REQUEST FOR (RFP) FOR THE REFURBISHMENT OF RAILS BY MEANS OF FIELD WELDING AND GRINDING OF RAIL MANUFACTURED CROSSINGS, WHEEL SPIN BURNS (SKID MARKS) BATTERED ENDS REMOVAL OF ULTRASONIC DEFECTS BY MEANS OF EXOTHERMIC WELDING OF RAIL JOINT (48KG/M,57KG/M AND60KG/M AND GRINDING OF OVERLAPS ON TURNOUTS ON “AS AND WHEN” REQUIRED BASIS FOR PERIOD OF 36 MONTHS IN THE METRORAIL GAUTENG REGION.