Abstract: Lower pipe stand racking combs are arranged to fold down from a side of the derrick at selected locations above the rig floor. In each racking comb an array of parallel fingers extend in a spaced array from a pivotable spine. The spine rotates to raise the fingers to a near vertical position to clear the rig floor activity area. A suspended pipe stand can pass laterally from the well center line past the ends of the fingers. The fingers, each, have a retractable extension that, when extended, will prevent the suspended pipe stand from passing the extended finger. The stopped pipe stand can then move transversely into the selected space between two fingers. Each finger extension has independent fluid power supply and control lines, the collection of the lines may extend to a control and power source selectively positioned on the rig floor or derrick. Raising of each comb assembly is, preferably, done by a fluid power cylinder attached to the derrick structure and to each comb assembly.

Abstract: Lower pipe stand racking combs are arranged to fold down from a side of the derrick at selected locations above the rig floor. In each racking comb an array of parallel fingers extend in a spaced array from a pivotable spine. The spine rotates to raise the fingers to a near vertical position to clear the rig floor activity area. A suspended pipe stand can pass laterally from the well center line past the ends of the fingers. The fingers, each, have a retractable extension that, when extended, will prevent the suspended pipe stand from passing the extended finger. The stopped pipe stand can then move transversely into the selected space between two fingers. Each finger extension has independent fluid power supply and control lines, the collection of the lines may extend to a control and power source selectively positioned on the rig floor or derrick. Raising of each comb assembly is, preferably, done by a fluid power cylinder attached to the derrick structure and to each comb assembly.

Abstract: The line system on a drilling rig is arranged to place the dead line clamp at the upper end of the derrick. A dead line anchor sheave is preferably located to accept wraps of the dead line to insure reduced load on the dead line clamp. The anchor sheave is preferably lockable to prevent rotation and releasable to rotate the anchor sheave for line feeding from a reserve line reel for maintenance operation. A load sensor is optionally provided to sense dead line load for sensing associated hook loads on the traveling block. An motor is provided, as an option, to rotate the anchor sheave for line feeding maintenance operations.

Abstract: A drilling rig derrick is adapted to direct the hoist lines reeved between the crown block and the traveling block such that they enter both in a vertical direction if the traveling block is moved laterally to clear the work area over the rotary table. Arrangements are provided to move the crown block laterally, and to move it back over the rotary table. Alternate provisions displace the reeved lines with idler sheaves to move the traveling block only and direct the reeved lines such that they enter both crown block and traveling block sheaves in a near vertical direction. Methods for both options are provided.

Abstract: The derrick is configured to place the lift axis of the crown block toward the aft end of the rig floor. Major floor loads such as draw works are moved closer to the platform. The spare line spool support is changed from rig floor to platform. The set back areas are distributed on both sides of the vee door.

Abstract: A heave compensator for a drill ship with a derrick and hoist system with a dead line provides a line reservoir on the dead line. The dead line is reciprocated to move the hook load relative to the vessel to control it relative to the sea bed. The line reservoir is expanded or contracted by changes in ballast pressure to counterbalance the hook load. To compensate for heave and friction in the hoist system a pressure source is provided to augment the ballast pressure for hook load and position control. Sensors and controls are provided to anticipate and compensate for oncoming heave excursions. The dead line being flexible permits latitude in selecting and orienting the compensator machinery. As an option, the vertical movement sensor is placed on the hook related structure for more responsiveness to hook load movements.