Apparatus and method for moving track guided equipment to and from a track

Apparatus for moving track guided equipment to and from a track, such as a drilling track extending along the length of the derrick of a subterranean drilling rig, in which the equipment is movable about axially along the length of the drilling track between the upper end and the lower end of the drilling track, the apparatus comprising:

• an articulated guideway having a first housing connected to the derrick and a second housing pivotably connected to the first housing;
• a movable working track movably disposed in the guideway and movable between a first position in which the working track is aligned with the drilling track and a second position in which the working track is transversely displaced from alignment with the drilling track, the working track being disposed in the first housing in the first position;
• a secondary track pivotably connected to the working track and movably disposed in the articulated guideway, the secondary section being pivotably connected to the working track and being pivotable between a skewed position in which the secondary track is not transversely coplanar with the drilling track and the working track and an in-line position in which the secondary track is about transversely coplanar with the drilling track and the working track, the secondary track being transversely movable with the working track so that the secondary track is disposed in the second housing when the working track is in the first position and is aligned with the drilling track when the working track is in the second position;
• and
• power means for pivoting the secondary track from the skewed position to the in-line position and transversely moving the secondary track in the in-line position and the working track to the second position of the working track;
• and for transversely moving the working track in the second position and the secondary track in the in-line position to the first position of the working track and pivoting the secondary track from the in-line position to the skewed position.

Method of moving track-guided equipment to and from a track, such as a drilling track extending along the length of the derrick of a subterranean drilling rig, in which the equipment is movable about axially along the length of the drilling track between the upper end and the lower end of the drilling track, the method comprising:

• connecting a working track to the derrick so that the working track is transversely movable between a first position in which the working track is aligned with the drilling track and a second position in which the working track is transversely displaced from alignment with the drilling track;
• connecting a secondary track to the working track so that the secondary track is pivotable between a skewed position in which the secondary track is not transversely coplanar with the drilling track and the working track and an in-line position in which the secondary track is about transversely coplanar with the drilling track and the working track, and so that the secondary track is transversely movable with the working track and is aligned with the drilling track when the working track is in the second position;
• pivoting the secondary track from the skewed position to the in-line position and transversely moving the secondary track in the in-line position and the working track to the second position of the working track so that the equipment may be lowered from the drilling track onto the secondary track;
• and
• transversely moving the working track in the second position and the secondary track in the in-line position to the first position of the working track and pivoting the secondary track from the in-line position to the skewed position in order to remove the equipment from the drilling track and align the working track with the drilling track.