building from line drawings

[Captain Mikey]

Hello all. I am new to this, but not to modeling. I have a question about building a model from line drawings (profile with sheer line, cross sections of the hull at stations, etc).

1) On the cross sections showing all the stations, is each station line inclusive of the thickness of the planking, or only the timbers?

2) Is the outermost line the midframe, and the same on both the right (bow stations) side and left (stern) stations? On my set of drawings the midframe outline looks like a double line, and when I count stations on the profile there are 6 fore and 6 aft of the midframe; would this mean the drawing is showing the midframe dimension without and with the planking?

3) Is there a convention on this?

Thanks for any help. Email (mikeslade1435@gmail.com) works well for me.

 

[JerryTodd]

Stations are normally to the inside of the planking. It often says that on the drawing somewhere, or it'll mention them being moulded or molded which means the same thing because it's intended to be used to make molds or patterns for making the frames. Builder's half models too, are made to the molded lines. Decorative half-models are anyone's guess.

Even when taking lines off an existing vessel, it's often done from inside to the inside of the planking. Sometimes though, especially with smaller craft, it's measured to the outside surface of the planking for whatever reason, like developing a blocking plan for dry-docking.

If your drawing doesn't say, one way or another, you have to look for clues. Look at the keel and see if the rabbet for the garboard plank is drawn; at the stem or stern post of the plan view (top-down) and see if the rabbet for the planking is drawn there. The pics below are drawn to the inside of the planking.


Your Gerda lines look like they are to the inside of the planking, but the profile view is not

 

[AndyA]

Cap'n Mikey:
I looked at the plans you attached and it took some head-scratching but here's the deal. The draftsman made a mistake. There is a mold line on the body plan (front/rear view) that is not shown on the sheer plan (side view) or on the half breadth plan (bottom view). The mold line in question is the second from the bow on the body plan. So, the mid frame is shown as the 8th mold on both the bow view and the stern view. Note that the two vertical dotted lines on the sheer plan are shown as mold lines on the body plan.
Fair winds!

 

[Frank48]

Good morning, I have some doubts about the measurements, can someone help me to figure out what system it was done with? Thank you . Frank

 

[AndyA]

Frank:
Best that I can figure out by trying to translate and looking at plan:

• length overall 39'-9"
• length between perpendiculars 35'-0" (vertical dotted lines on sheer plan and half breadths)
• beam at waterline 14'-0" (inside or outside planking?)
• depth below waterline 5'-10"

I have asked a Norwegian friend to help. Haven't heard back. The units to the left remain mysterious.
Have fun!

 

[Captain Mikey]

Frank:
Best that I can figure out by trying to translate and looking at plan:

• length overall 39'-9"
• length between perpendiculars 35'-0" (vertical dotted lines on sheer plan and half breadths)
• beam at waterline 14'-0" (inside or outside planking?)
• depth below waterline 5'-10"

I have asked a Norwegian friend to help. Haven't heard back. The units to the left remain mysterious.
Have fun!

 

[John Hendrix]

the units to the left seem to be mt (meters)..

 

[AndyA]

the units to the left seem to be mt (meters)..

Ahha, I figured it out. What threw me off to start was that I mistook the first "one" for a "seven" as to "LENGDE." Then the other numbers on the left, if they were meters, didn't quite convert to the feet and inches on the right. Once I saw that lengde was 12.46 meters instead of 72.46, I noticed the the meters were 3% smaller than they should have been if converted from feet. It turns out there is an older Norwegian measurement, the fod. One fod is equal to 1.03 Imperial feet. And there are 12 tommer in a fod. So the measurements in the table are in meters on the left and in fodder and tommer on the right.

I conclude that Norwegians have bigger feet than Englishmen.

 

[John Hendrix]

also.. the text seems to be Danish, not Norwegian "Farvandvaesenet" is Danish, in Norway it would be "vannmyndigheten".
And the drawing is signed off in Faaborg, which is a town in Denmark.
I am Dutch, lived in Norway before, and now in Sweden.. the Nordic languages are deceptively similar..;-)

 

[John Hendrix]

..and under 'middelspant' it says 'SKALA 1" = 1 FOD DANSK'

 

[Captain Mikey]

also.. the text seems to be Danish, not Norwegian "Farvandvaesenet" is Danish, in Norway it would be "vannmyndigheten".
And the drawing is signed off in Faaborg, which is a town in Denmark.
I am Dutch, lived in Norway before, and now in Sweden.. the Nordic languages are deceptively similar..;-)

My understanding is that Gerda III was a Danish built boat.

 

[AndyA]

It took a while, but the pieces of this puzzle are coming together. I have seen the Gerda III at Mystic Seaport Museum and didn't make the connection! Here's part of her story, according to the Museum:

"Built in 1926 as a lighthouse tender, the Gerda III appears to be a common Danish workboat. But in October of 1943, she played a much more important role. The boat was used by Henny Sinding, the 22-year old daughter of a Danish Navy Officer who commanded the country’s Lighthouse and Buoy Service, and a four-man crew to rescue Jews from Nazi-occupied Denmark."



So, who's going to make a model? Gerda III seems an excellent subject.

 

[Captain Mikey]

My understanding is that Gerda III was a Danish built boat.

It took a while, but the pieces of this puzzle are coming together. I have seen the Gerda III at Mystic Seaport Museum and didn't make the connection! Here's part of her story, according to the Museum:

"Built in 1926 as a lighthouse tender, the Gerda III appears to be a common Danish workboat. But in October of 1943, she played a much more important role. The boat was used by Henny Sinding, the 22-year old daughter of a Danish Navy Officer who commanded the country’s Lighthouse and Buoy Service, and a four-man crew to rescue Jews from Nazi-occupied Denmark."

View attachment 424183

So, who's going to make a model? Gerda III seems an excellent subject.

Yes. I am building it -or trying to. It seems the boat view stations going forward are narrower than the waterline width obtained from the overhead view waterline. I may have to loft my own, which is rather tedious. I know of another builder ising yhe same drawings who also had some difficulty with some frames being too narrow at the stern, which I have not even cut yet.

 

[AndyA]

It seems the boat view stations going forward are narrower than the waterline width obtained from the overhead view waterline.

I printed a copy of the lines, got out my trusty divider, and checked some of the lines on the body plan against the half-breadths. I'll admit that I was working with a small plan (8-1/2 X 11) but I didn't find any discrepancies. Where are you running into problems? Remember that the second bow mold shown on the body plan is not shown on the half-breadth view, per post #3. Have fun!

 

[Captain Mikey]

I cut five stations from the body plan. I made a building jig from the lwl on the half breadth plan. The foreward stations are very much narrower at the lwl than on the half breadth view. When comparing the half breadth plan to the view of the boat, yhe shape seems correct. Will try tto loft frames from the half breadth and profile(buttocks lines) plans and see what I get.

 

[AndyA]

I cut five stations from the body plan. I made a building jig from the lwl on the half breadth plan. The foreward stations are very much narrower at the lwl than on the half breadth view. When comparing the half breadth plan to the view of the boat, yhe shape seems correct. Will try tto loft frames from the half breadth and profile(buttocks lines) plans and see what I get.

Did you add mold #2 to the half breadths? See marked up plan below.