The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

170 First Production Steps
1" X 4" with
plywood
gussets
Large Squares
Pin or nail
Solid
Plywood
Figure 16-4 A lofting grid laid out for superimposed hull lines. Also pictured, various tools for lofting.
buttocks, waterlines, diagonals, centerlines, and station
lines. You can easily recognize the grid from the lines
drawing by the fact that all the grid lines are straight,
running either parallel with or at right angles to the
baseline. <strong>The</strong> only exceptions are the diagonals which,
in the body plan, are lines coming off from the centerline
at various angles. In small-scale drawings, most
designers draw separate grids for the profile, half
breadth and body plans to help eliminate confusion.
When the boat is lofted to full size, all these views are
generally superimposed to save space, as in Figure 16-4.
A common line then serves as the baseline of the profile
view and the centerline for the half breadth and diagonal
views. Sometimes a separate grid is laid down on a
portable board for the body plan so that it can be
moved to different areas of the shop in order to build
molds from it. Usually, however, the body plan is super-
Lofting weights or ducks–3 to 5 lb
Use different colored pens for each set of
lines to reduce confusion.
Bolts with wingnuts
Pencil
Adjustable bar compass
Use trammels or bar
compass to lay out
perpendiculars for
station lines.
Pick up sticks
Flat or Triangular
Awl
imposed on the other views, and the mid-station line of
the profile view serves as the body plan centerline.
<strong>The</strong> grid is not difficult to lay out, but it is important
that you do it with precision. If an error goes undetected,
it may not show up until many hours later, at which
time there will be little to do but get out the semi-gloss
paint and start over. <strong>The</strong> grid lines will be permanent,
and, after careful checking, they are drawn in ink.
<strong>The</strong> baseline: Because you use the baseline to lay out
all the dimensions for the grid, you must lay out this
key line very accurately. Our method is first to stretch a
locating cable alongside where we want the baseline.
We locate the baseline close to one edge of the lofting
board, being sure that there is enough room to loft the
boat above it.