Loose-tube neutral tether fiber optic termination procedure

Abstract

Neutral tethers for unmanned underwater vehicles may contain a bundle of single-mode, optical fibers that are protected inside flexible stainless steel tubing. To date the author knows of no commercially available systems or kits that substitute for the following procedure, which is a step-by-step method for terminating electro-optical, loose-tube tether assemblies when used in oil-compensated, underwater applications. This procedure alone will not result in a load-bearing assembly. It assumes that the tether's outer jacket and synthetic strain-relief layer have already passed through and been terminated to an unspecified, customized, load-bearing assembly. The procedure addresses in detail the preparation of three optical fibers and three copper conductors for repeated make-and-break installations into a vehicle's primary junction box. The user will need a large, clean workbench, plenty of light and a variety of specialized tools, most of which are listed. A spreadsheet is provided that describes the parts required and suggests appropriate vendors or other sources. The entire procedure can take up to four hours to complete per tether end.