Cable laying apparatus for burying cable in bed of watercourse comprising a towed sledge-mounted submerged mole-plough

摘要

A stationary winch-barge (2) hauls in a drag-line (6) connected both to a following cable-carrying pontoon (3) and to a submerged tubular-framed sledge (4) towed behind the pontoon, and equipped with a mole-plough (21). The cable (C), drawn off storage drums (10) is fed horizontally to fall on to the base of the trench (OL) cut by the plough in the river. The unsupported trench sides later collapse, burying the cable. The quadrant and plough subassembly pivot on a transverse axis to set the desired trench depth, and can deviate laterally to some extent. Sledge hydraulics are connected by an umbilical (17), also conveying operational and sensor signals, from the pontoon power unit (15), adjacent to a control center (14). A GPS link, via a marker buoy (39,42), maps the route. Route stages (L) are fixed by e.g. river bends and bridges. Laying stops when minimum separation (D) is reached. The barge, recovers the sledge by way of a crane (9), tows it to it's next station and reattached (8). In difficult trenching conditions a rotary cutter replaces the plough. An Independent claim are included for a cable laying procedure utilizing the described apparatus.