Defending the BSA With Indirect Fire

In November 1997, the 1st Brigade, 25th Infantry Division (Light), from Fort Lewis, Washington, conducted a light-heavy task force rotation at the Joint Readiness Training Center (JRTC), Fort Polk, Louisiana. In an effort to provide uninterrupted combat service support, the 25th Forward Support Battalion (FSB), as an integral part of the task force, established the brigade support area (BSA), integrating all aspects of a combined arms defense. The most effective combat multiplier in the defense of the BSA was indirect fire from the 2-8th Direct Support Field Artillery Battalion.

The 25th FSB's success in defending the BSA can be attributed directly to the detailed planning efforts and execution of the FSB staff and the indirect fire supporters. I hope this article will be useful to forward support battalions participating in future rotations at JRTC who must establish a proactive defense in order to accomplish our ultimate mission—support the combat soldier in battle. —Lieutenant Colonel Sam Holloway, Commander, 25th Forward Support Battalion

Defense of the BSA is critical to providing uninterrupted combat service support. Using effective indirect fires improves BSA defense. During a JRTC rotation in 1997, the 1st Brigade, 25th Infantry Division, proved that a dedicated fire support element (FSE) can make the difference in the success of those fires.

Although Army doctrine states that fire support in the rear is the responsibility of the brigade fire support officer (FSO), a full-time FSE is essential to the BSA. However, the brigade's modification table of organization and equipment does not authorize a BSA FSE. As a remedy, the direct-support field artillery battalion commander can use internal task organization to appoint an FSE for the brigade rear area. The commander of the battalion's headquarters, headquarters and service (HHS) battery usually is given the additional responsibility of planning fires as the BSA FSO.

Because the HHS battery commander has other work priorities, planning fires is often just a paper drill. When this occurs, fires fail and so do credibility, trust, and confidence in fire support. The leaders of the 1st Brigade know that indirect fires can influence all combat, combat support, and combat service support operations. The leaders of the 2d Battalion, 8th Field Artillery, and 1st Brigade have instilled this concept into the hearts and minds of every soldier by emphasizing fighting with fires in the close fight. The bottom line is to apply fires at the right time and place on the battlefield, to include the rear area.

My service as the BSA FSO during JRTC rotation 98-02 was a very rewarding experience. Since there is little information on how to employ fire support in the brigade rear area, we had the opportunity to try new techniques. Using the basic principles of defensive-fire planning, we constantly sought means to influence our area of operation with fire support. Let me offer some advice, based on our experience, that can help your unit create a successful BSA defense using indirect fire support.

It is critical to coordinate, rehearse, and execute the tactics, techniques, and procedures presented in this article while at your home station. Develop a BSA battle drill that allows for a rapid clearance and execution of fires. Working out of the FSB tactical operations center, the BSA FSE should include two soldiers, preferably a commissioned officer and a noncommissioned officer (NCO). The FSB should provide all the necessary equipment, including two radios connected to an OE-254 antenna.

The FSE NCO should accompany the advance party to a new position and begin surveying the BSA boundary. He should determine the grid location of each tenant unit in the BSA using a precision lightweight global positioning system receiver (PLGR). We used 10 grid locations to define the BSA perimeter during our JRTC rotation. At a minimum, use an 8-digit grid for each tenant unit or point on the perimeter. Plot each grid location on your map. This will give you an estimate of what the BSA looks like.

As soon as the perimeter of the BSA matures and tenant units complete occupation, these grid locations must be refined. Using a fine pencil, draw the new, refined BSA perimeter on your map and draw a risk estimate distance (RED) or minimum safe distance (MSD) line farther out depicting the area beyond which fires can be safely delivered. Planned targets and targets of opportunity should be on or beyond this line. Minimum safe distances are never exceeded during peacetime live-fire training.

BSA defensive fire plan layout.

^ Active OP

— BSA perimeter

...   MSD/RED line

Zone A   Active BSF patrol

Zone B   Proactive fires

— Zone boundary BSA clearance of fires boundary

Once you have marked the BSA on your map, locate your targets with a PLGR. Targets should be as close to the perimeter as the BSA commander allows. At JRTC, I advised him to use MSD until firing units met the five requirements for accurate predicted fire, then use a RED of 0.1 percent probability of incapacitation. Use PLGR waypoints to determine your targets instead of walking to each one. This offers force protection and expedites the refinement of targets when the perimeter is developed fully.

Once targets are determined, coordinate with higher headquarters and establish a 500-meter buffer zone beyond those targets. The FSB commander owns the ground within the buffer zone. Thus, he has the authority to clear fires in this zone. This facilitates the use of fires because he does not have to clear targets with adjacent units.

No-fire areas (NFA's) also are established as a control measure. Establish NFA's around air defense systems, drop zone security teams, observation posts (OP's), and the reverse osmosis water purification unit. Where possible, establish the location of all NFA's, especially OP's, using a PLGR.

Divide the 500-meter buffer zone around the perimeter into three or four segments. With three or four manageable segments, the reconnaissance and surveillance, OP, and obstacle plans can be synchronized easily with the fires plan. For example, if the buffer zone is broken into three segments, the defense could use OP's in one segment, patrolling in another, and proactive fires in the third.

Proactive fires are synonymous with harassing and interdiction fires. At any given time during our JRTC rotation, a dismounted base security force (BSF) patrolled one segment, an OP was manned in a second segment, and a schedule of fires was used in the third to balance out the entire buffer zone. The purpose of these fires was to enable continuous CSS operations by preventing the unconditional use of the buffer zone by the opposing force (OPFOR). Because of our random use of proactive fires, the OPFOR never had complete freedom of movement and the BSA did not receive contact without early warning.

By their nature, proactive fires also serve as deception fires because they disrupt the enemy's decision-making process. An occasional white phosphorous or high-explosive round will make the OPFOR seek cover. An illumination round will make the OPFOR think it has been observed and seek concealment.

The FSO should participate actively in planning, coordinating, and executing all perimeter defense elements—proactive fires, BSF, and OP's—to ensure that they integrate and synchronize smoothly. Proactive fires will result because the FSO has a part in the positive control of defense elements outside the perimeter.

During the JRTC exercise, we found that the perfect opportunity for the FSB commander, S3, S2, and FSO to coordinate perimeter defense for the next 24 hours was immediately after the 0600 hours shift changeover meeting. An 1100 hours tenants' meeting was part of the battle rhythm and served to brief everyone on the perimeter defense plan for the next 24 hours. The daily defensive plan included an updated sector sketch with new OP locations and NFA's. The defensive plan also included a schedule of when we would fire during the next 24 hours and when and where the BSF would patrol.

Stepped-up patrolling and our use of fires at night made up for a degraded level of security, particularly when soldiers were cold and wet. Most of the fires were nonlethal, using smoke during the day and illumination at night.

Fighting with fires in the close fight reflects the belief that we can support and influence all combat operations. It is critical that rear area defense is well-planned and executed. When they are in contact with the OPFOR, logisticians and all BSA tenants should be thinking about fires. If we can execute by attacking our planned targets, we can earn their respect. When we earn their respect, their first thought will be fires. ALOG

Captain Joseph D. Heck, Jr., is the commander of B Battery, 2-8th Field Artillery Battalion, at Fort Lewis, Washington. He served as the battalion fire support officer for the 25th Forward Support Battalion and the 5-20th Infantry Battalion, Fort Lewis. Captain Heck has a B.S. in personnel administration from Austin Peay State University and is a graduate of Officer Candidate School, the Aviation Officer Advanced Course, and the Combined Arms and Serv-ices Staff School.