Recovering and Testing Cable Segment 2

Thursday, July 12, 2012
Primary Node 1A Cable Layout

Two Cables Onboard

One cable going out, one cable coming in: Segment 2 (black line on deck on left side of photo; ship's starboard side) being paid out and Segment 1 (black line on deck on right side of photo; ship's port side) coming in.

--Photo by Cecile Durand

Two Cables Onboard

Beacon on Cable Segment 2

Mark Wardman, left, and Kirk Connally, right, L-3 MariPro members of the OOI installation team, are shown with the beacon installed on cable segment 2. The beacon is used to verify the cable shape in water (catenary).

--Photo by Cecile Durand

Beacon on Cable Segment 2

It's 9:00 am. We have just finished recovering 10km of Segment 2 and the cable is being tested once again. We are getting ready to relay it along its final path while heading towards the buoy that was attached yesterday at the end of Segment 1. The buoy is about 2.5 miles away. Once we get to the buoy, we will recover Segment 1 on the port side while continuing to lay Segment 2 off the starboard side.

When similar lengths of cables are recovered on each side, we will clamp temporary beacons to the cables to verify their shape in water (catenary) and to adjust their lengths before splicing in the primary node. This process will help us ensure that the node is set precisely at the planned location. We are aiming for a positioning accuracy of 2% of the water depth, or just about 60 meters at 2,900m at Primary Node N1A. Our precision act is just about to start! The drawing above, courtesy of L-3 MariPro, should help explain the relaying of cables that is occurring this year.

The deployment of the first node will be a major project milestone and we are all anxiously looking forward to operations this weekend. The weather is cooperating so far. Pictures to come soon!

--Cecile Durand, OOI Marine Maintenance Manager, University of Washington, at sea aboard the TESubCom Dependable