How to Achieve Seamless Track Replacement Within a Blockade Window Using a Lithium Rail Saw and Thermite Welding?
Introduction
On heavy‑haul and high‑speed lines, continuous welded rail eliminates most joints but increases the complexity of removing local defects. The work must be completed within scheduled blockade windows, placing demands on equipment reliability and process precision. This paper examines how specific tooling – a battery‑powered rail saw and a thermite welding system – supports efficient rail replacement.
Demolition: Precision Rail Cutting
The first step is accurate removal of the defective rail section. Traditional internal combustion rail saws have limitations: difficult starting, exhaust emissions in tunnels, and cable constraints.
The RailwayCare RCS‑L50 lithium rail saw operates on a 72 V Li‑ion battery pack and a 5.0 kW brushless motor. Cutting power is comparable to internal combustion units. For 60 kg/m rail, cutting time stays within 120 s, with stable speed and no power attenuation. The IP45 protection rating and industrial‑grade cells allow operation in rain or freezing conditions. The all‑steel construction absorbs vibration and helps maintain cut‑face perpendicularity. The emission‑free design eliminates exhaust gases – an advantage for tunnel work.
Rail Welding: Metallurgical joining
After the defective rail is removed, the new and existing rail ends must be connected. Thermite welding uses an exothermic reaction to inject molten steel into the rail gap, creating a metallurgical bond. Unlike mechanical joints, this eliminates the mechanical step and restores rail continuity.
The RCS TWS system includes high‑activity flux and an adaptive pouring mould to resist wind and rain interference. With precise pre‑heating, the weld achieves base‑metal strength under different ambient temperatures. The side and base moulds produce a full‑profile weld head. After grinding, the weld head reaches zero or minimal protrusion, meeting requirements for high‑speed operation.
Process integration
The RCS‑L50 and TWS systems form a sequential workflow. First, the lithium saw cuts the defective section cleanly, leaving a square end face. Next, rail end preparation and alignment are done with professional clamps to adjust the gap and straightness. Then, the TWS thermite process injects molten steel above 1350 °C for atomic‑level bonding. Finally, post‑weld normalising and grinding produce a smooth, continuous rail surface.
RailwayCare Maintenance Solution
RailwayCare provides the RCS‑L50 rail saw and TWS welding system as part of a rapid‑response solution for defective rail replacement. The focus is on reliable cutting and welding processes that minimise stress concentrations on the track. For detailed technical documentation, please contact RailwayCare.
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