Sri Lanka Railways S9Sri Lanka Railways S9 is a class of diesel-electric multiple unit train sets operated by Sri Lanka's state run rail operator, Sri Lanka Railways.HistoryThe Class S9 DEMU was introduced to Sri Lanka in the year 2000. They were built by the China South Locomotive & Rolling Stock Corporation, and are the first class of Diesel-electric multiple units to run on Sri Lankan rails.Technical specificationsThe Class S9 only has Third class accommodations as it is used exclusively for commuter services. The length of one car is.OperationThese DEMUs are operated on Sri Lanka's Main Line, Coastal Line, Puttlam Line and Northern Line, but not on the Kelani Valley Line.