An industry team led by L3Harris Technologies is working toward a December target for completing construction of a prototype medium unmanned surface vehicle (MUSV). The prototype will serve as the baseline design for a cadre of unmanned systems within the Navy’s future “distributed” surface force of unmanned ships and lighter manned combatants.
In March 2021, the Department of the Navy released its comprehensive Unmanned Campaign Framework, which defined broad mission requirements for the Navy and Marine Corps’ unmanned vehicle initiatives. In it, Chief of Naval Operations Admiral Michael Gilday writes: “The Navy is expanding and developing a range of unmanned aerial vehicles, unmanned undersea vehicles, and unmanned surface vessels . . . as we shift our focus toward smaller platforms that operate in a more dispersed manner.”
The $35 million Navy contract with L3Harris—awarded in a competitive bidding process in July 2020—includes options for eight additional MUSVs, which could bring the total contract value to about $281 million. The team might build a second prototype. L3Harris signed an agreement with Swiftships for MUSV construction last July. Gibbs & Cox and Incat Crowther are performing design work on the effort.
The MUSV will be a low-cost platform about 190 feet long with a 500-ton displacement. The vessel will accommodate an open-architecture sensor payload roughly the size of a 40-foot container for intelligence, surveillance, and reconnaissance and electronic warfare missions to provide fleet situational awareness.
L3Harris will act as the MUSV team systems integrator and will provide its ASView autonomous ship control system for the vessel. ASView consists of a core vessel interface manager and autonomy processor, a base server, a graphical user interface, and portable remote controllers. The company says ASView complies with international collision regulations and is currently in use controlling more than 100 autonomous vessels.
The MUSV effort is based in part on the Office of Naval Research’s Medium Displacement USV initiative, which developed the Sea Hunter and Sea Hawk USVs. Both vessels have served as testbeds for autonomous control technologies and operational payloads. In 2019, the Sea Hunter completed a successful autonomous round-trip from San Diego to Pearl Harbor.
Swiftships says it will build the MUSV along the lines of its successful 175-foot-long Riley Claire design, which is used to ferry crews and cargo to and from offshore oil-drilling platforms. The ship is powered by a 2,000 kW Cummins engine and is capable of 30 knots.
The design was adopted by the Department of Defense Strategic Capabilities Office (SCO) for its Ghost Fleet Overlord initiative, which aimed at rapid development of unmanned ships. The eponymous Riley Claire became the SCO USV Nomad, which was used extensively to demonstrate USV operations before being handed over to the Navy after SCO ended the Ghost Fleet project in December 2021.
The new shipbuilding plan, announced in June 2021, sets a force target of 321 to 372 manned ships. The Navy says the future fleet’s “distributed architecture” will consist of relatively few larger carriers, cruisers, destroyers, and amphibious ships and more smaller ships: frigates, light amphibious ships, and medium logistics ships. This replaces the former goal of 355 manned ships.
According to the Congressional Research Service, the future force structure will include a projected 77 to 140 unmanned vessels, including medium USVs, large USVs (LUSVs), and extra-large unmanned underwater vehicles (XLUUVs). The Navy says the three new unmanned types will have complementary but separate missions, and cost will be a major driver.
In contrast with the MUSV’s ISR mission, the Navy says the LUSV will be more of a weapon platform, between 200 and 300 feet long, displacing 1,000 to 2,000 tons, and armed with antiship and land-attack missiles. The XLUUV will deploy the Navy’s Hammerhead mine, which is tethered to the seabed and can deliver an antisubmarine torpedo.