Medieval longship by bolin - FINISHED - 1:30 - based on reconstruction Helga Holm

[Cathead]

I just stumbled across this fascinating build and so will jump in late. Great start with such an interesting and unique vessel.

[bolin]

Thanks Eric, you are welcome to tag along.

 

Now I have reach the state when the shell of the hull is almost complete.

There is one partial strake to add in the fore and aft. In the mid section the rowers will sit, so the sides cannot be as high. Initially I thought that I should add those planks after I had put the frames in. But now I realize that they will be easier to get in place with the correct angle while I can still use the mold. But in order to do that I need to modify the mold slightly. So I lifted the hull from the mold and took the opportunity to scrape some glue away.

 

 

 

 

 

[Louie da fly]

That's a major milestone, taking her off the mould (British and Australian spelling - Americans spell it mold).

 

She looks very good - very graceful hull shape.

Edited December 19, 2020 by Louie da fly

[bolin]

Thanks Louie, it feels like a big step.

 

I have now added the last planks in the fore and aft, and have started to construct a new build slip.

I still have need for the old mold a while longer while I drill the holes for the rivets. It's tedious work, but nothing compared to what it will be to actually install the rivets...

 

 

[bolin]

Visually there isn't much difference between this update and the last one, only a lot of small holes for the rivets. I will now cut out and fit in the frames, so I have started to measure out their positions. I could have proceeded with the rivets, but I think it will be easier to get the frames to fit if I do that while the inside is smooth.

[Wintergreen]

Yes, planning ahead is never a waste of time 😉

We have that saying in my team at work, that we are doing work for future-me, because future-me will be thankful to present-me when future comes and that task is already prepared 🙂

Btw, I've always admired the viking long boats.

[bolin]

The planning and need to figure out how to do things is one of the reasons why I will probably continue with scratch building rather than kits. Full freedom and full responsibility means that the feeling of accomplishment is higher.

 

Btw, this model is not a viking ship. It’s at least 250 years to late. The most telling evidence is the stern rudder, rather than a steering oar. The hull shape clearly follows in the same tradition though. Form follows function; what was already perfected didn’t need to change.

[Wintergreen]

No, not a viking ship, long boat. Got it. 😉

The interesting thing is that the long boat heritage can be seen in traditional crafts/small boats into 20th century. Look at small boats from lake Vättern, "vättersnipa". See one example on this page (halfway down):
https://blogg.ovedanielsson.se/category/category11/page/2/

Text in Swedish and no comment about age of that particular boat. My guess is that it's from early 20th century.

 

[bolin]

Yes the viking boat heritage is quite evident in many small / traditional crafts in Sweden and Norway. Maybe most evident in the "Nordlandsbåt" type from northern Norway, that not only maintained the clinker built hull but also the single mast square rig until mid/end 19th century.

 

When the Helga Holm reconstruction was rigged it was from the still living tradition of how Nordlands boats are sailed (and rowed) that a lot of the terminology and experience was borrowed.

 

[bolin]

Regarding the building I have started sawing out the frames.

 

To find the shape I use five cards and arrange them to find the angles.

 

Most of the frames only go up to the fifth strake. Then there will be a beam across and a knee that supports the sixth strake. The seventh strake is for most of its length not supported by any knee or frame, instead there are two stringers on the inside as reinforcement.

The first and last frames are more V-shaped and will not have a crossbeam. 

 

The fifth and fifteenth frame has two cross beams and has an additional knee which supports the seventh and eight strakes. The eight frame also has two crossbeams and sits just in front of the mast where there only are seven strakes.

 

 

Thus far I have eight (of seventeen) frames roughly sawed out. They are still to long and to thick, and will require adjustment to fit right.

 

 

[Wintergreen]

Looks good.

Question, will the frames overlap at the center line or will they meet butt end? With the cross beam the strength and stability will not be an issue of course.

[bolin]

Ah, I should have elaborated on this yesterday. In reality the frames should be full and made out of timber with a natural curve. I considered bending the frame timber before cutting them out, but went for the simpler option. Most of the frames will meet butt end. The joint will be covered by the keelson.

 

The keelson only goes between the third and fifteen frames, so for the rest I will need to make full frames in some way.

Edited December 29, 2020 by bolin

[Brinkman]

That's a really neat way to get the correct frame shape! Looking very good!

[bolin]

Thanks, I learned it on a ship model building course I attended for a few weeks in February and March (before it got canceled). I have also seen it used in some other build logs here. Unfortunately it is hard to use in smaller scales, like my Sloop from Roslagen.

[bolin]

Now I have all the frames cut out and fitted to shape. What remains is to thin them down to about 2 mm thickness. I do that last now when I know that the shape is good in all other dimensions.

 

In the end I cut the two first and two last frames from solid pieces. I determined the shape using the same method as for the other frames, that is using card and copying the angles of the planks to the frames. It worked OK, but since I could only fit the cards to one side at a time, I got the shape of two frame halves. The angle between the halves was a bit hard to get right. For one of the frames I ended up splitting it and gluing it back with the correct angel.

 

[Louie da fly]

That looks good, Bolin. It looks like it should work. There's always a bit of "try it and see" with this kind of activity.

 

Steven

[Schrader]

On 12/28/2020 at 4:53 PM, Wintergreen said:

Looks good.

Question, will the frames overlap at the center line or will they meet butt end? With the cross beam the strength and stability will not be an issue of course.

What a good idea!!!  I would never had that idea

[bolin]

As I mentioned in response to @Wintergreen, in the real ship (both original and reconstruction) the frames are full. I think that it is important for the strength of the hull, especially when handling  the forces of the mast and shrouds when taking the wind from the side.

 

The shrouds are attached through holes in the upper strake. When the wind comes in hard from the side the shrouds will pull the side up, while the mast will push down on the keel. This will create a force that will try to break the hull along the keel. The frames are not really connected to the cross beams, so they will not help as much as one would think with preventing this. The full frames should help here though. If the frames where already cut in the middle, they’re would not be as strong.

[Louie da fly]

Interesting. The frames in mediaeval (and earlier) Mediterranean ships in general followed a

 

 . . pattern of alternating floor timbers and paired half-frames . . . Floor timbers span the bottom of the ship, with their extremities extending just to the turn of the bilge [on each side of the ship]; in contrast, half-frames span the width of the keel and extend up one side of the ship, through the turn of the bilge to, or just beyond, the first wale . . . At each frame station, floor timbers and half-frames are paired with futtocks placed adjacent to, but not fastened to, the floor timber or half-frame, with ends overlapping by the width of one or more planks.

 

 

This combined ease of manufacture and construction with the requisite strength.

 

Steven

 

  

[Mike Y]

Great subject! 

I had the opportunity to help a bit to prepare it for the winter (just a few times, it's on the opposite side of town for me..)

It was a nice way to spend a weekend, the smell of tar and the joy of helping  Great for kids as well!

[bolin]

I actually read that yesterday on your Polotsk log😃

 

I don’t remember that we have met, but how knows maybe I have forgot. Next summer there might be some last chances to sail on her, before she will be donated to Sigtuna museum. It is no longer possible to maintain her as a sailing vessel, unless substantial (expensive) renovations are performed.

[bolin]

With all the frames fitted and trimmed down to size I have started with preparing the rivets. It's boring. 

 

Take a bristle. Hold it close to a flame (but not in it or it will burn) until it melts to a bead in the end. Then press the bead to a flat surface to get a flat head on the rivet. Repeat some 1500 times...

 

[Wintergreen]

Yeah, sounds tedious. It looks very good though!

I guess the clenched side will be a bit of a challenge, washer and all 😉 

[bolin]

You are right Håkan, this is the easy part. Making and clenching the roves will be even more tedious.

[bolin]

All the rivets are now ready for installation!

 

In between the sessions with preparing them I have started on some other parts, to be installed later. That is rudder, tiller, mast and yard. The mast has a "bulge" around the hole for the halyard will be a stop for the shrouds.

 

Yesterday I also received a package with some dark stains that might look like tar.

 

I have experimented with some mixes and found that three parts light oak stain mixed with one part ebony stain and eight parts water starts to look OK. That is the lowest right piece in the picture below. The other pieces are to black to look realistic. Tar, when mixed with linseed oil, is not ink black, but rather very dark brown.

 

 

 

 

 

[bolin]

And now the hull has been "tarred".

 

I think the stain turned out OK Compare for example with the pictures that @Mike Y shared earlier in this thread. The slightly uneven coloration looks quite realistic. I do plan to put a coat of dark shellac on top, so it will be become even darker.

 

In the end my mix was 3 parts light oak, 1 part mahogany, 1 part ebony stains and 5 parts water.

The riveting has also started.

 

[Wintergreen]

Yes, the colour is correct but what about the smell of tar? Have you managed that as well?

 

Looks excellent!

[Louie da fly]

Beautiful colour and those rivets are very believable.

 

Steven

[Schrader]

Agree about the rivets. They look so

real

[Mike Y]

Very realistic! Can you make it smell too?  

Might worth to scratch it a tiny bit with steel wool or some brite pad (aka the scratchy side of a dishwashing foam pad) to lighten the edges a bit. Though it definitely needs some experimentation first