For example, when launching the Sabertooth unit from the ship in the Weddell Sea, we will need to protect the upper section of the cable that connects the Sabertooth to the ship in order to keep it from being cut by passing chunks of ice in the water. We will do this by running the cable through a strong section of pipe. For our first several launch attempts, we sent the protective pipe section out first, followed by the Sabertooth. This put a lot of weight on the cable, and in several cases, it caused the cable to break. Seeing that our first idea wasn’t working, we decided to launch the Sabertooth first, and while it “held station” (stayed in one exact location, usually underwater), there was much less pressure on the cable when we launched the protective pipe. After some failures and a lot of on-the-spot problem solving, we found a solution that worked.
So, what happens if thick ice prevents the S.A. Agulhas II from reaching the Endurance sink site? It’s very possible, and that’s where “Plan B” comes in. Using two helicopters aboard the S.A. Agulhas II, we will move the entire sub-sea search operation onto the ice at the sink site. We spent most of the second and third weeks in France simulating different aspects of this ice camp set-up.
The first challenge was learning to launch and recover the Sabertooth AUV/ROV through a simulated hole in the ice. We positioned two small, inland dock barges together in the harbor, leaving just enough room for the Sabertooth to slip through in a vertical position. In our first attempts, we battled with buoyancy (the force that makes something float) as the leading edge of the Sabertooth hit the water and didn’t want to sink.
