Thursday, 30 August 2012

Day 7 - Isis goes from strength to strength

With the first Isis  dive completed successfully, the next objective was to test the vehicle at deeper depth. Preparing the ROV to dive is a lengthy process as there are multiple pre-dive checks and activities to complete. When the vehicle is ready to be deployed, the ROV team are in position either in the control van or on deck and they communicate between each other and the Bridge by radio.

Once cleared for launch, Isis  is raised up by the LARS (Launch and Recovery System) and manoeuvred out over the ocean. She is attached to the ship by 10,000 m of cable and it is through this cable that the ROV team transmit instructions and power to the vehicle.

Andy, Allan, Dave and James at the winch control

On Monday, Isis  descended to 1600 m and once near the sea bed, the team took the opportunity to refresh their skills in ‘push coring’. Push coring is a technique ROV pilots use to collect samples of sediment. Whilst the team’s pilot maintains the vehicle in a steady position, the engineer operates the vehicle’s manipulator claw arm to retrieve a cylinder from a tray on the vehicle. The cylinder is then pushed firmly into the sea bed.

The engineer operates manipulator arms to retrieve samples from the sea bed.

The engineer retrieves the core once it is full of sediment and returns it to the tray. This is no easy task as the engineer is looking at flat, two dimensional screens but must think in three dimensions to operate the arm. With great efficiency, the team collected a full tray of cores and then prepared the vehicle to ascend to the surface.

On board is Lucy Woodall, a scientist from the Natural History Museum who is researching the effects of environmental factors such as depth and habitat and anthropogenic factors such as fishing on marine nematode communities; also on board is NOC scientist Veerle Huvenne who is undertaking research on marine habitat mapping and sediment dynamics. As soon as Isis  was safely back on deck, Lucy and Veerle set to work retrieving the cores and preserving them in readiness for their analysis back at base.

Veerle Huvenne and Lucy Woodall