ATP-3-09-30 Observed Fires Download
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Appendix B B-4 ATP 3-09.30 28 September 2017 Figure B-3. Side-spay method LOW-ANGLE FUZE DELAY CRATERS (ARTILLERY) B-11. There are two types of fuze delay craters: ricochet and mine action. Ricochet B-12. The projectile enters the ground in line following the trajectory and continues in a straight line for a few feet, causing a ricochet furrow. The projectile normally deflects upward and, at the same time, it changes direction usually to the right as the result of the spin, or rotation, of the projectile. The effect of the airburst can be noted on the ground. Directions obtained from ricochet craters are considered to be the most reliable. The five steps to determine direction from a ricochet furrow (see figure B-4 on page B-5) are as follows: Clean out the furrow. Place stakes at each end of a usable straight section of the furrow. Set up a direction-measuring instrument in line with the stakes and away from fragments. Orient the instrument. Measure the direction to the weapon.