Oseberg Ship by KrisWood - 1:25 - Vibeke Bischoff Plans

[Louie da fly]

Thanks for that information, Binho. I didn't know about that. I wonder if there were differences in construction depending on when the ship was built, as well?

[Binho]

I don't want to over-stress the possibility regional differences too much, I may have even over interpreted what the authors were saying myself - it could also be different construction techniques based on different ship typologies. The ship carvings in the Fantoft stave church in Norway show a wide variety of different stem shapes. Here is a bit more about the Skjoldungen, including a comparison with the Kraka Fyr line drawing. There are photos of the different stem construction too.

 

I think Kraka Fyr looks stretched in part due to the angle of the photo.  The Skuldelev 5 however, where the stem was still attached to the keel and the port side planking and so the reconstruction is a bit more certain, looks just as stretched:

 

 

I'm almost certain construction and aesthetic styles would have varied over time! I don't think we have enough data to say exactly how though

 

[KrisWood]

Minor update...

 

I had painstakingly redrawn my top two strakes, because the planking diagram only has the starboard side and the two sides need to be proportional, and because I'm going to need to be able to eventually draw the frames to the inside of the planks, but the lines drawing for Saga Oseberg is only the PORT side. It took weeks but I finally ended up with beautifully curving, flattenable surfaces from which I could print a new planking diagram for these strakes...

 

Then, just as I was congratulating myself for a job well done, I realized I'd drawn them along the OUTSIDES of the planks, and because of this they no longer lined up with the lower 10 strakes. To make matters worse, I discovered that I'd inadvertently deleted the lines for the INSIDES of my planks at some point. I just about threw my laptop out the window, except that I was already outside, doing my CAD work on the porch. Weeks of work gone.

 

On the bright side I picked up the habit of making iterative saves periodically when I used to work as a videogame artist, so I likely have the true inner lines in one of them. I'll just have to dig through each save until I find the most recent one that still has them. Back to the grindestone...

[KrisWood]

It's a good thing I didn't throw my laptop in frustration because it turned out I still had the missing lines in my very last save. I now have the insides of the top two strakes fully modeled and ready for printing to templates!

 

 

 

Next up, designing new planking bulkheads and building jig.

[Louie da fly]

Nice save, mate (in more ways than one!)

[Schrader]

I’m here to see the next steps. I can not wait to see the construction process 😀

 

good job!!!

[KrisWood]

Not much to show at the moment. I'm still in the process of designing the new building jig. I'm currently halfway through the new planking bulkheads. It's somewhat on the time consuming side of things, but I'm very happy with the progress so far.

 

This time around, I've drawn the thickness of the bulkheads so I don't end up trying to bend planks around only one edge of the bulkheads like I did last time.

 

 

I hope to finish drawing the bulkheads tonight after work, and then I'll move on to drawing a frame for the jig to hold the keel and bulkheads in place.

 

After that I can get back into the wood!

 

There's a light at the end of the CAD tunnel now!

[AnobiumPunctatum]

Really interesting build log. Thanks for sharing

[KrisWood]

I've run into a problem designing the new jig. This thing is going to need to be removable once I get the planks in place. At that point I'll be replacing the bulkheads with the actual frames.

 

The curve of the stems will prevent removing this in one piece.

 

In my last attempt at a building jig I thought to get around this by building the jig in three parts so that the center could lift up and then the ends could be pulled out separately. This meant that the three parts weren't really attached though and it didn't really stay all that well aligned. I also had a false keel that required a cutout along the bottoms of the bulkheads, which destroyed the notches for the first couple strakes.

 

In these two images I've got my bulkheads, keel, and a cutout for the Hahn method @mtaylor suggested so I can see how it would work if I were to go that route. I'm not sure how I'd keep the temporary bulkheads lined up along the bottom since they're not going to be glued to the keel.

 

 

Any ideas?

[bigpetr]

I would glue spacers between bulkheads and then glue few bulkheads (three or four) to the keel. It should not be hard to cut them off later. Just a thought, I did not try it😀

[Louie da fly]

You could still use the three part system for the jig but bolt it together, so it can be unbolted and removed later. So long as the joins were solid enough that should work ok.

[liteflight]

Hi, Kris

if you mentioned a baseboard I must have blinked.  Your tall bulkheads I assumed would be fixed to a robust base board.  My preference is for substantial square bits of wood 3/4 inch sq to be glued to the bulkheads and screwed to the baseboard

As Louiedafly says you can also screw/ bolt the removable parts to the rest.  
 

this could also take care of the removability issue, as you could unscrew the end bulkheads (leaving them in the ship) and withdraw the rest of the planking jig) - having freed off the glued bulkheads (see later)
 

I can’t help feeling there is a more elegant way of fixing your masterpiece of a keel to the formers than glue.  But at the moment no bright suggestions.  Incidentally are you familiar with balsa cement?  Wonderful stuff and one of its best habits is that it can instantly dissolved with acetone even after many years.  So that might be a type of glue to consider?  Incidentally you can make your own, especially in a house with children  of the two most numerous genders, as it is table tennis balls ( celluloid) Dissolved in acetone (nail varnish remover).  Make sure you replace both after you have half-inched them to make glue.

if you choose to use nail varnish instead you should choose a fitting colour and be wary of the “likes” you might receive 😌

 

 

[AnobiumPunctatum]

I would buil the jig much higher, that you can build the complete keel and stem for putting it on the jig. Perhaps a design as for a paper model with a horizontal board is a good idea.

 

This is a picture of my jig I tried to build the Skuldelev ship III. My biggest mistake, was to use a stepped design for the jig. It's much easier to mark the position of every plank, than you dont't have truble with the small inaccuracies during the build.

[KrisWood]

Thanks for the great ideas, everyone! The screwed down bulkheads are a great idea!

 

I do have a baseboard but taller bulkheads will be tricky. My little table mounted jigsaw's guide rail only goes out to 6 inches so cutting a straight line any further out than that is near impossible. I don't own a table saw so I can't make larger ones.

 

I was thinking I'd just stack 2x4's on my baseboard on either side of the keel up to the height of my bulkheads, but now I'm thinking that might tend to wander a bit. I'll have to think on that.

 

@AnobiumPunctatum By "stepped design" do you mean the steps of the bulkheads where the planks fit in? I'll give some thought to curved bulkheads. They'd definitely be easier to cut out.

 

At this point I'm starting to lean toward just making my permanent frames and gluing them to the keel before planking. I know that's not how the Vikings built their ships, but it might be easier in the long run.

 

[AnobiumPunctatum]

@KrisWood Yes that's exactly what I mean. I've stopped my project, because the bulkheads didn't work for me.

[liteflight]

17 hours ago, KrisWood said:

I do have a baseboard but taller bulkheads will be tricky. My little table mounted jigsaw's guide rail only goes out to 6 inches so cutting a straight line any further out than that is near impossible. I don't own a table saw so I can't make larger ones.

Kris.   Good news!

 

if you can cut 6" wide planks in, say 1/8 ply (or a bit thicker - what would be the next size up? 17.5/64ths?)  you are cooking with gas!

 

Your inclination is to use the frames proper attached to the keel - and you could glue /screw these the jig bulkheads so that they are removable (the jig bulkheads not the frames proper 🙂) 

The bulkheads of the jig need only be 6 inches wide -  if really necessary they could have another shaped bit of 6 inch plank screwed/glued across the top (the dreaded hammerhead bulkhead!) to make more width

Christian's jig is pretty much what I have in mind - I don't think you need hundreds of bulkheads, as the strakes pretty well take up a viking shape on their own!

[KrisWood]

I've completed drawing one test frame! My top two strakes don't quite line up so I'll have to do some troubleshooting on those.

 

 

I will take all of your jig suggestions together and come up with a new jig over the next couple days. I'm getting so close I can smell the future sawdust from here!

[PhilB]

It's fascinating to see this laid out with CAD software. My primary tool is the mark one eyeball... which is another reason the lapstrake hull gives me the willies.

[KrisWood]

12 minutes ago, PhilB said:

It's fascinating to see this laid out with CAD software. My primary tool is the mark one eyeball... which is another reason the lapstrake hull gives me the willies.

 

@PhilB, I've been a software engineer my entire adult life. Solving things using software comes naturally to me. Solving things in wood using my "mark one eyeballs" is what gives me the willies.

 

[liteflight]

5 hours ago, KrisWood said:

've completed drawing one test frame! My top two strakes don't quite line up so I'll have to do some troubleshooting on those.

Really excellent modelling, Kris.

so all you have to do is to feed the model into your 7- axis mill and walla, a room full of sawdust!

[KrisWood]

6 minutes ago, liteflight said:

so all you have to do is to feed the model into your 7- axis mill and walla, a room full of sawdust!

 

Ha! I wish! I’d totally go that route if I had the money for it, or the time to build one.

 

 I’ll have to make do with printing paper templates and cutting everything by hand. 😆

[liteflight]

That works for me, with judicious use of the vernier eyeball.

 

I used to work in NC machine tools, and I have seen a big mill carving, basically, the bottom half of an aircraft wing from a massive billet.  Chips were thrown off at near- ballistic speeds and most of the billet finished on the floor as hot, sharp aluminium snow. (Hot only briefly, I hasten to add)

[KrisWood]

I figured out the problem with my top two strakes. I'd apparently dragged them out of position at some point without realizing it. Here's the corrected version with the frame in place. The knees fit much better now.

 

[mtaylor]

4 hours ago, KrisWood said:

 

@PhilB, I've been a software engineer my entire adult life. Solving things using software comes naturally to me. Solving things in wood using my "mark one eyeballs" is what gives me the willies.

 

 

I found the more you do the wood thing, the more comfortable you will be.  I did my share of software and very early on, I had the same worries.

[AnobiumPunctatum]

This looks so beautyful, Kris.

Please check the position of the frame. If it is the position of the middel frame near by the mast, it has a slightly different design. Before drawing the frames I would add the clamps on the planks to bind the frames. Than I woud add the  mastspoor. The frames are not sitting perpendicular to the keel. I could not see, if you remember this small detail.

I don't know if you answered the question: which software do you use for the drawings?

[KrisWood]

4 hours ago, mtaylor said:

I found the more you do the wood thing, the more comfortable you will be.  I did my share of software and very early on, I had the same worries.

 

@mtaylor, I know I'll be fine once I get used to it. At this point it's starting to feel like I'm just putting off cutting new wooden parts, the more I get into the smaller and smaller details in the CAD.

 

 

23 minutes ago, AnobiumPunctatum said:

Please check the position of the frame. If it is the position of the middel frame near by the mast, it has a slightly different design. Before drawing the frames I would add the clamps on the planks to bind the frames. Than I woud add the  mastspoor. The frames are not sitting perpendicular to the keel. I could not see, if you remember this small detail.

 

@AnobiumPunctatum, A couple pages ago in this thread we discussed the pros and cons of doing the frames perpendicular to the centerline. I opted to do them perpendicular both vertically and longitudinally to make designing easier. I'm certain the diagonal frames in the original served some purpose, but this is a model and just needs to float for a little while. I'll try for complete historical accuracy on another model.

 

The frame I've modeled in the images above is 1A in the the Saga Oseberg plans. It's the only one I could find plans for, which I took a screenshot of from one of the video lectures by Vibeke Bischoff on the Viking Ship Museum website.

 

 

It's one frame aft of frame 0, and the mastfish covers both of them. The vertical deck beam support is only there to test out how it looks with one in place. I'll be removing it when I add the mastfish.

 

I haven't drawn the plank clamps yet. I'll be adding those soon. At the moment I'm still trying to find some rhyme or reason as to how tall and how wide they are. It seems to vary, even on this one frame.

 

23 minutes ago, AnobiumPunctatum said:

which software do you use for the drawings?

 

I'm using Rhinoceros.

[KrisWood]

I just read the chapter on how the planks were made in the Saga Oseberg book. Mr Finderup pretty thoroughly lays the debate to rest on the positioning and dimensions of the frames and the plank clamps.

 

1. There is no systematic pattern to where the plank clamps are located, except that they line up perfectly with the frames. Some are riveted on.

 

2. The frames are neither perpendicular to the keel nor the centerline. Mr Finderup theorizes this is because it is very difficult to find trees that are exactly symmetrical with branches at exactly the correct angles.

 

3. The Vikings must have known at least approximately where the frames would cross each plank, otherwise they would not line up with the clamps.

 

4. Given the above, the builders of Saga Oseberg tried out a few different ways of making the planks. Only two worked. One was to cut a series of somewhat wider clamps along the length of the plank, and then the location of the frame was determined after the plank was attached to the hull, the extra clamps were trimmed off. The other was to identify the exact location of the intersection of the frame with the plank before cutting any clamps, then cut a slightly larger clamp than is needed and fine tune it when placing the frame.

 

 This tells me a few things about how to proceed with my model.

 

1. Sourcing trees with the correct curves to their branches is not an issue, so I can place my frames however I want as long as the curves of the hull remain the same and I don’t mind sacrificing authenticity for simplicity.

 

2. Unlike the Vikings, this means I have complete control over the placement of my frames, and therefore I can calculate the locations of the clamps ahead of time.

 

3. The book goes into great detail about how to actually make the clamps and their dimensions in general (they vary with no rhyme nor reason but can be averaged).

 

 

from here on out I think I’m going to go down the artistic license rabbit hole to make a good looking seaworthy model inspired by the Oseberg ship rather than agonizing over getting every detail historically accurate.

 

 This should be fun. 😁

 

 

 

 

[Louie da fly]

Sounds good. Apart from anything else, you'll be the only one who knows (apart from all of us, of course) that you've deviated from an exact copy of the original.

 

In my view, they probably didn't get too fussed with exact placement (unless there really is some reason for the frames to be off-square) - all they wanted was something to keep the sides from being squoze inwards by the pressure of the seawater. I doubt that a Viking would get upset with you for doing it this way. On the other hand . . .

 

                          

 

 

[Schrader]

Kris

 

this is just unique. Wonderful!!!  The quality of your research and the time you have invested in the drawings are just magnificent. 
 

i wish if you don’t mind we can use your material to construct our Viking

 

I’m here to see next steps

[KrisWood]

New keel complete and ready for cutting into layers!

 

I finally managed to get a perfect transition from T to rabbets:

 

 

The trick was to toss out the cross sections from the Saga Oseberg book entirely and cut them from the keel using the inner face of the garboard strake to define the shape. It's still nearly identical to the version in the book, but much easier to model.

 

Here's the completed keel altogether:

 

 

 

There are no rabbets cut on the stems because they had none on them in building Saga Oseberg until each strake was attached. They connected the stems without rabbets, and then cut the rabbets while fitting each plank to the stem and stern.

 

Next step: New smooth bulkheads per @AnobiumPunctatum's advice. I'm also going to do half as many bulkheads this time around, and only for the lower strakes. Once the lower strakes are in place I can add the frames and the rest of the hull should take shape on its own.