keel is unrealistic and could be enormously time consuming as defects in the chosen log’s grain might make each log half unusable and in large timbers the defects could be hidden inside the parent logs until too late. Roskilde (our colleagues at the Viking Ship Museum in Denmark) have already shown that this is a perennial problem for keels and stems in early clinker vessels that are made without any sawing length-ways.”
So the point is, that you could do a huge amount of work and up with a keel shaped piece of wood that is totally unfit for purpose and in essence wasted. A whole oak gone for nothing. We cannot risk that. Following Damian’s advice we will record the sawing for display and publication as a technical compromise. Shaping the best keel slab with Anglo-Saxon tools will still be a great spectacle and a huge challenge.
So, how do we think that using a non-traditional method as part of the construction affects the project? Is it still and authentic reception of the Sutton Hoo King’s Ship? Our overwhelming answer is – yes, it will still be authentic. Using sawn timber to construct the keel will not affect the weight, the strength or the appearance of the ship, and very importantly, will not impact on the validity of sea trials. It will reduce time and expense, as well as probably saving us from wasting trees. There are other obvious compromises that we have already accepted: did the Anglo-Saxons build indoors on a concrete floor? Did the fell their trees with chain saws? Were their labourers volunteers, and did they have protective equipment?
We can’t conceive of all the problems that the Anglo-Saxons overcame in building their King’s Ship. Adopting the practical compromises that we are choosing to make just leaves us all the more in awe of what they achieved.
We often get asked why we are using green oak to build the Ship and why we are (where practicable) using ancient techniques. Here, Dr Damian Goodburn who knows much, much more about medieval oak than most people, provides us with many reasons why we should do so. The photo above shows Damian using a side axe.
“Simply put, green logs and roughed out timbers are very, very much easier to work with human muscles than partially, or totally seasoned timbers – especially using simple hand tools, such as axes. This is probably principally why it was used in such a green state. And there is much evidence for the use of green timber in the early medieval period for ship building (including from Sutton Hoo and large scale woodwork elsewhere) – and no evidence against it.
Experiment and experience shows that if the surfaces of the timber are worked green an axe-finished surface is smooth with little or no tearing of the grain, with widely spaced axe marks. Well-preserved surfaces on early medieval boat timbers and other heavy woodwork show a smoothness that would fit with this. The impression that the Sutton Hoo Ship left in the ground was entirely smooth. Where second-hand seasoned timbers are re-used and refinished, because of the comparative hardness of dry oak the tool marks are much rougher and closer together.
Historical sources from the end of the early medieval period, and images such as the Bayeux tapestry, and other embroidery, show that timber was worked on in the woods where it was felled. This implies rapid, green roughing out at the very least.
Later medieval ship and boatyard excavations also show roughed out timbers arrived in the yards in freshly felled condition with some work having been done at the felling sites. The lack of drying shakes (cracks running through the timber) or any marked decay supports this – though in a few cases there was also some re-use of second-hand timber taken from earlier vessels.
Systematic tree ring dating studies of early medieval woodwork and boat timbers (all a little later than the ship burial at Sutton Hoo) show very little evidence of stock piling timbers for seasoning. Where we do have historical dates for medieval buildings and vessels made largely or entirely of oak, for the vast majority of timbers evidence from tree-rings shows that felling was usually only shortly before the recorded date of construction.
A quick turnaround – using green rather than seasoned oak – has benefits from an economic perspective, and to avoid timber degradation from drying shakes, rot or insect decay. Degradation is less problematic when timbers are worked into smaller sections.
In reality the terms seasoned versus green are rather misleading extremes, even today. We might accept oak as ‘seasoned’ when moisture content is down to about 20% or less, whereas green oak has much more moisture-sap in it. In the early medieval period totally seasoned timber (other than second hand material) is likely to have been a rarity and for use in small high status items.
Wet storage inhibits decay and slows down any hardening before finishing. Some strands of archaeological evidence suggest that early medieval boat and ship builders in NW Europe were well aware of the issue of controlling seasoning. There is evidence of wet-stored rough out timbers such as the Eigg stem. Very acid bog water or salt water would probably be best.
Splitting before use may reduce drying distortion. Radial cleaving, ie splitting the trunk across the diameter then again across the radius of each piece, produces the greatest natural strength in planks. A tangential split, ie splitting off a piece not directly across the diameter is less strong. We believe that the Anglo-Saxons did not have saws of any size (unlike the Romans or later the Vikings) so splitting using one of these methods would have been used to produce planks. The cleft plank would be finished (hewn) nicely with side axes.
A close look at the Bayeux embroidery shipbuilding scenes shows that the roughed out cleft boards were put up in the tree crotches to dry after splitting. This suggests partial rapid drying of those thin hull boards. This can only achieved without massive distortion and splitting using radially cleft boards (not tangentially cleft and hewn or sawn planks). Oak that has been converted into boards the ancient way using radial cleaving shrinks much less (about 50%) because of the way the timber is structured. Splitting and distortion is also limited.
Partial drying, when the wood is still relatively green, also has the advantage of making bending easier. Think of bending a fresh stick of celery compared with a slightly wilted one – the latter is much easier, but the celery is still green. With the easy lines and gentle bends of the Sutton Hoo Ship this is only of academic interest – it probably wouldn’t have been an issue.”