A Beginners guide to RC boats

Chapter 1 . The Lines plan

Ok. Here we go. The is the first of a series of articles which will chronicle the design and construction of a GRP sailing boat as it happens (more or less). I would like you all to follow progress and chip in with ideas, questions and suggestions as we go. I figured I would start with the linesplan since when I build a boat I start by drawing a?.. well you get the idea.

The linesplan is the cornerstone of a yachts design. It defines the shape of the hull and allows the designer to calculate the areas and volumes and where they are positioned in relation to the weights and forces that drive a boat through water. In other words is it gonna float or sink and will it fall over.

Have a look at the attached file. Its in JPG format so most of you should be able to read it (If you want a more detailed, full size printable PDF just let me know)

Beautiful, isn?t she??.<sigh>

Do you reckon it looks like a Twelve metre? As I stated in an earlier post I wanted a new hull under my old EC12 rig so here it is. She is big, fat and heavy. GO DINOSAUR POWER! No fins & bulbs here folks. The hull-only displacement is 11kg, up to nearly 12kg with keel. Big (well biggish) stable and good to sail.

Notice there are basically three views, each view showing ?slices? of the hull.

Starting with the body plan, you?ll see it shows the stations. These are the transverse slices of the hull, usually spaced at one tenth of the waterline length. Station 0 is generally at the forward end of the waterline and Station 10 at the aft end with the negative numbers defining the bow and those above 10 defining the aft overhang.

By looking at the profile you can position each of the sections as well as seeing her buttocks (I still remember the disappointment I felt turning up to class one day, seeing my fellow students all gathered around a desk muttering something about nice tight buttocks and bulbous bow only to find they were talking about a trawler??) Anyway where was I. Yes the buttocks are longitudinal slices through the hull. In this case they are spaced at 25mm and so are labeled Butt25, Butt50 and so on.

Finally there is the Plan View. It shows the shape of the various waterlines as well as the diagonals. The waterlines are the horizontal slices through the hull, again spaced at 25mm in this instance. The DWL is the Design Waterline and is position at which the boat is supposed to float. (Gotta keep track of the weight!)
The diagonals can be seen on the Body Plan as well as the Plan view. In this case there is one at 30? and one at 60?. The view in the plan view is a true view looking square on to them. These are a good final check to make sure the hull s fair. (Look around the aft end of the diags and you?ll see some funny shapes caused by the typical 12 metre style bustle)

So generally that?s about it for Lines plans from me.

Please post any comments and suggestions??.

Up next Chapter 2. From the Drawing Board to Reality

Download Attachment: 12mHull17(72dpiA4).jpg

19 out of 7 people have trouble with statistics

Download Attachment: 12mHull17(72dpiA4).jpg

Download Attachment: Clickme.jpg

sorry; cant access the pic!? is it me or anyone else got the same problem.

Great! continue; its VERY intersting


if it isn’t broken, don’t fix it!


Sorry Troy It will not open for me either?

Do it NOW before it`s too late.


Try now on the Clickme file or just email me if it doesnt work. Because I tried to keep the file size down its a little hard to read anyway.


19 out of 7 people have trouble with statistics

Troy, Looks good as far as can be seen at this scale and resolution.
Have you considered having her rate as an
<font color=“navy”><font size=“2”>A CLASS?</font id=“size2”></font id=“navy”>
My only concern as an A is the bustle, the A class rule you may recall does not allow any hollow sections in the waterline. There may be other things in the A rule that make it undesirable, I only know enough to be dangerous.[:-dog]

Do it NOW before it`s too late.

Thanks for the input.
I have actually sat down and looked at how she would rate in any classes. Although the point was to just have a new hull under an EC12 rig, she actually rates quite well as a 6 metre, just a little light on in displacement (Sixes are HEAVY!) As far as A class goes, I think the no hollows rule is only between the waterline and the deckedge so she can fit in there. She rated a lot better as an A-Class if instead of being built at 1/13.33 scale (as per EC12 scale) she was 1/10th. It all kinda got a bit hard - had to change keel to fin & bulb etc, didnt look as good - and got away from what I had originally intended. That was a new style boat you could stick under an EC12 rig for around $300. It was an interesting exercise though, if for no other reason than trying to get my head around A-Class & 6 metre rules! Its kinda selfish I guess, but I usually build boats for me. Even if no one ever wanted one the one I build for myself would be well worth the time & effort after just one 12metre style crawl to windward (Ive already sailed this boat around the course about a million times in my head!)

19 out of 7 people have trouble with statistics

i click on the pic. and only was able to get the drawings, no the first 2 pictures
good idea you have