Dehri-Rohtas Light Railway
The Dehri Rohtas Light Railway(DRLR) started off as Dehri Rohtas Tramway Company in 1907 promoted by the Octavius Steel & Co Ltd of Calcutta. The original contract was to build a 40 km feeder line from Rohtas to the East Indian Railway(EIR)'s Delhi-Calcutta mainline route at Dehri-on-Sone.
Soon thereafter, the tramway company was incorporated as a light railway in order to acquire the assets of the then defunct Dwara-Therria Light Railway in Assam.
The DRLR opened as a 2ft 6in/762mm narrow gauge(NG) railway to traffic in 1911 and was booming by 1913-14 when it carried over 50,000 passengers and 90,000 tons of freight, the goods traffic mainly consisting of marble and stone. 
In 1927, a 2.5 km spur was added to Rohtasgarh Fort from Rohtas.
Rohtas Industries brought the line up to Tiura Pipradih by adding another 25 km to the DRLR, most of which passed through their property.
Due to the decline in traffic and competition to road in the late 1970s, the DRLR succumbed and closed to traffic on July 16, 1984. 
For details of the locomotives and operations see “Industrial Railways and Locomotives of India and South Asia” compliled by Simon Darvill. Published by ‘The Industrial Railway Society’ 2013. ISBN 978 1 901556 82-7. Available at http://irsshop.co.uk/India. Reference: Entry BR21 pages 119-121
- " Administration Report on the Railways in India – corrected up to 31st March 1918"; Superintendent of Government Printing, Calcutta; page 224; Retrieved 2 Feb 2016
- "Indian / South-Asian Industrial Locos - Section 1.6" by Simon Darvill IRFCA Indian Railways Fan Club Retrieved on 2 Feb 2016