Dependable performance, extended time on station and quiet operation are key criteria when conducing acoustic underwater surveys. That’s why SeaRobotics selected an electric propulsion system from Torqeedo for their Endurance 7.0 autonomous surface vessel (ASV).
“Our power requirements for this Endurance 7.0 ASV were very specific,” said Don Darling, president of SeaRobotics. “The vessel required extended endurance on station as well as a quiet operating mode while performing acoustic research operations.”
The powertrain for the seven-meter (23 ft) aluminium boat consists of a Torqeedo Deep Blue 50i electric motor, a 360 VDC 30.5 kW lithium propulsion battery, a water-cooled DC-DC converter, a 24 VDC lithium battery for DC-DC backup, and a 25 kW diesel generator. The fully integrated computer-controlled propulsion system is designed for long-range unmanned hydrography and subsea mapping missions.
The system is designed to provide up to six days on station at survey speeds and up to 10 hours between automatic battery recharges from the onboard generator. The recharging cycles are fully automatic under computer control.
“The DeepBlue electric drive, with 80 horsepower-equivalent output, provides ample power for a wide range of towed or statically deployed systems,” Darling said. “In addition, the smooth, continuous and rapid transition from forward to reverse thrust assists in station-keeping as well as near-dock manoeuvring.”
The Endurance 7.0 can operate under remote control by an operator ashore or semi-autonomously to implement a mission plan. All on-board systems are monitored with data connections to the remote base station. The operator can control all interfaces, view video feeds or put the ASV into automatic waypoint navigation mode, in which throttle and steering are under full computer control. The boat’s helm station can be optionally manned for operation in congested waterways and ramp operations when required.
“Autonomous Surface Vessels are a perfect application for electric propulsion in terms of silent, emission-free performance and reliable, low-maintenance operation,” said Steve Trkla, president of Torqeedo, Inc. “Torqeedo also had extensive previous experience in working with ASV builders. The full range of Torqeedo drives, from 0.5 kW outboards up to the high-voltage 50 kW Deep Blue system, have been successfully integrated into ASVs by builders around the world.”
“Importantly, Torqeedo gave us the level of engineering and system integration support needed to create a fully meshed propulsion and control solution to meet our requirements for autonomous survey operations,” said Darling, who noted that SeaRobotics is also using Torqeedo outboards on other ASVs.