Eastport Pram - measurements in manual do not match plans

Hello all,

First time builder here!

    I am building the Eastport Pram (non-nesting) from plans. I just finished the lofting and have some concerns/questions.

    Q1. The full-scale plans did not include any measurements. Not sure how one is supposed to utilize the plans when they do not have measurements. The manual states that a full resolution version of the manual image of the panel layout with offset measurements is included in the plans, but this is not the case. Curious how exactly one is supposed to utilize the full-scale drawings.

    Q2. So, I just used the measurements from the low-resolution image in the manual to create the grid of offsets. Marked them all off, and all of the pieces look great and the appear to have the same shape/dimensions as those in the plans... however

    After rolling out the plans to see how close my lofting was, I found that all of the drawings that I laid down ended up being significantly smaller than their counterparts on the full-scale plans, by a few 1/8s of an inch on most of the ends.

e.g. the manual measurements (which I used) put the bottom offset of the bow end of PLANK 4 at 4-3/8" down, and 1-1/4" left of it's top offset. If my pythagorizing is right, that puts it at something like 4-35/64". My drawing is about 4-1/2", but the plans have it as 5-1/8".

    All of the pieces are like that, substantially smaller than whats shown in the plans, and some of the side boards are too small for the aft and bow transoms.

    Should the pieces match exactly (not flawlessly of course) the sizes of those shown in the fullscale plans? Could I have gotten one version of the boat in the manual and another in the plans–because my plans also don't include measurements but the manual seems to indicate that they should.




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RE: Eastport Pram - measurements in manual do not match plans


The problem is caused by the fact that the full-scale "plans" are actually full-scale patterns that are meant to be transferred onto your wood. That's why there are no dimensions written onto the full-scale sheets. The dimensions are set by the patterns themselves.

If you use them the way they are meant to be used, there's no issue. The discrepancies that you are seeing are caused by the fact that you lofted a low-resolution image so your offsets are seriously affected by the thickness of the lines and the scale of the initial image.

Now personally, I really really prefer a dimensioned subscale drawing, i.e., actual plans instead of full-scale patterns. I was extremely disappointed when I received the "plans" for a Kaholo 14 and found exactly what you did - patterns with no dimensions whatsoever. It's been years and I have yet to start that project.

It seems that real plans are too difficult for the average builder so, to serve the most numerous portion of their customer base, designers have been changing over to patterns from plans.  This is true not just for CLC and not just for boats. RC planes, for example, are also coming as patterns while being called plans. I blame it on the decline of shop classes in favor of computer programming and studying for standard evaluation tests.

I find it a lot easier to read dimensions off real plans, mark points on a sheet of wood and to connect them with a straight-edge or batten than to fool with transferring lines from a wrinkled sheet of paper that's as long as the actual boat. But to do that I have to be able to read actual plans and draw, skills that that are in short supply among the customer base these days. FWIW, I learned how to do that as part of a general shop class when I was 12.

Hope this fixes your problem,



RE: Eastport Pram - measurements in manual do not match plans

    Thanks Laszlo! That makes sense, and I completely agree with you on the desirability of actual plans over patterns. In fact when I first rolled the patterns out and saw that there were no measurements, my first thought was that I would have to do what you're saying, somehow trace them onto the wood… That is when I opted to use the measurements in the manual. Haha 

    To be honest I'm not even sure how one is supposed to go about using patterns for this. Am I supposed to cut out the shapes out and lay them onto the wood? Sounds a little kindergartner, and really don't like the idea of trying to trace a good shape off of the paper.

    My ideas so far is that I will drive a brad through one corner of each piece to align it onto the wood then get the paper laid out and use the outline of the plan for new lofting marks. Still have my 12" spaces marked out at least.

RE: Eastport Pram - measurements in manual do not match plans

Depends on the patterns. If each piece has its own outline then you could cut out each one, attach it to the plywood with some kind of cement and use it as a cutting guide.

Unfortunately, the trend is to put multiple pieces so that they overlap each other on the paper, which means that you can't cut them out and glue them. Instead, people use carbon paper, tracing paper, pricking wheels, pricking with an awl or doing some other truly Rube Goldberg thing to get the lines onto the wood. The possibilities for error are endless and each process is so much more complicated than just reading dimensions off a page and marking the wood with a pencil. But there's no math, which is what truly matters.

At the very least, I wish design houses would differentiate between real plans and patterns in their ad copy.

Good luck,




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