Abstract: A pipelaying system adapted for deployment on a vessel for use in a body of water and having at least one reel for storage and layout of a rigid walled pipeline and including a pipe take-off drum for mounting on the vessel for rotation about a horizontal drum axis, and a drive unit operably connected to the reel and adapted to permit control of the rate of movement of the pipeline, and methods of spooling on and spooling off.

Abstract: A cable clamp for securing a control cable to a kill or choke line in a mud riser used in offshore drilling of oil and gas wells is described. The cable clamp is comprised of two portions, a fixed portion which remains secured to the kill or choke line and a removable portion which can be engaged to or quickly released from the fixed portion to secure or disengage the control cable. The fixed portion includes a U-clamp, and the removable portion includes cooperating hinged members, each member mounting resilient pad and both members for securing said hinged members together to clamp said cable.

Abstract: The vessel comprises a pair of laterally spaced elongated hulls having a pair of upstanding columns at opposite ends thereof supporting a working platform and a drilling mast in spaced relation above the hulls. The hulls buoyantly support the vessel in a low draft in-transit floating condition with the hulls having freeboard. The hulls have ballast compartments to submerge the hulls and portions of stabilizing columns such that the waterline lies intermediate the height of the columns with the platform and drilling mast elevated above the waterline. The columns stabilize the vessel in the high draft condition and the number, cross-sectional area and configuration of the columns, the weight distribution of the vessel and the geometry of the submerged hulls and portions of the columns are such that the vessel obtains motion minimizing characteristics in the high draft condition.

Abstract: The navigation system permits remote maneuvering of a water-borne structure about a stationary object by utilizing dual sonar ranging. The structure can be self-propelled or towed by a surface craft. The transducer portion of the navigation system is mounted on the structure and the system's remaining portion is on the deck of the surface craft. For complete remote navigation, at least three but preferably four transducers are employed for positioning at the four corners of a rectangle. Each transducer is both sound-emitting and sound-receiving. The sonic impulses from each pair of port and starboard transducers are directed downwardly and inwardly. The travel time for each reflected sonic impulse is directly proportional to the slant range between the transducer and the object. The spacing between each pair of port and starboard transducers and the frequency of the emitted sound impulses are selected so that very accurate measurements are obtainable of the position of the object relative to the transducers.