Abstract: A system for moving personnel between two elevations has features that allow control of ascent and descent by the passenger. The system has a cage carried by a load bearing cable that is moved to raise and lower the cage. The cable also has a plurality of electrical conductors within it that are insulated from each other. Passenger controls are connected to the electrical conductors of the cable. The conductors are connected at the other end to the powered lifting device, preferably through a slip ring assembly.

Abstract: A self-contained elevator structure including a pair of vertical, laterally spaced, parallel standards mounting a carrier or carrying cage for vertical travel therealong. Movement of the cage is effected by a multiple-sheave system actuated by a hydraulic piston and cylinder unit in turn controlled by three selectively operated switches, respectively at the top and bottom of the elevator structure, and on the traveling cage itself. The cage switch is capable of activation only when the cage gates or retaining bars are closed. The structure is positionable parallel to and closely adjacent a drilling rig platform with the control system for the vertically traveling cage enabling a stopping of the cage, and access to the rig platform, at any point along the vertical travel of the cage. Safety features include physically actuatable brakes provided on the cage, the use of switches which require constant pressure for actuation, and safety cables and braces between the rig and the standards.

Abstract: A stabbing board assembly comprising a support platform mounted for powered vertical adjustment on a pair of laterally spaced vertical rails which are in turn fixed, preferably releasably, to structural members of a derrick by upper and lower sets of longitudinally adjustable mounting arms. The platform in turn includes a section slidably engaged therewith and power controlled for selective extension and retraction.