U.S. Marines 3D Print a 7-Meter Raiding Craft in Okinawa

Marines with Intermediate Repair Company, 3rd Maintenance Battalion, 3rd Marine Logistics Group put a 7-meter foam raiding craft into the water at White Beach Naval Facility in Okinawa on June 29. The vessel ran in both manned and unmanned configurations and completed autonomous waypoint navigation. The test proved a point: expeditionary forces can manufacture a working boat in theater instead of waiting for one to ship across the Pacific.

The effort fell under Resilient Advanced Manufacturing For Contested Environments, or RAMFORCE. Marines worked with engineers from Naval Surface Warfare Center Carderock to build the modular foam hull using three primary pieces of equipment: a CNC router, a large-format polymer 3D printer, and a spray foam and coating system. Materials were selected for worldwide availability so units could source them locally if needed.

From prototype to production

A previous 5-meter prototype took roughly 16 working hours and about $11,000 in materials. The team believes a 5-meter platform could be produced every four hours and a 7-meter platform every six hours once scaled with a 12-person crew. After fabrication, the hull received a protective polyurea coating and was fitted with a 300-horsepower Mercury outboard engine plus an autonomous control system from Fort Robotics.

The White Beach demonstration also included a RAMFORCE experiment called Print on the Move. Marines tested whether commercially available polymer 3D printers could keep producing parts while being transported on tactical vehicles and watercraft. One printer continued fabricating a component during the move to White Beach and even while aboard the foam craft as it operated on the water.

Beyond the boat, Marines trained on nScrypt's nRugged system, a ruggedized platform that diagnoses faults on circuit cards and repairs damaged electrical pathways in austere environments. Another team practiced cold spray repair, accelerating powdered aluminum and nickel onto worn metal surfaces without melting the base material. Oak Ridge National Laboratory's Manufacturing Demonstration Facility showed hybrid manufacturing that digitally scans a damaged part, recreates it with wire-fed additive manufacturing, then finishes it with subtractive machining in a single machine.

Major Daniel Krake, company commander of Intermediate Repair Company, emphasized that the real story is integration. On their own, each event is fascinating. Combined across commodities, they are game changing. The equipment and partnerships from RAMFORCE remained with the unit after the exercise so Marines can continue refining these capabilities.