Thursday, April 22, 2010

Last Source Mooring Deployment!

We have now deployed all six of our source moorings and confirmed that they are all working. Whew! Tomorrow we deploy our last mooring with all the hydrophones that will listen to these sources.

It doesn't take a scientist to figure out what would happen if we started with the anchor...it would sink right away! We start with the buoy because it floats. The ship then moves into the wind at a speed of about 1 knot (which is about 1 mile/hour) so the wire doesn't all pile up in one spot and get tangled. We keep feeding the wire out using a winch until we have the entire 3-1/2 miles of mooring floating on the surface behind the ship. When we reach the end we can't even see the buoy anymore! We then drop the anchor, and it pulls everything else down with it.

The wire comes in sections, usually 500 meters long, so we have to keep adding to the mooring as we go along. These shots of wire are on reels which are spun around by a winch to pay the wire out. The most important thing is to never let it go when we are adding another piece of the mooring! Sometimes we can hook onto a chain to hang onto the mooring, but if we are just adding another piece of wire there isn't anything to hook onto so we use a Yale grip, or Chinese fingers. This is a loop with 4 ropes attached that are wrapped around the wire very tightly so it looks like a braid (you can see it in the video). It holds onto the wire so tight that we can just hook onto the loop and that will hold the whole mooring.

The entire deployment takes about 10 hours, but the following video condenses it to just over a minute. Don't blink!

video

1 comment:

  1. Able Sea Chick momApril 26, 2010 at 6:59 AM

    I LOVE this video!! Can't stop watching it!

    ReplyDelete