Quiet Auxiliary Propulsion Unit for Combatant Craft

The development of technologies that advance military stealth and lethality in the face of notably increased aggression from U.S. adversaries is vital to maintaining tactical advantage. The U.S. Navy seeks to develop a ruggedized, quiet, transom-mounted, retractable electric propulsion system for high-speed planing craft - Special Operations Craft – Riverine (SOCR). The proposed Auxiliary Propulsion Unit (APU) will enable a SOCR to maintain the speed and endurance of its diesel propulsion while having electric propulsion capability for low-speed, silent operations. Martin Defense Group (MDG) is a leader in developing cutting-edge solutions in defense and maritime industries. Through research, technology, and partnerships, MDG strives to solve problems that can change the world. Progeny Systems Corporation (Progeny) specializes in developing and producing innovative hardware and software solutions for the Department of Defense (DoD) and other organizations. MDG will team with Progeny to leverage its previously developed and tested Advanced Submarine Control (ASC) scaled, motor drive and hubless Rim Driven Propulsor (RDP) thruster to provide a viable APU solution. The motor drive and RDP thruster has a Technical Readiness Level (TRL) of 6, which indicates that a system/subsystem model or prototype has been demonstrated in a relevant environment. MDG will leverage its naval architecture experience to make modifications to Progeny’s thruster design (i.e., propeller blades, aft stationary blades, duct inlet, and duct outlet). Design trade-offs will be made to balance the thruster’s hydrodynamic design (i.e., efficiency, cavitation, swirl recovery) against motor and motor drive performance (i.e., power factor, switching frequency, harmonics, voltage, current, EMI) versus energy storage constraints against APU component integration (i.e., thrusters with deploy/retract mechanisms) beneath the stern platform of the SOCR. A quiet APU solution will enhance the capabilities of a SOCR to successfully perform slow, extremely quiet operations in contested environments. MDG has specialized capabilities for electric propulsion system design, naval architecture, hydrodynamic analysis, and system integration and is uniquely positioned when teamed with Progeny to provide an extremely quiet and rugged APU system for SOCR use. The MDG and Progeny team’s revolutionary APU thruster, with its lightweight, compact, anti-fouling design, can easily provide these core needs observed across multiple industries, and its versatility allows for both retrofit and new construction. The stored energy components of the APU system have some of the highest energy density values available on the market today (147 Wh/L and 107 Wh/kg) which ensures a compact, lightweight system.