Barrier Planning

One way to win in spite of being greatly outnumbered is by defeating isolated portions of the enemy force one at a time at critical times and places during the battle. A superior enemy cannot be fought toe-to-toe across the entire front. Instead, his mass must be physically divided into manageable pieces that can be attacked individually with locally superior combat power. By first isolating and then destroying key pieces of the enemy’s total force, an inferior force can defeat a significantly superior enemy by destroying key enemy elements such as his air defense or artillery support; by disrupting his command and control; or by frustrating his operational timetable, preventing him from committing the follow-on echelons needed to achieve his deep objectives. Firepower itself will not defeat a vastly superior enemy. His advantage of mass allows him to return far more fire than he receives, and by Major David J. Ozolek in a battle of attrition, he can simply outlast his numerically inferior opponent. Before effective firepower can be employed, the enemy’s advantage of mass must be taken away from him. An effective barrier system can be used to disrupt the enemy’s mass. But to be effective, a barrier system must be an integral part of the concept of the operation and complement both the scheme of maneuver and the fire support plan. The keys to establishing an effective barrier system are sound concept development, careful siting, suitability of construction, and adequate defense and maintenance of the barriers. Concept Development An outnumbered commander must plan for a series of engagements against portions of the enemy’s overall force, instead of trying to take on the entire force at once. He must carefully choose the best times and places for his attacks and determine the size of the enemy force he can handle in each of these engagements. A barrier system complements the concept of the operation by ensuring the enemy force is channeled into the selected engagement areas. It complements the fire support plan by limiting the enemy to a size that can be successfully attacked and holding him in the engagement area until he is destroyed or until his attackers choose to break contact and move to their next selected engagement area. In the operational sense, barriers serve two purposes: they divert the enemy from his planned route, or they delay the enemy on a route over which he is moving. However, one fundamental truth of barrier planning is that barriers cannot realistically be employed to stop an enemy, especially a considerably larger one. A unit that trades its ability to maneuver for false hopes 14 novembei-december 1985 of being able to destroya superior enemy through a firepower solution based on completely stopping the enemy at a barrier is doomed to $destruction. Any barrier, manmade or natural, can eventually be overcome by an enemy determined to do so. Once its barrier is defeated, a unit without a viable maneuver plan will invariably be destroyed by the larger enemy force. The first rule of barrier planning is: Never trade maneuver options for the hoped-for effectiveness of a barrier. An example of this principle is shown in Figure 1. A company team has been assigned the mission of interdicting an avenue of approach capable of supporting a motorized rifle regiment. Unobstructed, the enemy on this avenue can mass roughly a 9-to-1 combat power ratio against the company team. Even when the advantages of the defender are considered (advantages such as camouflaged and covered positions, pre-planned fires, stable firing platforms, etc.), the company can realistically expect to engage the enemy successfully and survive the encounter only if the enemy’s combat power advantage can be reduced to a ratio of 340-1 or less. The team commander has emplaced two barriers, each only partially across the avenue of approach. The purpose of Barrier 1 is to delay the enemy’s 1st Battalion by forcing it either to breach the obstacle (which the commander estimates will take the enemy X minutes to do), or to bypass it on the trafficable terrain to its right. However, before the 1st Battalion can shift right for its bypass, it must wait for the 2d Battalion to clear the chokepoint. While the 1st Battalion is delayed, the 2d Battalion will continue to move forward, advancing unobstructed into Engagement Area Red, where the concentrated fires of the entire company team can be directed against it. The enemy’s initial 9-to-1 advantage has for a time been reduced to 340- 1, a manageable size for the company team to handle. At the near edge of EA Red, Barrier 2 will hold the enemy’s 2d Battalion in the engagement area while it breaches under fire, or moves laterally to bypass the obstacle. Regardless of which option the enemy takes, the barrier will Figure 1 give the team critical minutes either to complete the destruction of the lead battalion, or after inflicting the planned number of losses on the enemy for this engagement, the time necessary to move to the planned location for engaging the next enemy battalion to come down the avenue of approach. A different approach to the same situation is shown in Figure 2. Here the team commander has elected to, build a single barrier at what he has determined is the site that best supports the construction of an obstacle. At this location he plans to inflict as many casualties as possible on the enemy and then break contact before the enemy can breach. This scheme, however, allows the enemy’s 1st and 2d Bat-Figun, 2 talions to reach the barrier simultaneously. Instead of being able to mass its fires against one enemy battalion at a time, the company team will be subjected to the return massed fires. of two enemy battalions having a combined 640-1 combat power advantage, enough force to inflict more damage on the team than it can afford to accept. The enemy will have enough assets to allow it both to suppress the team and to conduct a breach of the obstacle. The contrast between these two approaches to this situation illustrates the second rule of barrier planning: Obstacles must be planned to support the best scheme of maneuver, and not the opera-tionalplan developed to fit the best location for obstacles. The family of scatterable mines (FASCAM) adds the dimensions of time and mobility to traditional barrier planning by giving the planner the flexibility to emplace a barrier quickly and remotely, virtually anywhere in the battle area. FASCAM can be used to place barriers between elements echeloned on the same route, reducing the enemy’s ability to mass and making his lead element vulnerable to attack. It can provide a barrier in reserve, allowing limited conventional engineer assets to be concentrated on the most dangerous and most likely enemy avenues while FASCAM is planned on contingency routes. It can also be used to seal barriers breached by the enemy, isolating elements which have passed through the breach from reinforcement. But FASCAM is not a barrier planner’s panacea and has operational disadvantages that must be considered during concept development. It is a single-system barrier vulnerable to defeat by such devices as plows or minerollers. It is limited in size and can serve only as a point barrier, not a linear one. Vital fire support assets must be shut down for critical minutes while the rounds are fired. It is subject to the same responsiveness and accuracy problems that degrade all indirect fire aimed at rapidly moving targets. Finally, FASCAM assets will be extremely limited and will have to be carefully husbanded to ensure their employment at the most effective time and place. 15

\ \ \\ / Figure3, Although bdrrier is physically tied in with the natural terrain obstacles oh the flank of the avenue of approach, it is not positioned to disrupt the enemy’s ability to mass. Siting I( The poi& to be considered ih selecting the specific sites for the obstacles include the general terrain characteristics of the battle area (particularly the natural or man-made, obstructions already there), the friendly scheme of maneuver, the range, rate of fire and probability,of kill of the weapons that will be available for the engagement, And the equipment and doctrinal characteristics of the enemy to be engaged. Obstacles become more effective when tied in with natural terrain features. However, while it is desirable to have them physically tied into natural terrain features, it is far more important that they be operationally tied in with them. This subtle but important distinction is illustrated by Figure 3. Here the wide avenue of approach could accommodate as many as four battalions abreast. (This is typical of desert terrain such as that found at the National Training Center (NTC)). The engineer assets available allow the obstruction of only two battalion’s worth of frontage. By physically tying the obstacle into the restrictive terrain on the flank of the avenue (as in Figure 3a), the enemy can still mass two of his battalions at once. However, by placing the same two battalion’s worth of barrier frontage in the center of the avenue (as in Figure 3b), the enemy’s lead bat- \ ‘ I This obstacle is not tied in with the restrictive terrain on flanks, but is operationally better sited than 3a. Splitting enemy battalions beyond mutual supporting range makes them vulnerable to individual attack. talions are dispersed laterally and can for a period of critical minutes no longer mutually support each other, making them vulnerable to separate attacks. An outnumbered force must gain and maintain a maneuver advantage if it is going to be successful in conducting multiple engagements of the enemy. This requirement leads to the third rqle of barrier planning: Never place an obstacle where it can obstruct friendly maneuver. Although this point sounds patently obvious, many after-action reviews of operations at the NTC have focused on units that were destroyed when trapped against their own obstacles deep in their sector. This can happen when planned passage points are closed too early by mistake or by the enemy. A corollary rule: Unless absolutely no other choice of routes is possible, routes must be planned around, and never through obstacles. A considerable amount of battlefield arithmetic goes into choosing the exact site for an obstacle. The computations begin from the battle position the unit will occupy during the engagement. Maximum practical ranges of the unit’s weapons systems must be plotted. Standoff distance is then computed by determining the maximum practical ranges of the weapons the enemy can use to return effective fire. Next, the enemy’s probable speed must be established so that the unit can determine how long the enemy will remain in the selected engagement area.l Return to Figure 1 for an example. The commander’s concept called for holding the enemy’s 1st Battalion at maximum standoff range in EA Blue so that it could be engaged but could not return effective fire. TOWS were assigned to cover the barrier from a position 2,700 meters away, out of the estimated 1,500-meter effective range of the enemy tanks, and ideally out of the Sagger range of the accompanying BMPs that will trail the tanks. Concentrations of indirect fire were planned on the barrier to disrupt breaching attempts. Barrier 2 was place at 1,500 meters in order to hold the enemy just beyond the effective range of his tank main guns. The team commander determined that his own tank guns firing from stable, hulldown positions would be effective to 2,400 meters, giving the team a 900-meter engagement area. A rehearsal showed the enemy could cross the engagement area at 300 meters per minute, and that the team’s 10 tanks could average three rounds per minute. Thus, the 10 tanks of the team can fire three rounds times three minutes times 10 tanks, or a total of 90 rounds for this engagement, which equals roughly two rounds for each target presented by a typical motorized rifle battalion. Another siting consideration is whether the enemy can see the obstacle. Some obstacles, especially those meant to divert the enemy, can be more effective when visible at long ranges. The enemy’s doctrine, much like ours, says that bypassing is preferable to breaching whenever possible. Sometimes he can be tricked into the selected engagement areas by clearly visible obstacles that he thinks he can rapidly bypass. Surface-laid mines or antitank ditches with high berms can be effective when such a role for the obstacle is desired. The visibility of an obstacle can sometimes add to its stength. When assets are not available for building a strong obstacle, an apparently strong obstacle may serve as a substitute. According to his doctrine, the enemy will only breach an obstacle when he has no other choice. If the enemy thinks he is 16 going to encounter an obstacle and plans in advance to bypass it, a weak obstacle meant to divert the enemy can be successful without its strength ever being tested. A phenomenon occasionally observed at the NTC is that at night or in heavy smoke, units will sometimes accidentally run right through obstacles that in better visibility would have stopped or diverted them. However, when the obstacles are clearly marked with orange engineer tape or chemical lights, they regain both their imagined strength and their actual effectiveness. Other obstacles, particularly those intended to hold the enemy in an engagement area, are more effective when they surprise the enemy. For this purpose, concealed mines, antitank ditches with the spoil leveled out, or obstacles placed on the reverse slope of a terrain feature can be effective. If the obstacle cannot be concealed by the terrain or camouflage, smoke can be used to hide it. When smokescreens are employed a few hundred meters forward of the obstacle, not only do they hide the barrier from advancing enemy elements, but they also provide an excellent white background for silhouetting enemy targets or marking the far edge of an engagement area. Construction After the nature of the likely enemy threat has been determined, the right type of obstacle must be selected to meet it. There are two general categories of barrier material: antipersonnel and antitank. Barriers on infantry avenues of approach should consist primarily of antipersonnel resources such as barbed wire and antipersonnel mines. Barriers on armor avenues should be constructed mainly of antiarmor resources such as antitank mines and antitank ditches. Barbed wire generally won’t stop tanks, and ditches generally won’t stop infantry. However, in mounted, combined arms combat, seldom will infantry or armor operate pure, and effective barriers must consist of a mixture of the two types of resources. Figure 4 shows the layout of a potentially effective barrier placed in anticipation of encountering an enemy combined arms threat. The primary obstacle is the antitank ditch, which will stop or divert the Figure 4 Y

0 (SURFACE) S 8 (BURIED).

’ tanks. However, the ditch is no barrier to dismounted infantry and can be used by the infantry for cover during breaching operations. To keep the infantry put of the ditch, it can be filled with concertina wire and antipersonnel mines placed on its floor. The ditch itself can be defeated by an armored vehicle launched bridge (AVLB) or a bladed vehicle that can fill in trafficable lanes. To prevent such mounted breaching, antitank mines are placed on the enemy’s side of the ditch. A combination of visible and hidden mines is most effective. However, the anti-. tank mines are vulnerable to fast breaching by dismounted infantry and must be reinforced and protected by clusters of antipersonnel mines. Two keys to the effective use of barrier devices are mix and depth. A mix of devices prevents the enemy from using any single breaching system to defeat the obstacle. In order to breach, he has to gather an assortment of equipment at the same place and time. Emplacing the devices in depth requires the enemy, in effect, to breach the same obstacle several times, multiplying the length of his delay. Barrier material is often limited by logistical constraints, but there are never any limits placed on creativity. Natural substitutes such as boulders or trees can be used effectively. The enemy can sometimes be fooled by phony tilt rods used to thicken an otherwise thinly seeded minefield. Scrounging can be a lucrative source of barrier material, and old barriers can be stripped to provide additional assets. These construction pointers can be summed up in the fourth rule of barrier planning: Almost anything can be used to build a barrier, so use everything available. A typical battle plan will call for multiple barriers, and a unit physically cannot simultaneously emplace them all. The planner must develop a prioritized work plan to ensure that all necessary barriers are constructed within the time and assets available. The obvious priority of construction should be from most important obstacle to least important. There is a temptation, however, to want to work from front to rear. In many cases, the engagements to be fought deeper in the sector may be more important to overall success than those fought first. The planner must always expect the battle to be fought now, and must arrange for his most important barriers to be in place first. And of course, bamer construction is only one priority among the 17 many battle preparations that must be conducted. Maintenance. unit’s limited personnel and equip- * ment assets. The tendency is to assume the attached engineers or the infantry can do the work while the skilled specialists of the unit focus on their individual preparations; however, there are usually too few engineers for the job and too many competing tasks for the infantry. The rule for the division of barrier labor is: Use whoever is available at the time, consistent with the unit’spriorities. This may have to be tank crews, medics, or cooks. The limited number of trained engineers are better used as special equipment operators and as advisers for work details selected from otherwise less critically occupied troops. Fighting the Barriers After construction, the primary prebattle task becomes securing the bamers. Before attacking, the enemy will conduct extensive reconnaissance of his planned routes to locate and, if possible, to clan-destinely breach obstacles. The rule here is: A barrier breached before the battle is no barrier at all. All obstacles, even those deep in the sector must be under constant observation, especially during periods of limited visibility. Additional security can be gained by constructing or maintaining surprise-essential obstacles during limited visibility conditions. Armed construction parties are in themselves security elements that can free combat elements that would otherwise be assigned dedicated obstacle security missions and diverted from other tasks. At a minimum, when dedicated security cannot be afforded, periodic patrolling of all obstacles to interdict enemy patrols and locate possible breaches must be conducted. This effort can be bolstered by ground surveillance radar support and interdicting fires placed on the obstacles. A fundamental tactical principle is that barriers must be covered by fire. The type and amount of fire, however, is governed by the location and purpose of the barrier. In some situations, long-range indirect fire may suffice. In others, the entire concentrated fires of the unit may be required. The tactical intent specified by the scheme of maneuver determines the degree to which the obstacle will be covered and the success and survival on the battlefield, even in the face of over- I whelming enemy strength. types of weapons used to do so. Once the initial engagement is successfully completed, it may be necessary to restore the barrier to prepare for the engagement of the next enemy echelon. The barrier plan must assign specific repair responsibilities for each of the obstacles and provide for pre-positioned repair equipment and materials. Conclusion To win outnumbered, a smaller force must seize the initiative from its larger enemy, disperse the enemy’s mass, and defeat his elements piecemeal. Fires and maneuver must be combined with an effective bamer plan to gain local superiority of combat power. The successful bamer plan necessary for making all this possible does not develop accidentally. It is the result of detailed consideration of the terrain, combat power ratios, and objectives of the forces involved. The careful application of the principles of bamer planning discussed.above can give an edge in ensuring Footnote 1 For a more complete discussion of the battlefield arithmetic necessary, see “Establishing Disengagement Criteria” in ARMOR, November-December 1984.

served at the NTC as the S3 of the OPFOR Motorized Rifle Regiment, a mechanized infantry battalion S3, and as an S3 observer-controller. His previous assignments include mechanized infantry platoon leader and company commander, adviser in RVN, and assistant professor of English at USMA. He is a graduate of the Infantry Officer Advanced Course and the Armed Forces Staff College. He received his BA and MA from John Carroll University and is presently assigned to the Supreme Headquarters Allied Powers Europe. 18