Patent ID: 8720128

Claim:
A method to disassemble a mast assembly having at least a substructure including a first and a second substructure sections, a first cylinder and a second cylinder, and a lower mast section, which method comprises: disengaging a pair of front mast legs of said lower mast section from a pair of front leg supports; moving said pair of front leg supports from an operational position to a transport position; lowering said lower mast section from a vertical position to a horizontal position by retracting said first cylinder and said second cylinder; removing a mast center spreader from said lower mast section; and removing a center drill floor section from between said first substructure section and said second substructure, for transportation of a combination of said first substructure section, said first cylinder and a portion of said lower mast and a combination of said second substructure section, said second cylinder and a portion of said lower mast.