Entrainment and Anchor Loss Reduction in An Optically Actuated MEMS. Modeling, Analysis and Experimental Verification

When bottom fish such as halibut are the target, a massive bar is placed across the front of the net with heavy tickler chains dangling from it; these flail against the bottom, stirring up the fish so they will rise up into the maw of the net. Mere impact can be enough to wreck a cable, if it puts a leak in the insulation. Frequently, though, a net or anchor will snag a cable. If the ship is small and the cable is big, the cable may survive the encounter. There is a type of cable, used up until the advent of optical fiber, called 21-quad, which consists of 21 four-bundle pairs of cable and a coaxial line. It is 15 centimeters in diameter, and a single meter of it weighs 46 kilograms. If a passing ship should happen to catch such a cable with its anchor, it will follow a very simple procedure: abandon it and go buy a new anchor. But modern cables are much smaller and lighter - a mere 0.85 kg per meter for the unarmored, deep-sea portions of the FLAG cable - and the ships most apt to snag them, trawlers, are getting bigger and more powerful ...»