I should think that the info you need can be found from these two sources:

http://www.smedleyco.com/Sassafras14/Building-The-Sassafras.aspx

https://www.amazon.com/Canoe-Shop-Elegant-Wooden-Canoes/dp/007137227X   

   Thank you, Birch

It would appear that the designs in the book contains mistakes

Do you have any suggestions / comments on the other question of lengthening / shortening a design ?

Many thanks, Tony

   The general rule-of-thumb in lengthening a design without adversely affecting the boat is to stay within 10% of the original length. You would keep the design beam/frames the same and open the spacing between each station/frame 10% or whatever ratio under that amount you choose. I'm not sure if canoe designs are as sensitive to stretching more than 10% but displacement hulls apparently are.

Your design would put you at about 13.2' long which is fairly close to what your aiming for....Hope this helps

Rob

 Lengthening (without also widening) a S&G boat isn't as easy as a strip built boat. The planks don't all lengthen by the same factor: a straight-ish piece near the keel might lengthen 10%, while a plank going around the curve of the sheer only changes 8 or 9% in length. You are drawing all new parts, without the information from the design software that it was drawn by. Designers don't even remember how to pull patterns from developed-panel hulls; they all use software to extract the shapes. It's some tedious, elaborate, and non-trivial geometry!

If you want to go bigger in all directions, the math gets easier: just increase everything by your chosen percentage. I'd keep that multiplier small though. A 5% increase yields a 16% bigger boat (cube law). The 10% length adjustment mentioned in an earlier post is for boats built on station molds (eg strippers), where only the length changes.

   Hey, I also might suggest you look into some of the free boat design software available. Years ago I picked up FreeShip off the internet which is a nice little program. You could even print out the panel shapes of your final design rendering to build a model (or the actual thing). I still have it on an old laptop which runs XP. Never been able to load properly on Win7 or later. I checked and they still offer the free version which now goes by the name DELFTship. The user manual is also quite good (user friendly) but will still take time to get comfortable with the software. Like any other complex program I imagine.

Anyway, it might be worth a go with Fall and Winter comimg on. Beats sitting around in front of the tube watching Dancing With the Stars....

   Here's Nick's formula for someone who scaled up a Petrel by 7%...

  Let's say the design displacement is 250# and his weight was 280#, the scale factor is 280/250 = 1.12 so, the volume needs to be increased by 12%. If you are just scaling in one dimension you would scale up 12%. But since he was scaling in width and height, the product of those 2 dimensions must equal 12% so take the square root of 1.12 = 1.058 or 5.8%

Dan

   Gentlemen,

Thank you so much for all your kindness & courtesy in your replies  & suggestions.

Thanks to hours of research on the net, and a few very helpful people much like yourselves, I have decided to build the Sassafras 14.

Original plans, a set of corrected plans and a lot of searching (Google is your friend) has equipped me to to attempt my fiorst boat build.

The design weight of a Sass 14 is 42 Lbs / 19 Kg and I will be aiming for approx 40 Lbs using lighter weight but more durable sheathing

Thank you again for all your inputs :)