Field Tests of the Hybrid Remotely Operated Vehicle (HROV) Light Fiber Optic Tether

The Hybrid Remotely Operated Vehicle (HROV), being designed and built by Woods Hole Oceanographic Institution (WHOI) with the support of the Space and Naval Warfare Systems Center San Diego (SSC San Diego), will provide a new level of accessibility for deep ocean research. HROV will be primarily an autonomous vehicle but will be reconfigurable to a teleoperated system by the installation of a fiber optic data link and a manipulator based work system. Development of the fiber optic link has been supported by both simulation and a series of field tests over the past 3 years. The November 2004 tests consisted of deploying two different types of fiber optic cable from an Oceanographic elevator deployed from a ship to 2000 m depth. Data collected from this test demonstrated the feasibility of using both the Fiber Optic Microcable (FOMC) and plain buffered optical fiber as a tether for the HROV. The December 2005 tests demonstrated the utility of the buffered optical fiber operating on an underwater vehicle using the WHOI ABE vehicle as a substitute for the future HROV. Five dives were made to 2000 m with real-time communication from the vehicle to the surface via the fiber. The May 2006 tests focused on the employment of a cable depressor and deployment system. Using a deep elevator as a substitute for HROV, the fiber was deployed from both the depressor and the elevator to a depth of 4200 m. Over the course of 4 deployments, over 16 km of fiber was deployed, operating for a total of 33 hours, demonstrating the feasibility of the planned approach