Infantry Drills

C-10: Offensive Echelonment

Previous: C-9: Defensive Echelonment

C-10. In the offense, weapons are scheduled based on the point of a predetermined safe distance away from maneuvering friendly troops. When scheduled, fires provide protection for friendly forces as they move to and assault an objective. They also allow friendly forces to get in close with minimal casualties and prevent the defending enemy from observing and engaging the assault by forcing him to take cover. The overall objective of offensive scheduled fires is to allow the friendly force to continue the advance unimpeded. (See figure C-2, page C-5.)

Figure C-2. Offensive echelonment of fires

C-11. As an example of echelonment of fires use during the conduct of a mission, consider an operation in which a platoon assaults an enemy position. (See figures C-3 through C-6, pages C-6 through C-9.) As the lead elements of the unit approach the designated phase line enroute to the objective, the leader orders the fire support officer to begin the preparation. Observers track friendly movement rates and confirm them. Other fire support officers in the chain of command may need to adjust the plan during execution based on unforeseen changes to anticipated friendly movement rates.

C-12. As the unit continues its movement toward the objective, the first weapon system engages its targets. It maintains fires on the targets until the unit crosses the next phase line corresponding to the risk estimate distance of the weapon system being fired.

C-13. To maintain constant fires on the targets, the next weapon system begins firing before the previous weapon system ceases or shifts. This ensures no break in fires, enabling the friendly forces’ approach to continue unimpeded. However, if the unit rate of march changes, the indirect fire support system must remain flexible to the changes.

C-14. The fire support officer shifts and engages with each delivery system at the prescribed triggers, initiating the fires from the system with the largest risk estimate distance to the smallest. Once the maneuver element reaches the final phase line, the fire support officer ceases the final indirect fire system or shifts to targets beyond the objective to cease all fires on the objective. Direct fire assets in the form of supporting fires also are maintained until the final assault, then ceased or shifted to targets beyond the objective.

Figure C-3. 81-mm mortars begin firing
Figure C-4. 81-mm mortars shift, 60-mm mortars and supporting fires begin
Figure C-5. 60-mm mortars shift
Figure C-6. Supporting fire ceases

Next: C-15: Fire Planning the Defense

Go Back To: U.S. Army FM 3-21.8: The Infantry Rifle Platoon and Squad