OOI Primary Node Installation Begins

Wednesday, July 11, 2012
Plan for Primary Node Installation

Grapnel and deep-water node

The grapnel (red "chain" of hooks), which is used to grapple and recover the ends of cable segments, is shown here lying on the fantail of the TE SubCom Dependable, with one of the deep-water Primary Nodes to the right. Photo by Cecile Durand

Grapnel and deep-water node

Buoy tied to end of cable segment

Image shows the buoy and retrieving line with flotation balls used to "buoy off" the end of cable Segment 1. Photo by Cecile Durand.

Buoy tied to end of cable segment

Our very first operation has been a success! We recovered the end of cable Segment 1 (see image to left in slideshow for segment locations) using a grapnel towed behind the vessel. Only one try was necessary; the cable was hooked by the last element of the grapnel! The photo to the right shows the grapnel (red "chain" of hooks lying on the aft deck of the TE SubCom Dependable).

We have "buoyed off" (connected a buoy to) the end of this cable (see buoy in below right photo) and are now transiting to the end of cable Segment 2, which we will grab and recover using the same method as we did for Segment 1. Once both cables are onboard, they will be tested, the cable length will be adjusted, and Primary Node 1A will be spliced in. This node site is located at the base of the continental slope near Hydrate Ridge. (See map of node installations above.) More details on node installation operations are available here.

We are pleased that operations are proceeding smoothly thus far and are hoping for cooperative weather for our first node launch planned to take place on the coming weekend.

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