Drawing aids, Continued
Special
irregular
curves
In general, special irregular curves are curves not common to a Navy
Drafting shop. These include ship’s curves, mechanical engineer’s curves,
conic sections, and logarithmic spiral curves.
SHIP’S CURVES: These curves are peculiar to ship building. They are
elongated curvilinear shapes in a variety of sizes.
Figure 2-48 shows ship’s curves.
Figure 2-48.
—Ship’s curves.
MECHANICAL ENGINEER’S CURVES: Irregular noncircular curves are
drawn with mechanical engineer’s curves. These curves are very similar to
french curves.
CONIC SECTIONS and LOGARITHMIC SPIRAL CURVES: These curves
are rarely found in a Navy Drafting shop.
Flexible curve
rules
This unusual rule is used for drawing irregular curves. Completely flexible,
most bend to a minimum radius of 2 inches. They have a metal or lead core
which makes them bendable to any desired shape. Some have clear plastic
edges graduated in increments.
Continued on next page
2-40
