Autonomous and rapid deployment of a compact taut-wire mooring

Abstract

The deployment time of a taut-wire mooring is reduced to the time any transportation/hoisting device needs to put a payload at the sea surface. This is a matter of minutes rather than hours needed for deployment of long deep-ocean moorings in the regular way. It is achieved by extending the basic function of mooring parts to temporarily form a Launcher for Oceanographic Equipment and Instruments (LOEI). Full preparation of the mooring is done onshore where the instruments are prepared and programmed, and spooled onto the top-buoy together with the line. At sea, no other gear is required than a device that is able to lift a load of, say, 2000 kg, even for long deep-ocean moorings. The compact mooring method realizes considerable budget savings through deployments from non-research vessels and airborne transportation-deployment. Limitations lay in size and weight of the oceanographic instruments. We present a test-design shaped as a barbell and loaded with 940 m line and 3 current meters. Unfurling speed was maximally 2.3 m s −1 and the descent speed amounted 1.2 m s −1 until landing on the seabed. These speeds are comparable to those acquired during a conventional free-falling mooring deployment.