Page 13: of Marine Technology Magazine (April 2019)

for US GEOTRACES. sample bottles. As it is lowered through the water column to

To support the scienti? c challenges, a suitable cable had to depths of 7,000 meters, it endures factors including cold tem- be non-metallic to meet non-contaminating criterium as any peratures, bending, tension cycling, corrosion, marine abra- exposed metal can interfere with the sample quality of trace sion, compression and even attack by sea-life. It must ? ex and elements, such as iron and zinc, by the time they return to bend to deal with winching, marine currents, and pressures the surface. A lighter-weight solution would also allow deeper exceeding 550 bar (55,000 kPa).

ocean sampling, compared with metal-clad electromechani- Each cable provides the physical connection for real-time cal cables ordinarily used for campaigns. These older models power and communication connectivity. Designs have to be of cables are considered too heavy for winching within safe rigorous, and manufacturing takes attention to detail and prov- working limits when lowered to depths of more than 5,000 en processes.

meters.

Ideally, the solution had to have no exposed metal, lower the Material gains weight and deploy rapidly. It also had to be strong enough to The requirements for underwater sampling and monitoring handle variable loads under tension due to the movement of are diverse. Projects can include seismic surveys, marine life the ship and be long-lasting. The cable and connected hard- studies and pollution tracking. The cables are manufactured ware would also have to endure more than 100 deployments differently from general industrial versions, hand-build for of- per expedition. ten unique purposes. Notably, Cortland has worked with the

Cortland’s cable has now been used on more than 600 ocean School of Marine Science and Technology at the University research deployments. It safely holds the weight of 500 ki- of Massachusetts to produce a specially designed electrical lograms of equipment, including a carousel of 24 12-liter coaxial cable to conduct a census of Atlantic sea scallops, and www.marinetechnologynews.com

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