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Lightweight Modular Causeway
System: Logistics Advanced
Concept Technology Demonstration

Since their inception in 1995, the Department of Defense’s Advanced Concept Technology Demonstration (ACTD) and Joint Capability Technology Demonstration (JCTD) programs have deployed critically needed warfighting solutions to every major theater.

The combatant commands drive ACTDs and JCTDs through their stated operational priorities and needs, which are then applied to a more agile acquisition process, yielding results years ahead of traditional materiel development cycles. By stressing technology and integration of capabilities rather than technology development, ACTDs and JCTDs can provide prototype capabilities to the warfighter more quickly and provide follow-on support in the evaluation of those capabilities.

A sterling example of these programs is the lightweight modular causeway system (LMCS), which comprises one-half of the Joint Enable Theater Access Sea Ports of Debarkation (JETA/SPOD) ACTD. LMCS’s development was strongly supported by the U.S. Pacific Command (PACOM), its combatant command sponsor; the Army Engineer, Research and Development Center, which provided technical team support; the Army TACOM Life Cycle Management Command, which provided transition team support; and the Space and Naval Warfare Systems Command, which provided operational management team support. Contractor support came from Alion Science and Technology, Booz Allen Hamilton, Demaree Inflatable Boats, Oceaneering International Incorporated, and Quantum Engineer Design Incorporated. The Marine Forces Pacific Experimentation Center provided an independent assessment at various points during this multiyear project, helping the teams to stay on task and focus on problem areas.

Concept and Development

DOD strategists continue to forecast a requirement for shallow-draft vessels to be used for conducting offload operations at austere sites. These operations and natural disasters require a new causeway system that is transportable by, and employable from, intratheater sealift vessels such as the joint high-speed vessel.

The core technologies used in designing and building the causeway prototype included quick-deploy, lightweight pneumatics; lightweight materials; high-strength elastomeric springs for joint compliance between modules (the same technology used to mitigate the effects of earthquakes in building construction); and high-strength fabrics for robust puncture- and abrasion- resistant floatation components. These technologies reduced the causeway’s size and weight by 50 percent. Based on successful initial tests at Fort Eustis, Virginia, and Vicksburg, Mississippi, LMCS segments were fabricated and the complete unit, including a shipboard emplacement and recovery system, was tested and demonstrated on the Army logistics support vessel 5 MG Charles P. Gross in September 2008.

Transformational and Interoperable Technology

This transformational logistics technology was designed from the ground up to meet the current and future operational needs of the joint warfighter. Whether the need is force projection, maneuver, sustainment, disaster relief, or noncombatant evacuation operations, the key elements of a successful military response include speed, agility, and access.

A hybrid of the tactical fixed bridging and the floating causeway system, LMCS will increase the number of potential landing sites by bridging the gap between an austere environment and a point offshore with sufficient depth for vessels to operate. It is lighter and more agile than current systems, allowing for rapid delivery of food, water, and needed medical supplies in case of a loss of roads, bridges, or port infrastructure. The system can deploy as many sections as needed.

Future plans include deploying LMCS across mudflat and tidal estuary barriers and testing its suitability for intermodal land, sea, and air transport, including transport by C–17 and C–5 military airplanes or heavy-lift helicopters. It also can be hauled by truck. The system is compact, allowing 120 feet of causeway to be shipped or stored in a space with a footprint equal to that of three 20-foot ISO (International Organization for Standardization) containers. LMCS is fully interoperable with existing and future Army and Navy watercraft and is designed to handle all classes of military vehicles, including the 70-ton M1A2 Abrams tank.

Unlike other systems, the LMCS uses no in-water connections. And in contrast to the current causeway systems, which can take over a day and a company of Soldier or Sailors to assemble, LMCS can be deployed by seven trained personnel and be operational in approximately 3 hours. An equal number of personnel can recover the system in approximately the same time. The system is stored in a folded configuration with floatation bladders empty. When deployed, the system is sequentially joined, or assembled, and the floatation bladders are inflated. The bladder nearest the shore can be partially inflated as needed to provide a ramp-like entry and exit point.

A unique feature of the LMCS is that the floatation bladders will not be filled with high-pressure air. Instead, they will be rapidly filled with only the volume of air suitable to provide floatation for the roadway system. This significantly speeds up deployment times and can be done with a prepressurized compressed air system (similar to that used to inflate aircraft emergency exit slides) or with a lightweight portable blower system that is smaller than a commercial vacuum.


No project is without challenges and solutions. A delay in funding and a 40-percent increase in some material costs, such as ship-grade aluminum, meant that the team had to develop, design, build, and test the new system in 15 months instead of the 24 months originally planned. This included breaking design paradigms in order to meet operational requirements and achieve compliance for austere coastal operations, to include survivability in high sea states. To meet this requirement, the LMCS teams developed a new double-compressive joint using high durometer urethane elastomers that provided dependable, repetitive compliance with very limited fatigue and that could support an M1A2 Abrams tank.

Another significant challenge came in the form of simple program management. As the operational managers, the Hawaii-based team was responsible for preliminary design reviews, critical design reviews, and outreach. The technical management team comprised engineers and scientists in Mississippi (causeway), Oregon (floatation system), and Maryland (shipboard deployment system). Transition management (insertion into a DOD Program of Record and outyear funding) was centered in Michigan. A successful ACTD program requires solid program management and, in this case, a balance between discipline and flexibility in scheduling, careful consideration of risk mitigation options, and concise but thorough communications.

Success and Transition

Active, engaged leadership is essential to the success of any program. Throughout this multiyear project, the ACTD team received support from senior PACOM leaders, successive Army Chiefs of Transportation, and the Army Deputy Chief of Staff G–8. Early support came from the Marine Corps Combat Development Command. In September 2008, PACOM hosted a successful Distinguished Visitor Day that culminated with a flawless demonstration of the LMCS.

The system was delivered on time, on budget, and within performance goals. Now the capability must be accepted by a DOD Program of Record, and funds must be identified for future life-cycle requirements. The Product Director, Army Watercraft Systems, and the Army Deputy Chief of Staff G–8 have agreed that PACOM will retain the prototype system for use in the Pacific theater during fiscal years 2009 and 2010. Transition of the causeway to the warfighter as a required capability is planned to occur as early as fiscal year 2012, in concert with the fielding of the Army’s first joint high-speed vessel.

Overall, this effort employed a team of teams from Government and industry and was dispersed organizationally among multiple commands, geographically among multiple locations, and culturally (from science and research and development to engineering, manufacturing, and operations). Maneuvering from concept through program approval by the Office of the Secretary of Defense, design, development, testing, training, assessment, and acceptance of a new capability in just 4 years is a strategic success and holds promise not only for DOD but also for non-DOD professionals conducting disaster relief and humanitarian assistance operations worldwide.

Margaret A. Deming is the readiness analyst, G–3/5, Marine Forces Africa, in Stuttgart, Germany. She was the deputy manager, Lightweight Modular Causeway System Advanced Concept Technology Demonstration, attached to the Space and Naval Warfare Systems Command at San Diego, California, and the U.S. Pacific Command Logistics, Engineering, and Security Assistance Directorate (J–4) when she wrote this article.