One of the most unusual creatures you might encounter on the Barkley Canyon sea floor is Wally, a specially designed remote-control deepsea crawler that has been collecting samples and exploring undersea terrain since deployment last October.
Wally I after deployment, October 2009.
A key task on our 2010 installation cruise was to replace Wally I with his new and improved heir, Wally II. To do this, we first needed to bring Wally I to the surface using ROPOS and a tool basket.
ROPOS was deployed with an empty tool basket and 8 chain weights sitting on its front porch. These chain weights are a perfect example of the usefulness of duct tape in scientific research. Each consists of a carabineer attached to a chain enclosed in sliced rubber hose. The hose is mummified in duct tape until the chain and the carabineer have a sturdy silver-coloured handle for ROPOS manipulators to grab.
ROPOS attaches weights to Wally's umbilical cord during recovery operations, 13 September 2010.
Why do we need these chain weights, you ask? Wally I is attached to the instrument platform by a buoyant cable, which stays out of his way floating above him when crawling. This cable had to be weighed down so it wouldn't interfere with ROPOS when he was plucked from the seafloor and "flown" to the tool basket. Once placed in the tool basket and disconnected from the instrument platform, Wally I was secured in place and carried to the ship by ROPOS.
ROPOS secures Wally the crawler in the 'tool tray' after retrieval from the Barkley Canyon gas hydrates field, 13 September 2010.
All went smoothly on the dive. Wally I returned safely to the ship, gas tight water samples and push cores were collected, the Barkley Hydrates instrument platform passed its inspection and a shell experiment was retrieved from the ocean floor.
You could tell something exciting was happening on Dive 1363. The operations room was full, and camera-toting scientists and crewmen crowded the deck like paparazzi. Why? Because Wally II was sitting in the ROPOS tool basket, ready for an 870m plunge.
ROPOS prepares to lift Wally II (sitting in the ROPOS 'tool basket') for deployment to Barkley Canyon, 14 September 2010.
Like Wally I, Wally II is equipped with cameras, lights and sensors for measuring water conditions on the seafloor. What's new is this crawler's custom-designed sediment microprofiler, developed by collaborating scientists at the Max Planck Institute for Marine Microbiology in Bremen, Germany. Like a high-tech acupuncture kit, this sensor array will help scientists study oxygen, pH, salinity, temperature and sulfide levels in seafloor sediments and bacterial mats.
Sensor needles on Wally II's sediment micro-profiler.
There were several steps to deploying Wally II. First, he was lowered in the tool basket to the seafloor and the basket was detached from ROPOS. Then, he needed to be freed from his "seatbelts" - a challenging task for the two ROPOS team members operating the platform's robotic arms. Next, ROPOS lifted Wally II and flew him to his new home in Wally's World over near the edge of the canyon.
The next step was to connect his cable to the instrument platform. This must be done very carefully to ensure proper power and communications transmission through the cable. Dust caps are essential to keep particles out of the sensitive connectors until the last seconds before a connection is made.
The final step was to power Wally II on and test him. We Skyped the Wally control team in Germany and told them give it a go. The next thing we heard in the operations room was the exclamation He's moving! Much to our delight, the Wally II deployment was a success!
A view of Wallyland from Wally II's new and improved webcam. The shell experiment frame (green) appears in the upper-right portion of the image.
Photos of Wally II, Wally I and the replacement operation.