HYDRAULIC POWER UNITS FOR USE IN THE OIL AND MINING INDUSTRIES, NAMELY, HYDRAULIC PRESSES, HYDRAULIC RAMS, HYDRAULICALLY POWERED LIFTING DEVICES, NAMELY, CRANES, HOISTS, AND CONVEYORS; ROTARY WASH PIPE SYSTEMS COMPRISED OF ELECTRIC PUMPS THAT ALLOW OIL FIELD FLUIDS TO PASS FROM THE STATIONARY PIPE INTO A ROTATING PIPE MEMBER WHERE FLUIDS UNDER PRESSURES OF 5,000 PSI ROTATE UP TO SPEEDS OF 250 RPM; REPLACEMENT PARTS FOR OIL FIELD TOOLS, NAMELY POWER SWIVELS IN THE NATURE OF TOP DRIVES; POWER SPIN TORQUE DEVICES, NAMELY IRON ROUGHNECKS WHICH ARE DEVICES THAT CONSIST OF A COMBINATION OF HYDRAULIC CYLINDER OR RAMS TO GRIP PIPE WHILE ANOTHER SET OF HYDRAULIC CYLINDERS TURN THE PIPE TO JOIN TWO PIECES OF PIPE TOGETHER, SPINNING BEING ACCOMPLISHED BY CLAMPING ON THE PIPE WITH STEEL ROLLERS AND THEN USING HYDRAULIC MOTOR TO TURN THE PIPE; PIPE HANDLING SYSTEMS NAMELY TALL AUTOMATED HOISTS WHICH ARE 90 FT TALL ROBOTIC MACHINES USED TO PLACE 90 FT STANDS OF DRILL PIPE IN STORAGE RACKS ON AN OIL FIELD PLATFORM; DRILLING MUD CONTROL SYSTEMS, NAMELY 3,000 HORSEPOWER PUMPS THAT ARE DRIVEN BY THREE 1,000 HORSEPOWER MOTORS; TRACTABLE FRAMES USED TO SUPPORT OIL DRILLING EQUIPMENT IN OIL DERRICKS OR MASKS WHICH GUIDE THE EQUIPMENT UP AND DOWN IN THE DERRICK AND WHICH CAN BE RETRACTED TO AID IN POSITIONING VARIOUS PIECES OF OIL FIELD DRILLING EQUIPMENT IN THE DERRICK; AND OIL FIELD SKIDDING UNITS, NAMELY A COMBINATION OF HEAVY PLATFORM COMBINED WITH A COUPLE OF LARGE BORE HYDRAULIC CYLINDERS USED TO SLIDE OR SKID THE OIL DERRICK ACROSS THE OIL RIG SUBSTRUCTURE TO POSITION THE DERRICK TO BOARD THE NEXT OIL WELL