Streamer connection system

Abstract

A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. An outer collar attached to an external device rotatably receives the inner collar and the encircled streamer in its bore to allow the streamer to rotate freely within the outer collar relative to the external device. The outer collar has an inner face bounding and defining the shape of the bore. The inner face is tapered from an intermediate position outward toward front and rear edges of the outer collar to form a bore that is wider at the front and rear edges than at the intermediate position. This flaring out of the bore provides the streamer three degrees of angular freedom to position itself within the bore. Roller bearings, such as ball bearings or pin bearings, retained in recesses in the collar opening onto the inner face at the intermediate position extend into the bore to provide a low-friction bearing surface to the inner race. The ball bearings are retractable against spring pressure to provide the streamer with two degrees of lateral freedom to translate itself within the bore. In a typical connection system, a single external device is connected to the streamer by a pair of associated inner and outer collars.