LAND RIG

摘要

A land rig comprising a mast (11), a substructure (40) beneath the mast (11), the substructure (40) having a top part (43: rig floor carrying drawworks 19, rotary table 13), movement apparatus comprising a winch (25a), A-frame (20a), cable (29a) running from winch over sheaves (26a, 27a) to sheave (16a) movably attached to the mast. For raising the mast (fig. 5B), sheave (16A) remains attached to the mast, for raising the top part (43), sheave (16a) is lowered on guide tracks on the mast and connected to the top part (fig. 5C).