September 9:
Yesterday we attempted to recover the mechanical leg of the vertical mooring, which was designed to be recovered with the anchor attached. Unfortunately, we ran into two issues which resulted in failure to recover the mooring. First, the winch being used to reel in the mooring line started making unusual sounds, which prompted an hours long investigation to identify the source of the sound. Once the winch was up and running again, we quickly learned that the anchor was stuck and the winch was unable to pull it out of the mud on the sea floor. With conditions too poor to launch the ROV to inspect and with limited sunlight, we were forced to reattach the buoys to the end of the mooring line and leave it behind. Although the original intent was to replace this mechanical mooring leg, I have heard speculation that we may attempt to reuse the stuck mooring for the next 8 years. I am curious whether this would create a significant risk of failure and if not, why it was supposed to be replaced in the first place.
In other news I have been having lots of fun trying to photograph the albatross that follow the boat.
September 7:
The first day of leg 4 was largely uneventful with a commute out to Slope Base starting in the late morning and high winds and waves preventing us from deploying the ROV in the afternoon. This turned out well for me as I was quite seasick after we got out into the open ocean and was able to spend most of the day acclimating to life at sea.
Today, day 2, has been much more interesting. I spent much of the day documenting the work on deck, which has included recovery of the vertical mooring and the EOM cable. The most entertaining part of this process was watching the top section of the EOM cable be cleaned of sea anemones and other life forms as it was winched onto deck. This resulted in a huge pile of gunk on the deck that was rather impressive in size.
One part of the deck work process that has surprised me is how long it takes to complete seemingly simple tasks. All the equipment is large and heavy which requires careful planning and safety procedures. In addition to this, the winches on the boat are rather slow and require a dedicated operator who much communicate with the deck via hand signals.
As I write this, the crew is working on recovering the bottom section of the EOM (a long cable that anchors the vertical mooring to the ocean floor and provides the vertical mooring with power and signal), which so far has taken over 2 hours and is just over halfway complete (the bottom depth here is 2900 m!). The bottom section of the EOM has buoys bolted onto it every 20-30m which slows down the process significantly. After about a third of the ~90 floats on the EOM, the crew have become experts at removing the buoys and watching them reminds me of the rapid pit stops in professional car racing. I am looking forward to documenting the remainder of the recovery process in the following days.
