Uncrewed Systems Technology 049 - April/May 2023

26 Dossier | Marine Advanced Robotics WAM-V Although the WAM-V as a concept is highly modular, with an inflatable catamaran hull design and a patented suspension system scaling up to potentially enormous systems, at present MAR is focused on making three models: the 2.5 m-long WAM-V 8, the 5 m WAM-V 16 and the 7 mWAM-V 22. As Mark Gundersen, formerly CEO of MAR and now VP of autonomous vehicles at OPT tells us, the ‘22’ is the main focus of the company’s effort, so its development forms the bulk of this article. By coincidence it was unveiled in 2022, while the 8 had been launched in 2020 and the 16 in 2012 (being the first production-focused iteration). The WAM-V 22 measures 7 x 3.66 x 0.56 m, weighs 1134 kg without payload, batteries or fuel (with a payload limit of 270 kg), and has a mission endurance of up to 72 hours, as well as a top speed of 20 knots, which is high for a USV. From crewed to uncrewed Although we have featured the WAM-V in short updates since our first encounter with it at Oceanology International 2018 ( UST 19, April/May 2018), a brief reminder of its patented suspension is in order. Its design is based around two pontoons with at least two legs each (for at least four in total) that support a central platform on top, where typically the electronics are mounted. The forward legs support the forward part of the central body via a ball joint. This joint is spring-supported and allows the forward legs to rotate as a unit relative to the central body, and the joints’ lower ends attach to forward sections of the pontoons. The stern legs are rigidly coupled to the central body, with their lower ends connected to the aft parts of the pontoons, allowing the legs to rotate vertically and transversely but not longitudinally. This suspension and articulation keeps the central platform highly stable, even in high waves and sea states. That provides a comfortable ride for passengers and crew, and an inherently stable system for any cameras, Lidars, sonars and other data-gathering sensors. “I joined in 2005 after the Contis had raised funds from angel investors and developed a proof-of-concept catamaran featuring a central top platform that was kept stable by a set of composite legs below,” explains Gundersen. “That concept soon morphed into what would become the Proteus, our 100 ft- long crewed WAM-V demonstrator. No computer model existed that could come anywhere close to simulating the motions of the vessel, so we built one ourselves and started testing.” The Proteus was unofficially launched in Washington state in the summer of 2006, with sea trials following in the Puget Sound before being relocated to California, for tests from San Francisco to Richmond, where MAR is now headquartered. Its official launch and unveiling came in 2007, and it went on to complete 3000 nautical miles of testing across the Pacific and Atlantic oceans, as well as the Mediterranean. “Those 3000 miles on the crewed prototype gave us a vast amount of data and a front row seat on how the WAM-V would move, and how its suspension, articulation, hinged engine pods and elevated central structure would work individually and together in a practical sense,” Gundersen says. These observations and some collaborative projects along the way gave the Contis and Gundersen some technical insights that informed the second generation of the WAM-V. “For instance, the Proteus had suspension parts installed fore and aft, but on the second generation we eliminated the aft suspension because we’d realised the front suspension was really the key to the WAM-V handling the waves and mitigating the wave- April/May 2023 | Uncrewed Systems Technology Transportability and deployability within existing infrastructure have been key targets for the WAM-V’s design iterations