Protective Technologies and Installation/Implementation Methods for Undersea Instrumentation

The proposed project will create an innovative Trawl Resistant Tether System to protect vertically suspended, bottom-tethered types of ocean bottom sensor installations from the vulnerabilities of trawl rig damage. It uses innovative geometry and fabrication techniques that do not impact the sensor performance in any way. The proposed system addresses two specific vulnerabilities: damage to the top of the tethered float and sensor assembly caused by contact with the trawl rig leading edge or door, and damage to the tether cable as it exits the truncated pyramid trawl resistant bottom mount base. To resist damage to the tethered float and sensor assembly, the solution incorporates a protective shield that prevents it from snagging in the trawl rigging at the point of transition between the tether and the float and sensor. To eliminate the risk of damage to the tether cable as it exits the base, a pinch- and shear-proof surround at the attachment point is incorporated and prevents the tether cable from being pinched or severed by the leading edge of the trawl rig or the bottom edge of the steel door. The proposed solution for feasibility study offers sensor protection not currently addressed by trawl resistant bottom mount products.