Figure 5-6.—Ship’s fallout template—a clear plastic template used to plot fallout diagrams on any scale chart.
marks on the underlying chart. Unlike the Land Fallout
Templates, the semicircles upwind of GZ on the Ship’s
Fallout Template do not refer to specific weapon yields,
but only serve as an aid in plotting. The 20° radial lines
to the left and right of the downwind axis are not
provided with units of measurement. In addition, since
geographical charts used at sea are not uniformily
scaled, the Ship’s Fallout Template is unscaled. To use
the Ship’s Fallout Template, follow the steps outlined
below.
1. Draw Grid North (downwind direction for
appropriate weapon yield from NAV EDM) on the
template from ground zero. Grid North is determined
from a NAV NBC 3 NUC message by averaging the left
and right radials from element "Y" of the message.
2. Plot the downwind distance to Zone I from
element "Z" of the message or use the nomogram (fig.
5-7) to determine the downwind distance to Zone I.
Double the distance to determine Zone II. Draw two
arcs between the radial lines.
3. Determine the cloud radius from the Ship’s Fall-
out Template using the appropriate yield group from
the NAV EDM. Element "Z" of a NAV NBC 3 NUC
message will contain more accurate cloud radius data.
4. From the intersections of the Zone I arc with the
radial lines, draw two more lines to connect the cloud
radius circle.
5. To determine the area where deposition of fall-
out is estimated to take place at a specific time, simply
multiply the effective downwind speed by the time (in
hours). Draw an arc between the two radial lines at the
distance calculated. For example: 10 knots x 1.25
hours is 12.5 NM.
6. Add and subtract the safety distance as
determined from the Ship’s Fallout Template for the
5-7
