•  Carrier

Improving Borders and Marines

Marines with the 7th ESB built a concrete road along the U.S.-Mexico border that will support closely coordinated international counternarcotics efforts.
By 1ST LT. Nicolas R. Martino, USMC
Building a road in support of the U.S. Border Patrol engaged 7th ESB Marines who were looking for an opportunity to improve, refine and implement techniques they learned while on a seven-month combat deployment to Afghanistan. PHOTOS COURTESY 7TH ESB, USMC

From March to June 2012, Marines with the 7th Engineer Support Battalion (ESB) constructed a 0.5-mi, 12-ft wide concrete road in support of the United States Border Patrol’s efforts to curtail illegal international immigration and interdict transnational criminal activities in the Western Hemisphere. The concrete road cuts through an area parallel to the Mexican border called Bunker Hill, located in Imperial Beach, Calif.

To train Marines without the advantage of recurring deployments, 7th ESB sent two platoons to the Mexican-U.S. border to build the concrete road. The multimonth project would provide an arduous training environment to improve each Marine’s critical thinking process related to horizontal engineering and swiftly enhance the Border Patrol’s mobility.


7th ESB was coming off a seven-month combat deployment to Afghanistan and was looking for a method to improve, refine and implement techniques and training learned while forward deployed, seeing that force drawdowns were cancelling any future combat deployment.

While deployed, the Marines had performed flawlessly, constructing roads throughout Helmand Province. But without future predeployment training and subsequent combat deployment operations, sustainment of 7th ESB’s advanced horizontal construction skills would be difficult. Devising other ways to maintain their ability, proficiency and motivation was uppermost in every leader’s mind. In addition to sustaining basic engineering capabilities, it is necessary to build upon the skills that young Marine engineers are taught at their primary occupational specialty school to be ready for any contingency as mobility enablers in expeditionary environments.

A unique, highly productive way to overcome training shortfalls would be by soliciting training through projects of Joint Task Force North (JTF North). Tasked to support our nation’s federal law enforcement agencies in the identification and interdiction of suspected transnational threats within and along the approaches to the continental U.S., JTF North’s mission incorporates an occasional engineering project that directly supports our nation’s federal law enforcement agencies and international relations. In the case of 7th ESB, the Border Patrol at Imperial Beach required engineering support specifically to maintain the closely coordinated U.S. and Mexico international counternarcotics efforts.


This JTF North project would be executed and utilized by 7th ESB as a remedy to counter foreseeable engineer training shortfalls. The location, known as Bunker Hill, is home to World War II-era bunkers that separate the east and west sides of the Border Patrol’s surveillance area. Due to steep slopes and treacherous landscape, the newly constructed fence line that fortified the old border fence did not connect parallel east-west black top roads on either side of the hill. The project would be to connect the blacktop roads with a 12-ft concrete road, replacing existing all-terrain vehicle trails that ran over Bunker Hill.

Because the location made it extremely difficult for agents to respond to an incident, by replacing trails with a 12-ft wide concrete road the tactical mobility and day-to-day operations of the Border Patrol would be significantly enhanced. This would improve observation, reaction time and homeland security efforts.


Following numerous site surveys, coordination with JTF North, Border Patrol and private contractors, 7th ESB accepted the project and was tasked to complete the first two of three phases.

Phase I. Scheduled for a six-week effort working six days a week, the work consisted primarily of earth moving as more than three-quarters of the project was designed on native soil with slopes varying between 50 percent to 75 percent. Due to strict guidelines and design specifications, the task organized platoon was augmented with drafters, surveyors, truck drivers and electricians, in addition to the primary heavy equipment organization. Contrasting with 7th ESB’s previous combat road construction on relatively level surfaces, Bunker Hill provided the assignment’s most challenging aspect since the design called for slopes from 17 percent to 25 percent.

The steep slopes on the west side of Bunker Hill presented a significant challenge as the slump of the concrete varied from three to five.

Operating commercial equipment much larger than standard Marine Corps equipment on the slopes challenged the team’s heavy equipment operating skills. More than 30,000-yd³ of earth was moved in 2,000 equipment hours. In addition to meeting designed slope and roadway width, a precise soil compaction of at least 90 had to be achieved. Compaction is not new to Marines, but having compaction tested and scrutinized was. Utilizing native soil, the team hydrated the soil at a separate location and transported the moistened soil in 9-yd³ lifts. Following the earthwork completion, electricians excavated an 1,100-ft-long by 3-ft-deep trench, and laid 3-in conduit to house more than 10,800-ft of electrical wire to enable installation of 40-ft steel light poles to illuminate the roadway.

Phase II. To commence the concrete pour, a separate task organized platoon was brought in, replacing heavy equipment operators with combat engineers. The platoon developed a battle rhythm to alternate prep and pour days throughout the six-day workweek. Prior to a “pour day,” each 40-ft segment of road had to be framed and reinforced with wire mesh. The majority of the platoon had never used a concrete pump truck before nor the 80-lb steel pipes. Moreover, the steep slopes on the west side of Bunker Hill played a significant challenge as the slump of the concrete varied from three to five.

Pouring the concrete thicker prevented it from running downhill. Every Marine pitched in as part of the pour and finishing teams, regardless of skill set. To pour the 483-yd3 of concrete needed consumed three of the six weeks allotted for Phase II. The Marines of 7th ESB then accelerated beyond the Phase II end-state, completing installation of one 40-ft light pole and installing wiring and ground work for two more before turning over light pole installation to a U.S. Army unit for Phase III.


From heavy equipment operator to combat engineer, every Marine increased proficiency while working on this road project. Each engineer was challenged with new and different situations. The mission commander had to prioritize activities, juggle civilian contractors and act as JTF North liaison. Small unit leaders had to meet daily critical tasks and timelines. Each member of the team had to take on roles with variables unique to what they had experienced before. Most importantly, the physical and mental demands of this project provided 7th ESB with the advanced skill training without a recurring combat deployment cycle.

Though a mile onto U.S. soil, the assignment played a critical role in the international effort to combat transnational criminals operating throughout the Western Hemisphere, and will prepare these Marines for future missions around the globe.

1st Lt. Nicolas R. Martino, USMC, was Mission Commander, Charlie Company, 7th ESB; 518-727-6086, or This email address is being protected from spambots. You need JavaScript enabled to view it..