The Theseus autonomous underwater vehicle. Two successful missions

Over the past five years, International Submarine Engineering Research and the Esquimalt Defence Research Detachment of the Defence Research Establishment Atlantic have worked together to develop a large autonomous underwater vehicle, named Theseus, for laying optical fiber cables in ice-covered waters. In trials and missions conducted in 1996, this vehicle showed impressive capabilities. It was able to lay a fiber-optic cable in a completely autonomous mode for a distance of 200 km under Arctic sea-ice and then return to the launch station for recovery. It demonstrated a navigational error of less than 0.5% of the distance traveled, and cross-track error was reducible to 0.05%. It operates in either depth-keeping mode or bottom-following mode, was designed to operate at a maximum depth of 1000 m, and has operated at a depths of up to 425 m. The vehicle is currently configured for cable laying. Other missions could be accommodated with minor changes to the payload section of the vehicle. Longer missions could be accommodated by replacing the current silver-zinc batteries with fuel cells or higher energy/density batteries. The paper describes the vehicle and presents the results of the evaluation trials and its first cable laying mission.