The US Navy Program Executive Office Unmanned and Small Combatants (PEO USC) has started the second phase of the Ghost Fleet Overlord programme.

The programme will form the basis of the navy’s new classes of unmanned surface vessels (USVs).

Under the second phase, the navy has awarded contract modifications to the two industry teams involved in the first phase of the Overlord programme.

The first phase ended last month and involved converting two existing commercial fast supply vessels into USVs.

Other focus areas of Phase I included autonomy system integration; hull, mechanical and electrical system reliability upgrades; and navigational autonomy.

The navy said in a statement: “Phase I concluded in September with a successful capstone demonstration of both Overlord vessels executing interactions compliant with the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS).

“Along with the reliability of systems tests, more than 600 hours of autonomy testing was successfully completed during Phase I, including several long-range autonomous transits in a complex navigational environment.”

The second phase will use the same ships involved in Phase I. The industry teams will work on the integration of command and control systems and payloads.

The service added that the new phase will involve more complex naval experimentation.

Following the completion of Phase II in 2021, the navy will conduct further experimentation on the Overlord vessels.

The navy will use experience from the Ghost Fleet Overlord programme to inform and accelerate its large and medium USV projects.

Last month, the US Navy issued a request for proposals for the development of the large USV (LUSV). The conceptual design contracts for the LUSV are expected in 2020.