ITP36 Deployment Operations

The first of 2 ITPs deployed on the 2009 NABOS cruise in the Eurasian Arctic was ITP 36. Due to the dramatic decrease of ice concentration and thickness, especially since 2007, the surface packages of the 2009 ITP builds were redesigned to be conical with a wide squat tube enclosing the electronics on top in order to foster the vertical displacement of the buoy during ridging events, and hopefully prolong the lifetime of the systems. It was anticipated that it would be difficult to find substantial icefloes to deploy the ITPs in the NABOS region, consequently, the WHOI deployment team was prepared for over-the-side installations in open water, and ITP 36 was the first to be deployed in this manner.

Ice coverage was 6 to 7 tenths at the deployment location on the morning of the deployment. Since the operation was performed over-the-side of the ship, a considerable amount of time was saved on reconnaissance, survey icefloes, and transporting gear off of the ship, so that the entire anchor first deployment took only 90 minutes from start to finish. Once released, the buoy with suspended mooring system drifted into the nearby marginal ice with a relatively shallow freeboard above the ice (which would be increased on future builds by reducing the density of the foam).

With the ITP deployment winch in position, Jeff Pietro and John Kemp make the final preparations for the open water deployment operation by securing the profiler to the wire above the anchor.

The deployment begins by lowering the profiler and anchor over-the side. (Jeff Pietro)

Spooling out the 790 m of cable with the ITp winch secured tot eh deck. (Jeff Pietro)

With the majority of the wire in the water, the upper potted section of tether is removed from the winch, fed through the buoy, and attached to the electronics housing. (Jeff Pietro)

Pietro verifies that the system is functioning properly before it goes into the water.

The completely assembled system is suspended from the ship’s crane.

Kemp slackens the quick release line as the system is lowered away from the side of the vessel. (Jeff Pietro)

The first ITP deployed in open water sits about 25 cm above the waterline with the 790 m profiler mooring suspended below. (Jeff Pietro)