Advanced Cargo Transfer Facility

ABSTRACT Since the planning phase of the Normandy invasion in World War II, the US Navy has been looking for better ways to move cargo across unimproved beaches. In recent years there has been a shift from breakbulk cargo to containers. Because of their larger size and weight, containers have placed additional demands on today t s Navy cargo offloading systems. The Advanced Cargo Transfer Facility (ACTF) developed by the Naval Civil Engineering Laboratory (NCEL) is a rapidly installed, cargo transfer system which provides berthing for a crane ship and containership. Cranes on the crane ship move containers directly to a pierhead eliminating the need for lighterage. Containers transit from the pierhead to the beach on folding spans supported by jackup foundation modules. Ship mooring is provided by self deploying mooring modules and rapidly installed mooring dolphins. This paper describes the development of this system. See Figure 1. INTRODUCTION Mission The ACTF transfers containers directly from commercial containerships offshore to troops ashore at an advanced base location. The system is transported by commercial vessels and offloaded and assembled by amphibious construction battalion personnel. The ACTF transfers containers at a rate sufficient to support a Marine Amphibious Force (more than 50,000 Marines and sailors). The system may be employed in total or specific hardware developments may be used to upgrade current Navy systems. Developmental Objective The technology developments fostered by the ACTF will expand the Navy's capability for transferring cargo while reducing the shipping required to transport the ACTF by two-thirds compared with current systems. Using ACTF technology a 2,500-foot-Iong pier can be deployed from a single ship. The ACTF consists of a series of foundation modules which are positioned and then jacked up. Folding spans stored inside the modules are then extended to provide the link to shore. Mooring modules and dolphin modules berth the containership next to the pierhead. The crane ship transfers containers directly to the pier, where the containermover transfers them to shore. Since small boat operations are not required, transfer can continue into sea state 4. Anchors and foundations that can function on rock or sediment seafloors will open up previously inaccessible areas. CONSTRAINTS Environment The development of technology to produce an ACTF was initiated because of shortfalls in the operational range of current cargo offloading systems. Current systems are ineffective in operations in sea state 3 and above because of reliance on lighterage for cargo transport. The ACTF objective is to develop technologies to permit operations in conditions up to sea state 4. Operational Requirements Efficiency. The ACTF must be installed with 50% manpower reduction when compared with current container discharge systems. This was accomplished by extensive use of pre-engineered structures and automated components. Logistics. The facility will reduce the shipping requirements by two-thirds when compared with other container discharge systems. The reduction of shipping was accomplished by designing space efficient components. SYSTEM EVOLUTION Concept Generation Work on the ACTF began with the formulation of a number of possible concepts. Concepts were generated by several Navy contractors and by personnel at NCEL.