West Coast Expedition
July 20 - August 30, 2002
West Coast of North America

August 13, 2002: Day #25

Randy Prickett demonstrating to Deb Kelley and Marv Lilley the strength and balance of the elevator design.

Debra Stakes writes: A notable difference between ROV’s and manned submersibles is the longer potential workday combined with a smaller sample/instrument payload capacity. One strategy to resolve this dilemma is the use of benthic elevators. These can include any variety of container, tracking beacons, flotation, and ballast that will permit the safe transport of items from the seafloor back to the ship. This sounds really simple in concept, RIGHT?

Predicaments arise however when the elevator is not properly ballasted and can travel in midwater away from the planned dropsite. Then both ship and tethered vehicle have to drop what they are doing and rescue the wayward basket. Similarly, once the elevator is filled with precious samples and tools, the ship must follow any aberrant track to be available for recovery. Thus the elevator is only useful with careful planning and implementation.

The elevators that we are using for the Keck dives are simple in design - two of the plastic milkcrates with syntactic flotation with beacons and droppable ballast. Before the UW scientists would risk their instruments in this simple design, Ops technician Randy Prickett had to personally demonstrate that the design was robust and safe.

Look at the dive update for Thursday, August 22 to see how the elevators worked in the field.

Figure 2 shows the elevator in the water. If you look closely, you can see the basket containing a biobox with tubeworms and the water samplers.

Figure 3 shows the elevator being recovered using the crane.


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