Centenary of Kalka Shimla Railway --- The railway was constructed on a 2' gauge by the Delhi-Ambala-Kalka Railway Company commencing in 1898. The 96.54 km line was opened to traffic on November 9, 1903. n 1905 the line was regauged to 2'6" gauge under guidelines from the Indian War Department seeking to ensure uniformity of narrow gauge systems. The line has 864 bridges, one of which is a 18.29 metre (60 ft) plate girder span and steel truss. The others are viaducts with multi-arched galleries like the ancient Roman aquaducts. Originally 107 tunnels were built on Kalka Shimla Railway Track. In 1930 they were renumbered and four of them were discarded so only 103 were left. In 2006 tunnel number 46 was dismantled so presently only 102 are in use. But tunnel number 103, the last tunnel in Shimla, is still famous as tunnel number 103 as this place has become a famous landmark of the town. The train makes an arduous climb of almost 4800 feet from Kalka to Shimla in almost five hours. Total change of altitude : From Kalka, 655 meters (2,150 ft) to Shimla of 2,076 meters (6,811 ft). Bridge No. 226 between Sonwara and Dharampur is an arch gallery bridge having 5 tier galleries of multiple spans, constructed with stone masonry and bridging a deep valley surrounded by high peaks. IndiaPost issued a commemorative stamp marking the 100 years completion of KSR in 2001 with denomination 500p (₹ 5/-). Stamp depicts the KC-520 steam locomotive going up-hill will Himalayan Queen Express over the snowcovered arch-gallery viaduct.