1st Cav: engineering countermobility for insurgent indirect fires and mobility for Coalition Forces.

On 21 February 2005, an Army-Marine combat operation systematically destroyed the far and near bridgeheads on a key enemy smuggling and infiltration route across the Euphrates River near Baghdad. The operation eliminated the anti-Iraqi forces' (AIF's) last passage from the eastern edge of northern Babil into southern Baghdad. This route commonly was used to launch deadly indirect fire attacks into the International Zone in Baghdad.

Days later, a Marine-secured combat assault and obstacle (A & O) engineer (EN) platoon "grubbed and cleared" debris and earthen berms along a 10-kilometer stretch of restricted terrain in northern Babil, allowing freedom of movement for civilians and Coalition Forces throughout the area of operations (AO). At the same time, a combat EN reserve platoon and its infantry (IN) brethren uncovered several rockets, improvised explosive devices (IEDs) and munitions caches in graveyards and mining pits in northern Babil. Combined intelligence (S2) and operational analyses of AIF smuggling patterns, primary IED trends and support zones led to these finds.

Through planning and execution, mobility and countermobility operations disabled the insurgents' power to disrupt the emerging Iraqi government and provided security to the Iraqi people.

The Threat. The 5th Brigade Combat Team (5th BCT), 1st Cavalry Division (1st Cav), deployed from Fort Hood, Texas, to southern Baghdad in March 2004 for Operation Iraqi Freedom (OIF) II. The BCT operated out of Camp Falcon, a forward operating base (FOB) along Highway 8, the road to Baghdad International Airport. The 5th BCT was commanded by the 1st Cavalry Division Artillery Commander, Colonel Stephen Lanza, after the Div Arty had been designated a maneuver BCT.

The 5th BCT's AO was a support zone for an AIF command and control ([C.sup.2]) center and the locus of most indirect fire attack points of origin (POO) in the Baghdad area.

The insurgents used aerial bombs from former Iraqi Air Force bases, ammunition depots and hidden caches to make several IEDs. These IEDs destroyed M1114s and up-armored high-mobility multipurpose wheeled vehicles (HMMWVs), killed and maimed 5th BCT Soldiers and hindered the division's mobility and patrol of designated "rocket boxes": named areas of interest (NAIs) from which insurgents launched rocket attacks.

Early in the deployment, the AIF attacked Camp Falcon with light and medium mortars (60-mm and 82-mm) integrated with deadly and accurate light to medium rockets (57-mm, 67-mm flechette, 100-mm, 107-mm, 122-mm and 127-mm) from improvised rocket launchers, trays and earthen berms. Indirect fire attacks produced Coalition Force casualties, a number of casualties second only to those caused by IEDs.

The AIF used open areas near schools, urban areas and religious sites to launch attacks, taking advantage of constraints imposed by counterstrike rules of engagement (ROE). Another limitation was the rapid displacement times of mortar and rocket teams, averaging less than two minutes. Rotary-wing air support was key to most missions but often resulted in deterring indirect fire instead of killing insurgents.

Terrain also favored the enemy: the southeastern border of the 5th BCT's AO totaled 70 square kilometers of farmland, abundant in date palm groves and bordered by the Tigris River. The enemy had the edge while area civilians could not report AIF activities due to limited visibility and no communications infrastructure.

During August and September 2004, many 60-mm and 82-mm mortars and 107-mm and 122-mm rockets hit Soldiers' living quarters on FOB Falcon, prompting the 5th BCT commander to implement an innovative and aggressive countermobility engineering solution.

This solution combined ongoing combat patrolling with aerial surveillance to stop enemy indirect fires. The BCT commander ordered the staff to analyze the enemy's terrain use leading into and out of the support zones and determine the enemy's tactics, techniques and procedures (TTPs) and operational patterns.

Operations Thunderstruck and Hardball. The brigade staff developed the enemy TTPs, patterns and terrain use and then reverse-engineered scenarios for mortar and rocket indirect fires.

The central analysis team included the S2; assistant brigade engineer (ABE); 1st Battalion, 8th Cavalry's (1-8 Cav's) assistant operations officer (A/S3) (primary area of focus); the terrain team NCO; and the fire support cell NCO. The team collected fragments of information from historical IED sites: exploded/found rocket POOs, destructive/unsuccessful mortar POOs and trajectories, rocket and mortar ranges, radar acquisitions, visual sightings and confirmed POO sites; it also determined major and minor roads, vegetation, waterways, bridges, urban and military graphics, and critical infrastructure of interest, including Sunni, Shi'a and radical mosques.

The terrain team put the information on terrain overlays for a graphic representation on a 1:5000 scale model of the 5th BCT's AO. The S2 reviewed the terrain model and added enemy operation cells, actions, movements and command cells within each of the threat support zones. 1-8 Cav's A/S3 compiled an additional overlay with the S2 to integrate more patrol debriefing information. The fire support cell NCO analyzed and briefed the POOs, other missed information from radar acquisitions, enemy indirect fire TTPs and the enemy weapons capabilities.

The ABE reverse-engineered the information into an obstacle overlay for countermobility and identified the need for Coalition Forces' mobility to apply direct pressure on areas the enemy had to cross: the AIF limit of advance (LOA).

The countermobility plan evolved into Operation Thunderstruck, and the mobility overlay became a comprehensive brigade plan, called Operation Hardball. Finally, the judge advocate general (JAG) played a critical role in ensuring Operation Thunderstruck didn't violate the ROEs.

Operation Thunderstruck was an overall obstacle (countermobility) plan to block the enemy's use of key terrain and hinder his movement, preventing immediate egress from the POO to south Babil. The BCT executed a combination of kinetic and mechanical blocking on the south-north routes in key terrain along the southern boundary of the 5th BCT's AO from the Baghdad Airport to the Tigris River. The block forced the enemy to use only checked and heavily patrolled routes and the 5th BCT's clearly defendable terrain during movement between his hiding positions and the indirect fire launch sites.

Operation Hardball was a mobility plan allowing Iraqi and Coalition Forces freedom of movement to and from key terrain, with minimal danger from IEDs and maximum accessibility with more speed. Heavy engineering assets shaped the terrain for maximum horizontal east-west movement.

Engineers developed a safe passage by expanding roadsides; clearing and grubbing ambush areas; constructing new roads; expanding culverts and culvert heads; and hardening the road surface with chip-rock, concrete and (or) asphalt. The heavy reserve engineers developed critical avenues of approach (AAs) to the terrain and rocket boxes. Construction contractors used the commander's emergency relief program (CERP) funds for most of the remaining AAs.

Together, Operations Thunderstruck and Hardball blocked the enemy's freedom-of-movement to the POOs and allowed Coalition Forces to close with the enemy while using economy-of-force. The collective planning and execution phases began in October 2004 and continued into February 2005.

Site reconnaissance and cross-terrain imagery scans followed initial planning with updated one-half meter imagery and imagery from the Shadow unmanned aerial vehicle (UAV).

Due to limited organic resources, the EN brigade brought in engineers from allocated reserve units. The 5th BCT organic resources included the 515th Forward Support Battalion-lift, B/8 EN, Headquarters and Headquarters Company (HHC)/1-8 Cav, the terrain team, psychological operations (PSYOP), medical support, an explosive ordnance detachment (EOD) team and the 1st Cav's 4th Brigade attack helicopters.

[ILLUSTRATION OMITTED]

The ABE briefed and rehearsed the operation. After conducting movement-to-contact, security elements established an outer and inner cordon with air coverage while PSYOP teams engaged the local people on the objective.

Addressing multiple sites simultaneously, the engineers used augers and dozers to bore holes and emplace explosives and tamp them. The explosives included C-4, TNT, mine-clearing line charges (MICLIC), 40-pound cratering charges and large unexploded ordnance (UXO) and satchel charges. Local people within the danger zone were removed.

The explosions produced surprising and effective results. Besides an enormous cut in the road with large canals tied in, the explosions sent a message to the local populace and the AIF: the Coalition is here to defend them and the enemy is no longer wanted.

Because PSYOP engaged them, the people no longer could straddle the fence; they turned to the Coalition for help, subsistence and security. The day after the cut, the heavy engineers came in, emplaced large Alaskan nine-ton barriers into the ground and brought payments to the Iraqi people who had broken windows or crop damage from the blast.

Then the 458th Corps Wheel Engineers and 411th Heavy Combat Engineers came into the communities and created, improved, grubbed and cleared, and developed roads from goat trails into highways. Finally, after creating and approving CERP packets, Coalition Forces hired hundreds of Iraqis to clean the parallel areas of foliage and trash; construct new culverts and culvert heads; widen shoulders; and asphalt, concrete or chip-rock the surface of the 10-meter wide road. The entire community benefited from the project.

In the last two months of deployment, the 5th BCT became the higher headquarters for the 2/24 Marines, which occupied the northern Babil AO. With that, the 5th BCT commander expanded Operations Thunderstruck and Hardball into the southern area of the AO to block the enemy again and destroy him in place. The last Thunderstruck/Hardball mission used 2/C and 2/A/612 Combat EN (Reserve) working with A/2-162 IN (Reserve) and F Company, 2/24 Marines (Reserve). These units' operations led to the capture of an AIF cell and a large cache along the Euphrates River that contained medium-range rockets, pre-made IEDs and tons of munitions.

Blocking the enemy from his ingress/egress to indirect fire sites and forcing him onto patrolled and controlled roads was the goal of the 5th BCTs countermobility engineering operations. These operations succeeded, decreasing the number of attacks in the AO, while engineers opened a mobility corridor for Coalition Forces to traverse with safety and speed.

Captain Patrick S. Marsh, Engineer (EN), was the Assistant Brigade Engineer for the 5th Brigade Combat Team (5th BCT), 1st Cavalry Division, Fort Hood, Texas, returning from a 12-month tour in Operation Iraqi Freedom (OIF) II in March. Among other assignments in the 1st Cavalry Division, he was an Assistant Brigade Engineer for the 4th Brigade Aviation and Assistant Operations Officer for the 8th Engineer Battalion.

Major Robert L. Menti was the 1st Cavalry Division Artillery (Div Arty) S3 at Fort Hood. Currently, he is a student at the Command and General Staff College, Fort Leavenworth, Kansas. Also in 1st Cav Div Arty he was the S3 for the 1st Battalion, 21st Field Artillery (1-21 FA) (Multiple-Launch Rocket System) and Aviation Brigade Fire Support Officer. He deployed to OIF II as 1-21 FA's S3 and, later in OIF II, served as the 5th BCT's S3.

Captain Luis M. Alvarez was the S2 of the 5th BCT during OIF II. Currently, he is the Commander of the Headquarters and Headquarters Detachment of the Research, Development and Engineering Command (Natick Soldier Center), Natick, Massachusetts. His previous assignments include serving as the S2 of 4-7 Cav, 2d Infantry Division, in Korea, and 1st Cavalry Division G2 Targeting Officer and S2 of the 1st Cav Div Arty, the latter two assignments at Fort Hood.

By Captain Patrick S. Marsh, Major Robert L. Menti and Captain Luis M. Alvarez