Eventually, we decided to use the Sabertooth’s own weight to our advantage. In close coordination with the AUV/ROV operation team, we got the unit into perfect vertical position, pulled the quick-release cord, and the Sabertooth plummeted straight down through the gap and into the water as the operators fired the thrusters. It quickly leveled-out beneath the surface and was ready to go exploring. Success!
After a short cruise around the shallow waters beneath the barges, it was time to attempt a recovery. It took us many tries to bring the AUV/ROV back to the middle of the hole, get it to stand up on end, and then slowly rise to the surface in a vertical position. At the end of several days of intense practice and trouble-shooting, we had the Sabertooth emerging from the water right on cue, ready to be hoisted out of the water.
For the final phase of testing in France, we had to find some actual ice. It’s not exactly beach weather in southern France in October, but it’s also nowhere near as cold as the Weddell Sea. So, we had to make our own! Have you ever seen a big shipping container on a train car? If so, imagine filling one up with water and freezing it to make the biggest ice cube you can imagine. We practiced setting up a mobile drilling rig over these huge ice cubes, and then we drilled hole after hole deep into the ice using custom drill bits that are over three feet (about one meter) in diameter. This was the one part of trials that went faster and better than planned, and expedition members who have been to the Weddell Sea assured us that the ice there will be easier to drill into.
Now that the testing phase is complete, there are still many things to do.
