Suction drag system

Claim 1

In a dredging vessel having a hold and coamings extending lengthwise of the vessel on opposite upper sides of the hold, the vessel having a suction drag system comprising a suction pipe with a suction pump, a discharge conduit for discharging dredged material into the hold, elbow means interconnecting the suction pipe and the discharge conduit, and derrick means by which the suction pipe may be moved outboard and lowered, and raised and brought inboard; the improvement comprising a plurality of support frames extending transversely across the hold and detachably secured at each end to a said coaming, at least one of said support frames carrying said derrick means and another of said support frames carrying said elbow means, said elbow means comprising parallelogram linkage disposed in a vertical plane transverse to the length of the vessel for raising and swinging inwardly, and lowering and swinging outwardly, the upper end of the suction pipe, a turnpiece providing a horizontal swivel joint between the elbow means and the upper end of the suction pipe about a horizontal axis transverse to the length of the vessel, and a horizontal cylinder for swinging said parallelogram linkage.