building the world’s most iconic viking ship, part 3

So in our next installment in Viking boatbuilding we take the planks that were previously cleft, rough hewn and planed and trial fit them to the boat. Each and every board is different and is an exact replica of a particular board on the original ship. This is the office with the masterplan and to the left you can see scaled versions of each plank.

These are then turned into full scale plans which are taken out to the rough planks, drawn around and the profile cut out. This is Jan finishing  a plank before trial fitting for the first time. Most planks have raised sections which will be used later for lashing the ribs to.

Next we take these simple but very effective clamps

and trial fit the board in place.

Working along the plank I bend it to shape whilst Jan applies the powerful clamps, once the base of the board is clamped tightly we can twist the outside edge to check it will take the correct shape. It is not so much a bend as a twist in each board that gives the boat it’s shape. You can see here the clamp with the rope is pulling the bow end inwards and the stern end is pulled outwards and downwards giving about 15 degrees of twist on this board, it will get a little more later.

 We have two datum lines to check the shape against, a row of pins set into the keel and a taught wire stretched above the ship. Using these two as measuring points it is possible to triangulate out to set each board in precisely the right place, we worked to a tolerance of ±5mm. Once each board was in it’s final place the props underneath were fixed holding it’s position.

Once we were happy with the trial fitting and had done any final rough shaping the board went into the steamer for 1 hour 20 minutes. When it comes out you have about a minute during which it moves very easily and then a couple of minutes for fine adjustment so everything has to be planned and to hand and everything happens quickly.

By the time the plank Jan and I had been working on was ready in the steamer it was already dark, it starts going dark at 3.30pm we did have big floodlights to work under sorry about dodgy pic quality.

Here the plank is in place and Jan is just tweaking the final line, you can clearly see the twist with the two ends of the plank being maybe 20 degrees out of line. We took the top and bottom corners 10mm further than they will end up expecting them to relax slightly when the pressure is taken off.

Now the board stays in place overnight after which time it’s shape is set, it can be removed and very precise fitting work done, planing the joint to that it fits without the slightest gap. Once that is done it’s time to rivet it in place, and that riveting, the whole essence of clinker boat building, is the next post.

You may also like to read:

10 Responses to building the world’s most iconic viking ship, part 3

  1. Kevin de Silva November 16, 2011 at 12:45 pm #

    Nice job Robin.Out of interest what wood are the clamps made from ?

  2. Robin Wood November 16, 2011 at 12:46 pm #

    clamps are oak offcuts Kevin as is pretty well everything on site.

  3. Rhugl November 16, 2011 at 5:02 pm #

    Fascinating-you are fortunate to witness and be part of this. It is curious how much we still don't know about the craftmanship of long ago. This underlines the importance of preserving knowledge.I notice that a steamer is used in the construction-surely the Vikings never had such a vessel? What means would they have used?

  4. Robin Wood November 16, 2011 at 5:53 pm #

    steaming wood is a very simple process used by many stone age cultures, you don't need a big metal firebox it can be done by heating rocks in a fire as the Haida people do with their canoes see a lovely slide show here http://greenwood-carving.blogspot.com/2009/12/two-nice-craft-slideshows.html

  5. Rhugl November 17, 2011 at 10:36 am #

    Thanks for your reply and the interesting link to the Haida slideshow. Maybe I did'nt explain myself fully,what I wished to query was not the process of steaming in itself,but what process the Vikings themselves would have used? It seemed a shame that all the work was carried out with period hand tools but the steaming was carried out using what looks like a fairly modern method.I have previously come across someone using boiling water applied directly to the wood,using force backed up with clamps to bend lapstrake on a boat,and wondered if the Vikings could have employed a similar method rather then the use of steam. The Romans were aware of the power of boiling water which they utilised for mining,again more knowledge lost than remembered!The tools that are being used are fascinating,I'm especially intrigued by the clamps and the spokeshave. Your comment about the similarity between the axes used on this project and modern Japanese axes also begs the question when did the Japanese begin using Swedish steel for some of their best quality tools? Again,just curious as I,m a big fan of Swedish tools.

  6. Robin Wood November 29, 2011 at 12:10 am #

    Rhugi,I didn't know Japanese were using Swedish steel they certainly make some of the best steel in the world themselves. In the 17th C then Swedish iron was imported into the UK in large quantities and turned into blister steel here in large bottle kilns there is just one left surviving.We don't know how the Vikings heated their wood whether steam or hot water. We do know that it is necessary to get the wood heated thoroughly through in order for it to bend then hold the bend once cool. This could easily have been done with hot rocks and hot water or steam as per the Haida method. I am not sure how much there would be to gain or learn from creating steam with hot rocks against working with a boiler. There is much to learn and a very different end result from using hand tools and cleft wood rather than sawing. I guess they have to focus their funds, the timber was no doubt brought to site with a lorry rather than dragged or floated.

  7. Rhugl November 29, 2011 at 9:03 am #

    Robin,The reason I asked about the Viking method of bending was to establish-1. whether they used some method unknown[unlikely] and whether anyone actually knew what method they used2. whether the bending method they used altered the structure of the wood in a manner more conductive to Viking shipbuilding[given that the first reconstructed ship sank due to unknown reasons] than steaming didI do not doubt that they had to target their funds,but to compare a method employed in the constructionof the ship[bending] and the method of transporting the logs to the site is not a valid comparison in my opinion.As to Swedish steel it is currently on offer through the 'tools from Japan' website.It is available for instance in the Tsunesabara Hira-Kanna handplane where there is the option of ordering a Shizuki bladelaminated from Kamaji wrought iron and Swedish Sandvik plain carbon steel. The question was raised regarding Japanese use of Swedish steel due to my regard for the Scandinavian quality of steel and the fact that the Vikings were Master mariners,and it is not inconceivable to me that they could have reached Japan a long time ago.I did not realize that Swedish steel was used in Sheffield,but again should not be surprised given it's superior qualities. When did this come to an end[if it did] and did this coincide with some of the inferior products that Sheffield is now mostly known for?

  8. Robin Wood November 29, 2011 at 9:26 am #

    Hi Rhugi,I am not sure there is any way to answer question 1. There are no written records I know of and steaming leaves no archaeological evidence. There are piles of burnt rocks from the Bronze age in the Humber estuary which have been identified as cooking rocks but are possibly from steaming dug out canoes Haida style. I don't know of Viking equivalent but I am not a maritime archaeologist.The fist ship was a very different shape, constructed based on the 1910 archaeologists reconstruction of the original in the museum the current team think the parts were put together slightly incorrectly and hence the replica built an unseaworthy shape. Only time will tell if they are right. Swedish steel was not imported to Sheffield, Swedish iron was and turned into blister steel here. It was at the time some of the best steel in the world. Blister steel was a long and expensive process. It stopped when Huntsman invented the crucible process in the 1740's which was the first "cast steel" the best, most consistent in the world and built Sheffield's world renowned reputation for high quality at reasonable price. It is sad if Sheffield is now known for inferior products, they still make some excellent work here though many of the old names have been bought by companies marketing cheap Chinese tools, I hope discerning folk know the difference.

  9. Brennen Johnson April 23, 2012 at 2:35 pm #

    are the blue print of the ship public?

  10. Robin Wood April 23, 2012 at 2:56 pm #

    I don't know you would have to ask. Visit the website for new oseberg ship foundation.

Leave a Reply

Powered by Wordpress and Woocommerce and tweaked by Tom Broughton 2013