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Ran – Autonomous Underwater Vehicle (AUV)

An autonomous underwater vehicle (AUV) can be used for studies under glaciers, thick sea ice and in the deep sea. The AUV 'Ran' was a part of the University of Gothenburg's research infrastructure for several years. In January 2024, Ran was lost during a mission - but the data collected by the AUV continues to contribute to a better understanding of ocean processes.

Ran - an international research infrastructure in Sweden

The autonomous underwater vehicle Ran was an important part of the University of Gothenburg's research infrastructure for many years and often included in R/V Skagerak expeditions.

Unlike a remotely operated vehicle, Ran is an autonomous underwater vehicle that is pre-programmed to dive below the surface and make its own decisions based on information about its environment. This allows Ran to reach very inaccessible environments under floating ice masses or in the deep sea.

Few research AUVs in the world have this exceptional capability and navigational accuracy - the University of Gothenburg's Ran also carried high-resolution acoustic sonar and other mapping instruments.

Ran was funded by the Knut and Alice Wallenberg Foundation as part of the then nationally important infrastructure programme MUST (Mobile Underwater System Tools).

The riskiest and most innovative results have been in connection with research under Antarctica's floating glaciers.

Ran was delivered in 2018 and used for several years. When the AUV disappeared in the West Antarctic in early 2024, the submersible had completed many successful missions and contributed much new knowledge, particularly in the field of Antarctic research.

Anna Wåhlin, Professor in oceanography at the University of Gothenburg, points out that Ran contributed not only to groundbreaking research, but also to education and technology development in the years before the AUV was lost. "The riskiest and most innovative results have been in connection with research under Antarctica's floating glaciers," Anna Wåhlin writes about Ran.

During the active years, Ran was used for research, training of young researchers and as a platform for tests and exercises within the Swedish Maritime Robotics Centre's (SMARC) AUV development project.
Anna Wåhlin believes that this AUV has contributed to Sweden's prominent position in AUV-based polar research on a global scale, and that Sweden is at the forefront of international developments.

Orangecoloured, torpedoshaped Autonomous Underwater Vehicle — Photo: Kongsberg Maritime A/S

Data, performance and equipment of Ran

Manufacturer: Kongsberg Maritime A/S, Horten, Norway
Model: Hugin
Length: 7.5 metres
Weight: 1850 kg (dry)
Speed: 1-7 knots, cruise speed 4 knots
Maximum dive depth: 3000 metres
Maximum dive length and time: 300 km and 36 h

Equipped with:

multibeam echo sounder, Multibeam Kongsberg EM2040, 200-400 kHz, 0.7° x 0.7° beam width, swath coverage sector up to 140°
conductivity, temperature and depth sensor (CTD), dual systems SeaBird 911 19plusv2
oxygen sensor, SeaBird SBE43 (dual system)
carbon dioxide sensor, Contros HydroC
nitrate sensor, SeaBird Deep SUNA
chlorophyll/turbidity sensor, SeaBird WetLabs ECOtriplet (FLBBCD)
side scan sonar (= acoustic ”camera”), EdgeTech 2205. Frequencies 75/410 kHz (1-6 km range)
bottom-penetrating sonar (= acoustic ”X-ray camera”), EdgeTech DW216 with configurable chirp
navigation system: DVL-supported Honeywell Hg9900, gives accuracy of better than 0.08% of distance travelled
acoustic communication below surface, 2-3 km between ship and AUV
satellite, radio and WiFi communication in surface mode