with a travelling block 30 and associated hook 32 using the power of the rig draw works 16 the drilling line 28 in association with traveling block and hook 32 are utilized to erect the derrick mast 18 into its upright or operational position whereupon it is pin secured with necessary safety precaution and support structure to enable function in the upright position a bridle line or mast raising line 34 is utilized in coaction with the powered traveling block 30 to effect raising of mast 18 referring also to fig2 a top view schematic diagram of the rigging the mast raising line 34 consists of a first wire rope open socket 36 as secured to cable or wire rope 34 having a generally mid point screw connector assembly 38 and terminating in an open socket 40 as an example a standard mast raising line for a 131 foot derrick consists of an a section 42 of 108 feet and a b section 44 of 112 feet the sections being secured together by a pin connector 38 however it should be understood that mast raising lines in general will range in diameter from 11 8 inches to 31 2 inches and they can be assembled from either 1 part 2 parts 3 parts or 4 parts this usually depending upon the size and the particular mast design referring also to fig1 the respective end open sockets 36 and 40 are securely affixed to respective mast anchor point brackets 46 located on each side of mast 18 and the respective ends of mast line 34 are then led over the respective sheaves 48 and 50 as rotatably supported on top of.