Carl H. Clark

The type chosen as being the easiest for the amateur to build is that known as the "square sider," as the lines are to a large extent straight with few sharp turns, thus making the easiest possible boat to build. As will be seen from the illustration, the lines of the top sides and of the bottom are all straight, meeting at a more or less sharp corner. While at first sight it might seem as though this corner were a disfigurement, it proves not to be so in the actual boat, the lines being a close approximation to those of a round bottomed boat similiar to the popular "knock about," but as this boat is intended for rough all around weather it was thought advisable to shorten the overhangs to make her easier in a sea way.

How To Build A Sailboat I Lines and Laying Out 53How To Build A Sailboat I Lines and Laying Out 54How To Build A Sailboat I Lines and Laying Out 55

The boat as laid out will be found very easy to build, and at the same time very strong, and a good heavy weather boat. While this type is, of course, not quite so fast as an extreme round bottomed boat with long overhangs, it is nevertheless a good sailer and a much better sea boat than she would be with long ends as the latter are apt to pound and throw spray aft.

The boat as laid out is about 16 feet on the water-line and is not so large but that she can be easily built, and yet large enough for two people to sleep aboard comfortable, a small cabin trunk being pro vided for that purpose.

In starting to build, the first thing is to choose a suitable place. The best place is one where there is plently of light and with strong beams overhead. The latter is a very important consideration, as the beams are used to brace against, and it would be almost impossible to do any boat building without them. A wooden floor is also disirable to which braces and blocking may be nailed.

In order to make patterns, or moulds as they are termed, of the several parts, it will be necessary to reproduce a part of the lines full size on a smooth floor. If this is not available a temporary one of boards may be laid, one about four feet wide, and the length of the boat being needed. If desired, in place of this floor a piece of drawing paper may be laid down on any available floor, and removed after the work is done. This will be a good way to preserve the lines for reference.

Laying Down Table









Height of sheer above base line


3'3 1/2"


2'11 1/2"




Breadth „ „ „ ,, „

2'10 1/8"

3' 1 7/8"

3'7 3/4"

3' 9 1/4"

3' 7 1/2"



Height ,, knuckle above base lined

2'1 1/2"

1'8 1/2"

1'4 7/8"

1'3 1/2"

l'5 1/4"

1'9 7/8"


Breadth „ ,, ,, „ „

1' 7 1/2"

2'9 3/8"

3'3 1/4"

3'4 1/2"

3'3 1/4"

2' 10 3/4"


Height ,, rabbet ,, ,, ,,


10 1/2"

5 1/2"



l'4 3/8"


Breadth „ ,, ,, ,, „

l 1/2"

2 5/8"

3 1/2"

3 1/2"

3 1/2"

2 1/2"

Height of bow at rabbet 3' 11 1-4"

Distance forward of section 1 of rabbet at bow,

2' 11 1-2" Height of sheer at stern 3' 3"

Breadth ,, „ „ „ 2' 4 3-4"

Height of knuckle at stern 2' 5"

Breadth,, ,, „ „ 2'2"

Height of rabbet ,, ,, 3' 1 3-4"

Breadth „ ,, ,, ,, 2 1-2"

The point x above base line is 2' 6 1-4"

,, ,, ,, forward of section 1, is 2' 6 3-4"

In order to make a portion of the keel, stem and cross section moulds, it will be desirable, if possible, to lay out the outlines of the sheer plan and the cross sections. The measurements will be found on the drawing. The base line is struck in with a chalk line and the cross sections laid off three feet apart, being sure to make them square with the L. W. L. (Load water line.) The distances are then laid off above or below this line, and fair lines run through them. It may be found that a line exactly through the points would not be fair on account of the unavoidable error in scaling from a small drawing, and laying off again, with a little judgment, a fair line can be struck.

For running curved lines a battern or staff about 1 1-4 in. square and 20 feet long is used, held in place by nails or awls driven alongside of it. When satisfactory lines are secured, they are scratched into the floor with a sharp awl. In the sheer plan the only lines necessary are the deck line, the rabbet, and the top and bottom of the keel. The measurements given are to the rabbet, but the bottom of the keel is 1-2 in. below the rabbet, and the keel is 2 in. thick, So that these lines are easily put in. The cross sections are the only other lines needed, and are laid off as in the drawing; the height of the upper corner being made to agree with the sheer already laid out.

The accompaning table gives the required data for laying out this mould and also those for the moulds for the cross sections and keel. Line 1 gives the height of the top of each section above the base line, which is 18" below the waterline. Line 2 gives the breadths of the corresponding points from the centreline. Line 3 gives the height of the before mentioned knuckle, or line of jointure of the two straight lines composing each section and line 4 shows the half breadths of the same points. Line 4 and 5 gives the height and half breadths of the rabbet, or the line where the outer surface of the plank joins the keel.

The sheer plan and the half breath should be laid out as shown in Fig. 1 and 2, these are laid out from the table above, and the outlines made fair. The only lines required are the sheer, the knuckle line and the rabbet line, the dimensions of the overhangs are shown additionally in Fig. 1. The cross sections, shown in Fig. 3 are obtained by coupling the other two plans, for instance, on section 1 the height and half breath of the sheer point are shown at a and b which height and half breadth are used to locate the point in Fig. 3. The points c and d show the height and half breadth of the knuckle on the same frame, which dimensions are used to locate the point n in Fig. 3. In the same way the point o is located from e and f. The three points m, n, o thus gotten are connected by straight line to complete the outline of the frame.

The frames are all to be drawn in the same manner, and used later as patterns to which to fit the moulds or forms upon which the boat is built. The line of the keel is drawn in 1-2 inch below the rabbet, and the line of the top of the keel so drawn as to make the keel 2" thick. The lines as laid out so far are drawn to the outside of the plank, whereas the moulds which are to be made and used to set up the boat must be made to fit the inside of the plank, as the latter are to be bent around them. It will thus be necessary to draw inside of each cross section or mould already drawn, another one smaller by the thickness of the plank and deck as shown in Fig. 4. This thickness is 3-4" and the new section is formed by drawing the new lines inside the old ones at a distance of 3-4". It is also desirable to lay in the keel for convenience in trimming the moulds to fit over the keel when set up.

The bottom of the keel is 1-2" below the rabbet and the keel is 2" thick. The top side of the keel projects over on to the plank 1-2" to form a back rabbet and give fastening for the plank. The widths across the top also give the widths of the keel at each point, which makes it easy to lay off the keel outline.

The laying off on the floor may seem rather tedious but it is the easiest in the end, and also makes a pattern upon which the several parts may be laid to test their fairness. It will be well to take considerable pains with this. part of the work, in order that the boat may come fair when set up, and thus save all paring and filling out.

The sternboard, as shown in Fig. 5, is also laid out. Following the lines laid on the floor, a wooden pattern is to be made out of stock about 1-2" thick to fit the line of the bottom of the keel. It should run the whole length of the keel and stem, and at the forward end should follow the forward side of stem, and at the stern a piece should be fastened on showing the angle of the sternboard. The positions of the cross sections are marked on this mould and also the position of the centreboard slot. It must be so braced that it can be carried about without springing out of shape. This mould is very important as it fixes the shape of the boat and must be accurately laid out.

So much depends upon the shape of the keel, that hits must be correct. The best way to assume this will be to build a solid foundation. A 2" spruce plank about 10" wide is set up on edges about 15" from the floor, and strongiy braced in position. Then using the mould just made as a pattern, the plank is cut to fit it and the ends built up with other pieces of plank and the whole trimmed out until the mould rests evenly on it from stern to the round of the bow. It is then braced sidewise and endwise to be able to stand considerable pressure. This gives a solid foundation to bend the keel into and prevents its changing shape during building.

The same shape could of course, be built up of blocks fastened one on top of another, and securely braced, the tops being beveled off to fit the moulds this is, however not as good as a solid foundation and the former method as much to be preferred.