Abstract: A system or method of repairing railroad rails which includes a head, upright and base sections. The method includes at least the following steps: identifying and locating a defect in the rail, removing the defect by removing material from the rail surrounding the defect in at least the head section so as to form a void and a rail void interface while maintaining continuity of the rail, filling the void with molten metal having a high carbon content and causing the molten metal and the rail void interface to bond. The molten metal may be produced by gas shielded arc welding. The carbon content of the molten metal is near that of the rail to decrease carbon migration from the rails.

Abstract: An on site railroad rail welding repair apparatus wherein a railroad rail is an operating railroad track and a defect in the rail has been removed to provide a void and a rail-void interface while maintaining continuity of the rail having pair of cooling blocks which have an internal configuration to complement the rail, and an arc welder that fills the void with appropriate molten metal and causes the molten metal and the rail at the rail-void interface to bond. Also, a robotic welding apparatus and a weld containment apparatus engageable with the rail-void interface by movement having a pivotal and longitudinal component. Further, a mobile weld delivery unit delivering materials through an umbilical to a robotic welding apparatus having a welding device proximate the rail-void interface so that a weld can be made joining the rail-void interface.