The U.S. Defense Advanced Research Projects Agency (DARPA) has awarded a $13.9M US contract to Applied Physical Sciences – a wholly owned subsidiary of General Dynamics – for the Sea Train project. The Sea Train program aims to enable long range deployment capabilities for a distributed fleet of tactical unmanned surface vessels (USVs) capable of extended transoceanic transit and long-range naval operations.
The Sea Train has three potential solutions:
- a connected sea train with a physical connection between four or more vessels during transit to form a long parallel mid-body for the vessel to decrease the vulnerability to waves;
- a connector-less sea train which uses compressive forces to keep four or more vessels together in a long parallel mid-body; and,
- a formation sea train which involves four or more vessels moving together in groups formed closely front and back, and side to side, to exploit wave interference between the vessels.
A key limitation of unmanned ships is their limited ranges because of the effects of large ocean waves on medium-sized vessels.
“At-sea refueling, use of heavy-lift ships, strategic airlift, and increasing overall vessel size are all solutions to this limitation but are fraught with operational vulnerabilities against peer adversaries,” the DARPA announcement stated.
The project will address two technical areas: developing an integrated design composed of a hull form, hull connector, propulsion, and gap mitigation between the vessels; and, developing a control architecture to monitor environmental conditions and handle multi-vessel alignment, spacing, and structural loads. Sea Train sensors will include techniques that perceive sea conditions for path planning and route optimization, identify vessel spacing and orientation, identify structural loads, and handle vessel autonomy.