About Kalka-Shimla Railway (KSR):
- It is a narrow-gauge railway in North India which traverses a mostly mountainous route from Kalka (Haryana) to Shimla (Himachal Pradesh).
- Construction:
- The railway was built in 1898 to connect Shimla, the summer capital of British India, with the rest of the Indian rail system.
- The project's chief engineer was S. Harington.
- The 96 km. long, single-track line, often called the toy train line, was opened in 1903.
- It passes through 18 stations, 102 tunnels, and over 850 bridges.
- Total change of altitude: From Kalka (655 meters) to Shimla (2,076 meters).
- The world's highest multi-arch gallery bridge at Kanoh and the world's longest tunnel at Barog (at the time of construction) of the KSR were the testimony of the brilliant engineering skills applied to make this railway line.
- It was a UNESCO World Heritage Site in 2008.
- The rail network holds the Guinness Book of World Records for its 96-kilometers steepest rise in altitude with a crossover of 800 bridges and viaducts.