The Senior Toolpusher (STP) instructed the Driller to prepare the wire line for the next survey. The Driller delegated the task to the Assistant Driller who in turn assigned a Floorman to don the man-riding belt and be hoisted to near the Monkey Board, then go outside the mast on the drawworks side, and be lowered back down to floor to pick up the wire line. The wire line was attached to the riding belt and he was being hoisted again, towards the monkey board where he was to install the wire in its sheaves (30 meter height) (99 feet). As the individual was being hoisted, the buckle/strap of the riding belt caught a mast beam and the riding belt was pulled against two opposing forces and was sheared. The Floorman fell from a height of 15 meters, (50 feet) struck against the drawworks and landed on the rig floor where he died instantly.