Methods
Thermite Welding
This method commonly involves on-site thermite welding, creating a continuous rail. Iron compound chemicals are placed between the two rails, reacting at high temperatures to melt and connect the rails. The remaining material from the chemical reaction is then cut and leveled with the rail.
Flash Butt Welding
Involves bringing the ends of two rail pieces, electrically charged with a substantial current, together. The electric flash heats and melts the ends, and pressure is applied (150 to 300 kg/cm3) to fuse and flatten the incandescent ends. This method doesn't require additional materials like thermite welds, produces stronger weld joints, and is quicker, requiring only 15 minutes per weld point compared to 25-30 minutes of thermite welding. However, this method may pose risks in densely populated areas, especially where accidental contact with the electrically charged rail is possible.
Fish Plate
Image: (Railway Fish Plate, Rail Joint Bar, Splice Bar for Sale | AGICO Rail, 2019)
Involves using a support called a fish plate, secured with 4 or 6 bolts on the two connected rails. This joint type introduces a gap between the joined rail ends to prevent warping during rail expansion in the sun. While preventing warping, this gap can lead to uneven rail heights, resulting in the distinctive ticking sound of wheels against the rail ends when a train is in motion.