The Delhi-Umballa-Kalka Railway(DKR) Company was formed in 1889. The broad gauge(BG) line ran north from Delhi via Umballa+(Ambala) to Kalka in the Himalayan foothills where it joined the Kalka-Simla Railway.    The line was worked by the East Indian Railway(EIR) and taken over by the Government of India(GoI) in 1925.
The DKR Company signed a contact in 1898 with GoI for the construction and working of a 2ft/610mm narrow gauge(NG) line from Kalka to Simla. The line was opened to traffic in 1903 and as a result of high capital cost and high maintenance cost the Delhi-Umballa-Kalka Railway Company was by 1904 in severe financial crisis. The Kalka-Simla Railway was purchased by GoI in January 1906. The line was later converted to 2ft 6in/762mm narrow gauge.
Umballa is used in this text as it was the name of the Railway Company.
Amballa and Ambala are also recorded in differet documents as various spellings .
None of these three place names appear in The Imperial Gazeteer of India 1908 which is taken to be the definitive source
- National Archives "Records of the Delhi-Umballa-Kalka Railway Company" IOR/L/AG/46/9; Retrieved 10 Dec 2015
- Wikipedia Delhi-Kalka Line"; Retrieved 10 Dec 2015
- " Administration Report on the Railways in India – corrected up to 31st March 1918"; Superintendent of Government Printing, Calcutta; page 69; Retrieved 17 Dec 2015