Curator Jerry Bode Describes the Catwalk

The Catwalk is a work area where cores are received from the drill floor and processed before being taken indoors for further processing and analysis.  The catwalk is like a porch attached to the side of the Core Lab.  It has a roof and the grating on the floor is sitting on a solid base, making it a worker-friendly area.  The open side faces the main deck two levels below and looks out over the ocean.  It is quite a view.  The catwalk abuts the Drill Floor, but is several feet lower so they are connected by a small stairway. 

Catwalk Activities
As the Roughnecks remove the core from the core barrel, they hand it directly to the techs, who carry the nearly 10 meter butyrate (clear plastic) tube to specially designed holders that hold the core at a good working level.  There, the Curatorial Specialist and Assistant Lab Officer measure off 1.5 meter sections from the top of the tube to the bottom – or at least to where collected material (recovery) ends.  As the measurements are made, each section is marked, using a felt tipped pen, with the core number and a section number.  If you are lucky (or unlucky if you’re at the wrong end of your 12-hour shift) and have full recovery (a completely full tube), this will give you six 1.5 meter sections and a seventh section about 50 centimeters long. 

Once the core is measured, then the liner is cut using a specially designed cutter.  Studies such as interstitial water and microbiology that require whole round samples are cut next, generally at the bottom of a particular section, and given to the appropriate technician or scientist.  The ends of the sections are closed with end caps melted on with acetone, a blue end cap at the top, a clear one at the bottom and yellow on the end that has had whole rounds removed.  The color scheme is a not quite foolproof way of insuring the sections travel through the various testing equipment with the proper orientation.

But this is not the only activity taking place on the catwalk.  In the process of extracting the core liner from the core barrel, the core catcher must be removed.  The core catcher is just what the name implies; it catches the cored material and prevents it from slipping back out the bottom.  But it doesn’t have a liner in it so the sediment (or hard rocks) must be extracted.  This needs to be done, as the material in the core catcher is the oldest material recovered, and being able to age-date it is quite important. 

The extraction process for sediments is fairly easy when the sediments are from close to the sea floor, as they are very wet and are easily pushed out of the core catcher assemblage.  As you go deeper and the sediments get harder and drier, things get more interesting.  The drier the sediments are, the more tenacious they are, and it is not uncommon to see the core catcher tech pounding a steel piston with a 10 pound sledge hammer to get the sediment out.  This is a particularly good job for a person who needs to work out frustrations, as no one questions the use of this type of force. Once the sediment is out, it is placed in a liner of its own, capped and labeled with a CC for Core Catcher, and treated as a section from that point on.

The sections are then carried into the Core Lab where their information is entered into the computer. Labels with complete identifiers (Expedition, Site, Hole, Core, Core Type, Section, working/archive designations) are generated and attached to the liners and taped in place using a special polyethylene adhesive tape. Then this same information is engraved into the liner itself using a Dremel tool, as a precaution in case the label comes off in the future.

If the catwalk functioned just as described it would be a very boring place to work in. In fact, scientific drilling operations sometimes present challenges such as shattered liners or perhaps cores with sediments being extruded out of the liner because of expanding methane gas. On rare occasions there have been instances of exploding liners because the trapped gas produced too much pressure. Every cruise offers up unusual catwalk problems, which test the ingenuity and humor of the Core Lab Techs. But that is the beauty and draw of working on such a unique ship: to test your problem solving abilities while working at the forefront of science—and all this with a spectacular view.

Why just read about it when you can watch the video?

 

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