Page 36: of Marine Technology Magazine (October 2016)

delivery and vehicle recovery. ing cable recovery, a position update neath ? oating ice shelves. The Autosub

In April 1996, following initial endur- was provided and the journey home be- Under Ice (AUI) program of the U.K.’s ance testing and trial, Theseus complet- gan. Near the end of the return trip, a Natural Environment Research Council ed a one-way transect of 175km in the failure to home on one of the beacons (NERC) would investigate both the Arc- ice-covered waters north of Canadian enacted the fault control and Theseus tic and Antarctic using the Austosub-2

Forces Station Alert. Launching con- again parked under the ice. Using te- AUV, designed and built at the U.K.’s sisted of a gantry launch through a 2m lemetry, ? nal instruction was given to National Oceanographic Center, South- x 13m ice hole. The mission had a series return to the launch hole. Following ampton. This 7m long, high-endurance of six acoustic beacons along the path this record-setting run of 350km, The- AUV included an advanced positioning to aid in directional homing, with the seus completed a follow up mission of system which consisted of a ? ber-optic ? rst two monitored for telemetry con- 320km. gyro and both upward and downward tact. At the mission terminus, Theseus Doppler velocity logs (DVLs) for bot- was required to ? y through a 200m wide The AUTOSUB story tom, under-ice, or water column speed metal loop to capture the cable; as it ap- Following successful missions be- tracking. The Autosub-2 had a obstacle proached, manual control was enacted neath sea-ice in the North Weddel sea in avoidance scheme that could allow it to to ? y the vehicle through the goal. 2001 to survey Antarctic Krill, an ambi- venture into unknown environments.

At this point, Theseus parked under tious ? ve-year program was initiated to From 2003 to 2005 the Austosub2 the ice and awaited instruction. Follow- investigate the marine environment be- performed under-ice missions in both

Theseus from International Submarine Engineering (ISE)

Photo: Damien Guihen

October 2016 36

MTR

MTR #8 (34-49).indd 36 9/27/2016 2:43:33 PM