Hulls. Part 1
When you have obtained the plans for your ship model, your first job will be to construct
the hull. If your model is to be a replica of the original, its hull, above all things,
must be carefully shaped according to the accurate hull lines given in the drawings. To do
this in the quickest and easiest way, you must follow some standard method of procedure.
Of course, the most workmanlike process would be to build the hull of tiny ribs and thin
planks like a real vessel. This, however, is a big undertaking and much too difficult for
the average amateur. Besides, there are other and easier ways of obtaining the same
effect. Simplest of all standard methods of model hull construction is the "bread and
butter" method of lifts. This particular method gets its name from the fact that lifts of
wood, cut approximately to the various horizontal sections of the hull, are placed one on
top of the other and glued together. When first assembled, the side of a glued-up "bread
and butter" hull resembles a series of narrow steps. Most ship model plans provide for
building the hull by this particular method, but any ship model drawings can be adopted.
In either case, your first step will be to measure the depth of the lifts, making them all
the same, and buy wood of this thickness. If wood of the exact thickness is not
obtainable, take a size larger and have it planed down. What may be still easier, however,
is to redesign the lifts to suit the thickness of the wood you can get. To do this, mark
the desired thicknesses on the body plan and from that plan make a new half-breadth plan
by marking the widths from the body plan on a new set of construction lines.
These construction lines, of course, must coincide with the vertical lines on the original sheer plan. Just what these various plans represent is shown in Fig. 1. In any redesigning of the lifts, be sure that the deck does not cut entirely through the top lift at any point. If the plans you have do not show the lift method of construction, this same procedure can be followed in planning the lifts and developing a half-breadth plan to agree. With the lumber on hand, your next job will be to transfer your half-breadth plan lines to the lifts so that they can be shaped and assembled. Take a piece of tracing paper and from the half-breadth plan mark the center line, all the construction lines, and one pf the half-breadth lines (the line to which the particular lift is to be cut). This will give you one half of the curve. Then turn the paper over and, with the center line and other construction lines coinciding, draw in the other half, making a closed curve. Do this with all of the lifts, using the same construction lines throughout.
However, after each lift line is completed, pin the tracing paper to the strip of wood
that is to be used for that particular lift and transfer the outline and the construction
lines by means of carbon paper. (See Fig. 2.) Next, cut each lift to within about 1/16 in.
of the outline and, finally, hollow out all but the top and bottom lifts. This can be done
by marking on the bottom of each lift the outline of the lift below and cutting to within
about 1/4 or 3/8 in. of that with a coping saw as in Fig. 3. An extra allowance of wood
for the final finishing also should be left at both ends of each lift. Hollowing the
center lifts not only makes the hull lighter but lessens its tendency to warp. When the
lifts all have been cut to size, you are ready to start assembling your hull. Most experts
work from the bottom up, placing their bottom lift flat on a bench or table, and gluing on
the next lift, lightly nailing it in place from the inside (Fig. 4) to hold it. When all
the lifts have been built up, one on top of the other, clamp the entire hull with hand
screws or place it in the improvised clamps shown in Fig. 8 of the preceding
chapter.
Once the "bread and butter" lifts of your hull have been assembled, you are ready for the
roughing and final shaping. However, do not pass over the cutting of your lifts lightly.
The more accurate you are in cutting them to the exact lines of your plans, the easier it
will be to get the finished effect that is necessary if your model hull is to look real.
For the final shaping, you will need a series of templates cut to the shape of the lines
in the body plan (Fig. 5). Cut these from cardboard, tin, or thin plywood and mark on each
the exact point where the joint of two center lifts will come. This will give you a
reference mark that will allow you to hold the template at the right height. Also, mark
the deck line carefully at the edge of each template.
In use, the templates are placed along the hull at their respective positions at right angles to the keel. The bottom edge of each template, of course, should coincide with the center line of the hull. If the hull slopes considerably from the water line to the deck line, cut the templates vertically upward in a straight line neglecting the "tumble home," as this slope is called. Then, later on, when the rest of the hull has been shaped, the extra wood above the widest part of the hull can be shaved down to the deck to agree with the tumble home. Another method that is often used in making a hull, especially on models such as galleons and other older types of ships having long beakheads and high poops, can be referred to as the "half-hull and centerboard" method. It consists of assembling the hull from two solid sides and a plywood centerboard. (See Fig. 6.)