Surf-Zone Capable USV for Messenger Line Delivery

Expeditionary Advanced Base Operations (EABO) require the delivery of fuel, cargo, and electric power from a ship 2,000 feet offshore to personnel and facilities ashore. Environmental conditions during this transfer may include wind, current, waves, surf, temperature extremes, and varying beach gradients that complicate the transfer. The transfer traditionally begins with the passage of a pilot or messenger line from the ship to the shore. The High Molecular Weight PolyEster (HMPE) tow line is then pulled ashore using the messenger line. MAPC proposes the use of a Surf-Capable Small-Unmanned-Surface Vessel to eliminate the need for pilot or messenger lines by directly delivering the two-part HMPE tow line and it’s turning block ashore in one step. The proposed vessel is a modified version of our unmanned diesel GARC craft. MAPC’s Phase 1 Base effort conducts a high-fidelity simulation of the environmental loads that the towing vessel must overcome to operate successfully under the full range of environmental conditions listed in N221-047. Initial estimates suggest that the towing vessel must be capable of 2,000 pounds of thrust to complete the direct transfer of the tow line and its turning block to the shore. The Phase I Option involves propulsion modifications to the GARC vessel that are required for high-tow-force operation. If awarded, Phase II delivers a high-tow-force variant of the GARC that has been tested under representative environmental conditions.