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> July 31, 2006
post Aug 3 2006, 01:04 AM
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Group: TREC Team
Posts: 27
Joined: 19-July 06
Member No.: 39

July 31, 2006

The Sunday that never ended. At 12:30, the guns and the cage were ready to deploy. The decision was made that we would put it in the water, ramp up the guns and start taking some data. This would be a shake out run for the equipment. At 1:00 all of the science people and all of the Coast Guard that would be directly involved with operating the ship and managing the deck were there.

Preparation of Core
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The captain and the executive officer were both present as an overview of the plan for deployment was reviewed. A formal evaluation of all the potential safety concerns was given with special care taken to note any on deck hazards. Each individual's responsibilities while deploying were discussed. Everyone was required to have safety glasses, hearing protection, steel-toed boots, mustang suit and gloves or they were not permitted on deck. Watches and rings also had to be removed.

By 2:30 the cage had been moved by crane to the aft portion of the fantail. The cage was then transferred to the A frame which is a crane that can extend back beyond the transom of the ship. On three attempts to lower the cage it hit in the top edge of the transom and would not lower into the water. Finally a 2 x 4 was used to nudge the cage an inch away from the transom as it was being lowered, and finally we were able to move onto the deployment of the seismic streamer and to start firing the air guns.

Preparation for Transport
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Since this was the first time that the streamer was used on the cruise, we had to remove small plastic and aluminum collars that are used to hold devices called birds that help keep the streamer at a certain level below the water. The streamer would be loosely connected to the cage to keep it below the ice, so the collars were not needed.

Steffen was in charge of managing the air guns. He seated all of the air guns just before we finally lowered the whole cage with the guns into the water. We contacted the bridge at about 3:00 and asked for permission to start the ramp up procedure for the guns. On the bridge throughout the entire cruise we have one person on watch to look for marine mammals. The scientists on the cruise are concerned about any impact that noise produced while doing the seismic might have on the marine mammals that live in the research area. No seismic work is done if any mammals are sighted in a half-mile radius at any time. The marine mammal observers are on watch 24 hours a day.

Muddy Sediment
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The first half hour was an experiment in getting the cage to track properly behind the ship and testing each one of the guns. After forty minutes of having the cage working in the water, it was determined that we would have to make some changes in the attachment locations of the two towing ropes. We were able to collect data for that forty minutes and establish that the dozens of individual components that make up the how system

It took about an hour to get everything back on deck and secured. We all took a break for breakfast and reconvened to debrief and make suggestions for improving the process for the second deployment. The cage and guns had no damage. Minor changes to the tow mounting rope positions would be made and all bolts and connections would be checked and rechecked. The MST's and the Boson Mate were super on deck. They kept us safe, handled all the cranes and made some very important observations and criticisms that will really help make the next deployment even more successful.

At 9:00 I finally went to bed. While I was asleep the ship moved to a new station on the ridge to take two cores. They used the Big Bertha Corer and got some nice sediment. At 4:00 I started watch and helped with the repair work on the guns until midnight. Marcy worked on annotating the current position of each of the seven instruments on the ice on the map, getting ready for tomorrow and another trial with the cage.
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