Rosette Recovered

Before sunrise, ROV lead Jared Schwartz readies the ROV for its recovery mission.

The team was on deck as the sun came up to prepare a remotely operated vehicle (ROV) for a rescue mission. During an expedition earlier this summer aboard the R/V Neil Armstrong, a CTD rosette (pictured below) was lost. The Pioneer 17 cruise with its ROV onboard provided the perfect opportunity to recover the CTD. The position of the CTD rosette on the seafloor at a depth of about 450 meters was known. The challenge was to dive the ROV to the seafloor, find the rosette, and hook in a recovery line to pull it to the surface – not as easy as it sounds when the rosette is 450 meter underwater.

After locating the rosette, the ROV team onboard the Armstrong used the ROV’s manipulator to hook a recovery line onto the rosette, with little margin of error. Once hooked, the ~1000 pound rosette was pulled back up to the surface and onto the stern of the ship with the heavy lift winch normally used for mooring deployments and recoveries. It now is safely aboard the ship and ready for refurbishment.

The recovery operation took more than three hours. The following pictures show the highlights of the multi-step process.

An example of a fully loaded CTD rosette. The rosette recovered did not have the sampling bottles when it went down.

The Pioneer 17 team prepares to lower the ROV and a spool of recovery line, on a descent weight, to 445 meters depth in the vicinity of the missing rosette. The recovery line was attached to a titanium hook held by the ROV manipulator.

The red-hatted team of Collin Dobson, Jared Schwartz, and Diana Wickman (l-r) successfully drove the ROV to the site of the rosette.

Cheers erupted as the ROV manipulator successfully hooked the missing rosette with the recovery line.

The Pioneer 17 team secures the ROV as it was brought on board. Note the red line tied to the A frame remains in the water attached to the rosette.

Deck Ops Lead Chris Basque and team member Nico Llanos ensure that the recovered rosette has a smooth landing on the back deck of the R/V Armstrong.

Last but not least, the rosette was moved by crane to a storage area on the R/V Armstrong so that it can be refurbished and put back into operation.

Images and Text by Darlene Trew Crist©WHOI.