Thursday, 30 August 2012

Day 6 - TOBI2 launch

Today the weather was perfect for the test dive of TOBI2. TOBI stands for Towed Ocean Bottom Instrument; this vehicle is a deep-towed 30kHz sidescan sonar system develop at NOC, designed to acoustically image the deep ocean floor.

Cruise P.I. Robin Plumley (centre)

Used in depths between 200 m and 6000 m, the vehicle is fitted with sidescan, profiler sonars, magnetometer, CTD instruments, vehicle orientation and attitude sensors, fibre-optic telemetry, Inverted Ultra Short Baseline Navigation (iUSBL), a fibre-optic gyroscope, a bathymetric phased array and a built-in self test and health check system.

Duncan Matthew gives the TOBI2 'tool box' talk

A 600 kg depressor weight linked to TOBI2 helps the vehicle maintain depth, as much of its bulk is syntactic foam, a buoyant material used widely in oceanographic technology. The depressor weight has a box of electro-optical connections which enable the deployed vehicle to maintain communications with the ship. There were some problems with this initially which the team quickly rectified and the launch was given the green light. Duncan Matthew gave the team the ‘tool box’ talk and once the team had completed final checks, TOBI2 was deployed over the rear deck of the James Cook  and recovered several hours later.

TOBI2 is recovered onto the rear deck

TOBI vehicles are used for exploring mid ocean ridges, monitoring gas hydrates and slope stability of the continental shelf, undertaking environmental impact studies and monitoring the Exclusive Economic Zone (EEZ).

James, Dave and Allan working on the depressor weight