Through the Defile: Attacking Through Restrictive Terrain

THROUGH THE DEFILE:

Attacking Through Restrictive Terrain

Damn it. “Checkpoint 8 into Checkpoint 54 again,” thought the armor team commander as he walked away from the battalion operations order (OPORD). “I know the OPFOR has that defile covered with both direct and indirect fire weapons systems. How the heck am I going to get through that defile without losing all my combat power again?” How many times has this question entered your mind? Whether during combat or at one of the Combat Training Centers (CTCs), getting through the defile is one of the toughest missions for a mounted unit. As the U.S. Army continues to fight in restrictive and limited terrain, the Armor force must transform its thinking away from the open plains of Europe and the rolling sands of the Middle East. Mounted forces must overcome restrictive terrain, whether mountain passes, thick forests, or urban buildings. Using a planned attack through Combat Maneuver Training Center (CMTC) Checkpoint (CP) 8 into CP54 allowed us to work though a successful defile drill. Situation The mission is to attack from east to west, up Regulator Valley through CP8 and seize Objective Grant, the high-ground vicinity of CP54 (The Griffen-wang), to restore the international boundary line. See Figure 1. The company team consists of two tank platoons equipped with four M1A1s (White and Blue platoons); one Bradley platoon equipped with M2A2 Operation Desert Storm (ODS) (Red platoon); two dismounted squads; the commander’s tank; the executive officer’s tank; the first sergeant’s M113; one maintenance M113; and one medic M113. The fire support team (FIST) officer is riding in his M981 FIST-vehicle (FIST-

V) to call in accurate indirect fires. Based on the intelligence report from the battalion S2, we can expect eyes forward of CP8 covering the Regulator Valley, possibly one BMP (Russian infantry combat vehicle) and one BRDM (Russian threat scout car). On the other side of CP8, overwatching the deadly defile is one reinforced platoon, three BMPs and one T-80. The enemy situational template (SITTEMP) below clearly indicates the potential enemy engagement area covering the exit of the defile. U.S. Army Field Manual (FM) 71-1, Tank and Mechanized Infantry Company Team, discusses clearance in restrictive terrain, which describes a defile drill exactly.1 FM 71-1 states, “Conducting clearance in restricted terrain is both time-consuming and resource-intensive.” During the planning process, the commander evaluates the tactical requirements, resources, and other considerations for each of the three pieces of the operation:

• Approach (the restricted terrain).

• Clear (the area in and around the restricted area).

• Secure (the far side of the objective area).2 Our attack will therefore be broken into three parts. The first is the approach up to CP8. In this case, up through the Regulator Valley and eliminating the eyes forward of the defile. Our next part will be clearing through CP8 and out of the defile. Our final part of the assault to seize CP54 is securing our objective. Approach. Some critical tasks listed in FM 71-1 approaching the defile are:

• Move dismounted infantry elements along axes that provide cover and concealment.

• Provide support-by-fire for the dismounted infantry. Be prepared to cover infantry elements from their dismount points to the points at which they enter the restricted terrain.

• Provide additional security by incorporating suppressive indirect fires and obscuring or screening smoke.

• Establish support-by-fire positions with the team’s tanks and Bradley Fighting Vehicles (BFVs); destroy or suppress any known enemy positions to allow forces to approach the restricted terrain. 18 ARMOR — January-February 2003 “As the U.S. Army continues to fight in restrictive and limited terrain, the Armor force must transform its thinking away from the open plains of Europe and the rolling sands of the Middle East. Mounted forces must overcome restrictive terrain, whether mountain passes, thick forests, or urban buildings.”

These tasks are listed in the reverse order of FM 71-1 for a specific reason. Due to time constraints and the highly lethal use of OPFOR artillery, speed is critical to get to the defile. The commander develops a rather unorthodox plan to clear the Regulator Valley up to CP8. Operating in split sections, the infantry platoon (Red) moves with two M2A2 Bradley’s up each side of the valley in the wood line. The Bradley’s orient their fires forward. Approximately 150 meters behind each Bradley section is a two-tank section (White) orienting their fires across the valley to the opposite walls. Figure 2, from FM 71-1, demonstrates this crossfire technique when clearing up a valley. Based on the enemy SITTEMP, the company commander designates a probable line of contact (PLOC) at Phase Line Maine for the infantry platoon. Approximately 100 meters from this line, the Bradleys will drop ramps and let the dismounted squads clear the woods forward. The dismounted infantry carry enough firepower to knock out light armored vehicles and are supported by their organic Bradleys. This technique is much more effective in combat where the 25mm’s full capabilities can be seen. In combat, an 8-inch tree will not stop a 25mm antipersonnel round and the suppressive effects against dismounted infantry with a 25mm high explosive (HE) round is devastating. Acting as the beaters, the infantry platoon is to clear the woods for the enemy eyes forward. The split sections of tanks are the hunters, orienting ahead of the infantry platoon, looking to make the kill shot. The XO with the FIST officer follows behind White platoon. Key to successful direct fire controls of the split sections operating with dismounted infantry is to know exactly where the dismounted squads are operating in the wood line. Although the tanks have thermal sights capable of sighting troops in the woods, only with established signals can the vehicles correctly identify friendly soldiers. Some techniques to mark the frontline trace of the dismounted squads include:

• Marking the man nearest to the wood line with a VS-17 panel, chemical light or phoenix beacon.

• Using smoke grenades with color to indicate position (violet) or contact with enemy bunkers requesting armor support (yellow).

• M203 parachute flares (remove parachute) shot toward open areas to show dismounted progress, or star clusters during night operations. Following approximately 300 to 500 meters behind Red and White is the Blue platoon. Acting as the assault element, Blue platoon’s mission is to assault through the defile and destroy enemy vicinity CP54. Alpha 6 and his crew move with Blue platoon to maintain control over the company and to be with the assault force. “All Alpha elements, this is Alpha 6, line of departure (LD) time now.” As Team Alpha moves toward CP8, a steady roll of armored forces advance toward the enemy. Fortunately, no contact is made prior to the PLOC. Red 6 pushes his dismounts forward while the Bradleys maneuver to provide cover. White platoon continues to scan the wood line for any enemy forces while continuing a slow move staying within 150 meters of the advancing Bradleys. Frontline traces are continually called over the company net to advise all players on Red’s progress. Slowly, dismounted infantry controlled by their squad leaders push through the cold, wet pines looking and listening for enemy sounds. The northern squad leader pauses as he focuses on a glint of sunshine to his front. Suddenly, an engine starts to their front and a BRDM breaks toward the valley. An AT-4 fires but misses by a long shot. As the BRDM ARMOR — January-February 2003 19

OBJ

Grant PL Florida (LOA) Regulator Valley PL New York PL Maine

(PLOC)

PL Texas

(LD/LC)

OBJ

Grant PL Florida (LOA) Regulator Valley PL New York PL Maine

(PLOC)

PL Texas

(LD/LC)

Figure 1 Figure 2

tries to maneuver around thick trees, it disappears in a shower of sparks and flames as Red 8 pumps three 25mm HE rounds into the wheeled vehicle, destroying it completely. “Alpha 6, Red 7. Engaged and destroyed one BRDM, time now. Continuing mission, Slant 4, over.” “So, the SITTEMP was fairly accurate,” thought Alpha 6. “Red 7, Alpha 6. Roger, Out.” Continuing their move, Team Alpha advances toward CP8. Just as the southern dismounted squad hears metal on metal, a BMP opens fire, launching round after round of 30mm toward the Bradley platoon. Red 9 feels the impact of rounds against his vehicle, blowing the track off his Bradley. Before he has time to slew the turret, 30mm rounds explode through the hull, killing the crew. Red 7 spots the flashes through the pines and immediately begins to suppress. The dismounts start to flank around the BMP. Realizing dismounts are maneuvering on his position, the OPFOR tank commander (TC) decides to break contact. Backing his BMP up, the TC pivots past an opening in the trees when… BOOM! A 120mm high explosive antitank round fired from White 8 puts an end to his maneuvering. The valley is clear. Dismounted infantry squads start their climb up to CP8. Alpha 6 realizes the enemy must have preplanned artillery all around CP8. Knowing his team is approaching the defile, he contacts his FIST. “Alpha 17, Alpha 6. Fire linear smoke target AE4041, over.” Prior to beginning his assault, Alpha 6 and his FIST plan artillery and mortar targets to assist in their mission. Alpha 6 requests and receives battalion mortar priority of fires from his commander. Knowing the battalion 120mm mortars will provide rapid and lethal fires, Alpha 6 plans two targets on the templated enemy position, AE 2020 and AE 2021. The task for each target is to suppress the enemy with the purpose of facilitating the attack through the defile. With his field artillery priority of fires, Alpha 6 plans three linear smoke targets, AE 4041, 4042, and 4043. Alpha 6’s thought process is to plan different smoke targets depending on the winds. Once the initial fire mission is called and smoke rounds start landing, the FIST officer in his track will adjust the smoke to obscure the positioning of the support-by-fire elements, and to facilitate the attach to Objective Grant. Clear. FM 71-1 lists critical tasks in the clearance part of a defile operation as:

• The infantry conducts clearance operations in concert with the BFVs or tanks. Combat vehicles provide a base of fire to protect infantry elements as they clear an area. The infantry stops at a designated point or terrain feature where observation is affected; it provides a base of fire to allow the vehicles to bound to a new support-by-fire position. This cycle continues until the entire area is clear.

• BFVs may be better suited than tanks to support the movement of the infantry in defiles and in urban areas with multiple-story buildings. This is the result of the BFV’s ability to elevate its main gun to an angle of +60 degrees (an M1-series tank can only elevate to +20 degrees). Tanks, however, are very effective in destroying bunkers and other fortified positions; they can also neutralize and/or penetrate ground-level floors in buildings, providing the infantry with support and access to this type of restricted terrain.

• Within the restricted area, tanks should be brought forward only to accomplish specific missions that are within their capabilities. Factors that may limit the usefulness of tanks in clearance operations include the following: - Short engagement ranges, which may be prevalent in these operations. - Limitations in elevating the main gun. - Significant blind spots associated with targets above the tank.

• At the same time, tanks have more effective armor protection than do BFVs and thus have greater survivability. They can also provide cover for infantry elements that move behind them when crossing danger areas.

• Direct fire plans should cover responsibility for both horizontal and vertical observation and direct fire.

• Infantry squads should clear a defile from the top down and should be oriented on objectives on the far side of the defile.

• Dismounted engineers with manual breaching capability should move with the infantry. Additionally, engineers should move with the overwatching vehicles to reduce obstacles.

20 ARMOR — January-February 2003 “The commander develops a rather unorthodox plan to clear the Regulator Valley up to CP8. Operating in split sections, the infantry platoon (Red) moves with two M2A2 Bradley’s up each side of the valley in the wood line. The Bradley’s orient their fires forward. Approximately 150 meters behind each Bradley section is a two-tank section (White) orienting their fires across the valley to the opposite walls.”

• During the clearance process, tanks and BFVs may be required to operate in direct support of infantry elements.3 Slowly the team moves toward CP8. The dismounts move through the cover of thick pines to where they have observation into the bowl surrounding CP54. Red platoon and the dismounted infantry ensure the wood line on either side of the CP is clear. The three remaining Bradleys cover the movement of the dismounts up to CP8. A brief firefight ensues as the northern dismount squad makes contact with a possible OPFOR forward observer team. With the help of Red 6 and deadly HE rounds, the enemy dismounts are killed, eliminating the enemy eyes on CP8. The Bradleys push forward to find good support-by-fire positions south of CP8 while the dismounted infantry assists in guiding the White platoon tanks into positions north of CP8. A quick scan of the valley reveals no enemy and no visible obstacles. Smoke begins to build as the linear smoke target (20-minute duration) lands. Things now move rapidly for Alpha Team. Red and White platoons are set in two support-by-fire positions on either side of the defile, orientating toward the objective. The movement of the tanks into their positions, guided by the dismounted infantry does not go unnoticed. A BMP begins to engage White 6. Tracer rounds ricochet into the sky as rounds land short of the tank platoon. White 8 turns his flank toward the BMP as he tries to maneuver and feels rounds slap against his side, tearing the track off the road wheels. Screaming at his gunner to traverse left, White 8 pops his onboard smoke grenade launchers to cover his disabled tank. Quickly the gunner lays on the BMP as it backs up toward the wood line. “Identified!!!,” screams White 8’s gunner. “FIRE!!!!,” yells the TC. Immediately, White 8 Golf (gunner) shouts, “ON THE WAYYYYY!” and de-presses the triggers on the Cadillac, launching a 120mm SABOT into and through the BMP. Its turret spins 20 feet in the air as the hull bursts into flames. Alpha 5 and the FIST-V maneuver into the wood line to get a better view of the valley. With eyes on the bowl, the FIST begins to shift the smoke to better accommodate the assault. “Alpha 6, White 7. Engaged and destroyed one BMP. White 8 is a mobility kill. Slant 4, over.” “Alpha 17, Alpha 6. Give me a status on the smoke over.” “Alpha 6, Alpha 17. We have 10 more minutes of smoke left. Providing good concealment from CP54. Recommend launch assault in 5 minutes, over.” “Patience,” Alpha 6 thought. Knowing enemy artillery would start blanket-ing his support-by-fire positions at any time, possibly cutting off his assault force positioned approximately 300 meters on the western slope of CP8. However, a number of painful experiences were fresh in Alpha 6’s mind about not having the conditions sets prior to an assault through the defile. It was like balancing on the edge of a canoe. Too far in either direction could cause you to go in the deep end. “All Alpha Elements, Alpha 6. Red and White, continue to lay suppressive fire. Blue, start your assault when artillery impacts on Objective Grant. Alpha 17, fire targets AE2020 and 2021, over.” Like a conductor, Alpha 6 was setting the conditions for his assault. With his support-by-fire positions in place covering suspected enemy positions, his assault force in place, smoke obscuring the defile from direct enemy observation, and suppressive fires about to land on templated enemy positions, Team Alpha was ready. Secure. Team Alpha was entering the secure phase of the defile operation. FM 71-1 gives possible actions a company team must prepare for prior to securing the far side of the defile:

• Within the capabilities of the company team, assault to destroy enemy forces and secure the far side of the restricted terrain.

• Maneuver mounted elements to establish support-by-fire positions on the far side of the restricted terrain.

• Conduct support-by-fire to protect the deployment of the follow-on force that is assuming the fight, or destroy or suppress any enemy elements that threaten the task force as it exits the restricted terrain.

• Defeat any counterattacks.

• Protect the obstacle reduction effort.

• Maintain observation beyond the restricted terrain.

• Integrate indirect fires as necessary.4 After five long minutes pass, Red and White have identified one more BMP and are engaging with direct fire. Where is the T-80? Finding its position is the linchpin of the assault. Knowing he is down to 5 minutes of smoke and his luck with enemy artillery is not going to last much longer, Alpha 6 launches the assault. “Blue 7, Alpha 6. Assault, time now!” Blue immediately begins their move. No fancy maneuver yet, just simply armored speed to get through the defile, out of the kill zone. Like infantry soldiers clearing a room, Blue 6 knows he needs to get out of the “fatal funnel” as fast as possible. As Blue crests CP8, White 6 reports contact with the second enemy BMP. White 6 notices too late the lone BMP creep out of the woods again and launches an antitank missile toward his tank. Screaming “SAGGER!” to his crew, White 6 grabs the TC override and attempts to bring the main gun on the BMP. His driver, hearing the traditional command to begin evasive maneuvers, tries to lurch forward only to hit a large tree with the traversing gun tube. White 6 watches in horror as the antitank missile flies closer and closer until a shower of sparks flies from the White 6 tank. White 7 was already directing his gunner on target when he notices the antitank missile slam into his platoon leader’s tank. Giving the fire commands, he watches with grim satisfaction as his uranium depleted SABOT round slices through the enemy BMP. “Alpha 6, White 7. Engaged and destroyed second BMP. Slant 3, White 6 is down. Alpha 7, meet me A&L.” White 7 was meeting the company first sergeant on the company’s internal administrative and logistics net to give a grid to direct the medics to White 6’s tank. Alpha 7 briefs the maintenance and casualty plan during the company OPORD. Using each of the company personnel carriers (PCs), the first sergeant develops a casualty evacuation (CASEVAC) plan, which gives a dedicated CASEVAC vehicle to each platoon. The medic track, with the most medical experience aboard, is assigned to the platoon expected to have the most casualties. In this case, White platoon was anticipated to have the most casualties. The first sergeant’s PC and the maintenance PC were already precon-figured with litters to accommodate casualties. The first sergeant was assigned to cover Blue platoon and the

ARMOR — January-February 2003 21 maintenance PC was ready to evacuate any casualties from Red platoon. By using an internal administrative and logistics (A&L) frequency, the requests for medics, grids of damaged vehicles, and maintenance reports do not tie up the company net during a fight. “All Alpha Elements, Alpha 6. Be on the lookout for that T-80. Alpha 6 out!.” Alpha 6, following behind his assault platoon, clears the intervisibility line and has eyes on Objective Grant. There’s the smoke screen. Blue advances toward PL New York. Still no contact. Once Blue reaches PL Florida, the platoon will turn south and attempt to assault Objective Grant from the rear. Loader’s keep a vigilant watch for air threats as the tanks continue to speed past the objective. TCs and gunners strain to locate any enemy vehicles in their sectors of observation amid the bouncing of man and steel. Suddenly… “Contact T-80 vicinity CP54 OUT!” “Well at least we know where it is now,” thought Alpha 6. Soon the northern support-by-fire position is attempting to destroy the T-80 with direct fire. Alpha 17 calls a shift for AE2020 attempting to get raining steel on the T-

80. Through wisps of smoke, Alpha 6 catches a flash of the T-80’s 125mm main gun. Blue continues to move toward its turning point. Blue 7 is continually on the net giving front line traces. Soon Blue platoon calls out “Phase Line Florida,” and the tanks immediately wheel toward the Objective. The support-by-fire elements plaster the T-80’s area with machine gun fire and main gun rounds. Bradley 25mm rounds arch around the T-80 as ranging shots are quickly followed by 3- round bursts. The T-80 commander has years of experience fighting on this terrain and knows exactly where to maneuver for a good shot. He has his driver ease up into an old half-filled-in fighting position and glances through is binoculars. There! He spots an M2A2 maneuvering for a better position. Quickly he relays the location to his gunner and immediately a 125mm round flies into Red 7’s Bradley. “Alpha 6, Red 6. Slant 2. Lost Red 7 to the T-80. Continuing to suppress, over.” “All Alpha elements, Alpha 6. Be advised Blue is closing in on CP54, time, now. ID all targets. 6 out.” “Alpha 6, Alpha 5. We have eyes on you and Blue. We’ll cover.” “Good,” thought Alpha 6. At least the team can see… “CONTACT FRONT!!,” screams Alpha 6’s gunner. Before he could key the mike, Alpha 6 hears three simultaneous explosions as Blue platoon executes a near-perfect contact drill. Three 120mm SABOT rounds tear through the air, striking the T-80 in less-than-a-quarter second, obliterat-ing the enemy tank and crew. Blue continues to sweep through CP54 finding no more opposition. Apparently, only one T-80 and two BMPs defended this position. The team commander keyed the mike to report to his battalion commander. “Dragon 6, Alpha 6. CP54 secure. Blood count 1/3/1/1. Slant 9/2, over.” “Alpha 6, Dragon 6. Roger. Stand by for FRAGO. Good job, out.” Alpha 6 already knows that his first sergeant is coordinating the evacuation of the wounded and the maintenance team is checking on damaged vehicles. Gazing back at the dissipating smoke toward CP8, Alpha 6 remembers an old “Willie and Joe” cartoon. Thinking aloud, “There we were and here they wuz!” With much of his combat power intact, Alpha 6 begins setting up his hasty defense in case of an enemy counterattack. By following the rules set in FM 71-1, and bending some to his advantage, Team Alpha successfully assaults through a defended defile. Hopefully this article will assist armor leaders in planning, preparing for, and executing a defile drill. Think outside the box to win! Good hunting tankers!

Notes 1U.S. Army Field Manual 71-1, Tank and Mechanized Company Team, U.S. Government Printing Office, Washington, D.C., 26 January 1998, chapter 3, section 6. 2Ibid. 3Ibid. 4Ibid.

CPT Mike Sullivan is an observer controller, Combat Maneuver Training Center, Hohenfels, Germany. He received an infantry commission from the United States Military Academy in 1994. As an infantry officer, he served in various command and staff positions, to include airborne antitank platoon leader, airborne antitank company executive officer, and an airborne rifle platoon leader with 3-505 PIR, 82d Airborne Division, Fort Bragg, NC. Following his branch transfer to armor, he has served as a primary maneuver instructor, Warrior Preparation Center, Kaiserslautern Germany; battalion S3, 1st Battalion, 63d Armor Regiment, 1st Infantry Division, Vilseck, Germany; commander, A Company, 1-63d Armor; and commander, HHC, 1-63d Armor. “The support-by-fire elements plaster the T-80’s area with machine gun fire and main gun rounds. Bradley 25mm rounds arch around the T-80 as ranging shots are quickly followed by 3-round bursts. The T-80 commander has years of experience fighting on this terrain and knows exactly where to maneuver for a good shot. He has his driver ease up into an old half-filled-in fighting position and glances through is binoculars. ” 22 ARMOR — January-February 2003