Patent ID: 8875911

Claim:
A method for erecting a rig mast section on a substructure, the substructure comprising a first substructure box that is positioned laterally adjacent to and spaced-apart from a second substructure box, the first substructure box comprising a first upper box that is raisable above a first lower box and the second substructure box comprising a second upper box that is raisable above a second lower box, each of the first and second upper boxes having an upper roller apparatus coupled thereto and each of the first and second lower boxes having a lower roller apparatus coupled thereto, the method comprising positioning a mast section on a mover, moving the mast section with the mover to a position adjacent the substructure, after positioning the mast section on the mover, moving the mast section relative to the mover, positioning a lower end of the mast section over each of the upper roller apparatuses, and after positioning the lower end of the mast section over each of the upper roller apparatuses, raising each of the first and second upper boxes above the respective first and second lower boxes so that each of the upper roller apparatuses contact the mast section and lift the lower end of the mast section off the mover.