METHOD OF CONNECTING RAIL LENGTHS OF CONTINUOUS WELDED RAIL TRACK Russian patent published in 2007 - IPC E01B11/52 E01B29/42 

FIELD: railway transport; permanent way.

SUBSTANCE: invention relates to methods of repair of continuous welded rail tracks with elongation of rail lengths by welding at laying and restoration. Proposed method of connection of rail lengths of continuous welded rail track comes to the following: tensioning device is mounted on ends of two adjoining rail lengths, by means of which ends of rail lengths are moved towards each other, required clearance is set and thermal welding is done. After welding, in process of cooling of butt joint to acquire sufficient strength, tension is increased by valve defined by calculation using tensioning device for this purpose. Prior to tensioning adjoining rail lengths by tensioning device, value of longitudinal displacement of ends of rail lengths is approximately determined by calculation. If displacement actually exceeds calculated value, ends of rail lengths are cut off additionally. If displacement is less than that found by calculation, rail lengths are disconnected from ties, starting from ends of lengths, until clearance is equal to designed value. After thermit welding, in process of butt joint cooling until welded seam acquire sufficient strength, process of disconnection of rail lengths and ties is continued, accompanied with checking length of cooling part of rail length in zone of weld butt joint. After removal of tensioning device, part of rail length from both sides of weld butt joints is disconnected from tie and then, before opening traffic on said section, ties are tamped and rail lengths are fastened.

EFFECT: prevention of excess stresses caused by clamping longitudinal forces in rail lengths.