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As at 2330 h last night V4 officially completed all Voyage Objectives. The V4 objectives were:
1. Deliver 1,050,000L's of SAB to Casey,
2. Support deployment of ARGO floats,
3. Support retrieval and deployment of Whale Moorings, and
4. Trial the AAD's new ICT fly-away communication suite for chartered vessels
Last night we successfully recovered a whale mooring and deployed the new one which was our final voyage objective.
The whale mooring has been sitting 2880m below the surface of the ocean for approx. 12 months. Yesterday when we arrived at the location the mooring was deployed, DVL Trent and VL Cam set up on the back deck in preparation for the activity.
Once the vessel had come to a complete stop we dropped a transducer into the ocean from the stern of AIVIQ. The transducer was at the end of a 30m cable which was attached to a system specially designed to communicate with the mooring.
The first step was to send a signal to the mooring to let it know we were there and also to check we were in range. Trent punched in the code and .......... nothing. This was not good as we were waiting for 15 return pings from the mooring which would be received at 2 second intervals. We tried again. Ping........... nothing.
We were confident that we were in the right area and that the mooring was hearing us, but we thought the issue was we were not hearing the mooring. We radioed through to the bridge and requested they clutch out the vessel. In essence this means the propellers stop spinning and we just float in the ocean, quietly.
Once this had occurred Trent again entered the codes into the system. Ping, Ping, ping..... 15 sweet pings. We sent another signal which allowed us to range the mooring. The range indicated the mooring was 2920m away and noting it was at a presumed depth of 2880m, it meant we were right on top of it. In order to avoid the mooring resurfacing and hitting AIVIQ we moved away approx 500m.
Once we were stationary and clutched out again we sent release codes to the mooring. The mooring is designed so when it is released from the weights the entire system floats to the surface completely connected and only leaves two small weights on the ocean floor.
The mooring proved difficult to find on the surface, but after about 1-2 hours and multiple moves it was the Ships CAPT who finally caught sight of the buoys.
Recovery was also tricky as the swell very quickly picked up forcing us to abandon our plan due to safety concerns. We had initially planned to drag the mooring to AIVIQs crane with an IRB but the sea state did not allow for this. Instead we came alongside the mooring, fired a pneumatic grappling hook towards it and dragged the mooring on using the ships tugger.
After we had safely recovered the old mooring we deployed the new mooring which was a far simpler activity.
A large part of today was spent sitting down with the team to conduct an after activity review (AAR) on all aspects of the voyage. The intent behind an AAR is draw out things that we have done well and would like to maintain and things which need to be fixed or can be improved.
There was a lot of robust discussion which now needs to be turned into a document. Overall this was a successful activity and vital for ensuring continuous improvement.
Regards,
Trent and Cam
Map
A map showing Australia and Antarctica. The map shows the journey of one voyage that has occured in the season, with each route highlighted in a distinct colour.