The industry's recognized authority for design, engineering and application of equipment and services in the global ocean community
Issue link: http://sea-technology.epubxp.com/i/887058
18 st / October 2017 www.sea-technology.com simply isn't workable. Ocean Infinity's AUV fleet is operated and maintained out of a 1,700-sq. ft. insu- lated, climate-controlled hangar that was built and installed on the main deck of the ship as part of the fleet mobilization. The hangar contains all the req- uisite support services for the HUGINs, two launch and recovery stingers, battery chargers, cranes for lifting the vehicles and the batteries, power-sliding storage for the AUVs, tools, air compressors, work benches, networking equipment and more. Having all the vehicles in one large space al- lows the crew to work efficiently by breaking up into teams. A team can complete battery changes for charging and routine vehicle maintenance, while another team focuses on launching or recovering another AUV. The AUVs can spread out and survey one at a time, or all eight simultaneously, and still maintain contact with the main vessel—a key part of the fleet's efficiency. Ocean Infinity is able to do this through the use of USVs (one for each AUV), which act as communications relay from the AUVs to the ship. Equipped with acoustic modem/ USBL systems, the USVs position, monitor and communi- cate with the AUVs and then relay that data back to the vessel. Surface-to-surface communications are handled through a multifrequency mesh radio network, not unlike the network that wireless communications providers use for mobile phones. The USVs are bespoke pieces of equipment, built to spec- ifications for continuous, long-endurance offshore opera- tions and rated for weather up to Sea State 5. The USVs have tion. A fleet of eight Kongsberg Maritime HUGIN AUVs, rated to work at 6,000 m of water depth, makes up the heart of the system. The HUGINs are each equipped with a multibeam echosounder, triple-frequency side scan sonar, sub-bottom profiler, magnetometer and a color-stills cam- era. Ocean Infinity's AUVs come in a set of eight and have roughly double the battery capacity of the average AUV, making a single AUV mission of more than 50 hours pos- sible. Applied across the fleet of eight, that equates to 400 hours of survey time before a battery swap or recharge is required. With eight AUVs mobilized from one ship, the practice of operating out of standard ISO shipping containers for launch and recovery, vehicle turnaround and maintenance Seabed Constructor and USVs deployed.