View Full Version : Plank Widths

Paul Wild
03-12-2002, 10:48 AM

I just received my plans for a 95% Ness Yawl from Iain Oughtred. I have his Clinker Plywood manual too. I am sort of looking over the plans right now and trying to get a feel for some of the details. One thing that is not plainly obvious to me right now is how you determine the widths of the planks that you must cut.
I have half breadth and offset measurements, but I understand that those give the beam of the boat at the various stations. When I'm ready to cut the planks, how do I know how big to cut them? I was expecting a table of offsets for each plank, kinda like when building a S&G kayak.
Your advice is appreciated,



dale o
03-12-2002, 10:56 AM
Read the Clinker Plywood Boatbuilding Manual. After you set up the moulds on the building frame, each plank is measured out and custom fit, using a pattern. There are no drawings of each individual plank.

Don Maurer
03-12-2002, 11:22 AM
You can get some idea of how wide the planks are by looking at the mould sections. Usually section 4 or 5 will be the widest. This does not take into account any curvature in the planks, which can be considerable. Starting with the garboard, the plank should be a couple of inches wider than the widest section on the moulds. From there, the planks very roughly follow the curve of the plank before it. Add a couple of inches to the width of each one. You can use this method for material estimation, but you really need to spile each plank or make a pattern as described in Iain's book or Ultralight BoatBuilding by Thomas Hill to get the correct shape.

[ 03-12-2002, 02:44 PM: Message edited by: Don Maurer ]

03-12-2002, 12:08 PM

I am sitting at my desk, Iain's Design Catalog in one hand and check book in the other ready to order plans for the J II Yawl (a.k.a. 95% Ness Yawl).

You are the first person I have heard of who has actually mentioned having plans and building this boat.

I expect to use the boat primarily for solo beach cruising. Do the actual plans make the boat look as good (with the 6 strakes/side) as I imagine? By the way, there are 4 photos of the J II under construction at Duck Flats Wooden Boats web page.

Please keep me posted on your progress. I will be in Ohio in June and probably again in October. I would really like to see your boat if that is possible.

Thanks in advance for any information you may be able to provide.


03-13-2002, 06:52 AM
Hi Paul. I want to second the recommendation of Oughtred's and Tom Hill's books. But I wouldn't use Tom Hill's ribband method on the Ness Yawl. I built the hull for my Whilly Boat using this method and I had to add four extra station molds to get the ribbands to conform to the shape of the boat. Oughtred mentions this problem in his book (which I got too late, hence the warning). You'll see what I mean when/if you get the books.