5.3.1 Rail ends should be aligned properly, both laterally and vertically. Rail ends should be secured to prevent movement during the welding process.
5.3.2 The root opening between rails may be oxyfuel gas cut, sawed, or cut with an abrasive disc. Of these, oxyfuel gas cutting is the least desirable.
5.3.2.1 If the final gap is to be prepared by OFC, the rail should be preheated to 700°F (370°C) prior to the oxyfuel gas cut to prevent cracking.
5.3.2.2 Care should be exercised to ensure smooth cut surfaces. An end squareness of ±1/16 in. (±2 mm) both horizontally and vertically is recommended.
5.3.2.3 Ends of oxyfuel gas cut rails should be cleaned thoroughly to remove all residual oxide and must be welded prior to cooling.
5.3.3 The root opening between the rail end faces may vary depending on the specific commercial process.
5.3.4 At least 6 in. (150 mm) on each side of the gap should be free of all moisture and foreign substances such as dirt, grease, loose oxide, burns, fins, and metal flow. In addition, a 6 in. (150 mm) hole free zone is recommended.
5.3.5 Copper material from track circuit bonds shall be removed for at least 2 in. (50 mm) on each side of the weld area.