Taking lines for a model

chortle

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Herreshoff Coquina, 1972 Jarvis Newman 36, PT11
I decided last Fall to have a model made of my boat so that I would have something to remember her by in my dotage. One of the challenges for the model maker has been to replicate the hull shape below the waterline to my satisfaction. I have been pleased with his ability to capture the proportions on the rest of the model by using a lot of photos but the shape of the bottom has been difficult to for him to replicate.

My Jarvis Newman 36 was an early fiberglass build for Maine lobster boats (1972) and the mold for the hull was made by using an old Raymond Bunker wooden hull for the plug so there are no lines available for the hull that would help my model maker replicate the shape of the hull to my satisfaction.

To this end I have been developing lines from my boat to help make his hull look more correct and thought I would share my process with a few photos. I am not attempting to recreate the hull lines as a museum might do but only trying to get a good ballpark representation of the shape. I am fortunate to have the boat indoors for a few months this winter on a relatively flat concrete floor so it seemed like a good opportunity to have a go at this.

As you will see in the photos I am using simple tools. In concept, I have drawn a line on the floor that is parallel to the centerline of the keel and is one foot away from the maximum beam of the hull. I marked points at two foot centers on this line as reference points to take measurements. I used a laser level on a fancy tripod that I borrowed to help me keep my measurement points in a line that is perpendicular to the keel centerline. I doubt that I am perfectly square but at least I have a means for repeatable results suitable for a scale model to sit on my bookshelf. Today I plan to take the data and draw the station shapes to scale to verify that I have enough data points to have a smooth line for each station before I send the numbers to the modeler. I am about two thirds done taking the data and expect to finish taking numbers Monday or Tuesday.

Newman & Gray 36 (1).jpg

1.jpg

2.jpg

3.jpg

4.jpg
 

Old Mud

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Eastporter

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Ditto on the model- very detailed.
 

Keelboater

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chortle - what scale is your model being built to? It's looking real good and is something to admire for years to come.
 

Toolate

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Looks likea fun project and great model.

I have a laser that projects a plumb line, level line and a pair of dots at 90 degrees to the plumb line (you could put it on your parallel line and it would always be square to the centerline of the boat). Great tools.
 

Old Mud

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Last edited:

chortle

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Herreshoff Coquina, 1972 Jarvis Newman 36, PT11

chortle

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Herreshoff Coquina, 1972 Jarvis Newman 36, PT11
That looks great! Here is another model that was done of Ojibway a Newman 36'. These guys did take the lines off of this boat and have it in autocad. I do not know if they would be willing to share them with you so that you could check your lines plan. Yacht Models - Handcrafted Replicas - Yacht Models - Ojibway

captj, thanks for the link on Ojibway, really, really nice model, I can't imagine how much time and effort went into that one, museum grade work.
 

plyandglass

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taking off hull lines

Chortle,
Looks like you've got the right idea. Years back when I was boat building ,when a new boat was hauled (Carolina sportfisherman) we other builders would take some measures and discuss what worked or not so much.
I have a book on model building that covers the taking off on lines. It was written by a local (Eastern shore) that may help. I'm local to Annapolis , so if you need a hand let me know.
By the way , the model you have looks really well done
 

chortle

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hull line data developed in Autocad

Here is an example of one hull line that I have developed in Autocad from the measurements that I took. Looks to me like it will work just fine for a model.

hull line.jpg
 

chortle

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Herreshoff Coquina, 1972 Jarvis Newman 36, PT11
more lines for the model

Here is a complete set of lines for the model broken down into four screen shots.

1.The first one is all of the lines together.

2.The second pic is the first 12 feet.

3.The third pic is the mid section transition from bow shape to flatter sections aft.

4.The last pic is the last 10 feet transition from midships sections to flat sections aft.

Because my goal was to get the bottom below the waterline developed for refinement of the model that I am having made the outboard lines all stop at the waterline. I may go back and take some measurements from the waterline up to the gunwale and see if I can generate a file that my buddy in England can use to develop a 3D printer model of the hull. He is just coming up to speed with building his own 3D printer and is looking for projects.:p

This was a good project for a nasty day, about four inches of fat wet snow here in Annapolis today, really heavy stuff to shovel but it makes the beer taste better.

combined lines.jpg

first 12 from the bow.jpg

mid section transition.jpg

last 10 feet.jpg
 

Keelboater

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Nice work! 3-D printing has it limits........at least for now. Immagine being able to print a full sized D.E. boat that is structurally sound?
 
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